PT104674A - COMPOSITE STRUCTURES BASED ON GELANA GUM FOR USE IN REGENERATIVE MEDICINE AND ITS PREPARATION METHODS - Google Patents

Abstract

The present invention relates to the production of composite structures based on gellan rubber for use in regenerative medicine approaches, namely in the field of bone regeneration. THE APPLICATION OF THESE STRUCTURES IS INTENDED TO FILL EXISTING DEFECTS CREATED BY TRAUMATIC OR DEGENERATIVE SITUATIONS IN WHICH THE PROTECTION OF LOST TISSUE IS REQUESTED OR ONLY A FILLING OF A DEFECT. In this invention, aspects related to the biomaterial used, especially the types of gellan and its preparation, the types of composites formed by the gellan and one or more ceramic components, their methods of preparation and application are set forth.THE INVENTION PROPOSES A NEW COMPOSITE SYSTEM BASED ON GELANA GUM WITH APPLICATIONS IN THE ORTHOPEDIC AND MAXILOFACIAL FIELD, MOLDABLE BY INJECTION IN DEFECT OR PRE-PROCESSING, AND IT MAY BE INCORPORATING BIOACTIVE AGENTS AND / OR CELLS OF INTEREST WITH A VIEW TO ITS FINAL APPLICATION.

Description

DESCR

COMPLEX DETERGENTS Λ GELANA GUM BASE PAYS UTILIKAÇAO AND REGENERATIVE MEDICINE AND SEDS METHODS OF

PREPARATION

OBJECT OF THE INVENTION The present invention has the objective object and production of moldable composite structures based on gum. for use in regenerative medicine approaches, and it is well known in the area of bone regeneration. The main characteristics of the composite systems proposed here are related to. their capacity cr may be available. You look like silverware! For the purpose of this invention, the invention relates to a method for producing a non-woven fabric which is capable of being applied by injection into the defect of the fabric having, for that purpose, bioadhesive capacities which promote its locating, preformed shape by prior use of a mold, which systems can then be surgically implanted into the defect. The possibility of inducing the formation of bioactive coatings facilitates bone regeneration and formation of a. functional bone tissue. In order to assure or reinforce the osteoinductive or osteoinductive capacity of these composite structures, they may be conjugated with. bioactive agents and / or cells of interest capable of promoting and sustaining osteogenic and / or angiogenic differentiation processes. The gellan gum-based composite structures disclosed herein may be used for the regeneration or filling of congenital defects, or of traumatic origin in the bone in the orthopedic and maxillofacial fields, or as fill material and / or volume increase of non-bone tissues in apii cavities. c omp 1 ene et;

STATE OF TECHNICA

Conventional methods of tissue transplantation for pre-treatment / treatment of defects, including bone, encompass, among other methods, the use of donor tissues which, in addition to not being available in most situations, immunological rejection and disease transmission to the reactant. The use of patient tissues is an option that may eliminate some of these inconveniences. However, surgical methods used in tissue procurement for bone grafting often create morbidity at the harvest site and require extended surgery times, which are In the specific case of bone fixation, bone cement represents an alternative solution for prosthesis fina- tion, however one of the limitations of this solution is the brittle fixation to the bone tissue that can bring about in the long term to the mechanical king and biological in that it reduces the fixation of the material at the intended location. the gellan gum is one. poly-ssaccharide produced by fermentation of the bacterium Sphi.ngomoncis elodea to è largely used to eat in the food industry and is also used in ophthalmic formulations in the biomedical area, gellan gum has the ability to form gels, gelling is dependent on the polymer concentration, temperature, and the presence of mono or diva lenses in solution.

Due to its properties, gellan gum has been investigated for a number of biomedical applications, among which the development of nasal islets is noteworthy owing to its gellability in contact with the mucosa (animal studies) the incorporation of drugs in gelisable solutions for further controlled release into the digestive tract, in addition to these examples, gellan gum has also been suggested as a bio-material for areas of regenerative medicine, in particular in cartilage regeneration. Gellan gum has a high application potential in regenerative medicine due to the high biocompatibility of the available antibiotics, as well as the ability to be delivered by minimally invasive surgical procedures. Oh yes, yes. These properties also justify the high potential application of this material in the context of. regeneration of bone, However, a. The present invention proposes the incorporation of several corvi.ponent.es into gellar gums which ensure osteoconductive and osteoinductive properties. The incorporation of bioactive ceramics allows to develop composite structures capable of iodos to the formation of calcium phosphates in physiological media due to the presence of the bioactive ceramic phase. Ceramic materials called bioactive materials are already used in clinical practice as important bone repair materials. Bioramic ceramics include materials such as hydrazine and other similar calcium phosphates including substituted hydroxyacids, bioglass and ceramic glassware. These: materials may be purchased commercially and used as ceramic components within the scope of the present invention.

In the technical field in which this invention is inserted, the development of a composite based on gneiss and ceramic particles may have benefits for regeneration and bone reconstruction in the orthopedic and maxillary areas. This material is intended to be used as a bone substitute for filling bone defects of congenital origin, or caused by trauma or disease, presenting some advantages to current approaches. various patents and scientific works have described the use of polysaccharides for the development of composites under different forms and for various application areas. The patent application US20080262121 claims the use of hydroxylapatite substituted with synthetic and natural polymers, including gellan gum, although specific surgical processing and implantation methodologies in the case of formulations based on gellan gum are lacking, WO / 20077053 5353 relates to an apatite-based composite and cross-linked polysorbate of vegetable origin for controlled transport and release of biologically active drugs and / or molecules. In this case, the aurors are removed in the preferred use of the alginate for this purpose, The present invention relates to compositions for the preparation of gellan gums which are suitable for use in the field of medical, pharmaceutical, using alginate-based hydrogels for treatment of oropharyngeal deformations, reflux and incontinence. A scientific paper titled Apatite-Corning ability af carboxyl-groin-polymerase gels in the si & ulated body of H. Kawashita et al., Published in January 2003 describes a study on the formation of apatite in some gels , among them the Gellan groan. The study demonstrated that a treatment with Ca (OH); and subsequent immersion in simulated body fluid (FBS), there was formation of apatits on the surface of gellan gels, note the study is however silent on composites based on gypsum and ceramic bioactive-

DETAILED DESCRIPTION. OF THE INVENTION The present invention has as its object the production of moldable composite structures based on gelau gum for use in medical, regenerative approaches, more particularly in the area of bone regeneration.

The combination of gellan hydrogels and various components of ceramic, as well as the combination thereof with other broccoli substances and components of the patient's tissue, including fractions of the blood and target tissue, such as cells, blood plasma, among others. Goian gum is an anionic polysaccharide composed of repeating units of glucose, gucci, and racemic acid. The native gellan gum, a product obtained by ionizing bacteria, contains two additional substances (.acetyl and L-glycerol) as compared to gellan gum, the degree of acetylation and which is the commercial form comx.xm However, the formulations may form thermoreversible gels having, however, different mechanical behavior. The gellan gum has an ionotrophic gelation mechanism, similar to other polysaccharides with guanidine as the carrageenan, the presence of ions being necessary for the formation of a stable heterocyclic. The gellan gum can be homogeneously dispersed in an aqueous solution at a temperature which promotes the linearization of the chains and can, through the dilution of temperature and in the presence of cations, give rise to a hydrogel.

Some ceramics such as bioactive glass (also known as bioavid): hydroxyapatite and calcium phosphates are currently used as bone substitutes and are a good alternative to the use of tissues from donors or from the patient himself. Hydroxyapatite (HA) 6 is characterized by biodegradable, immunogenic, and onteoconductive, being used in the area of bone regeneration for a period of 3.0 years. Other materials such as biopsies are also already used. Examples of commercially available biofungals incinerate sicgiesso

Ceravitai®, AWP, Durapatite1 and Calcite; b The intrinsic atrophic character of the gum justify its use in combination with ceramic ceramics, insofar as they may constitute a norephobic approach to the treatment of bone defects in the orthopedic and maxillofacial surfaces.

Generally, the preparation of the composites can be made using; 1

Dispersion of geomagnetic gum in an aqueous solution of controlled mineral construct in order to allow its packaging without occurrence of premature gelisation, combining the ceramic component (s) with the gum solution and the combined administration of both components in the bone defect of the patient to be treated by localized injection; D-isomer of gellan gum in an aqueous solution of the constitution is monitored in the presence of a mineral phase using a mold for subsequent forcing of a hydrogel. solid composite forceps for later implantation; * A dispersion of goat gum in an aqueous solution of controlled mineral constitution, the combination thereof with a ceramic phase according to any of the above-mentioned methods, so as to enable the combination with bioaccidal agents and / or cells of interest for the formation of a tissue Functional bone.

One of the main advantages of gum based systems is its storage capacity, which allows storage at room temperature. Another advantage of composite systems based on goat gum is that they can be infected at the site of the defect and gel at the body temperature in an expeditious manner and may retain ceramic components or cells in the locus of the defect, in combination or not with blood fractions. These advantages include the oil taste and the excellent biocompatibility of goat gum, which make this system a therapeutically afferent. Because of the ability to gelase the gellar® under minimal conditions, the ceramic ceramic composites can be molded by injection into either a pre-inhibited mold or a preexisting or induced body cavity constituting such a possible template for the systems These systems will present a considerable degree of versatility that will allow them to be adapted to various contexts of clinical application. Another fact that may be of added value is the bioactivity of these composites due to the presence of the ceramic component or the treatment by the immersion of the composite in divalent ion solutions. The composites may further be prepared in combination with thermostable agents of interest, among which, growth inhibitors, peptides, painkillers, steroid anti-inflammatory drugs or biphosphonates. Similarly, cells of interest may be combined in the composite structure. Both the active agents and the cells in question may be used to promote and sustain processes of osteogenic and / or angiogenic differentiation to cellular and tissue culture. Two advantages of this composite system include the greater compatibility of these systems with collagen - based animal systems, and the advantage in terms of cost of production, with a lower cost being incurred. account is taken of the age of the fermentation process as an industrial fermentation when compared to processes for obtaining extraction and purification of animal collagen.

The composites a based on gypsum and ceramic components can be used as bone substitutes in the regeneration of bone tissue, in particular in the orthopedic and maxillofacial area, as well as, in a complementary approach, as materials and / or increase of volume of non-bony tissues. The description of the. present invention is complemented with examples which are intended to provide a better understanding thereof,

EXAMPLES

Example 1 " Production of composite structures based on gum and a ceramic component for injection and gsiification in a bone defect.

Gel gum powder was prepared using a temperature basis for the production of homogeneous dispersions capable of being combined with one or more ceramic components and forming a gel upon injection into the defect. the powdered gelatin was added to a predetermined volume of distilled water at a final concentration of 0.5 wt% ip volume and kept under constant stirring at room temperature; The mixture was progressively heated to a temperature of 30 ° C and held at this temperature for 20-30 minutes; I observe, after this time, a complete and homogeneous dispersion of the gum; Thereafter, the temperature was progressively readjusted to 25 ° C always under constant stirring. After stabilization at the temperature mentioned above, the dispersion was transferred to glass containers for storage and kept at room temperature (250Â ° C) for no further stirring. After 21 hours, the dispersion was re-suspended several times with a suitable syringe and mixed with sintered hydroxyapatite (CaptaMS, Plasma Brotai; to a ratio of 50/50 by weight between goat gum and ceramic component. The mixture was then injected into a bone defect and allowed to remain for a few minutes until a solid,

Example 2 - Production of solid composite structures based on gum and a ceramic component for implantation into a bone defect.

Gum powder was processed using temperature dependent methods giving rise to various structures. In this example, only disk formation is discussed. The discs foraja produced the following form the gum powder was. mixed with distilled water and kept under constant stirring at room temperature resulting in a final concentration of 2 wt% (w / v) The mixture was progressively heated to 90 ° C and maintained at this temperature for 20-30 minutes After this time a complete and homogeneous dispersion of the gellan was observed. Next, synthesized hydroxyapatite tCaptayS, Plasma Brotai) was added to the sample at a ratio of 35%. between gypsum and ceramic and the temperature was

U progressively readjusted to 5 ° C; The mixture was allowed to stand in cylindrical molds for a few minutes at room temperature until a solid gel formed.

Guimarães, September 22, 2009.

Claims (17)

Composite or water-based composites which are based on goat gum only have bioactive properties for applications in the area of tissue regeneration, 2, Composites according to. Claim 1, characterized in that the gum base hydrogels may have different degrees of acetylation and may be subject to chemical modifications, Composites according to claim 2, characterized in that the hydrogels based on goat gum can be prepared in neutral aqueous solution or U 1 ... U, Composites according to claim X, characterized by a. or other components are ceramic bioactiv. Composites according to claim 1, characterized in that the ceramic components can be in the form of spheres, particles, fibers, or other forms of dimethyl amines. Composites according to claim 5, characterized in that they have bioactivity, Composites according to claim 6, characterized in that the bioactivity may be conferred by the presence of hydroxylamine and / or other calcium phosphates including substituted hydroxypstites, bioacid glazes, and the like. cos Composites according to claim 6, characterized in that the biosactivity can be imparted by immersion of the composite systems in saturated divalent ion solutions, Composites according to claim 1, characterized in that they can contain bioactive agents capable of promoting and / or supporting osteogenic differentiation and / or cell angiogenesis, Composites according to claim 9, characterized in that the bioactive agents may be growth hormones, peptides, hormones, non-steroidal anti-inflammatory drugs, or bifonionates. Composites according to claim 1, wherein the cells are of autologous, allogenic, xenogeneic, or a cell line origin can be incorporated into cells of animal origin in order to promote the regeneration of bone and / or vascular tissue. previously established, Composites according to claim 1, in which the weight ratio of the hydrogen and the ceramic component is in the range of from 99 to 1:99, Composites according to claim 1. cured because they are honey. by injection into a pre-defined mold. 1". Composites according to claim 4, characterized in that they are injection molded into a pre-existing or indurated body charity, this being the final mold of the systems. Composites according to claim 14, characterized in that they are capable of placing and maintaining at the defect site the ceramic component (s). 16 < Composites according to claim 1, characterized in that the hydrogel component is biodegradable over a period of time from one week to one year. Composites according to claim 1, characterized in that they can be cross-linked by mixing with phosphate buffered saline in a controlled constitution during molding. Composites according to claim X, characterized in that the hydrogeomer component can be crosslinked through the ions physiologically present in the body cavity, pre-existing or induced upon administration by injection. Composites according to claim 3, characterized in that the cross-linking of the hydrogen components can be catalysed as co-adjuvanted by the active component at 20 ° C. Composites according to claims 1 to 5, characterized in that they are applied as bone substitutes for the regeneration of bone tissue in the orthopedic and maniocfacial areas. Composites according to claims 1 to 19 characterized in that they are applied as filler and / or augmentation material of volume of non-osseous tissues - Goimarles ,; September 22, 2009.