JP5746617B2 - Injectable hydrogel forming a chitosan mixture - Google Patents

Description

  The present invention relates to a combination of chitosan that forms hydrogels in a pH-dependent and temperature-sensitive manner, aqueous solutions used to form such hydrogels, and uses thereof.

  Hydrogels are highly hydrated, polymeric networks that are dispersed in water or other biological fluids. Hydrogels are temperature sensitive (or thermosetting) that increase in viscosity as temperature increases. Such hydrogels have favorable applicability at the site of application and long survival times compared to non-temperature sensitive hydrogels, which is advantageous as a vehicle for sustained release drug delivery systems.

A variety of polymers including chitosan can be used in the preparation of hydrogels. Chitosan occurs in part as a family of polymers obtained by substantial N-deacetylation of chitin , the latter being a linear polysaccharide of N-acetyl-D-glucosamine (GlcNAc) in the β-1,4 linkage. It is. Chitin is abundant in the exoskeleton of invertebrates, especially clusterian (eg, shrimp, crab, lobster). Commercial deacetylation processes used for chitosan production generally include treatment of edible shellfish processing waste with concentrated alkaline solutions, usually sodium hydroxide. Depending on the deacetylation achieved during its production, chitosan is a heteropolymer of D-glucosamine (GlcN) and GlcNAc, or a homopolymer formed only from GlcN. A variety of techniques are available for changing the degree of deacetylation and also for reacetylation to obtain chitosan having a predetermined degree of acetylation. Deacetylation results in free amino groups along the polymer chain, providing a polymer that dissolves in the selected acidic system. The solubility of chitosan, which is a predetermined degree of deacetylation, depends on a variety of parameters such as polymer molecular weight, temperature and concentration and nature of the acid solvent.

  Thus, one parameter used to characterize chitosan is the ratio of GlcNAc units to GlcN units, expressed as the degree of acetylation (DA) or the reverse degree of deacetylation (DD or DDA). The structure of chitosan is further characterized by the mode of distribution of GlcNAc and GlcN within the polymer chain, for example, non-homogeneously deacetylated chitosan occurs in various sizes and / or block locations in the chain, Homogeneously deacetylated chitosan has deacetylated units randomly distributed along the polymer chain. In addition, molecular weight is an important parameter and defines the characteristics of chitosan such as solubility, biodegradability and viscosity along with the degree and distribution pattern of acetylation.

  Chitosan is bioadhesive, biocompatible, non-toxic and non-immunogenic and can be used in the fields of medicine, pharmacy, cosmetics and tissue engineering. For example, the use of chitosan for topical ocular use, intraocular injection and transplantation near the retina has been disclosed (Felt et al., 1999; Patashnik et al., 1997; Song et al., 2001). Additionally, uniform submicron chitosan fibers by electrowet spinning and uses in artificial muscle, biosensor, and artificial organ component applications have been disclosed (Lee et al., 2006). Chitosan is biodegradable and biodegradable because it is specifically recognized and cleaved by certain enzymes such as lysozyme (Muzzarelli, 1997; Koga, 1998).

  Various hydrogels with cross-linked chitosan and / or chitosan in combination with further polymers are known, eg encapsulate genipin cross-linked chitosan chloride or chitosan glutamate (Mwale et al., 2005), intervertebral disc cells Effective as a skeleton (Roughley et al., 2006); chitosan-grafted poly (N-isopropylacrylamide), reported to be effective in taking up chondrocytes and meniscal cells (Chen et al., Chitosan / poly (acrylic acid) pH-sensitive hydrogel (Shi et al., 2004); chitosan, β-glycerol phosphate and hydroxyethylcellulose (Li et al., 2002); chitosan / polyvinylpyrrolidine pH-sensitive hydrogel (Risbud et al., 2000); N-acetylchitosan and trop collagen (H irano et al., 2000); chondroitin sulfate and chitosan (Sechriest et al., 2000); palmitoyl glycol chitosan (Noble et al., 1999); poly (caprolactone) -copoly (ethylene glycol) -co-poly (caprolactone) There are diacrylate and chitosan (Zhu et al., 2005); oxidized and N-carboxyethyl chitosan (Weng et al, 2007).

  U.S. Patent No. 6,057,077 discloses a polysaccharide-based gel solution having 0.1-5.0 wt% chitosan; and 1.0-20 wt% polyol or sugar monophosphate dibasic salt, said gel solution Is a solution at a pH of 6.5 to 7.4 and a temperature of 20 ° C. or less, and forms a gel within a temperature range of 20 to 70 ° C. According to this disclosure, a temperature sensitive chitosan hydrogel is prepared by neutralizing chitosan about 80% deacetylated with β-glycerin phosphate.

  Temperature sensitive chitosan hydrogels containing β-glycerin phosphate include BST-CarGel ™ for cartilage defects and cartilage repair; BST-DermOn ™ for wound treatment; and BST-InPod for treating knee pain ( Trademark).

  The aforementioned prior art products and many of the disadvantages associated with them have limited degradation rates and limitations imposed by the use of glycerin phosphate or similar plasticizing salts, and β-glycerin phosphate is positively charged. Is a negatively charged molecular entity that can react with the drug, leading to their precipitation or perturbing their release from the hydrogel. Thus, the presence of β-glycerol phosphate reduces the range of drugs that can be used with the chitosan / β-glycerol phosphate hydrogel.

  Furthermore, the regulation of hydrogel characteristics such as gel time and viscosity is dependent on the concentration of glycerin phosphate and is therefore limited by the solubility of β-glycerine phosphate. In particular, the concentration of β-glycerin phosphate is necessary for short gel times and is also necessary to avoid rapid elimination of the hydrogel after administration. However, high concentrations of β-glyceryl phosphate also reduce the viscosity of the hydrogel. Thus, these hydrogels lack the desirable combination of short gel time and high viscosity. Furthermore, high concentrations of β-glyceryl phosphate have hydrogel precipitates at the site of administration. In addition, chitosan / β-glycerol phosphate gel is blocked by turbidity, making it unsuitable for certain administrations such as the eyeball or typical administration.

  The preparation of transparent chitosan / β-glycerin phosphate hydrogels using deacetylated and acetic anhydride reacetylated chitosan has been disclosed (Berger et al., 2004). According to this document, the turbidity of the chitosan / β-glycerin phosphate hydrogel is controlled by the degree of chitosan deacetylation and the homogeneity of the medium during reacetylation and affects the dispersion mode of the glucoseamine monomer. Thus, the preparation of transparent chitosan / β-glycerin phosphate hydrogels has been reported to require chitosan under uniform reacetylation to the extent of 30-60% deacetylation.

  Patent document 2 discloses a pseudo-thermosetting neutralized chitosan compound, having 0.1 to 2.0% by weight, preferably 0.5 to 1% by weight, based on all compounds, 80 to 90% 30 to 60% consisting of uniformly reacetylated chitosan derived from chitosan having a degree of deacetylation of, having a molecular weight greater than 200 kDa, preferably greater than 600 kDa, neutralized with a hydroxide base such as NaOH, Preferably at a degree of deacetylation of 45-55%, the compound forms a transparent hydrogel free of phosphoric acid at temperatures above 5 ° C. According to this document, the uniform distribution of chitosan acetylated and deacetylated monomers is an important criterion for obtaining the hydrogel of interest. Furthermore, the integrity of the subject hydrogel is improved by adding diols, especially 1,3-propanol.

  U.S. Patent No. 6,057,037 discloses a controlled release formulation having a center Kinoshita drug in combination with chitosan from an angiotensin converting enzyme inhibitor and ascorbic acid, the gel-like complex is chitosan in the drug and neutral to acidic range environments. Consists of. According to this document, chitosan is 80-90% deacetylated and is present in the formulation at a concentration of about 5-70% by weight.

  U.S. Patent No. 6,057,031 discloses an encapsulating device having an essentially non-crosslinked chitosan core matrix encapsulated in a thermoplastic semipermeable membrane with living molecules dispersed in three-dimensional particles, wherein the chitosan core matrix is , Formed by precipitation of a chitosan solution containing the cells. According to this disclosure, chitosan precipitates are obtained by any method that removes or hides the charge of a sufficient number of free amino groups, such as replacement of chitosan-containing capsules in a buffer solution with monovalent ions or pH adjustment of the chitosan solution. Can be achieved.

  U.S. Patent No. 6,057,032 discloses the use of chitosan and a drug combination having heparin immobilized on chitosan to prevent unwanted tissue adhesion. According to this disclosure, chitosan has a degree of N-acetylation of as much as about 90% and this drug is used in particular in the form of a solution or gel.

  U.S. Patent No. 6,057,031 discloses a composition having a degree of acetylation of less than about 40%, preferably about 2 to about 6%, for use in the recovery and scar formation of skin lesions in chronic or acute wounds. .

  U.S. Patent No. 6,057,031 discloses an ionic chitosan iodine complex in the form of a solution or hydrogel, having chitosan or a derivative thereof, a water soluble carrier; elemental iodine; and an iodine source. According to this disclosure, chitosan has an average molecular weight of 10-1000 kDa, preferably 100-800 kDa, and most preferably 250-750 kDa and a degree of deacetylation of 40-95%, preferably 60-90%.

  U.S. Patent No. 6,057,031 discloses drug release fibers having chitosan fragments with different degrees of deacetylation and methods for their production. This document does not indicate the degree of deacetylation of a particular chitosan. Patent Document 9 discloses an adhesive for a biological tissue having a recombinant human serum albumin as an adhesive and a bifunctional and multifunctional aldehyde as a cross-linking agent. According to this document, the adhesive has further components, in particular partially acetylated chitosan such as 50% acetylated chitosan, and is further lyophilized before using an aqueous solution of adhesive, Reconstitute with saline.

  In Patent Document 10, for example, a specific chitin that is low-temperature expanded with an aqueous solution of 10N alkali or the like is administered for at least 36 hours, and then the chitosan is reacted by reacting the alkaline solution with the specific expanded chitosan at a high temperature to cause deacetylation. A method of preparation is disclosed. According to this document, the expansion is carried out at a maximum of 30 ° C., the deacetylation is carried out at a temperature that is at least 5 ° C., preferably at least 25 ° C. higher than the stage of expansion, and the acetylation is carried out by 0.2 to 0.7, In particular, a chitosan product having a degree of 0.45 to 0.6 is provided. The disclosed method further comprises a washing step after deacetylation, and the product is optionally further modified, for example by gel or solution form. According to this disclosure, a chitosan product that is completely water soluble, ie, 97% by weight, dissolves in a dilute acidic solution.

U.S. Patent No. 6,057,031 discloses a pharmaceutical composition having a sustained release or mucoadhesive agent and a bioactive agent, the sustained release or mucoadhesive agent comprising at least two chitosans having different degrees of acetylation (F _A ). having at least one of chitosan, 0.25 to 0.80 (e.g., 0.30 to 0.60 or 0.33 to 0.55) with the _{F a} value in the range. The document is at least 0.1, and preferably discloses mixtures of two or more of chitosan with at least 0.2 different F _A, the chitosan has a 5 to 98% by weight of the composition. According to this document, the composition is in a form suitable for administration in the gastrointestinal tract, eg, buccal or rectal, such as a gel.

Patent Document 12 discloses a food product having a mixture of chitosan or chitosan having a degree of acetylation of nutrients and 0.25~0.80 _{(F A).}

  Patent documents 11 and 12 do not present an injectable solution or a solution in gel form. These documents do not present chitosan hydrogels of a defined viscosity and do not disclose the preparation of hydrogels from a mixture of chitosans. In fact, the compositions and products described in U.S. Patent Nos. 6,099,086 and 5,973, are highly deacetylated chitosan that precipitates at pH values in the neutral region and cannot form hydrogels under physiological conditions, or at neutral pH and 37 ° C. Has any of the highly acetylated chitosan that remains soluble.

  U.S. Patent No. 6,057,031 discloses a chitosan composition disclosed after the priority date of the present invention and having at least one chitosan having a degree of acetylation in the range of about 30% to about 60%, and at least one chitosan. Has a degree of acetylation of at least 70% and the composition provides pH and Indian dependent gelation from the hydrogel. According to this document, the molecular weight of each highly deacetylated and highly acetylated chitosan ranges from 10 kDa to about 400 kDa, and the highly deacetylated chitosan preferably has a molecular weight greater than about 200 kDa and is highly acetylated. Chitosan preferably has a molecular weight greater than about 60 kDa.

  There is an unmet need for a hydrogel that forms a chitosan composition that combines viscosity, mechanical strength, rate of preferred gel formation, degradation under physiological conditions and predictable drug release profile, delayed release drug formulation Can be used for development and transplantation for skeletal and regenerative medicine.

US Pat. No. 6,344,488 International Publication No. 2005/097871 U.S. Pat. No. 4,738,850 US Pat. No. 6140089 US Pat. No. 6,486,140 US Patent Publication No. 2005/0042265 US Pat. No. 6,512,243 US Pat. No. 6,858,222 US Pat. No. 6,329,337 International Publication No. 03/011912 International Publication No. 2004/069230 International Publication No. 2004/068971 International Publication No. 2008/072230

  The present invention provides pH and temperature dependent hydrogels that form chitosan compositions, gels having a mixture of chitosan and their uses.

  The present invention is such that a composition having two different chitosans that differ in terms of the degree of acetylation / deacetylation has a specific molecular weight range and forms a hydrogel at physiological conditions of pH and temperature. Is based on being in a liquid state at a pH value below the neutral range and / or at a low temperature, for example a temperature below freezing.

  In particular, the composition is a first type of chitosan having a degree of acetylation in the range of about 20% or less (shown in this specification as “highly deacetylated chitosan” or “type 1 chitosan” in much the same sense herein). And a second type of chitosan having a degree of acetylation in the range of about 40% to about 60% (shown almost interchangeably herein as "highly acetylated chitosan" or "type 2 chitosan"); Have. In other words, the degree of deacetylation of each of the first and second types of chitosan is in the range of about 80% to about 100% and in the range of about 40% to about 60%, respectively.

  The chitosan hydrogel of the present invention is advantageous over chitosan gel-forming compositions having one type of chitosan of the prior art. In particular, the combination of chitosans shown herein improves the physical, chemical and pharmaceutical properties of the resulting hydrogel compared to a gel or hydrogel having a single type of chitosan.

  Without being bound by any theory or mechanism of action, the present invention takes advantage of the ability of highly acetylated chitosan to interact with highly deacetylated chitosan, thereby the same in the presence of a ratio of highly acetylated chitosan. Avoid precipitation of highly deacetylated chitosan that normally occurs under pH conditions. More particularly, highly deacetylated chitosan precipitates in aqueous solution at a pH value higher than about 6.5 due to protonation of free amino groups and is therefore injected by itself into human subjects for hydrogel formation Is inappropriate. On the other hand, highly acetylated chitosan is advantageous for hydrogel formation because it provides mechanical strength and hardness, and because it is a low substrate for lysozyme, it exhibits a relatively long time stability and thereby degrades slowly. Highly acetylated chitosan can be used to complement the properties of highly deacetylated chitosan, which allows the former to dissolve at physiological pH, impart elasticity and softness to hydrogels containing them, and lysozyme This is because it can be decomposed more quickly. The interaction of highly acetylated chitosan with highly deacetylated chitosan is thought to be through a combination of hydrogen bonds, hydrophobic bonds and van der Waals forces, resulting in the formation of hydrogels that are stable at pH values in the neutral region. Enabling and maintaining its solubility even when the pH of the microenvironment is greater than the pKa value of highly deacetylated chitosan. The disclosed hydrogels forming the composition can be utilized in a variety of medical applications, particularly in delayed release drug formulations, viscoelastic treatment of degenerative conditions such as osteoarthritis, and transplantation and scaffolds for tissue regeneration.

  According to one embodiment, the present invention provides a chitosan composition having a highly acetylated chitosan having a degree of acetylation in the range of about 40% to about 60% and a highly deacetylated chitosan having a degree of acetylation of less than about 20%. At 25 ° C. and pH in the neutral region, the composition has a viscosity of at least about 100 mPa · s at a shear rate of 50 rpm. According to certain embodiments, at 25 ° C. and pH in the neutral region, the composition has a viscosity of less than about 70 mPa · s at a shear rate of 200 rpm.

  The neutral pH used in the present specification indicates pH 7.0 ± 0.2.

  In certain embodiments, at 25 ° C. and a pH in the neutral region, the composition has a viscosity of at least about 400 mPa · s at a shear rate of 20 rpm and a viscosity of less than about 200 mPa · s at a shear rate of 100 rpm. Have.

  In certain embodiments, at 25 ° C. and pH in the neutral region, the composition has a viscosity of at least one-half, preferably at least one-third that of the same composition at pH 6.0. Is defined by a shear rate of 20 rpm.

  According to a particular embodiment, at 1 ° C. and pH in the neutral region, the composition is in liquid form.

  According to a particular embodiment, at 25 ° C. and pH 6.5 ± 0.2 or less, the composition is in liquid form.

  According to another aspect, the present invention further provides chitosan in the form of a hydrogel, the composition comprising highly acetylated chitosan having a degree of acetylation within the range of about 40% to about 60% and less than about 20%. A chitosan composition having a highly deacetylated chitosan having a degree of acetylation is provided, and at 25 ° C. and pH 7.0 ± 0.2, the composition has a viscosity of at least about 100 mPa · s at a shear rate of 20 rpm. .

  According to certain embodiments, at 25 ° C. and pH 7.0 ± 0.2, the composition has a viscosity of at least about 100 mPa · s at a shear rate of 50 rpm. According to certain embodiments, at 25 ° C. and pH 7.0 ± 0.2, the composition has a viscosity of at least about 200 mPa · s at a shear rate of 50 rpm. According to certain embodiments, at 25 ° C. and pH 7.0 ± 0.2, the composition has a viscosity of at least about 400 mPa · s at a shear rate of 20 rpm.

  According to yet another embodiment, the present invention further provides a chitosan composition in the form of an injectable solution, wherein the composition has a high acetylation having a degree of acetylation in the range of about 40% to about 60%. A chitosan composition having a highly deacetylated chitosan having a degree of acetylation of less than about 20% is provided, and at 25 ° C. and a pH below the neutral region, the composition is about 150 mPas at a shear rate of 50 rpm. Has a viscosity of less than s.

  According to certain embodiments, at 25 ° C. and a pH below the neutral range, the composition has a viscosity of less than about 100 mPa · s at a shear rate of 50 rpm.

  According to certain embodiments, the highly acetylated chitosan has a degree of acetylation within the range of about 45% to about 55%, and the highly deacetylated chitosan has a degree of acetylation of about 15% or less.

  According to certain embodiments, the highly acetylated chitosan is a homogeneously reacetylated chitosan. According to certain embodiments, the highly deacetylated chitosan is a heterogeneously deacetylated chitosan.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight of at least about 100 kDa and the highly acetylated chitosan has a molecular weight of at least about 200 kDa.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight of about 100 kDa to about 2000 kDa, and the highly acetylated chitosan has a molecular weight of about 200 kDa to about 2000 kDa.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight of about 100 kDa to about 700 kDa, such as about 100 kDa to about 400 kDa or about 400 kDa to about 700 kDa; the highly acetylated chitosan has a molecular weight of about 200 kDa to about 250 kDa. Have.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight of about 400 kDa to about 700 kDa, and the highly acetylated chitosan has a molecular weight of about 200 kDa to about 250 kDa. According to certain embodiments, the highly deacetylated chitosan has a molecular weight selected from the group consisting of about 100 kDa; about 400 kDa, and about 650 kDa; the highly acetylated chitosan has a molecular weight of about 200 kDa to about 250 kDa.

  According to certain embodiments, the highly deacetylated chitosan and the highly acetylated chitosan are each present at a concentration of about 0.2% to about 3% w / v of the total composition. According to another particular embodiment, the highly deacetylated chitosan and the highly acetylated chitosan are each present at a concentration of about 0.5% to about 2% w / v of the total composition. According to another particular embodiment, the highly deacetylated chitosan and the highly acetylated chitosan are each present at a concentration of about 1% to about 1.2% w / v of the total composition.

  According to certain embodiments, the proportion of highly deacetylated chitosan and highly acetylated chitosan in the composition is selected from the group consisting of 1: 1, 1: 2, 1: 3 and 1: 4.

  According to certain embodiments, the highly deacetylated chitosan and the highly acetylated chitosan are each present at a concentration of about 1% to about 1.2% w / v of the total composition, and the highly deacetylated chitosan in the composition And the ratio of highly acetylated chitosan is 1: 1.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight of about 400 kDa to about 700 kDa, the highly acetylated chitosan has a molecular weight of about 200 kDa to about 250 kDa, and the highly deacetylated chitosan and the highly acetylated chitosan Are each present at a concentration of about 1% to about 1.2% w / v of the total composition; the ratio of highly deacetylated and highly acetylated chitosan in the composition is 1: 1.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight of about 2000 kDa, the highly acetylated chitosan has a molecular weight of about 200 kDa to about 250 kDa, and the concentration of the highly deacetylated chitosan is 0% of the total composition. The ratio of highly deacetylated chitosan and highly acetylated chitosan is selected from the group consisting of 1: 2, 1: 3 and 1: 4.

  According to certain embodiments, the hydrogel has a degradation profile in which less than about 50% of the hydrogel degrades 4 days after its formation.

  According to certain embodiments, the composition further comprises a lysozyme inhibitor, wherein the lysozyme inhibitor is selected from the group consisting of proteins and monosaccharides. According to a particular embodiment, the monosaccharide is tri-N-acetyl-glucosamine. According to certain embodiments, the lysozyme inhibitor binds to highly acetylated chitosan. According to certain embodiments, the composition has tri-N-acetyl-glucosamine bound to highly acetylated chitosan.

  According to certain embodiments, the chitosan composition further comprises at least one negatively charged material selected from polysaccharides, phospholipids, and combinations thereof. According to certain embodiments, the negatively charged polysaccharide is selected from the group consisting of animal derived polysaccharides, plant derived polysaccharides, glycosaminoglycans and combinations thereof. According to a particular embodiment, the glycosaminoglycan is selected from the group consisting of chondroitin sulfate, deltaman sulfate, dextran sulfate, heparan sulfate, heparin, hyaluronic acid, keratan sulfate.

  According to a particular embodiment, the phospholipid is phosphatidylcholine. According to certain embodiments, the chitosan composition further comprises hyaluronic acid and the phosphatidylcholine is used in the treatment of viscoelasticity, such as exchange of synovial fluid and / or treatment of, for example, osteoarthritis.

  According to certain embodiments, the composition has chitosan encapsulating the drug and / or electrospun chitosan microspheres incorporated in a gel.

  According to certain embodiments, the composition further comprises at least one drug, polypeptide and cell (such as an animal cell or plant cell).

  According to certain embodiments, the composition further comprises an emulsifier. In certain embodiments, the chitosan and emulsifier are in the form of nanoparticles. In certain embodiments, the nanoparticles are encapsulated in a hydrogel.

  According to certain embodiments, the composition is formulated for administration by a route selected from direct infusion, injection, and endoscopic administration.

  According to certain embodiments, the implantable device has a composition in the form of a hydrogel. This implantable device has applications selected from tissue repair, tissue remodeling, tissue knowledge, and tissue replacement.

  According to certain embodiments, an anti-adhesion device has the composition of the present invention and is used in applications such as cardiothoracic surgery and abdominal surgery.

  According to certain embodiments, the drug delivery device or system has a composition of the invention. The drug delivery device or system is for delayed release of the embedding agent. Non-limiting examples of drugs used in this system include, for example, proteins and non-protein agents such as ACE-inhibitors, anti-inflammatory drugs, ophthalmic drugs, urological drugs and the like. In other embodiments, a cosmetic delivery device has the composition of the present invention. An example of a suitable cosmetic product is a wrinkle remover. The drug delivery device or system or cosmetic delivery device also optionally has one or more minerals, vitamins, food additives or natural extracts such as plant-derived extracts. The hydrogel itself can be used as a food additive, optionally with active ingredients.

  In certain embodiments, any drug, cosmetic, mineral, vitamin, food additive or natural extract is in the form of nanoparticles and the nanoparticles are encapsulated in the hydrogel of the invention.

  According to certain embodiments, a three-dimensional gel construct has the composition of the present invention, and the hydrogel is a cell support. According to certain embodiments, the cell is an endogenous or exogenous cell and the construct optionally further comprises an exogenous growth factor. According to a particular embodiment, the cell-loaded artificial matrix has a hydrogel of the invention. According to certain embodiments, the cells consist of chondrocytes, fibrochondrocytes, ligament fibroblasts, dermal fibroblasts, tendon cells, myofibroblasts, myofibroblasts, mesenchymal stem cells and keratinocytes Select from group.

  According to certain embodiments, the use of the composition of the present invention provides for the preparation of a medicament for treating colic. According to certain embodiments, the use of the composition of the present invention provides for the preparation of a medicament for treating wounds. According to certain embodiments, the use of the composition of the invention provides for the preparation of an agent that disrupts cell membranes. According to certain embodiments, the use of the composition of the present invention provides for the preparation of a medicament for preventing or treating surgical adhesions. According to certain embodiments, the use of the composition of the present invention provides for the preparation of a medicament for treating rotator cuff injury such as rupture of the key board, which medicament optionally further comprises autologous cells. According to certain embodiments, the use of the composition of the present invention provides for the preparation of a medicament for treating osteoarthritis, the composition optionally further comprising hyaluronic acid and synovial fluid as shown herein Has phosphatidylcholine.

  According to some embodiments, chitosan hydrogel is used as a smoothing agent to treat conditions such as vaginal atrophy, dry eyes, dry conjunctivitis, respiratory infections after dry nose, and a general sedative for various abrasions Use.

  According to a further aspect, the present invention provides a highly deacetylated chitosan having a molecular weight in the range of about 100 kDa to about 4000 kDa, such as about 100 kDa to about 2000 kDa, and a degree of acetylation of less than about 20%, and a range of about 200 to about 20000 Da. A chitosan composition having a monosaccharide oligomer of the molecular weight is provided, wherein the composition is in the form of an aqueous solution.

  According to a particular embodiment, the monosaccharide oligomer is selected from the group consisting of chitosan oligomers; D-glucosamine oligomers and N-acetyl-D-glucosamine oligomers. In certain embodiments, the chitosan oligomer consists of a highly deacetylated chitosan oligomer having a degree of acetylation of less than about 20% and a highly acetylated chitosan oligomer having a degree of acetylation of about 40% to about 60%. Select from group. According to certain embodiments, the highly acetylated chitosan oligomer has a degree of acetylation ranging from about 45% to about 55%. According to certain embodiments, the highly deacetylated chitosan oligomer has a degree of acetylation of about 15% or less. According to certain embodiments, the N-acetyl-D-glucosamine oligomer has a maximum of about 7 units. According to certain embodiments, the D-glucosamine oligomer has from 3 to about 100 units. According to certain embodiments, the D-glucosamine oligomer has from 3 to about 50 units.

  According to certain embodiments, the proportion of monosaccharide oligomers and highly deacetylated chitosan having a molecular weight in the range of about 100 kDa to about 2000 kDa is greater than 1: 1.

  In certain embodiments, the ratio is about 2: 1 to 20: 1.

  In certain embodiments, at 25 ° C. and a pH below the neutral range, the composition has a viscosity of less than 150 mPa · s at a shear rate of 50 rpm. In certain embodiments, at 25 ° C. and a pH below the neutral range, the composition has a viscosity of less than 100 mPa · s at a shear rate of 50 rpm. In certain embodiments, at 25 ° C. and pH in the neutral region, the composition has a viscosity of less than 70 mPa · s at a shear rate of 200 rpm.

  According to another aspect, the present invention provides a method for producing a stable hydrogel comprising at least one highly acetylated chitosan having a degree of acetylation in the range of about 40 to about 60%, and about 20 Dissolving at least one highly deacetylated chitosan having a degree of acetylation of less than% in an acidic aqueous solution to form a complex solution; adjusting the pH of the complex solution to a value of 6.5 to 7.2; Increasing the temperature of the composite solution to 37 ° C. while raising the pH from 7.0 to 7.6 to form a hydrogel having a viscosity of at least 100 mPa · s at 25 ° C. and a shear rate of 50 rpm .

  Unless defined otherwise, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art of the present invention. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below. In case of conflict, control the specification, including definitions. In addition, the materials, methods, and examples are illustrative only and not necessarily limited.

  Several embodiments of the present invention are described herein by way of example with reference to the accompanying drawings. It is for the purpose of illustrating the examples and exemplary embodiments of the invention, which are specifically indicated, along with the details of the detailed drawings in the specification. In this context, the description with the aid of the drawings allows those skilled in the art to understand how to practice the embodiments of the present invention.

FIG. 1 illustrates the formation of a hydrogel according to some embodiments of the present invention from a liquid composition having two different chitosans. FIG. 2 shows the time degradation of different hydrogel compositions formed from a combination of Type 1 and Type 2 chitosans. FIG. 2A shows type 2 chitosan (MW220 kDa; DA50) combined with type 1 chitosan (MW65 kDa; DA15) in the ratio of 1: 1 (diamond mark); 1: 2 (square mark); and 1: 3 (triangle mark). And shows the degradation of the composition with a percentage of the weight of the gel remaining undegraded. FIG. 2B shows a hydrogel composition formed from a combination of type 2 chitosan (MW 220 kDa; DA50) and 65 kDa and DA15 (triangle mark) or 100 kDa and DA9 (square mark) type 1 chitosan in a 1: 1 ratio. Degradation with time is shown. FIG. 3 shows the release of hemoglobin from a hydrogel composition formed from a combination of type 1 chitosan (MW 65 kDa; DA15) and type 2 chitosan (MW 220 kDa; DA50), measured by the amount of protein (μg / mL) in the eluent. To do. This system, indicated by diamonds, squares, triangles, stars, and asterisks, indicates experimental repeats, and circles indicate the average of experiments. FIG. 4 shows the release of bovine serum albumin (BSA) from a hydrogel composition formed from a combination of type 1 chitosan (MW 65 kDa; DA15) and type 2 chitosan (MW 220 kDa; DA50), and the optical density (OD) of the eluent. Measure by. This system, indicated by diamonds, squares, triangles, stars, and asterisks, indicates experimental repeats, and circles indicate the average of experiments. FIG. 5 is a bar graph showing the release of BSA from a hydrogel composition formed from a combination of type 1 chitosan (MW 65 kDa; DA15) and type 2 chitosan (MW 220 kDa; DA50). FIG. 6 shows a hydrogel composition formed from a combination of type 1 chitosan (MW65 kDa; DA15) and type 2 chitosan (MW220 kDa; DA50), either with BSA (square mark) or not (diamond mark). It shows degradation over time and is expressed as a percentage of the weight of the undegraded gel. FIG. 7 shows the release profile of BSA (square marks) with degradation profiles (triangle marks) from hydrogel compositions formed from a combination of type 1 chitosan (MW 65 kDa; DA15) and type 2 chitosan (MW 220 kDa; DA50) and BSA. Shows integration. FIG. 8 is taken from either a treated (FIG. 8A) or untreated (FIG. 8B) rat with a hydrogel composition formed from a combination of type 1 chitosan (MW 65 kDa; DA15) and type 2 chitosan (MW 220 kDa; DA50). Figure 5 shows the histopathological form of biopsy of a wound bed. FIG. 9 shows the results of treatment of wounds in diabetic rats with a hydrogel composition and acetylglucosamine oligomer (Gel) formed from a combination of type 1 chitosan (MW65 kDa; DA15) and type 2 chitosan (MW220 kDa; DA50) It is shown by the surface area of the wound bed biopsy 7 days after the examination. In the control group of animals, the wounds were either covered with a Gibbs bandage (control + cover) or left uncovered (uncovered control). FIG. 10 shows the results of an in vivo experiment performed on rats with a keyboard injury. Tissue slices from rats treated with chitosan hydrogel containing bone marrow cells after suturing (FIG. 10A) show migration of inflammatory cells and recovery in the defect, while slices from untreated rats after suturing (FIG. 10B) Shows empty defects with no sign of recovery. FIG. 11 shows a schematic drawing for measuring the coefficient of friction. FIG. 12 shows the static coefficient of friction measured between two layers of normal cartilage, a hydrogel composition formed from a combination of saline; highly deacetylated chitosan (MW 660 kDa; DA15) and highly acetylated chitosan (MW 220 kDa; DA50). The same chitosan combination further containing chondroitin sulfate (+ CS); the same chitosan combination further including chondroitin sulfate and phosphatidylcholine (+ CS / PC); or hyaluronic acid (HA) is used. FIG. 13 shows the viscosity of various chitosan compositions as a function of pH measured at 25 ° C. Compositions comprising highly acetylated chitosan (MW 220 kDa; DA50) and highly deacetylated chitosan (MW 420 kDa; DA9) are either themselves or in combination. FIG. 14 shows the viscosity of a composition having two types of chitosan as a function of pH measured at 25 ° C. The composition is a combination of 1: 1 ratio of highly deacetylated chitosan (MW65 kDa; DA15) and highly acetylated chitosan (MW220 kDa; DA50), or 1: 1 ratio of highly deacetylated chitosan (MW100 kDa; DA9). And a combination of highly acetylated chitosan (MW 220 kDa; DA50). FIG. 15 shows the viscosity of a composition having two types of chitosan at different pH values as measured at 25 ° C. and various shear rates. The composition can be a combination of 1: 1 ratio of highly deacetylated chitosan (MW 100 kDa; DA9) and highly acetylated chitosan (MW 220 kDa; DA50) at various pH values (FIG. 15A); A 1: 1 ratio of highly deacetylated chitosan (MW 65 kDa; DA15) and highly acetylated chitosan (MW 220 kDa; DA50) combination (FIG. 15B). FIG. 16 shows the viscosity of a composition having two types of chitosan at different pH values as measured at 1 ° C. and various shear rates. The composition comprises a combination of 1: 1 ratio of highly deacetylated chitosan (MW 100 kDa; DA15) and highly acetylated chitosan (MW 220 kDa; DA50) (SK10: 50) at various pH values; or at various pH values A 1: 1 ratio of highly deacetylated chitosan (MW 65 kDa; DA15) and highly acetylated chitosan (MW 220 kDa; DA50) in combination (FVL 10:50). FIG. 17 shows a 1: 1 ratio of highly deacetylated chitosan (MW 100 kDa; measured at various pH values, both at 1 ° C. (FIG. 17A) or 25 ° C. (FIG. 17B). Figure 2 shows the viscosity of a composition having a combination of DA9) and highly acetylated chitosan (MW 220 kDa; DA50). FIG. 18 shows a 1: 1 ratio of highly deacetylated chitosan (MW 65 kDa; when measured at various shear rates at 1 ° C. (FIG. 18A) or 25 ° C. (FIG. 18B), both at various pH values. 2 shows the viscosity of a composition having a combination of DA15) and highly acetylated chitosan (MW 220 kDa; DA50). FIG. 19 shows the viscosity of a composition having two types of chitosan at different pH values as measured at 25 ° C. and various shear rates. The composition has a 1: 1 ratio of highly deacetylated chitosan (MW 660 kDa; DA15) and highly acetylated chitosan (MW 220 kDa; DA50) at various pH values.

  The pH-dependent and temperature-sensitive chitosan hydrogels of the present invention are advantageous over prior art chitosan gel-forming compositions having one type of chitosan. In particular, the chitosan combination applications shown herein exhibit the resulting physical, chemical and pharmacokinetically improved properties of the resulting hydrogel compared to a gel or hydrogel having a single type of chitosan. As used herein, a composition “having one kind of chitosan” refers to a composition in which either highly deacetylated chitosan or highly acetylated chitosan is the only chitosan present in the composition. In particular, hydrogels containing only highly acetylated chitosan, such as disclosed in WO 2005/097871, for example, are much more mechanically than the hydrogels of the present invention, probably due to different interactions involved in gel formation. weak. In addition, gels formed solely from highly acetylated chitosan require high chitosan concentrations that affect gel formation and / or as disclosed in eg WO 2005/097871 Additives such as 1,3-propanediol are required to improve viscoelastic behavior. Further, in some cases, compositions containing only highly acetylated chitosan form gels only at low temperatures and are not valuable for in vivo applications. Finally, gels formed solely from highly acetylated chitosan are rapidly enzymatically degraded by a preferred substrate, a serum enzyme such as lysozyme. Thus, such gels have a relatively short half-life in vivo compared to the hydrogels of the present invention, and therefore the former is a delayed release drug formulation that requires long-term resilience and stability, Not appropriate for implantation and device preparation.

In addition, highly deacetylated chitosan confidence precipitates at pH values greater than their pKa, and thus their stability at pH values in the neutral region, for example as disclosed in US Pat. No. 6,344,488. And additives such as β-glyceroline sulfate that affect gelation are required. This gel is hampered by limitations on degradation rate, gel time and viscosity, as described in the background art.
Definition

  As used herein, the term “about” when used in numerical terms means a value of ± 10%.

  As used herein, the term “pseudo-thermosetting” related to the composition of the present invention refers to the gelation time when the temperature does not induce gelation of the composition, but increases in temperature. It functions as a catalyst that dramatically shortens

  As used herein, the term “hydrogel” refers to a three-dimensional polymer network having a degree of hydration of at least 90% and shows little flow in steady state. The chitosan hydrogels of the present invention generally reach a steady state at a pH of about 6.5 or higher and a temperature of about 4 ° C. or higher. It is clearly understood that the chitosan hydrogel according to the present invention does not include a chitosan gel formed from one type of chitosan such as highly deacetylated chitosan in the expanded state.

  As used herein, the term “viscosity” refers to the measurement of fluid resistance deformed by either shear force or elongational stress. Newtonian fluids exhibit a constant viscosity over a wide range of shear rates, i.e., independent of shear rate, while non-Newtonian fluids (such as polymer gels) exhibit different viscosities for different shear rates. Non-Newtonian fluids exhibit different interactions between shear forces and shear rates. In general, the viscosity of a non-Newtonian fluid decreases at a high shear rate (a phenomenon known as squealing) and the viscosity increases at a low shear rate.

The SI physical unit of dynamic viscosity is Pascal-second (Pa · s), which is the same as kg · m ⁻¹ · s ⁻¹ . The millipascal (mPa · s) is 0.01 Pa · s. Other units are used to indicate the viscosity at equilibrium, and the relationship between Pascal-seconds and equilibrium is 10P = 1 kg · m ⁻¹ · s ⁻¹ = 1 Pa · s. The viscosity of the non-Newtonian fluid is measured with a blood flow meter and deformed against a specific stress field or fluid and the resulting deformation or force is monitored.

  As used herein, the term “heterogeneous deacetylation” in relation to chitosan means that the deacetylated units of D-glucosamine occur in blocks of varying size and / or distribution. . As used herein, the term “homogeneous deacetylation” in relation to chitosan means that the deacetylated units of D-glucosamine are randomly distributed in the polymer.

  As used herein, the term “homogeneous reacetylation” related to chitosan means that deacetylated chitosan is distributed randomly in the polymer with N-acetyl D-glucosamine units and D-glucosamine units. Means reacetylation.

  As used herein, the terms “neutral pH”, “pH in the neutral region”, “neutralization”, “physiological pH” and the like mean a pH of 7.0 ± 0.2.

  As used herein, the term “monosaccharide oligomer” means a monosaccharide having a degree of polymerization of from 3 to about 100 monomers. Oligomers are formed from a single monosaccharide, for example only of D-glucosamine units, or contain different types of monosaccharide units, such as D-glucosamine units and N-acetyl-D-glucosamine units, as chitosan oligomers.

  The terms “comprising”, “including”, “having” and the like mean “including but not limited to”.

  The term “consisting of” means “including but not limited to”.

  The term “consisting essentially of” means that the composition, method or structure has additional components, steps and / or parts, but the additional components, steps and / or parts are fundamental to the claimed composition, method or structure and Only when new features cannot be materially changed.

  As used herein, the singular forms “a” [an] and [the] include the plural unless specifically stated otherwise. For example, the term “compound” or “at least one compound” includes a plurality of compounds, including mixtures thereof.

  Chitosan (ie, up to about 30% degree of acetylation, DA) deacetylated to a degree of deacetylation of about 70-100% such as commercially available chitosan (denoted herein as DD or DDA) is In this specification, it is expressed as type 1 chitosan or chitosan type 1. These chitosans are insoluble at physiological pH and are not easily recognized by lysozyme. Such chitosan, when used in vivo, is generally characterized by a relatively slow biodegradation and lasts days to months depending on the degree of deacetylation. Gels formed with this type of chitosan have a low degree of acetylation and the free amine groups have a high density of hydrogen bonds with many hydrophobic interactions.

  The degradation rate of chitosan indicates a function of the degree of deacetylation. Chitosan degradation affects cell growth and remodeling.

  Highly uniformly deacetylated or reacetylated chitosan (having a degree of acetylation of about 30% to about 60%) is referred to herein as type 2 chitosan or chitosan type 2. This chitosan is easily digested / degraded by lysozyme, thus allowing for controlled drug release, eg, drug encapsulation.

  If the degree of deacetylation of chitosan is less than 30%, chitosan becomes a polymer close to chitosan that is insoluble under acidic conditions and unsuitable for use in embodiments of the present invention. With a degree of deacetylation of 70% or more, chitosan precipitation occurs.

  The degree of deacetylation of chitosan can be determined, for example, by RA Muzarelli and R. Richetti [Carbohydr. Polym. 5, 461-472, 1985 or RA Muzarelli and R. Richetti in "Chitin in Nature and Technology", Plenum Press 385-388, 1986] as defined by spectrophotometry. Briefly, for example, in the latter method, chitosan is dissolved in 1% acetic acid and DD is N-by UV with 200, 201, 202, 203 and 204 using N-acetyl-D-glutamine solution as a standard solution. It is measured by measuring the amount of acetyl-glucosamine.

  According to one embodiment, the present invention has at least one highly acetylated chitosan (type 2) having a degree of acetylation in the range of about 40% to about 60% and a degree of acetylation of less than about 20%. Relevant to polysaccharide chitosan compositions having a combination of at least one highly deacetylated chitosan (type 1). Highly acetylated type 2 chitosan interacts with highly deacetylated chitosan type 1 through electrostatic, hydrogen and hydrophobic interactions. The degree of interaction increases with increasing pH. A composition having a solution of both types of chitosan can form a gel stable at physiological pH without the need for glycerophosphate. Accordingly, the resulting composition lacks glycerophosphate.

  Accordingly, the chitosan composition described is either in aqueous solution or hydrogel form. The transition from the liquid state to the hydrogel occurs at pH conditions above about 6.5. The hydrogel is stable at physiological conditions, i.e. pH in the neutral region and 37 [deg.] C.

  Note that the compositions described herein form a gel at or below room temperature (eg, 4 ° C.). Nevertheless, gel formation under these conditions is slow and lasts days to months, allowing the composition to be stored and transferred as an aqueous solution.

  Type 1 chitosan in the unprotected state precipitates at a pH of about 6.5 below the physiological condition pH. The interaction of highly hydrophobic and uniformly acetylated chitosa type 2 with chitosan type 1 prevents this precipitation of non-homogeneously acetylated type 1 chitosan by formation of hydrogen and hydrophobic bonds, resulting in a stable quasi-solid hydrogel Allows formation at pH 7.0 in the neutral region.

The formed second bond allows for the encapsulation of non-homogeneous chitosan chains and maintains its solubility at a pH greater than its pKa. In general, this second strand interaction is the main molecular force involved in gel formation (Chenite et al. ₃ 2000; Berger et al., 2005).

  Type 1 chitosan contributes mainly to the stability, strength and hardness of the gel and slows down degradation, whereas type 2 chitosan contributes to the softness, elasticity and fast dissolution of the gel. The degradation profile of compositions having type 1 and type 2 chitosan is further described in Example 2 below and is shown in FIG. In particular, the present invention provides that hydrogels formed from type 1 chitosan having a molecular weight of about 100 kDa and type 2 chitosan having a molecular weight in the range of 200-250 kDa provide a substantially linear degradation rate, but at least 50% of the hydrogel Remains undegraded for 4 days after gel formation (FIG. 2B). Conversely, gels formed from the same low molecular weight type 2 chitosan and type 1 chitosan show a less desirable two-phase degradation pattern (FIG. 2A). Type 2 chitosan is recognized as a “protecting group” or “coating” and provides a shell around type 1 chitosan to prevent precipitation.

  In addition, type 2 chitosan is recognized by lysozyme. This feature allows control of the degradation rate of hydrogels formed from the compositions described herein. For example, lysozyme inhibitor binding to type 2 is a protein or monosaccharide and slows the degradation rate of the formed hydrogel. A suitable example of a lysozyme inhibitor is the monosaccharide tri-N-acetylglucosamine. Alternatively, the composition has a relatively fast degradation rate, eg, in wound healing, as described in Example 4.

  The physical and chemical properties of hydrogels formed from the described compositions can be altered by increasing or decreasing the molecular weight and / or degree of acetylation of chitosan or by the diversity of natural acetylation of chitosan from different sources . The properties of the gel can be further controlled by selection of the type of reacetylation (ie uniform or non-uniform) or by drawing a distribution pattern of deacetylated / acetylated states.

  Preferably, the highly acetylated chitosan is uniformly reacetylated. More preferably, chitosan under high deacetylation is non-uniformly deacetylated.

  In general, commercially available chitosan is industrially prepared by deacetylation of dried chitin flakes (Muzzarelli, 1986). Deacetylation preferably takes place in the amorphous region of the chitin molecule on the surface of the flakes, resulting in a heterogeneous monomer having a distribution of deacetylated units of various block sizes. In comparison, reacetylated chitosan under homogeneous conditions allows for a messy distribution of deacetylated monomers, reducing the crystallinity of chitosan and conversely reducing its solubility (Aiba, 1991, 1994). Ogawa and Yui, 1993; Milot et. Al., 1998).

  Non-uniform methods of deacetylation are described, for example, in US Patent No. 4,195,175; Varum et al., Pages 127-136 in "Advances in chitin chemistry", Ed. CJ Brine, 1992; Ottoy et al., Carbohydrate Polymers 29 : 17-24 (1996); Sannan et al., Macromol. Chem. 176: 1191-1195 (1975); Sannan et al, Macromol. Chem. 177: 3589-3600 (1976); Kurita et al., Chemistry Letters 1597-1598 (1989); and CA 2,101,079.

  Uniform reacetylation of chitosan has the effect of increasing the number of hydrophobic sites by substituting the amine group with an acetyl group, and also reduces the crystal structure that makes chitosan apt to break, and in the increased solubility of chitosan. accumulate. Reacetylation prevents polymer refolding and maintains linearity, thus preventing pH-dependent solubility reduction. In general, any pharmaceutical grade and sufficient molecular weight commercial chitosan can be used in the preparation of reacetylated chitosan. Homogeneous reacetylation methods are disclosed, for example, in WO 2005/097871 and WO 03/011912.

  After reacetylation, the product is measured with respect to the degree of deacetylation as measured, for example, by the UV method (Muzarelli et al. In "Chitin in Nature and Technology", Plenum Press, New York, 385-388, (1986)), and For example, it is characterized in terms of molecular weight as defined by size exclusion chromatography (Felt et al. Int. J. Pharm. 180: 185-193 (1999)).

  In certain embodiments, the chitosan compositions described herein have a viscosity of at least 100 mPa · s at a shear rate of 50 rpm when the composition is at 25 ° C. and pH in the neutral region. At higher 200 rpm shear rates, the viscosity does not exceed 70 mPa · s when the composition is at the same temperature and pH conditions. According to another embodiment, at 25 ° C. and pH 7.0 ± 0.2, the composition has a viscosity of at least 100 mPa · s at a shear rate of 20 rpm. According to another embodiment, at 25 ° C. and pH in the neutral region, the composition has a viscosity of at least 400 mPa · s at a shear rate of 20 rpm. According to another embodiment, at 25 ° C. and pH in the neutral region, the composition has a viscosity of less than 200 mPa · s at a shear rate of 100 rpm. According to another embodiment, at 25 ° C. and pH 7.0 ± 0.2, the hydrogel composition has a viscosity of at least 100 mPa · s at a shear rate of 20 rpm. According to other embodiments, at 25 ° C. and pH 7.0 ± 0.2, the hydrogel composition has a viscosity of at least 100 mPa · s at a shear rate of 50 rpm, or at least 200 mPa · s. Preferably, at 25 ° C. and pH in the neutral region, the composition has a viscosity at least twice that of the same composition at pH 6.0 when the viscosity is defined at a shear rate of 20 rpm. Also preferably, the composition has a viscosity of at least 3 times that of the same composition at pH 6.0, when the viscosity is defined at a shear rate of 20 rpm at 25 ° C. and a pH in the neutral region. According to other embodiments, at 25 ° C. and a pH below the neutral range, the liquid composition has a viscosity of less than about 150 mPa · s at a shear rate of 50 rpm. According to another embodiment, at 25 ° C. and a pH below the neutral range, the liquid composition has a viscosity of less than about 100 mPa · s at a shear rate of 50 rpm.

  For example, as shown in FIG. 19, a demonstration that the viscosity of the composition increases as the shear force decreases is to show the behavior of non-Newtonian fluids, a characteristic of gels including hydrogels. That is, when the composition is in an undistributed state, it “gets” into a gel with solid-like properties, which in fact is a highly hydrated state with a more similar density to the liquid compared to the solid. Because. Furthermore, when a strong force is applied to the composition, it remains substantially liquid. Furthermore, as described in Example 9, the chitosan hydrogel of the present invention is formed only when the composition is in the neutral pH region and exhibits a low viscosity that is almost independent of the applied shear force at low pH values. In other words, at a pH below the neutral range, the composition is almost in the liquid state and is stable to low pH in the liquid state and / or refrigerated storage prior to administration, eg, injection to in vivo gel formation. It shows that. Increasing the molecular weight of chitosan increases its viscosity, making this polymer highly hydrated and highly hydrophobic. This is demonstrated, for example, in Example 9 and FIG. 19, which shows that the viscosity of composition FM80: 50 1: 1 with type 1 chitosan with a molecular weight of 660 kDa is much higher than composition SK10: 50 1: 1. The latter has type 1 chitosan with a molecular weight of 100 kDa. More specifically, in the gel state, these compositions exhibit viscosities of about 420 and about 110 mPa · s, respectively. Thus, the present invention allows the formation of hydrogels of varying strength and moisture retention. This can produce hydrogels with degradation rates, drug release, and mechanical strengths also selected by those skilled in the art.

  Preferably, each of the highly acetylated chitosan and the highly deacetylated chitosan has a molecular weight greater than about 100 kDa. In certain embodiments, the highly deacetylated chitosan has a molecular weight of at least about 100 kDa and the highly acetylated chitosan has a molecular weight of at least about 200 kDa. In other specific embodiments, the highly deacetylated chitosan has a molecular weight in the range of about 100 kDa to about 2000 kDa, and the highly acetylated chitosan has a molecular weight in the range of about 200 kDa to about 2000 kDa. According to certain embodiments, the highly deacetylated chitosan has a molecular weight in the range of about 100 kDa to about 700 kDa, such as about 100 kDa to about 400 kDa, or about 400 kDa to about 700 kDa, and the highly deacetylated chitosan is , Having a molecular weight in the range of about 200 kDa to about 250 kDa. According to certain embodiments, the highly deacetylated chitosan has a molecular weight in the range of about 400 kDa to about 700 kDa, and the highly acetylated chitosan has a molecular weight in the range of about 200 kDa to about 250 kDa. According to certain embodiments, the highly deacetylated chitosan has a molecular weight selected from the group consisting of about 100 kDa; about 400 kDa, and about 650 kDa, and the highly acetylated chitosan is in the range of about 200 kDa to about 250 kDa. Has a molecular weight.

  The molecular weight of chitosan is reported, for example, in O. Felt, P. Purrer, JM Mayer, B. Plazonnet, P. Burri and R. Gurny in Int. J. Pharm. 180, 185-193 (1999). Defined by size exclusion chromatography. The upper limit of MW is defined by the required ease of administration, which depends on the application chosen.

  As a result of the high degree of acetylation, the hydrophobicity increases in the range of 0-30% DA, high values of 40-60%, and the polymer becomes more soluble as the DA increases. Furthermore, when the number of N-acetylglucosamines increases, the degradation rate in the body increases due to an increase in recognition sites for lysozyme. Thus, the rate of drug release from the hydrogel can be controlled by changes in chitosan acetylation.

  Changes in molecular weight, degree of deacetylation and distribution of acetylation sites, concentration and proportion of two or more chitosans affect the conditions (pH, temperature, etc.) under which gel formation occurs; solubility; biodegradability; protein As an active drug ingredient or other chemical; hydrophobic / hydrophilicity; degree of hydration; biological and biocompatible properties of the gel, effects on cell growth, proliferation and survival, as an inflammation or anti-inflammatory mediator Such as the ability of chitosan to function, and the effect of chitosan on acceleration or deceleration of wound healing.

  For example, high molecular weight type 1 chitosan has high hydrophobicity and high viscosity, resulting in a stronger gel due to high intermolecular interactions. High DDA type 1 chitosan has a low degradation rate. Type 1 chitosan having high crystallinity has a low decomposition rate due to its insoluble crystal form. Thus, those skilled in the art can predict the properties of the resulting gel mixture and thus use a unique combination of different types of chitosan to form gels with predetermined properties.

  As shown in Examples 7 and 9, changes in the molecular weight of chitosan used, their concentration and the ratio between type 1 chitosan and type 2 chitosan affect the conditions under which gel formation occurs. Thus, one skilled in the art can select appropriate parameters to produce a hydrogel under physiological conditions.

  Preferably, the highly acetylated chitosan and the highly deacetylated chitosan are each present at a concentration of about 0.2% to 3% w / v of the total composition.

  In some embodiments, the highly acetylated chitosan and the highly deacetylated chitosan are each present at a concentration of about 0.5% to 2% w / v of the total composition.

  In some embodiments, the highly acetylated chitosan and the highly deacetylated chitosan are each present at a concentration of about 1% to 1.2% w / v of the total composition.

  In some embodiments, the highly acetylated chitosan and the highly deacetylated chitosan are 1: 1 such that the above concentrations are for the highly acetylated chitosan and the highly deacetylated chitosan, respectively.

  In other embodiments, the ratio may be 2: 1, 3: 1 and 4: 1 depending on, for example, the molecular weight of chitosan used and their concentration. Further, it is conceivable that any ratio may be within the range of 1.1: 1, 1.2: 1, 1.5: 1, 1.8: 1 and 1: 1 to 4: 1.

  According to certain embodiments, the highly deacetylated chitosan and the highly acetylated chitosan are present at a concentration of about 1% to 1.2% w / v of the total composition, wherein the highly deacetylated chitosan and the highly acetylated chitosan in the composition The ratio of modified chitosan is 1: 1.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight in the range of about 400 kDa to about 700 kDa, and the highly acetylated chitosan has a molecular weight in the range of about 200 kDa to about 250 kDa, the highly acetylated chitosan and the high Deacetylated chitosan is present at a concentration of about 1% to 1.2% w / v of the total composition; the ratio of highly deacetylated chitosan and highly acetylated chitosan in the composition is 1: 1.

  According to certain embodiments, the highly deacetylated chitosan has a molecular weight in the range of about 2000 kDa, the highly acetylated chitosan has a molecular weight in the range of about 200 kDa to about 250 kDa, and the concentration of the highly deacetylated chitosan is the composition 0.5% w / v of the product, and the ratio of highly deacetylated chitosan and highly acetylated chitosan in the composition is 1: 2, 1: 3 and 1: 4.

  In general, increasing the MW of any chitosan used to form a hydrogel, particularly type 1 chitosan, conversely decreases its concentration, and reducing the chitosan's MW increases their high concentration to form a hydrogel. Is estimated to be necessary.

  The compositions described herein may control the properties of the formed hydrogel, such as hydrogel strength, degradation rate, release rate, etc., for example as compared to the chitosan / β-glycerophosphate hydrogel described above. is necessary.

  The hydrogel of the present invention has a third chitosan selected from either type 1 or type 2 with different molecular weights or degrees of deacetylation, and controls the resulting hydrogel.

  The polysaccharide hydrogel according to the present invention optionally further comprises a negatively charged substance such as a negatively charged polysaccharide or a negatively charged phospholipid. Negatively charged polysaccharides include various animal-derived polysaccharides, plant-derived polysaccharides, glucosaminoglycans and combinations thereof. Examples of glycosaminoglycans include chondroitin sulfate, dermatan sulfate, dextran sulfate, heparan sulfate, heparin, hyaluronic acid, keratan sulfate, and combinations thereof.

  An exemplary suitable phospholipid is phosphatidylcholine. According to certain embodiments, the chitosan composition further comprises hyaluronic acid and phosphatidylconine. This composition can be used as a synovial fluid replacement in the treatment of osteoarthritis and is highly effective and reduces friction between cartilage surfaces as described in Example 6.

  In some embodiments, the chitosan products described herein further have both glycosaminoglycans and phospholipids.

  Thus, these two different chitosan-based compositions and mixtures are used to provide hydrogels with suitable properties for a wide range of applications. Exemplary applications include, but are not limited to, drug delivery systems, eg, delayed release of drugs or drugs, various concentrations of scaffolds, and gels that support cell growth or support skeletal structures; Synovial fluid recovery; tissue remodeling; wound dressings that promote scar-free treatment and macrophage activation; artificial skin manufacture; artificial kidney membrane; bone filling; and colic recovery and synovial fluid recovery compositions.

  Hydrogels form in vivo, subcutaneously, intraperitoneally, intramuscularly or in biologically relevant tissues, bone defects, fractures, joint cavities, body vessels, eye bags, or solid tumors.

  The polysaccharide solution is introduced into the animal or human body by injection or endoscopic administration.

  Drugs, polypeptides, micro-organisms, animal or human cells are taken up in a polysaccharide solution before gelling.

  In accordance with the present invention, polysaccharide gels formed from the compositions described herein are also provided for generating biocompatible degradable materials for use in cosmetics, pharmacy, medicine and / or surgery.

  Here, the hydrogel surrounds the quasi-solid gel formed from the aqueous chitosan solution described herein when these solutions are exposed to the physiological conditions described herein. The hydrogel is preferably formed in vivo when the chitosan composition is administered, but alternatively, it is formed ex vivo prior to use, for example, for implantation.

  The gel is incorporated in whole or as a component into implantable devices or implants for recovery, tissue and / or organ remodeling and / or replacement in either animals or humans.

  Gels are used in whole or as a construct for implantable, transdermal or dermal drug delivery systems.

  Gels are used in whole or as constructs for ophthalmic implants or drug delivery systems.

  Gels are used to produce similar biotechnological hybrid materials and cell-loaded artificial materials for use in tissue engineering and culture.

  The loaded cells are chondrocytes (artificial synovial fluid), fibrochondrosarcoma (meniscus), ligament fibroblasts (ligament), skin fibroblasts (skin), tendon cells (tendon), myofibroblasts (muscle), Selected from the group consisting of mesenchymal stem cells, keratinocytes (skin), and nerves, and adipocytes or bone marrow cells. In fact, cells from any tissue that can proliferate can optionally be incorporated into the construct.

  The main damage of wound healing is the presence of biofilm. Biofilms consist of normally positively charged extracellular macromolecules similar to chitosan, present at least 80 percent. Chitosan is optionally used as a biofilm blocker to limit the biological membrane's inhibitory effects when hygienizing wounds and destroying bacteria. Chitosan gel mixed with lactoferrin optionally serves as a delayed release reservoir that destroys biological membranes in any chronic wound or chronic wound. Chitosan gel mixed with xylitol also optionally becomes a specific biomembrane barrier.

  In accordance with the present invention, an injectable or implantable that functions as a support, carrier, reconstitution device or replacement for bone-like, fibrocartilage-like, or synovial fluid-like in situ formation in an animal or human physiological location The use of the loaded polysaccharide gel as a novel gel biomaterial is also provided.

  For example, the chitosan gel according to the present invention is effective as a sustained delivery drug system for ocular treatment. The results based on the eye irritation test of chitosan compounds show that chitosan preparations are suitable for use as ophthalmic gels based on their superior durability (Molinaro et. Al., 2002).

  According to a further embodiment of the present invention, a delayed release drug delivery hydrogel system is provided having highly acetylated type 1 chitosan and highly deacetylated type 2 chitosan.

  Any drug delivery system of the present invention can be used to deliver a variety of drugs including, but not limited to, analgesics, anesthetics, anti-acne agents, anti-aging agents, anti-bacterial agents, constituents, anti-burn agents , Antidepressant, anti-dermatitis agent, anti-edema agent, anti-histamine agent, anti-helminth infection agent, anti-cholesterol drug, anti-inflammatory agent, anti-irritant agent, antilipidemic agent, antibacterial agent, antifungal agent, antioxidant agent , Anti-itch agent, antilipidemic agent, anti-rosacea, anti-seborrheic agent, antiseptic, anti-swelling agent, antiviral agent, anti-yeast agent, cardiovascular agent, chemotherapeutic agent, corticosteroid, There are anti-fungal agents, hormones, hydroxy acids, keratolytic agents, lactams, mitides, non-steroidal anti-inflammatory agents, lice control agents, progestins, therapeutic agents, scabicides, and vasodilators.

  According to another aspect, the present invention provides a method of producing a stable hydrogel, which method comprises at least one highly acetylated chitosan having a degree of acetylation in an aqueous acetic acid solution in the range of about 40 to about 60% and Dissolving at least one highly deacetylated chitosan having a degree of acetylation of about 20% or more to form a complex solution; adjusting the pH of the complex solution to a value of 6.5 to 7.2; Raising the temperature of the composite solution to 37 ° C. and raising the pH value to 7.0-7.6 to form a hydrogel having a viscosity of at least 100 mPa · s at 25 ° C. and a shear rate of 50 rpm.

  In some embodiments, the dissolution of the highly acetylated chitosan and the highly deacetylated chitosan occurs simultaneously in the same vessel.

  Optionally, the dissolution of highly acetylated chitosan and highly deacetylated chitosan is performed in separate solutions to produce two solutions. In this embodiment, the process further comprises the step of mixing these two solutions to form a composite solution.

  Further, according to some embodiments of the present invention, there are provided pH-dependent and temperature-dependent hydrogels formed by the processes described herein.

  The present invention further shows that mixtures of various monosaccharide oligomers such as highly deacetylated chitosan and chitosan oligomers also form hydrogels with certain properties as described herein.

  Thus, according to a further aspect of the present invention, at least one high deacetylation having a molecular weight and a degree of acetylation of about 20% or more in the range of about 100 to about 4000 kDa, such as about 100 kDa to yaku 2000 kDa (chitosan polymer). There is provided a chitosan composition having a modified chitosan and at least one chitosan oligomer having a molecular weight in the range of about 200 to about 2000 kDa, wherein the composition is in the form of an aqueous solution. The chitosan oligomer is a highly deacetylated chitosan oligomer having a degree of acetylation of about 20% or more, or alternatively, a degree of acetylation in the range of about 40% to about 60%, such as about 45% to about 55%. It is a highly acetylated chitosan oligomer. In certain embodiments, the highly deacetylated chitosan oligomer has a degree of acetylation of about 15% or less. According to certain embodiments, the monosaccharide oligomer is between 3 and about 100 D-glucosamine oligomers. In certain embodiments, the D-glucosamine oligomer has 3 to about 50 units. In certain embodiments, the monosaccharide oligomer is an N-acetyl-D-glucosamine oligomer having up to 7 units. In some embodiments, the ratio between the monosaccharide oligomer and the highly deacetylated chitosan polymer is 1: 1, especially depending on the MW of the highly acetylated chitosan and chitosan oligomer 2: 1 to 20: 1. The range of is also good.

  Therefore, the concentration of highly acetylated chitosan is, for example, 1%, 2%, 4%, 10%, and any concentration is in the range of 1-20% (w / w).

  The concentration of the oligomer is selected according to a predetermined ratio.

  Monosaccharide chitosan oligomers are water soluble at pH 6.5 and above, function as “protecting groups” for highly acetylated chitosan, and analogs affected by highly acetylated chitosan as described herein. It is the same.

  In certain embodiments, at 25 ° C. and pH in the neutral region, the composition has a viscosity of at least 100 mPa · s at a shear rate of 50 rpm. In certain embodiments, at 25 ° C. and pH in the neutral region, the composition has a viscosity of less than 70 mPa · s at a shear rate of 200 rpm.

  Hydrogels having a combination of chitosan polymer and chitosan oligomer can be utilized in any of the applications described herein and are prepared as described in Example 8.

  Throughout this specification, various embodiments of this invention exist in a range format. The description in range format is merely for convenience and brevity and is not to be construed as an inflexible limitation of the invention. Accordingly, the description of a range is considered to have all the possible subranges described in detail and each numerical value within the range. For example, the description of the range of 1 to 6 etc. is a partial range specifically described such as 1 to 3, 1 to 4, 1 to 52 to 4, 2 to 6, 3 to 6 and the like, for example 1, 2, Considered as each number in the range of 3, 4, 5 and 6. This applies regardless of the range width.

  Whenever a range of numbers is given herein, it is meant to include any indicated number (fractional or integer) within the indicated range. The “range” between the first number and the second number and the “range” of the first number “to” and the second number “to” are interchangeable herein, and the first and second numbers and all Is meant to include fractions and integers between them.

  As used herein, the term “method” means a method, means, technique and procedure for accomplishing a given task, including but not limited to chemical, pharmaceutical, biological Those methods, means, techniques and procedures, either known to those skilled in biochemical and medical technicians, or readily applicable by methods, means, techniques and procedures, are indicated.

  As used herein, the term “treatment” refers to negating, almost inhibiting, delaying or reversing the progression of a condition, substantially improving a clinical or aesthetic symptom of a condition, or clinical of a symptomatic condition. This includes almost preventing the onset of symptomatic or aesthetic symptoms.

  Certain features of the present invention are also provided in combination with one embodiment, as clearly described in the context of separate embodiments. Conversely, as described for simplicity in the absence of one embodiment, the various features of the invention are also provided separately or in any appropriate combination in any other illustrated embodiment of the invention. Certain features that are described in the content of the various embodiments are considered to be important features of those embodiments, unless the embodiment is effective without those elements.

  As described above and as set forth in the following claims, various embodiments and aspects of the invention are experimentally supported in the following examples.

Example 1
Preparation of Chitosan Hydrogel Chitosan (Koyo, Japan) having a degree of acetylation of 15% and a molecular weight of 65 kDa is dissolved by mixing with 0.9% HCl for 24 hours and has a chitosan concentration of 3% (w / v) A chitosan solution was produced.

  Uniformly deacetylated chitosan (Koyo, Japan) with a degree of 51% deacetylation and a molecular weight of 220 kDa was dissolved by mixing with 0.9% HCl for 24 hours to obtain a chitosan concentration of 3% (w / v). A type 2 chitosan solution was produced.

  Type 1 and Type 2 chitosan solutions were mixed so that the ratio of Type 1 to Type 2 was 1: 1, 1: 2 and 1: 3, titrated at pH 6.8 and left at 4 ° C. for 24 hours. Thereafter, it was further titrated with sodium hydroxide to pH 7.3 at 4 ° C.

  The resulting composition was liquid at room temperature. When the temperature rose to 37 ° C. and rose to pH 7.4, the liquid solution produced a stable quasi-solid hydrogel as shown in FIG.

Example 2
Degradation profile of chitosan hydrogel A pseudo-thermosetting hydrogel (3% w / v) was prepared from homogeneously acetylated type 2 chitosan and non-homogeneously deacetylated type 1 chitosan as described in Example 1 above. (Hydrogel A). Hydrogel A was prepared at 1: 1, 1: 2 and 1: 3 ratios. A different hydrogel (hydrogel B) was prepared using the same type 2 chitosan used for hydrogel A and a type 1 heterogeneous chitosan with a molecular weight of 100 kDa.

  One gram of each gel was placed in a triple 50 mL plastic tube.

  A 3 mL aliquot of 10% bovine serum culture was added to each tube at predetermined time intervals (1, 2, 3, 4, 5, 6 and 7 days). At the end of each time interval, 50 mL of purified water was repeatedly added, left at room temperature for several hours, and washed three times for 24 hours or more by removing water. The washing process removed all soluble material from the gel.

  The gel was then frozen, lyophilized and weighed. The weight resolution was calculated from the change in sample weight as a function of time interval.

  Degradation of the hydrogel by serum enzymes is shown in FIG. 2A.

  Two different degradation kinetics are shown by each composition shown in FIG. 2A; the first rapid phase is terminated within 3-6 days, and the slow phase shows partial degradation after 14 days. The degradation rate of the gel is more rapid in compositions having a high ratio of type 2 to type 1, ie, a 1: 1 composition degrades more rapidly than a 1: 3 composition. The rapid phase is highly soluble and easily reflects in the degradation of type 2 chitosan and is easily recognized by serum enzymes. The delayed kinetic phase is associated with chitosan type 1 and is not easily recognized or digested by serum enzymes.

  Controlling the reacetylation of glucosamine polymers is a very important tool for manipulating the degree of chitosan recognition by lysozyme and consequently manipulating the rate of hydrogel degradation. The main factor controlling enzyme activity is the percentage of N-acetylglucosamine (GlNAc) in the polymer (Ran et al., 2005). The reason for this is that a reduction in the degree of reacetylation from 50% to 35% in chitosan type 2 greatly reduces the degradation rate, resulting in a much shallower slope. On the other hand, increasing the degree of acetylation of type 1 chitosan results in faster polymer degradation. The selection of the appropriate combination of the two types of chitosan results in one linear decomposition curve over time instead of the two slopes shown in FIG. 2A. In addition, increasing the molecular weight of type 1 chitosan to at least 100 kDa reduces the degradation rate of the composition, resulting in a linear rate of degradation, as shown in FIG. 2B.

Example 3
Delayed release of protein by chitosan hydrogel To study the potential of the chitosan pseudo-thermosetting hydrogel shown here as a delayed release vehicle, hemoglobin and bovine serum albumin (BSA) were used as solutes. These compounds are often used as protein standards.

To a 1 mL solution containing the chitosan mixture described in Example 1 above, with a final concentration of both chitosans of 3.5%, 25 μl aliquots of BSA and 40 μl hemoglobin were added so that the final concentration in the hydrogel was 4 mg / mL each And 1 mg / mL. Protein-containing hydrogel in 3 mL PBS for 1 week at 37 °
In culture. The medium was changed daily and the amount of protein released from the hydrogel was measured as shown in FIGS.

  As shown in FIG. 3, in all tests, a large amount of hemoglobin was first released and the release rate decreased with time. No initial burst was shown.

  BSA showed the same profile as hemoglobin (Figures 4 and 5). A nearly linear slope was obtained (FIG. 4). Mixing BSA with the gel improved the stability of the gel and decreased the protein release rate compared to the chitosan mixture alone.

  A comparison of the ratio of the amount of BSA released to the amount of gel degraded (FIG. 7) showed that the rate of protein release was faster than the rate of gel degradation.

  The data shown in FIG. 7 is related to the degree of acetylation and molecular weight of type 1 chitosan, resulting in a decrease in daily release rate in the protein release profile. However, by proper selection of additional variables such as the degree of acetylation and molecular weight of the two chitosans, the properties of the gel can be defined and the affinity of the protein drug for the chitosan structure can be improved. This particular combination is expected to provide a constant release rate for a particular drug and reflects a combination of diffusion and matrix degradation rates.

Example 4
In vivo study of chitosan hydrogel as a wound dressing Debsna rats are known to develop diabetic symptoms when raised on a high fat diet and were used as a model for type 2 diabetes. These animals are prone to develop severe infections, gangrene and sepsis, cause morbidity and even death, thus stimulating diabetic chronic skin ulcers and considered as excellent models for studying skin wound healing .

Common parameters for evaluating the skin and healing the wound include
1. 1. Neovascularization time seen in repaired tissue 2. reduced neutrophil activity 3. Accelerated macrophage activity 4. Time of wound closure due to complete epithelialization of the wound 5. Formation of keratinocyte monolayer There is an epithelial and dermal phase connection by a fibroblast-deposited extracellular matrix network.

  The composition of the chitosan mixture is a mixture of highly deacetylated chitosan (660 kDa, DA15), highly acetylated chitosan (220 kDa, DA50) and 1-7 units of N-acetyl-D-glucosamine oligomer (Koyo, Osaka, Japan). including. Each formulation has three components in a ratio of 1: 0.8: 0.2.

  Twenty-five female mature fatsna rats, each weighing 150-160 grams, were used.

  Thirteen animals developed diabetes after administration of a high fat meal starting 4-6 weeks before Day 0.

  Six animals with normal blood glucose levels (normoglycemia) have antibodies against diabetes when fed a high fat diet, used as a primary control, and fed a normal low fat, low calorie diet Six animals with normoglycemia were used as the second control.

  On day 0, a 2 mm diameter round penetrating punch biopsy was performed on the shaved skin of the neck using a Metriconventer-production device and on the subcutaneous tissue down to the epidermis, dermis and muscle.

  Seven diabetic animal injuries were treated by administering the chitosan-based gel of Example 1 to the wound area and a further six animals were untreated. The gel was reapplied daily to the wound area of the treatment group. In half of the animals in the control group, the Gibbs bandage was covered over the entire wound and the other half was not covered.

  For 7 days, all animals were super close-up photographed and wound size was measured every 3 days. Body weight and blood glucose concentration were measured once a week using a digital glucometer (Ascensia Elite of Bayer) by cutting the rat's tail and sucking drooping blood.

  Seven days later, the animals were killed and a penetration biopsy was performed. The skin was collected and placed in an immobilization solution. Skin samples were further histologically and immunohistochemically stained to assess differences between treated and untreated wounds.

  The results obtained show that rats treated with the gel have a statistically significant increase in wound healing as assessed by wound surface area (FIG. 9). A representative histological sample demonstrates wound healing as shown in the smooth surface shown in FIG. 8A, whereas the control untreated sample (FIG. 8B) does not demonstrate wound healing.

Example 5
Rotator Cuff Recovery A rotator cuff tear is a common cause of shoulder pain. Incidence of rotator cuff increases with age, most frequently due to tendon degeneration rather than sports or trauma. Proposed treatments range from rehabilitation to ruptured tendon surgery. The best treatment is different for all patients, and in fact many patients have not obtained a satisfactory recovery of their injuries.

  The present invention, in some embodiments, overcomes these drawbacks of the background art by providing an injectable product that can deliver autologous cells to a rotator cuff tear under the control of an ultrasound diagnostic device. In other embodiments, the injectable product enables bone marrow cell transplantation, such as tissue healing.

  Preferably, this procedure is performed on an outpatient or an outpatient in need of local anesthesia.

  The initial liquid properties of the gel can all be adhered to the tendon laceration area.

  In vivo experiments were performed on rats (surgically damaged tendons) for tendon injury and recovery. Injured tendons were sutured and treated with chitosan hydrogel and bone marrow cells as indicated herein; the control animals were only sutured. Twenty animals were tested for 3 months. Histologically, both tendon recovery and prevention of muscle atrophy were achieved.

  In addition, in vivo experiments were performed on rats with surgically damaged rotator cuffs. This damage was treated as described above. A histological slice of tissue 6 weeks after surgery shows that endogenous cells have been captured from adjacent tissue and improved the condition of the injury site compared to an untreated control defect on the contralateral shoulder. . Exemplary results are shown in FIG. 10A (processed) and FIG. 10B (unprocessed).

Example 6
The chitosan mixture was designed to function as a reservoir for negatively charged substances such as proteoglycans (eg chondroitin sulfate), hyaluronic acid, and / or phospholipids (eg phosphatidylcholine). This mixture has rheological properties that stimulate normal synovial fluid and can be used for cartilage regeneration and correction of joint mechanisms, and for example in osteoarthritis.

  To evaluate the properties of these compositions, the coefficient of static friction was measured in vitro between two flat cartilage surfaces and various test compositions were used. After use of the composition, the cartilage surface was placed one on top of the other and one end slowly lifted manually. The exact angle at which movement began was measured with a digital inclinometer. The regulation is performed three times, and the average static friction coefficient μ is disclosed in http://www.pa.uky.edu/~phy211/Friction_book.html and shown in FIG. 11 according to the formula μ ≦ tan (inclination angle). Calculated.

  FIG. 12 represents the coefficient of static friction between the two layers of normal cartilage: a control system without hydrogel (shown as “Saline”); chitosan type 1 (660 kDa MW; DA15) and chitosan type 2 Chitosan hydrogel combination (denoted “Combination”) with MW of 220 kDa (DA50); chitosan hydrogel previously described with 0.1% chondroitin sulfate (denoted + CS) in addition to the chitosan hydrogel combination previously described In combination with 0.1% chondroitin sulfate and 0.1% phosphatidylcholine (shown as + CS / PC), and 1% hyaluronic acid solution (shown as HA).

  The data obtained clearly shows that the combination of hydrogel compositions with type 1 and type 2 chitosan combined with chondroitin sulfate and phosphatidylcholine results in a synovial fluid-like coefficient of friction.

Example 7
Control of formation conditions of chitosan hydrogel A chitosan polymer (or oligomer) is defined by its molecular weight, its degree of deacetylation, its degree of crystallinity and its distribution mode of acetyl groups.

  There is a limit to the dissolution of deacetylated chitosan in aqueous solution. For example, with HCl 0.15N, chitosan with a MW of 200 kDa or more becomes a solution with a concentration of less than about 10% (w / v), and as the molecular weight increases, the maximum solution concentration becomes the physiological NaCl concentration. High concentrations of HCl (or other acids such as acetic acid) can be highly concentrated chitosan solutions.

  The most common commercially available chitosan has a low DA (degree of acetylation) of 5-30% and is referred to herein as type 1 chitosan. Type 1 chitosan precipitates out of solution at a pH of 6.5 or higher. Thus, there is no Type 1 chitosan solution in a physiological environment, and current applications such as chitosan practice use various types of solid chitosan.

Chitosan that has been uniformly deacetylated to 50% or uniformly reacetylated to 30-60% is designated as type 2 chitosan. This chitosan has superior solubility in aqueous solution compared to highly deacetylated chitosan (type 1) and generally dissolves at neutral and physiological pH depending on its concentration. This exemplary chitosan having a MW of 220 kDa and a concentration of 3% (w / v) or higher forms a gel at a pH of 7.5 or higher.
Hydrogel formation using a mixture of chitosan polymers

  When Type 1 chitosan and Type 2 chitosan are mixed under physiological pH and certain conditions, no polymer precipitation is observed, instead the mixture forms a hydrogel. Hydrogel formation includes a “coating” (or “protection”) of type 1 chitosan with type 2 chitosan, which is influenced by the affinity between the two types of chitosan, resulting in an interaction between them (eg, hydrogel binding Hydrophobic interaction and / or van der Waals forces).

  The gelation process takes minutes or days and is evidenced by a continuous increase in the viscosity of the system.

  In ex vivo experiments, hydrogel formation is accomplished by rotating a glass tube with the original solution on the side and the solution flows or instead a quasi-solid gel is formed and deposited at the bottom of the glass tube. It is specified by evaluating whether or not. Gel formation depends on tube type, morphology and parameters (eg diameter) and evaluation time.

In this experiment, hydrogel formation was defined as follows: 1 mL of the solution was incubated overnight at 37 ° C. in a 14 mm (diameter) round bottom glass flask. The glass tube was then leveled to determine if there was a liquid flow. The absence of liquid flow indicates the formation of a hyde gel. The hydrogel contained all of the water and was hard in the quasi-solid state. Structures where there is a flow but are not well distinguished also indicate that a hydrogel has formed. The presence of a liquid stream and / or the formation of two different phases, solid and liquid, indicates that no hydrogel has formed.
Control materials for hydrogel formation

Two commercially available highly deacetylated polymers (chitosan type 1) were used in this experiment:
FM® 80 (MW = 660 kDa; 85% DDA (degree of deacetylation); and FM® 80S (MW = 420 kDa; 91.3% DDA) were both purchased from Koyo, Osaka, Japan. .

Highly acetylated chitosan (chitosan type 2), DAC® 50 (MW = 220 kDa; 50% DDA) was also purchased from Koyo, Osaka, Japan.
Analysis protocol

Stock solution preparation. The chitosan polymer (powder) was mixed with HCl 0.15N and the solution was stirred for 24 hours at room temperature. The stock solution was made as follows:
FM (registered trademark) 80-2 2% (w / v) solution FM (registered trademark) 80S-2 2% (w / v) DAC (registered trademark) 50-3 3% (w / v)

  Mixture formation. Using the stock solution described above, a mixture having a predetermined final concentration (w / v) of each chitosan and a predetermined ratio thereof was prepared. An exemplary mixture is FM® 80: DAC® 50 is 1.2: 1.2, each chitosan is at a final concentration of 1.2% (w / v), their proportions Is 1: 1.

  Titration. The above mixture was slowly titrated in an ice bath (0 ° C.) with NaOH (2N, 1N and 0.5N concentrations) to a pH of about 7.3. A 1 mL sample was then taken continuously from the mixture during the titration and each sample was placed in a 14 mm glass tube. Samples were sealed and incubated overnight at 37 ° C.

  Gel formation test. Each glass tube was leveled and gel formation was defined as described above.

  result. Table 1 below shows the results obtained for various FM® 80: DAC® 50 mixtures.

  This result shows that a mixture of 15% DA 660 kDa chitosan type 1 (and similar crystallinity as FM® 80) and DAC® 50 with an equal (1: 1) w / w ratio for each chitosan When the final concentration of is 0.8% (w / v), it indicates that a gel is formed around pH 7.5.

  This mixture has a final pH of 1.2% (w / v) for each chitosan compared to a mixture of 1% (w / v) final concentration of each chitosan (7.6-7.7) and a broad pH. It forms a hydrogel in the region (7.42-7.66), thus indicating that a higher final concentration indicates a wider pH region for hydrogel formation (described herein).

  When the FM80: DAC50 ratio is higher than 1: 1 (eg 1: 0.6), no hydrogel is formed.

  Table 2 below shows the results obtained for various FM® 80S: DAC® 50 mixtures.

  These results further support that a minimum concentration of about 1% of each polymer is necessary to form a hydrogel near pH 7.5 under the indicated conditions.

  These experiments show that parameters affecting hydrogel formation in the tested system include pH, relative proportions of chitosan type 1 and type 2 polymers (w / w), molecular weight of each chitosan polymer (MW), Indicates final concentration and temperature.

  pH. Gel formation is pH dependent and the solution mixture forms a hydrogel only at certain pH regions. This pH range becomes wider as the final concentration of chitosan increases. The absolute pH value increases with decreasing chitosan final concentration.

  For example, chitosan type 1 having a MW of 420 kDa and type 2 chitosan having a MW of 220 kDa have a 1: 1 w / w ratio at a concentration of 1 to 1.2%, respectively, and a pH region in which a gel is formed at 4 ° C. Is 7.4 to 7.7. At high pH values, precipitation is observed.

  Note that the pH value at 4 ° C correlates with a pH value that is 0.5 lower at 25 ° C. Therefore, the pH at 4 ° C. becomes pH 6.9 at 25 ° C.

  Final concentration of type 1 chitosan. Type 1 chitosan is considered the backbone of the hydrogel. Thus, hydrogel formation depends on the final concentration of type 1 chitosan. Increasing the MW of Type 1 chitosan decreases the final concentration in the composition, conversely, decreasing the MW increases the final concentration in the composition.

  Molecular weight of type 1 chitosan. The use of high MW type 1 chitosan reduces the pH functional area, ie the area where hydrogel formation is possible. For example, a composition having a MW 660 kDa type 1 chitosan forms a hydrogel in the pH range 7.4-7.7, whereas a composition having a MW 2000 kDa type 1 chitosan is in the pH range 7.0-7.3. Form a hydrogel. Furthermore, increasing the MW of type 1 chitosan increases the required relative concentration of type 2 chitosan. Furthermore, as the concentration of type 1 chitosan increases (eg, up to 0.5%), the pH region where hydrogel formation occurs shifts to 7.2-7.4 (at 4 ° C.).

  Furthermore, as the MW of type 1 chitosan decreases (eg from 420 kDa to 200 kDa), the concentration of chitosan required for hydrogel formation increases. Exemplary concentrations required for MW type 1 chitosan below 200 kDa are 1.2-1.5% (w / v) or higher. Under this condition, the pH value for hydrogel formation shifts to 7.5-7.8 (at 4 ° C.).

  Concentration of type 2 chitosan. A minimum relative concentration of type 1 chitosan and type 2 chitosan is required for hydrogel formation (eg 1: 1 ratio). In addition, maintaining Type 1 chitosan at a constant final concentration and increasing Type 2 chitosan concentration broadens the range of other parameters for hydrogel formation (eg, increases the pH functional area). Increasing the type 2 chitosan concentration further lowers the pH at which the hydrogel forms.

  Molecular weight of type 2 chitosan. Using a MW type 2 chitosan higher than 220 kDa results in a lower relative concentration of type 2 chitosan in the mixture. High MW type 2 chitosan provides high protection and improves the stability of chitosan type 1 (extensive type 1 chitosan MW). Under this condition, the pH region where the hydrogel is formed is expanded.

  For example, when using MW 2000 kDa type 2 chitosan and MW 660 kDa chitosan, the pH for hydrogel formation is about 7.8, but when using 2000 kDa type 2 chitosan and 2000 kDa type 1 chitosan, the pH for hydrogel formation is about 7 .6.

  temperature. Temperature linearly affects the hydrogel formation rate. Thus, at 37 ° C, the hydrogel forms faster than room temperature or 4 ° C.

  Relative proportion of type 1 chitosan and type 2 chitosan. The proportion required for hydrogel formation depends on the MW of each chitosan. For example, as the MW of type 1 chitosan increases (eg up to 2000 kDa), the required concentration may decrease to about 0.5%. However, it is estimated that the ratio between Type 2 and Type 1 increases to, for example, 2: 1, 3: 1, and 4: 1.

  As the MW of type 2 chitosan increases from 220 kDa to, for example, 2000 kDa, the minimum concentration required for hydrogel formation decreases to, for example, 0.5% (instead of 1%), which is proportionate with high MW type 1 chitosan Is about 1: 1.

Example 8
Chitosan hydrogels formed from highly acetylated and highly deacetylated chitosan oligomer and highly deacetylated chitosan polymer Soluble at high pH. Therefore, the formation of hydrogels from mixtures combining chitosan oligomers (eg 200-2000 kDa MW) of highly deacetylated chitosan polymers (eg 200-2000 kDa molecular weight) was tested.

  A solution of type 1 chitosan polymer (MW 660) was each mixed with a highly deacetylated oligomer (MW 200-1500 Da) solution to evaluate hydrogel formation. Highly deacetylated oligomers were present in solution at final concentrations of 1%, 2%, 4% and 10%, and highly deacetylated polymers were present at a final concentration of 1%. The ratios tested (oligomer to polymer) were 1: 1, 2: 1, 4: 1, and 10: 1.

  Except for the 1: 1 solution, all test mixtures formed chitosan hydrogels, and surprisingly, a mixture of highly deacetylated chitosan highly deacetylated chitosan polymer and highly deacetylated chitosan oligomer formed a hydrogel. .

Similarly, hydrogel formation was evaluated using various ratios with combinations of type 1 chitosan polymer (MW420; DA9) and highly deacetylated chitosan oligomer (MW200-2000 Da). In addition, combinations with different monosaccharides at the chitosan oligomer position were tested. As shown in Table 3, the results show that chitosan hydrogels are formed with: monosaccharides and oligomers of N-acetyl-D-glucosamine; monosaccharides and oligomers of D-glucosamine; fructose; methylcellulose and hydroxyethylcellulose. Conversely, hydrogel formation was not observed with oligomeric starch, laminarin or inulin.

  Similar results, i.e., hydrogel formation, is obtained for a mixture of highly deacetylated chitosan polymer (e.g. MW 200-2000 kDa) and highly acetylated chitosan oligomer (e.g. MW 1000-20000 Da).

Example 9
Viscosity experiments of chitosan hydrogels formed from highly acetylated and highly deacetylated chitosan polymers The main points described in Example 7 were demonstrated in the viscosity experiments of various hydrogels formed from chitosan polymers.

Materials and Methods All chitosan polymers used in this experiment were purchased from Koyo (Osaka, Japan) and are shown in Table 4.

  A combined chitosan solution was prepared in one of two ways. In one method, stock solutions of type 1 and type 2 chitosan were each prepared at a predetermined concentration as shown in Example 7. A slow titration with NaOH at either 1 ° C. or 25 ° C. was performed until a predetermined pH was reached. In an alternative method, pre-weighed powder type 1 and type 2 chitosan were mixed with an acidic solution such as HCl (0.15 N) or acetic acid (0.25 N). After solubilization, the solution was slowly titrated with NaOH at either 1 ° C. or 25 ° C. until a predetermined pH was reached.

Solutions with a mixture of either FML®, SK® 10 or FM® 80 and DAC® 50 were each 1: 1 (FVL: 50 1: 1 respectively; SK10 : 50 1: 1 and FM 80:50 1: 1). Samples (0.5 mL) were analyzed on a Brookfield RVDV-II + Pro viscometer attached to a cone spindle with a range factor of 51780. Dividing the range factor by the rotational speed (RPM) defines the maximum viscosity measured in centipoise (cP). Thus, for example, a viscosity of up to 250 cP can be measured in this system at 200 RPM.
result

  FIG. 13 shows DAC® 50 at 1% (diamond mark) or 2% (square mark); or FM® 80 at 1% (asterisk mark); or FM® 80 and DAC ( The result obtained from the composition which has a ratio (registered trademark) 50 of 1: 1 (oval mark) is shown.

  As shown in FIG. 13, a 1% solution of type 1 chitosan (FM® 80S or FM® 80) has a low viscosity in the tested pH range of about 4.5-6.5 at 25 ° C. Have. When titrated to high pH values, the viscosity of these compositions cannot be defined as chitosan precipitates and clearly exceeds the pKa of chitosan. These results indicate that a solution with one highly deacetylated chitosan is not suitable for in vivo applications. A 1% solution of type 2 chitosan DAC® 50 is soluble in the tested pH range of about 5.4 to about 7.6 at 25 ° C., comparable to that it can be used in vivo. It exhibits a low viscosity and does not form a hydrogel. Conversely, a 1: 1 combination solution of solution FM 80:50 transitions from a liquid to a quasi-solid gel at a pH of about 6.5 and 25 ° C., as shown in FIG. In particular, at this pH, the composition begins to exhibit non-Newtonian behavior and increases at higher pH, i.e., at a pH of 6.9, a viscosity of about 175 mPa · s. These results show that a 1: 1 mixture of 15% acetylated (ie, highly deacetylated) chitosan with a molecular weight of 660 kDa and 50% acetylated (ie, highly acetylated) chitosan with a molecular weight of 220 kDa was observed at physiological conditions. It is appropriate to form a hydrogel.

  FIG. 14 shows a 1: 1 ratio combination of highly deacetylated chitosan FVL® and highly acetylated chitosan DAC® 50 (diamond marks); or highly deacetylated chitosan SK®. 10 shows the results obtained with a composition having a 1: 1 ratio combination (squares) of 10 and DAC® 50. FIG. 14 shows that each mixture FVL: 50 1: 1 and SK10: 50 1: 1 greatly increases in viscosity at near-neutral pH values to form a quasi-solid hydrogel. These results confirm that the combination of highly acetylated chitosan with highly deacetylated chitosan prevents the latter precipitation at neutral pH and allows hydrogel formation. In addition, the 1: 1 viscosity of SK10: 50 is much higher than FVL: 50 1: 1 across pH values. In particular, at a pH of about 7, these mixtures exhibit viscosities of about 55 and 42 mPa · s, respectively. Since these mixtures differ only in the molecular weight of the highly deacetylated chitosan, ie, 100 and 650 kDa, respectively, the molecular weight of the highly deacetylated chitosan defines the viscosity and non-Newtonian fluid behavior of the hydrogel composition of the present invention. It shows that it is an important factor together with pH.

  These conclusions are further obtained in a 1: 1 ratio combination of SK®10 and DAC®50 (FIG. 15A) pH 5.13 (marked x); 5.67 (open squares); 6 (White triangle mark); 6.24 (white diamond mark); 6.51 (asterisk mark); 6.65 (black circle mark); 6.75 (white circle mark); 6.87 (black diamond mark) and 7 ( (Black square mark); or in a 1: 1 ratio combination of FVL® and DAC® 50 (FIG. 15B) pH 5.45 (white diamond mark); 5.7 (black square mark); 6 .04 (white triangles); 6.3 (x symbols); 6.56 (asterisks); 6.68 (black circles); 6.82 (black triangles); 6.88 (black diamonds) and Results in FIG. 15 obtained with a composition having 7.03 (white squares) Thus it is supported.

  FIG. 15A shows that when the pH value of the solution is in the neutral region, ie 6.87 and 7, the 1: 1 viscosity of SK10: 50 increases dramatically with decreasing shear rate, but is the same at lower pH values. It shows that the composition does not show an increase in viscosity with decreasing shear rate. That is, 1: 1 of SK10: 50 shows Newtonian fluid behavior at pH values below the neutral region and non-Newtonian fluid behavior at pH in the neutral region. Conversely, 1: 1 for FVL: 50 has only a slight increase in viscosity when the shear rate decreases at neutral pH and remains in the liquid state (FIG. 15B), with 105 mPa · s at SK10: 50 1: 1. The peak viscosity is about 35 mPa · s compared to s.

  FIG. 16 shows that at low temperatures, ie 1 ° C., the increase in pH-induced viscosity in the compositions of the present invention was reduced. The results in this figure are pH 5.35 (black circles); 5.92 (black diamonds) at a 1: 1 ratio combination of SK® 10 and DAC® 50 (SK 10:50); 6.22 (asterisk mark); 6.81 (black square mark); 6.95 (black triangle mark) and 7.01 (x mark); or 1 of FVL and DAC® 50 (FVL10: 50) : PH 5.85 (white diamond mark); 6.2 (gray square mark); 6.44 (white triangle mark); 6.76 (gray triangle mark); 6.94 (white square mark) ) And 7.00 (open circles).

  At 1 ° C., SK10: 50 1: 1 shows only a gradual increase in viscosity compared to the dramatic increase observed at 25 ° C. More specifically, at 1 ° C. and at low shear rates, the viscosity of SK10: 50 1: 1 increases from 50 to 65 mPa · s as the pH increases from about 5.3 to about 7 (ie 30 % Increase), at 25 ° C. and a low shear rate, the viscosity of the same composition increases from 20 to 110 mPa · s (ie, a 55% increase) when the pH is similarly increased (FIG. 15A). This suggests that the chitosan composition according to the present invention is stored at a low temperature for storage in a liquid or relatively ungelled state. Note that at neutral pH and low shear rate, FVL: 50 1: 1 shows a greater viscosity at 1 ° C. compared to 25 ° C. (compare FIG. 15B and FIG. 16), room temperature and above. Since the viscosity tends to decrease with increasing temperature up to the temperature of, a use of this composition for hydrogel formation in vivo is proposed.

  FIG. 17 is a composition having a 1: 1 ratio combination of SK® 10 and DAC® 50 when measured at various shear rates and 1 ° C. (FIG. 17A). PH 5.35 (vertical bar symbol); 5.92 (circle symbol); 6.22 (asterisk symbol); 6.45 (x symbol); 6.81 (triangular symbol); 6.95 (square symbol) and 7.01 (diamond mark); or at 25 ° C. (FIG. 17B), the composition has a pH of 5.13 (x mark); 5.67 (white square mark); 6 (white triangle mark); 6.24 (white diamond) 6.51 (black circle mark); 6.75 (white circle mark); 6.87 (black diamond mark) and 7 (black square mark). Indicates. For both 1 ° C. and 25 ° C., SK 10:50 1: 1 shows Newtonian fluid behavior throughout the pH value range of 5.35 to 6.8, and the viscosity remains relatively unchanged regardless of shear force, ie It indicates that no change in viscosity is observed between the resilience of 200-50 rpm. However, at pH values above about 6.8, the composition exhibits an increase in viscosity when shear force is increased and exhibits non-Newtonian fluid behavior. This increase is particularly evident at 25 ° C., and the viscosity increases from 65 to 110 mPa · s when the shear force decreases from 200 to 50 rpm at pH 7 (FIG. 17, panel B). Under these conditions (pH 7, 25 ° C.), the composition continues to increase in viscosity and undergoes hydrogel formation over time. Conversely, at 1 ° C., the viscosity only increases from about 55 to about 65 mPa · s (FIG. 17, panel A). It should be noted that a composition having a pH of 6.8 and below exhibits a lower viscosity at 25 ° C compared to the same composition at 1 ° C, and the physiological pH and temperature conditions contribute to hydrogel formation. Suggested to be optimal.

  FIG. 18 shows that a combined chitosan composition having a high deacetylated chitosan with a molecular weight of less than about 100 kDa is not suitable for gel formation under physiological conditions. The results in this figure are a combination of FVL® and DAC® 50 in a 1: 1 ratio, measured at various shear rates and 1 ° C. (FIG. 18A), and the composition has a pH of 5. 85 (circle); 6.2 (asterisk); 6.44 (x); 6.76 (triangle); 6.94 (square) and 7.00 (diamond); or at 25 ° C. Measure (Figure 18B). The composition is 5.45 (white diamond mark; 5.7 (white square mark); 6.04 (white triangle mark); 6.3 (x mark); 6.56 (asterisk mark); 6.68 (circle) 6.82 (black triangle mark); 6.88 (black diamond mark) and 7.03 (black square mark).

  As shown, FVL: 50 1: 1 increases in viscosity as the pH approaches neutrality, but gel formation does not form at 1 ° C. (FIG. 18A) or 25 ° C. (FIG. 18B). In fact, as mentioned above, this composition exhibits a higher viscosity at 1 ° C compared to 25 ° C (neutral pH, low shear rate). This result shows that the molecular weight of the highly deacetylated chitosan is an important parameter for defining the gel formation in the composition of the present invention.

  FIG. 19 shows children whose increased molecular weight of highly deacetylated chitosan improves their viscosity, with a 1: 1 ratio of FM® 80 and DAC® 50 at a pH of 4.81 ( A composition having diamonds); 5.93 (squares); 6.24 (triangles); 6.43 (xs); 6.64 (asterisks) and 6.91 (circles) is shown. At 25 ° C., FM80: 50 1: 1 exhibits hydrogel formation at a lower pH (about 6.4 to about 6.6) compared to SK10: 50 1: 1 (about 6.8 to about 6.9). Start (see FIG. 17B). Furthermore, the viscosity reached at neutral pH is very high in compositions with high molecular weight type 1 chitosan, ie 420 mPa · s for FM 80:50 1: 1, whereas SK 10:50 1 : 1 is about 110 mPa · s. These results indicate that the molecular weight of type 1 chitosan varies depending on the application, but can still form a hydrogel. For example, higher viscosity hydrogels are desirable for implants that require sustained durability in vivo, while low viscosity hydrogels are sufficient to achieve the predetermined release characteristics of delayed release drug formulations.

Although the present invention has been described with reference to particular embodiments, many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, all such alternatives, modifications and variations are intended to be within the scope of the appended claims.
[References]
Aiba, 1991: Int. J. Biol. Macromol. 13: 40-44.
Aiba, 1994: Carbohydr. Res. 261: 297-306.
Berger et al., 2004: Int. J. Pharmaceutics 288: 197-206
Biagini et. Al., 1992: in: CJ. Brine, PA Sandford, JP Zikakis (Eds.). Advances in
Chitin and Chitosan; Elsevier Science, Barking; 1: 16-24
Calvo et. Al., 1997: Int. J. Pharm. 153: 41-50.
Chen et al., 2006, Macromol Biosci. 6 (12): 1026-39)
Chenite et al., 2000: Biomaterials 21: 2155-2161
Felt et al., 1999: Int. J. Pharm. 180: 185-193.
Felt et. Al., 2000: J. Ocul. Pharmacol. Ther. 16: 261-270
He et. Al., 1998: Int. J. Pharm. 166: 75-88.
Hirano et al., 2000 Biomaterials (10): 997-1003.
Hoemann et al., 2005: J. Bone Joint Surg. Am 87: 2671-2686
Junginger and Verhoef, 1998: PSTT 370-376
Katsube et al., 2000: Arch. Orthop. Trauma Surg. 120: 121-127
Koga 1998: Adv. Chitin Sci. 3: 16-23.
Kotze et.al., 1999: in: E. Mathiowitz, DE Chickering III, CM. Lehr (Eds.).
Bioadhesive Drug Delivery Systems, Marcel Dekker Inc. New York, 341-385.
Lee et al., 2006: Smart Mater. Struct. 15: 607-611.
Li et al., 2002 J. Pharm Sci. 91 (7): 1669-77.
Liu et. Al., 2001: J. Appl. Polym. Sci. 79: 1324-1335
Mi et al., 2000: J. Polym. Sci. A: Polym. Chem. 38: 2804-2814
Milot et.al., 1998: J. Appl. Polymer. Sci. 68: 571-580.
Molinaro et.al., 2002: Biomaterials 23: 2717-2722.
Muzzarelli, 1986: In: Muzzarelli, RAA, Jeuniaux, C, Gooday, GW (Eds.), The
Determination of the Degree of Acetylation of Chitosans by Spectrophotometry.
Plenum Press, New York, (1986) 385-388.
Mwale et al., 2005 Tissue Eng. 11 (1-2): 130-40.Muzzarelli 1997: Cell MoI. Life Sci.
53: 131-140.
Noble et al., 1999 Int. J. Pharm. 192 (2): 173-82.
Ogawa and Yui, 1993: Biosci. Biotechol. Biochem. 57: 1466-1469.
Patashnik et.al .; 1997: J. Drug Target 4: 371-380.
Risbud et al., 2000 J. Control. Release 68 (1): 23-30.
Roughley et al., 2006: Biomaterials 27: 388-396.
Sechriest et al., 2000 J. Biomed. Mater. Res. 49 (4): 534-41.
Shi et al., 2004 J. Biomater. Sci. Polym. Ed. 15940: 465-74.
Song et. Al., 2001: J. Nucl. Med. 28: 489-497
Ueno et.al., 2001: Adv. Drug Delivery Rev. 52: 105-115.
Weng et al., 2007 Biomacromolecules 8 (4): 1109-1115.
Zhu et al., 2005 J. Biomater. Sci. Polym. Ed. 16 (3): 301-16.

Claims (13)

  A chitosan composition in the form of a hydrogel comprising a highly acetylated chitosan having a degree of acetylation in the range of 40% to 60% and a highly deacetylated chitosan having a degree of acetylation of 20% or less. And at 25 ° C. and pH 7.0 ± 0.2, the composition has a viscosity of at least 100 mPa · s at a shear rate of 20 rpm, the highly deacetylated chitosan is non-uniformly deacetylated and the highly acetylated chitosan is A chitosan composition that is uniformly reacetylated, wherein the highly acetylated chitosan and the highly deacetylated chitosan are each present in a concentration of 0.2% to 3% w / v of the total composition.   The chitosan composition of claim 1, wherein the highly deacetylated chitosan has a molecular weight of at least 100 kDa and the highly acetylated chitosan has a molecular weight of at least 200 kDa.   Highly deacetylated chitosan and highly acetylated chitosan are each present at a concentration of 0.5% to 2% w / v of the total composition, and the proportion of highly deacetylated chitosan and highly acetylated chitosan in said composition is The chitosan composition of claim 1, selected from the group consisting of: 1: 1, 1: 2, 1: 3 and 1: 4.   The chitosan composition according to claim 1, further comprising at least one negatively charged substance selected from the group consisting of polysaccharides, phospholipids, and combinations thereof.   The negatively charged polysaccharide is selected from the group consisting of animal-derived polysaccharides, plant-derived polysaccharides, chondroitin sulfate, deltaman sulfate, dextran sulfate, heparan sulfate, heparin, hyaluronic acid, keratan sulfate, and combinations thereof. A chitosan composition according to claim 1.   The chitosan composition according to any one of claims 1 to 5, further comprising at least one of a drug, a polypeptide, an animal cell, and a plant cell.   An implantable device comprising the composition according to claim 1.   A chitosan composition according to any of claims 1 to 6 for preparing a medicament for at least one application selected from the group consisting of prevention or treatment of surgical adhesions, wound healing, tissue regeneration and tissue exchange. Use of.   A chitosan composition in the form of an injectable solution, said composition comprising a highly acetylated chitosan having a degree of acetylation in the range of 40% to 60% and a high deacetylation having a degree of acetylation of 20% or less The composition has a viscosity of less than 150 mPa · s at a shear rate of 50 rpm at a pH below 25 ° C. and a neutral range, and a highly acetylated chitosan and a highly deacetylated chitosan Chitosan compositions each present at a concentration of 0.2% to 3% w / v.   The chitosan composition of claim 9, wherein the highly deacetylated chitosan has a molecular weight of at least 100 kDa and the highly acetylated chitosan has a molecular weight of at least 200 kDa.   Highly deacetylated chitosan and highly acetylated chitosan are each present at a concentration of 0.5% to 2% w / v of the total composition, and the proportion of highly deacetylated chitosan and highly acetylated chitosan in said composition is The chitosan composition of claim 9 selected from the group consisting of: 1: 1, 1: 2, 1: 3 and 1: 4.   The chitosan composition according to claim 9, further comprising at least one negatively charged substance selected from the group consisting of polysaccharides, phospholipids, and combinations thereof.   The negatively charged polysaccharide is selected from the group consisting of animal-derived polysaccharides, plant-derived polysaccharides, chondroitin sulfate, deltaman sulfate, dextran sulfate, heparan sulfate, heparin, hyaluronic acid, keratan sulfate, and combinations thereof. A chitosan composition according to claim 1.

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