JP4470410B2 - Polysaccharide complex - Google Patents

Description

  The present invention relates to a complex comprising a polysaccharide derived from a natural product, and further relates to a polysaccharide complex excellent in biodegradability, biocompatibility, stability, and gel physical properties when wet.

  In recent years, natural polysaccharides have attracted attention as new types of biodegradable polymer materials and biocompatible materials, and many studies have been made on their use, and various findings have been reported. For example, a medical adhesive using a polysaccharide complex in which a polyion complex is formed (see Patent Document 1), a wound therapeutic agent using chitosan, alginic acid, and chitin (see Patent Document 2), and the like.

  In particular, chitin and chitosan are attracting attention as biocompatible materials having bioactive effects.

  Chitin is a natural product that exists as a skeletal material of crustaceans such as crabs and shrimps, insects such as beetles and crickets, and also in fungal cell membranes, and has many N-acetyl-D-glucosamine residues, β- (1 4) -linked polysaccharide. Chitosan is a deacetylated compound, has many amino groups in the molecule, and is also used as the only natural cationic polysaccharide. General chitosan forms an acid salt such as acetic acid, lactic acid and hydrochloric acid and dissolves in water, but does not dissolve from neutral to alkaline.

  On the other hand, when polycationic substances and polyanionic substances are mixed in the presence of water, it is well known that they quickly form polyion complexes and become insoluble in water, and are used in a wide range of fields including pharmaceuticals and medical devices. Has been. As a material for forming a polyion complex, various water-soluble polymers are used. In particular, in a polyion complex made of a polysaccharide, compared to a polyion complex made of a polyamino acid, a protein, or a synthetic polymer material, It is inexpensive, has a low risk of infectious diseases, and has excellent biodegradability.

  Conventionally, polysaccharide complexes in which a polyion complex is formed using chitosan and natural acidic polysaccharides such as hyaluronic acid, chondroitin, alginic acid, and pectin have been reported (for example, see Patent Document 1 and Patent Document 3). . However, these natural polysaccharides are mainly heteropolysaccharides, and because of natural products, there are many uncontrollable parts such as the distribution of sugar residues and the influence of introduced side chains.

  In addition, a complex in which a polyion complex is formed using chitosan and a polysaccharide derivative in which an anionic functional group is introduced into a natural polysaccharide is also known, but these polysaccharides are intermolecular and intramolecular. The distribution of substituents is difficult to control, and the introduced substituents may affect the living body.

  On the other hand, a method of oxidizing polysaccharides to form a highly biocompatible uronic acid structure and imparting water-solubility to polysaccharides is known. There is a problem that the toxicity of the agent is strong, and it is difficult to control the oxidation, and it is difficult to control the distribution of substituents between molecules and within the molecule.

  Furthermore, when it is applied as a pharmaceutical or medical device, it must exist in the living body without being dissolved or disintegrated for several days, and after that, it is eventually required to have properties that can be decomposed and absorbed to disappear. There is. The polyion complex material composed of the above-mentioned polysaccharides is particularly swelled in water containing a large amount of ionic species such as body fluids and phosphate buffered saline, resulting in a decrease in physical strength and collapse within a short period of time. It often ends up. Moreover, in the polysaccharide complex which consists of mucopolysaccharide, it received the effect | action of enzymes, such as a lysozyme, and had decomposed | disassembled at an early stage. Therefore, in order to meet the above requirements, synthetic polymer materials and cross-linked gels are generally used while the final decomposition / absorbability is unclear.

In addition, in applications characterized by maintaining a form for several days in a living body, it is common to apply a material formed into a film shape or cloth shape, but the applied affected tissue is a complicated tertiary. In the case of having the original shape, there are also problems such as difficult application and poor usability, such that it is supplied with powder or liquid, wetted in the affected area to form a gel film, and satisfies the above required characteristics There is a strong demand for materials, but no material has sufficient performance.
JP 2000-5296 A JP-A-8-224293 JP 2000-116765 A

  An object of the present invention is to provide a polysaccharide complex that is easy to process and excellent in biodegradability, safety, and biocompatibility, and is also moist, especially in water or phosphate buffered saline. The present invention provides a polysaccharide complex that maintains its physical strength and maintains its form for several days without dissolving or disintegrating.

  Furthermore, the present invention provides a polysaccharide complex that maintains its morphology for several days even in the presence of lysozyme.

  Furthermore, the present invention provides a polysaccharide complex that forms a gel film having sufficient physical strength when it is wetted in water while being in a powder form that is easy to store and handle when dried.

The invention of claim 1 is a polysaccharide complex in which an anionic polysaccharide and a cationic polysaccharide form a polyion complex structure, and at least chitin / chitosan is oxidized as the anionic polysaccharide, It contains an oxidized polysaccharide introduced with a carboxyl group or a salt thereof at the 6-position of N-acetyl-D-glucosamine, which is a constituent monosaccharide, and further oxidizes polysaccharides other than chitin / chitosan to form 6 of the pyranose ring of the polysaccharide. A polysaccharide complex characterized in that it contains amyloulonic acid or seurouronic acid introduced with a carboxyl group or a salt thereof at the position, and at least chitosan as the cationic polysaccharide.

  The invention of claim 2 is characterized in that the oxidized polysaccharide is oxidized using alkali regenerated chitin or N-acetylated chitosan having reduced crystallinity in an aqueous system using an oxidizing agent in the presence of an N-oxyl compound catalyst. The polysaccharide complex according to claim 1, wherein the polysaccharide complex is obtained by the method described above.

  The invention according to claim 3 is the polysaccharide complex according to claim 1 or 2, wherein the oxidized polysaccharide has a chemical structure represented by the following general formula (1).

Invention of Claim 4 oxidizes chitin * chitosan in the said anionic polysaccharide, and the oxidized polysaccharide which introduce | transduced the carboxyl group or its salt into 6th-position of N-acetyl-D-glucosamine which is a constituent monosaccharide And a ratio of amylouronic acid or ceurouronic acid in which a polysaccharide other than chitin / chitosan is oxidized and a carboxyl group or a salt thereof is introduced at the 6-position of the pyranose ring of the polysaccharide is from 8: 2 to 1: 9 by weight. The polysaccharide complex according to any one of claims 1 to 3, wherein the polysaccharide complex is present.

The invention according to claim 5 is a biocompatible material using the polysaccharide complex according to any one of claims 1 to 4 .

  According to the present invention, a water-insoluble polysaccharide complex can be obtained easily and inexpensively by a simple method. The polysaccharide complex of the present invention is a polyion complex composed of chitosan composed mainly of an oxidized polysaccharide having a highly biocompatible uronic acid structure in which the chemical structure is controlled, and N-acetylglucosamine and glucosamine. Easy biodegradation, high safety, high biocompatibility, and material design that meets various required physical properties, so it can be used in various fields such as pharmaceuticals, medical devices, food and cosmetics, and functional fibers. The application of can be expected.

  In addition, the polysaccharide complex of the present invention has plasticity, binding properties, adhesiveness, etc. when wet with water and dissolves or disintegrates in water containing a large amount of ionic species such as phosphate buffered saline. It remains in shape for several days and has high physical strength. Furthermore, it is possible to control such as delaying the decomposition rate for lysozyme while maintaining the above characteristics.

  In addition, the polysaccharide complex of the present invention is stable under drying, pulverized into a powder form, and even when it is in a form that can be easily stored and supplied, it binds when wetted again and reproduces the physical properties of a wet gel. It is also possible to form a gel film having physical strength.

  Details of the present invention will be described below.

  The polysaccharide complex of the present invention is mainly composed of an oxidized polysaccharide in which a carboxyl group or a salt thereof is introduced into the 6-position of the pyranose ring by chitin / chitosan as a polyanion component by a highly selective oxidation method. As a component, chitosan having a cationic amino group is mainly used, and both form a polyion complex.

  The oxidized polysaccharide used as the anionic polysaccharide of the polysaccharide complex of the present invention is a highly biocompatible uron that selectively oxidizes the 6-position of the pyranose ring of a natural polysaccharide and introduces a carboxyl group or a salt thereof. It is a polysaccharide having an acid structure, and it is mainly composed of an oxidized polysaccharide having a carboxyl group or a salt thereof introduced into the 6-position of N-acetyl-D-glucosamine, which is a constituent monosaccharide, using chitin / chitosan as a raw material. is there.

  As a selective oxidation method of the 6-position of the pyranose ring of the polysaccharide, the degree of oxidation can be controlled, and almost all the 6-positions of the pyranose ring are oxidized to the carboxyl group without oxidizing the 2nd or 3rd position of the pyranose ring. A method of oxidizing using an oxidant in the presence of an N-oxyl compound catalyst in an aqueous system is also preferable.

  As the N-oxyl compound, 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (hereinafter referred to as TEMPO) is preferably used. Examples of the oxidant include halogens, hypohalous acid, halous acid, perhalogen acids or salts thereof, halogen oxides, nitrogen oxides, peroxides, and the like that can promote the target oxidation reaction. Any oxidizing agent can be used as long as it is present. Furthermore, in the present oxidation reaction, it is more preferable to oxidize in the presence of bromide or iodide because the oxidation reaction can proceed smoothly even under mild conditions and the efficiency of introducing carboxyl groups can be greatly improved.

  In the method for oxidizing the polysaccharide, it is particularly preferable to use TEMPO as the N-oxyl compound and sodium hypochlorite as the oxidizing agent in the presence of sodium bromide.

  Here, the N-oxyl compound may be an amount as a catalyst, for example, 10 ppm to 5% is sufficient with respect to the number of moles of the constituent monosaccharide of the polysaccharide, but 0.05 to 3% is preferable, Moreover, the usage-amount of a bromide or iodide can be selected in the range which can accelerate | stimulate an oxidation reaction, for example, is 0-100% with respect to the number of moles of the constituent monosaccharide of a polysaccharide, More preferably, it is 1-50%.

  Further, for the purpose of increasing the selectivity of oxidation of the constituent monosaccharides to primary hydroxyl groups and suppressing side reactions, the reaction temperature is desirably room temperature or lower, more preferably 5 ° C. or lower. Furthermore, it is preferable to keep the inside of the system alkaline during the reaction. The pH at this time may be kept at 9 to 12, more preferably pH 10 to 11.

  Furthermore, in this oxidation method, the degree of oxidation can be controlled by the amount of the oxidizing agent and the amount of alkali added when the pH is kept constant. For example, when an alkali is added in an equimolar amount with a sugar residue, almost all primary hydroxyl groups at the 6-position of the pyranose ring are oxidized to carboxyl groups, and water-soluble polyuronic acid is obtained.

  Moreover, when performing this oxidation reaction using polysaccharides with high crystallinity, such as chitin, as a raw material, it is preferable to perform the regeneration process which reduces crystallinity as a pretreatment. Examples of the chitin regeneration treatment include alkali regeneration treatment. After dipping chitin in a high-concentration alkali, it becomes a viscous liquid by diluting under low temperature while adding ice. When hydrochloric acid is added thereto and neutralized, flake-like chitin precipitates, but an almost amorphous chitin is obtained, which is subjected to the above oxidation reaction without being sufficiently washed with water and dried to obtain a molecular weight. The decrease is suppressed as much as possible, and almost all primary hydroxyl groups at the 6-position of the pyranose ring can be oxidized to carboxyl groups. However, since the deacetylation reaction of chitin also proceeds in an alkaline atmosphere, it is important to maintain the temperature in the system during the dissolution and neutralization treatment with alkali and the oxidation reaction at a low temperature of 5 ° C. or less. is there.

  Alternatively, a chitosan that is a deacetylated product of chitin may be used as a raw material, and a material that is N-acetylated under a uniform reaction may be subjected to the oxidation reaction. For example, after dissolving chitosan in acetic acid and diluting with methanol, it is easily N-acetylated by adding 1.5 to 3 times the molar amount of acetic anhydride to the amount of amino groups in the chitosan, and again the chitin Can return to chemical structure. Through this operation, by washing the well-washed product without drying or freeze-drying it and subjecting it to the above oxidation reaction, only the primary hydroxyl group at the 6-position is oxidized with high selectivity like the alkali-regenerated chitin.

  Furthermore, in this case, it is also possible to control the degree of N-acetylation of the oxidation raw material by the amount of acetic anhydride added.

  When chitin and chitosan are oxidized by controlling the conditions as described above, polyuronic acid having a structure represented by the following general formula (1) (hereinafter referred to as chitouronic acid) is obtained. The chitouronic acid is particularly preferred as the anionic polysaccharide of the polysaccharide complex of the present invention. Here, (a + c) / (a + b + c + d) in (Chemical Formula 1) represents the degree of N-acetylation of chitouronic acid, and the degree of N-acetylation is low, that is, if the amount of amino groups in the molecule is large, This is not preferable because the stability during the oxidation reaction is lowered and the molecular weight is lowered, or the water solubility of chitouronic acid is lowered. When used in the present invention, the N-acetylation degree is preferably 80% or more. Further, (a + b) / (a + b + c + d) in (Chemical Formula 1) represents the degree of carboxylation (degree of oxidation) of chitouronic acid. If the degree of oxidation is low, it is not preferable because it does not become water-soluble and the uniformity in forming an ion complex with the cationic polysaccharide is reduced. In the present invention, it is desirable to have an oxidation degree of 70% or more. Therefore, it is desirable to adjust the ratio of (a + c) :( b + d) in the range of 8: 2 to 10: 0 and the ratio of (a + b) :( c + d) in the range of 7: 3 to 10: 0. When the polysaccharide complex is used, characteristic properties as described below can be obtained.

Furthermore, the oxidation method using the N-oxyl compound can be applied to other polysaccharides. For example, water-soluble polysaccharides such as starch, pullulan, and hyaluronic acid can be dissolved in water and oxidized as it is, and water-insoluble polysaccharides such as cellulose are reduced in crystallinity as chitin. If so, it can be dispersed in water and oxidized. In the case of cellulose, regenerated cellulose such as rayon is commercially available, and these can also be used. Here, polyuronic acid obtained by oxidizing starch by the above-mentioned oxidation method and introducing a carboxyl group at the 6-position of D-glucose was treated with amylouronic acid, and regenerated cellulose was oxidized to introduce a carboxyl group at the 6-position of D-glucose. Will be referred to as cellouronic acid.

  The 6-position carboxyl group of the oxidized polysaccharide is more stable when present in a salt such as a sodium salt, and these oxidized polysaccharide salts are particularly highly water-soluble. Further, a desalted COOH-type oxidized polysaccharide can be obtained by adding an acid such as hydrochloric acid to the aqueous solution of the oxidized polysaccharide salt or treating with an ion exchange resin. In particular, the aforementioned chitouronic acid and amylouronic acid are water-soluble even in the COOH type, and have high water-solubility in a wide pH range.

  Here, the polysaccharide complex of the present invention is an anionic polysaccharide that oxidizes chitin / chitosan and is oxidized by introducing a carboxyl group or a salt thereof at the 6-position of the constituent monosaccharide N-acetyl-D-glucosamine. It is characterized by mainly containing polysaccharides, and when a polyion complex is formed with cationic chitosan as will be described later, a polysaccharide complex having very characteristic physical properties can be obtained. For example, it has plasticity when wet, can be transformed into various shapes, or once wetted into a dry powder, it has good binding properties and forms a film with physical strength. The contribution of using an oxidized polysaccharide obtained by oxidizing chitin / chitosan is great. In particular, in order to make a polysaccharide complex having these characteristics, chitin and chitosan occupying in the anionic polysaccharide are oxidized to form a carboxyl group at the 6-position of the constituent monosaccharide N-acetyl-D-glucosamine. Or it is preferable that the ratio of the oxidation polysaccharide which introduce | transduced the salt is 80 to 100% by weight ratio.

  The polysaccharide complex of the present invention may contain other anionic components as the anionic polysaccharide, but in particular, the polysaccharide complex containing the oxidized polysaccharide oxidized by the N-oxyl compound as a containing component. The body is particularly preferable because it maintains its safety and biocompatibility, and a polysaccharide complex having a wider range of physical properties can be obtained. For example, in the polysaccharide complex composed of chitosan and oxidized polysaccharide in which chitin / chitosan is oxidized to introduce a carboxyl group or a salt thereof at the 6-position of N-acetyl-D-glucosamine which is a constituent monosaccharide, the action of lysozyme However, when the above-mentioned amylouronic acid or seurouronic acid is contained as an anionic polysaccharide, the resistance to lysozyme is increased, and the degradation rate of the polysaccharide complex can be slowed. In this case, the chitin / chitosan in the anionic polysaccharide is oxidized, and an oxidized polysaccharide in which a carboxyl group or a salt thereof is introduced into the 6-position of the constituent monosaccharide N-acetyl-D-glucosamine, and chitin / chitosan The ratio of the oxidized polysaccharide in which a polysaccharide other than the above is oxidized and a carboxyl group or a salt thereof is introduced into the 6-position of the pyranose ring of the polysaccharide can be appropriately set according to the required physical properties of the polysaccharide complex. However, the weight ratio is preferably 8: 2 to 1: 9.

  As described above, the anionic oxidized polysaccharide used in the present invention is selected only at the 6-position in one pyranose ring, unlike the introduction of a carboxyl group by derivatization to a polysaccharide such as carboxymethylation. In addition, a carboxyl group is introduced, the distribution between molecules and within the molecule is uniform, and there is a feature that there is no influence of a substituent after being decomposed inside and outside the living body.

  Naturally, uronic acids such as alginic acid, pectin, and hyaluronic acid exist and can be used as the anionic polysaccharide of the present invention. However, these are mainly heteropolysaccharides, and are sugar residues because of natural products. Since there are many uncontrollable parts, such as distribution, it is desirable to use in the range which does not have a bad influence on the physical property control of a polysaccharide complex.

  Subsequently, chitosan used as the cationic polysaccharide of the polysaccharide complex of the present invention will be described.

  As explained above, N-acetyl-D-glucosamine and a polysaccharide in which D-glucosamine is β-1,4 glycoside-bonded, generally having a high ratio of D-glucosamine is chitosan, N-acetyl-D-glucosamine Those with a high percentage are called chitin. Chitin is present as a skeleton material for straw and shrimp and in cell membranes of fungi, and is obtained through purification processes such as decalcification, protein removal, lipid and pigment removal. Alternatively, the chitin obtained in the above step is generally obtained by further hydrolyzing with an acid or alkali and subjecting it to a deacetylation treatment. Further, N-acetyl-D-glucosamine and D-glucosamine, which are constituent monosaccharides, exist also in the living body, and are easily decomposed inside and outside the living body, and it can be said that their safety is high.

  As chitosan used as the cationic polysaccharide of the polysaccharide complex of the present invention, the above-mentioned general chitosan is applicable, and the raw material, purification method, degree of polymerization, etc. are not particularly limited, It is selected according to the required physical properties in the application. Further, the ratio of D-glucosamine and N-acetyl-D-glucosamine in the constituent monosaccharide is not particularly limited, but in the range of 40:60 to 100: 0 from the viewpoint of solubility in water or acid. Preferably there is. Since D-glucosamine has one cationic amino group, this ratio is one of the important factors for controlling the physical properties of the polysaccharide complex of the present invention.

  The ratio of the above-mentioned D-glucosamine and N-acetyl-D-glucosamine, that is, the ratio of amino group and N-acetyl group is determined by deacetylation by hydrolysis with acid or alkali, or conversely using acetic anhydride or the like. -Controllable by acetylation technique. In the deacetylation reaction, the amino group ratio can be controlled by the hydrolysis reaction time, and in the N-acetylation reaction, the amount of reagent added.

  The ratio of D-glucosamine and N-acetyl-D-glucosamine in this chitosan is generally the degree of deacetylation or N-acetylation ((N-acetylation (%)) = 100%-(deacetylation ( %))), But can be determined by elemental analysis, colloid titration, infrared spectroscopy (IR) by the KBr tablet method, or nuclear magnetic resonance spectroscopy (NMR) dissolved in an acidic solution.

  Here, chitosan forms a salt in a dilute acid solution and dissolves, but it is insoluble in water from neutral to alkaline. However, it is known that the ratio of D-glucosamine to N-acetyl-D-glucosamine is soluble in water in a wide pH range in the range of 40:60 to 60:40. When preparing this water-soluble chitosan, N-acetylation or deacetylation is performed in a homogeneous system to make the distribution of D-glucosamine and N-acetyl-D-glucosamine more uniform between molecules. It becomes important.

  This water-soluble chitosan is soluble in water in a wide pH range from acidic to alkaline, and thus is produced by mixing in water with anionic polysaccharides that are water-soluble in a wide pH range such as chitouronic acid and amylouronic acid. It can be said that the water-insoluble product is a highly uniform polyion complex that does not include a single component insolubilized. Accordingly, chitosan having a ratio of D-glucosamine to N-acetyl-D-glucosamine in the range of 40:60 to 60:40 is particularly preferably used as the cationic polysaccharide of the polysaccharide complex of the present invention.

  As described above, the polysaccharide complex of the present invention is based on the base material of the oxidized polysaccharide used as the polyanion component and its oxidation degree (carboxyl group introduction amount), average molecular weight, molecular weight distribution, composition of the polyanion component, and the like. Further, as described above, depending on the degree of deacetylation of chitosan used for the polycation component, the average molecular weight, the molecular weight distribution, the composition of the polycation component, etc., the blending ratio of the anionic polysaccharide and the cationic polysaccharide, Furthermore, it is possible to form a polyion complex gel having various physical properties depending on the production conditions of the polyion complex, etc., and easily meet various required physical properties in a wide range of applications.

  Here, the mixing ratio of the anionic polysaccharide and the cationic polysaccharide is preferably such that the molar ratio of the anionic carboxyl group to the cationic amino group is about 5: 1 to 1: 5. In the polyion complex produced (recovered) in the present invention, the carboxyl group and the amino group are not necessarily obtained at 1: 1. That is, not all carboxyl groups in the polyanion component and all amino groups in the polycation component form ionic bonds, and it can be said that free carboxyl groups or free amino groups exist in the complex. Therefore, the blending ratio of the anionic polysaccharide and the cationic polysaccharide can be variously set so as to satisfy the required physical properties. However, since the collection efficiency as a polyion complex decreases because the blending ratio is extremely biased, Not very good.

  Furthermore, in the polysaccharide complex of the present invention, in addition to the anionic polysaccharide and the cationic polysaccharide for forming the polyion complex, components for adjusting the physical properties of the polysaccharide complex, and the polysaccharide complex A component for imparting functionality or a component that is secondarily generated when forming a polyion complex may be included.

  As a method for producing a polyion complex of the polysaccharide complex of the present invention, the anionic polysaccharide and the cationic polysaccharide are dissolved in a medium mainly containing water, and both solutions are mixed, or a mixed solution By adding an acid or an alkali to the solution to control the pH in a neutral range, a polyion complex insolubilized in water can be formed, and the polysaccharide complex of the present invention can be obtained. Also, the aqueous solution concentration in this case is not particularly limited as long as it is within the range where the polyion complex is formed, and can be selected according to the required physical properties of the polysaccharide complex.

  Here, for example, a solution obtained by dissolving the water-soluble chitosan as a cationic polysaccharide in water without a counter ion and a COOH-type polyuronic acid desalted as an anionic polysaccharide are mixed together. Then, a polyion complex is immediately formed. In this case, since there is no generation of a salt between counter ions, the step of removing the counter ion can be omitted, and it is particularly suitable for an application that dislikes the mixture of salts.

  Further, for example, if the mixed solution of both components is made acidic or alkaline to obtain a uniform solution and then the pH is returned to neutral while stirring, a more uniform polyion complex can be formed. In this case, although the salt of counterions coexists as a by-product, it can also be set as the polysaccharide complex except this salt by carrying out the water washing process etc. of the produced | generated polyion complex gel.

  Furthermore, it does not specifically limit as a form of the polysaccharide composite_body | complex of this invention, The form suitable for a use can be taken. For example, it can take the form of block, sheet, film, fiber, sponge, capsule, flake, powder and the like. The polysaccharide complex of the present invention forms a polyion complex in water and is first obtained as a wet gel. Depending on the production conditions, the polysaccharide complex has a physical strength sufficient to maintain the shape, or has plastic properties. It can be formed into various forms. Furthermore, even if the dried gel once dried is re-wet, it is possible to reproduce almost the same physical properties as a wet gel and to deform it. However, it is possible to express the adhesiveness and the binding property and return to the block or sheet shape again. For example, if the powder is deposited on a sufficiently wet three-dimensional surface, a gel film can be formed on the three-dimensional surface and the physical properties of the wet gel are reproduced. It is.

First, production examples of anionic polysaccharides and cationic polysaccharides as raw materials used in Examples and Comparative Examples will be described.
<Production Example 1>
(Preparation of N-acetylated chitosan (1))
Daiichi Seika Kogyo Co., Ltd. Daichitosan 100D (VL) was used as 100% deacetylated chitosan. 10 g of this chitosan was dissolved in 190 g of 10% acetic acid, diluted with 1 L of methanol, and acetic anhydride with stirring. When 12.68 g (2 eq.) Was added, it gelled in a few minutes. After leaving this for 15 hours, 1 L of methanol was further added and stirred with a homogenizer, and 2N-NaOH aqueous solution was added to neutralize to pH 7, which was filtered to obtain a solution of methanol and water: acetone = 1: 7. After washing, it was thoroughly washed with deionized water and lyophilized to obtain 11.6 g of N-acetylated chitosan. The degree of N-acetylation by elemental analysis was 95%.
<Production Example 2>
(Preparation of N-acetylated chitosan (2))
The same treatment as in Production Example 1 was carried out except that the amount of acetic anhydride added in Production Example 1 was changed to 5.71 g (0.9 eq.) To obtain 11.4 g of N-acetylated chitosan. The degree of N-acetylation by elemental analysis was 80%.
<Production Example 3>
(Preparation of N-acetylated chitosan (3))
Daiichi Seika Kogyo Co., Ltd. Daichitosan 100D (VL) was used as 100% deacetylated chitosan. 10 g of this chitosan was dissolved in 190 g of 10% acetic acid, diluted with 1 L of methanol, and acetic anhydride with stirring. 3.17 g (0.5 eq.) Was added, and the mixture was stirred at room temperature for 15 hours. When 2N-NaOH aqueous solution is added to neutralize to pH 7, flaky chitosan is precipitated. This is filtered, washed thoroughly with a solution of methanol and water: acetone = 1: 7, and then washed with acetone. It dehydrated and dried under reduced pressure at 40 ° C. to obtain 10.3 g of N-acetylated chitosan. This chitosan was water-soluble and had a pH of 8.2 with a 1 wt% aqueous solution. Furthermore, even if acid and alkali were added and pH was changed, it was melt | dissolving. From the result of ¹ H-NMR analysis measured by dissolving in an aqueous solution of deuterated hydrochloric acid, the degree of N-acetylation was 45%. FIG. 1 shows a ¹ H-NMR spectrum.
<Production Example 4>
(Preparation of chitouronic acid sodium salt (1))
10 g of N-acetylated chitosan prepared in Production Example 1 was suspended in 400 g of distilled water, and a solution prepared by dissolving 0.15 g of TEMPO and 2.0 g of sodium bromide was added to 100 g of distilled water and cooled to 5 ° C. or lower. . 84 g of an aqueous 11% sodium hypochlorite solution was added dropwise thereto to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. When the amount of alkali added corresponding to 100% of the total number of moles of the primary hydroxyl group at the 6-position is reached, ethanol is added to stop the reaction, and the reaction solution is poured into 2 L of ethanol. Then, the product was precipitated, washed thoroughly with a solution of water: acetone = 1: 7, dehydrated with acetone, dried under reduced pressure at 40 ° C., and white powdery 100% oxidized sodium chitouronic acid salt 10 .8 g was obtained. FIG. 2 shows a ¹³ C-NMR spectrum. The solubility in water was high, and the pH was 6 with a 5 wt% aqueous solution. Furthermore, even if acid and alkali were added and pH was changed, it was melt | dissolving. The weight average molecular weight in terms of pullulan determined by the GPC method was 32,000.
<Production Example 5>
(Preparation of sodium chitouronic acid salt (2))
10 g of N-acetylated chitosan prepared in Production Example 2 was suspended in 400 g of distilled water, a solution prepared by dissolving 0.15 g of TEMPO and 2.0 g of sodium bromide was added to 100 g of distilled water, and the mixture was cooled to 5 ° C. or lower. . 84 g of an aqueous 11% sodium hypochlorite solution was added dropwise thereto to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. When the amount of alkali added corresponding to 100% of the total number of moles of the primary hydroxyl group at the 6-position is reached, ethanol is added to stop the reaction, and the reaction solution is poured into 2 L of ethanol. Then, the product was precipitated, washed thoroughly with a solution of water: acetone = 1: 7, dehydrated with acetone, dried under reduced pressure at 40 ° C., and white powdery 100% oxidized sodium chitouronic acid salt 10 0.6 g was obtained. FIG. 3 shows a ¹³ C-NMR spectrum. The solubility in water was high, and the pH was 6.5 with a 5 wt% aqueous solution. Furthermore, even if acid and alkali were added and pH was changed, it was melt | dissolving. The weight average molecular weight in terms of pullulan determined by GPC method was 26,000.
<Production Example 6>
(Preparation of chitouronic acid sodium salt (3))
10 g of chitin manufactured by Wako Pure Chemical Industries, Ltd. was immersed in 150 g of 45% aqueous sodium hydroxide solution and stirred at room temperature or lower for 2 hours. To this, 850 g of crushed ice and the surroundings were cooled with ice water or the like and added with stirring. Chitin is almost dissolved by this alkali treatment. After neutralizing with hydrochloric acid and thoroughly washing with water, the one that did not dry was used as the oxidation raw material.

A solution prepared by dissolving 0.08 g of TEMPO and 1.0 g of sodium bromide in 50 g of distilled water was added to 200 g of the suspension having a regenerated chitin concentration of 2.5% and cooled to 5 ° C. or lower. An 11% sodium hypochlorite aqueous solution (35 g) was added dropwise thereto to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. When the amount of alkali added corresponding to 80% of the total number of moles of the primary hydroxyl group at the 6th position is reached, ethanol is added to stop the reaction, and the reaction solution is put into 1 L of ethanol. Then, the product was precipitated, washed thoroughly with a solution of water: acetone = 1: 7, dehydrated with acetone, dried under reduced pressure at 40 ° C., and white powdery sodium chitouronic acid salt having an oxidation degree of 80% 5 0.2 g was obtained. FIG. 4 shows a ¹³ C-NMR spectrum. The solubility in water was high, and the pH was 6 with a 5 wt% aqueous solution. Furthermore, even if acid and alkali were added and pH was changed, it was melt | dissolving. The weight average molecular weight in terms of pullulan determined by GPC method was 35,000.
<Production Example 7>
(Preparation of sodium amylouronate)
10 g of starch was dissolved by heating in 400 g of distilled water and cooled. To this solution was added a solution prepared by dissolving 0.18 g of TEMPO and 2.5 g of sodium bromide in 100 g of distilled water, and 104 g of an aqueous 11% sodium hypochlorite solution was added dropwise to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. When the amount of alkali added corresponding to 100% of the total number of moles of the primary hydroxyl group at the 6-position is reached, ethanol is added to stop the reaction, and the reaction solution is poured into 2 L of ethanol. Then, the product was precipitated, washed thoroughly with a solution of water: acetone = 1: 7, dehydrated with acetone, dried under reduced pressure at 40 ° C., and white amylouronate sodium salt 11 having an oxidation degree of 100%. 0.7 g was obtained. FIG. 5 shows a ¹³ C-NMR spectrum. The solubility in water was high, and the pH was 7 with a 5 wt% aqueous solution. Furthermore, even if acid and alkali were added and pH was changed, it was melt | dissolving. The weight average molecular weight in terms of pullulan determined by GPC method was 58,000.
<Production Example 8>
(Preparation of sodium cellulonate)
Using Benize manufactured by Asahi Kasei Kogyo Co., Ltd. as regenerated cellulose, 10 g of regenerated cellulose is suspended in 400 g of distilled water, and a solution of 0.18 g of TEMPO and 2.5 g of sodium bromide is added to 100 g of distilled water and cooled to 5 ° C. or lower. did. To this, 104 g of an aqueous 11% sodium hypochlorite solution was added dropwise to initiate the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH in the system was lowered, but a 0.5 N NaOH aqueous solution was sequentially added to adjust the pH to 10.75. When the amount of alkali added corresponding to 100% of the total number of moles of the primary hydroxyl group at the 6-position is reached, ethanol is added to stop the reaction, and the reaction solution is poured into 2 L of ethanol. Then, the product was precipitated, washed thoroughly with a solution of water: acetone = 1: 7, dehydrated with acetone, dried under reduced pressure at 40 ° C., and white powdery 100% cerulouronic acid sodium salt 11 0.6 g was obtained. FIG. 6 shows a ¹³ C-NMR spectrum. The solubility in water was high, and the pH was 7 with a 5 wt% aqueous solution. When an acid was added to this solution to adjust the pH to 3 or less, the solution became cloudy but was a uniform dispersion. The weight average molecular weight in terms of pullulan determined by GPC method was 52,000.
<Test Example 1>
Oxidized polysaccharides of Production Examples 4, 7, and 8, N-acetylated chitosan of Production Example 3, and microcrystalline cellulose powder, and carboxymethyl cellulose sodium salt MLD = 250,000 DS = 0.7 manufactured by ALDRICH The biodegradability by aerobic microorganisms in the soil was evaluated by the method. The results are shown in FIG. It can be seen that carboxymethylcellulose sodium salt hardly decomposes, whereas oxidized polysaccharides and chitosan as raw materials of the present invention decompose substantially in the same manner as cellulose.
(Evaluation method for biodegradability)
Using a microbial oxidative degradation measuring device (MODA) manufactured by Yawata Bussan Co., Ltd., standard compost (YK-2 manufactured by Yawata Bussan Co., Ltd.) 250 cc adjusted to 60% moisture and adjusted to 18% moisture as test soil. A mixture of 250 cc of sea sand was used. 10 g of the sample was uniformly mixed with the test soil, filled in a column-shaped reaction cylinder, and the temperature in the reaction cylinder was kept constant at 35 ° C. Further, decarboxylated air saturated with water vapor is vented at 40 ml / min from the bottom of the reaction cylinder, and the gas is not leaked from the top of the reaction cylinder, passes through a sulfuric acid bath to remove ammonia gas, and silica gel to remove moisture. And the moisture absorption cylinder filled with calcium chloride, and further led to the absorption cylinder filled with soda talc and soda lime. Since all the carbon dioxide generated by aerobic biodegradation of the sample is absorbed by the absorption cylinder, the amount of carbon dioxide generated by biodegradation can be quantified from the weight change of the absorption cylinder. In addition, the blank test of only the test soil which does not put a sample was performed simultaneously, and the amount of carbon dioxide generated by decomposition was calculated by subtracting the amount of carbon dioxide generated in the blank test. The theoretically generated carbon dioxide amount was calculated from the carbon content in 10 g of the sample, and the ratio of the generated carbon dioxide amount to the theoretical amount is shown in FIG. 7 as the degree of biodegradation.

  Next, the polysaccharide complex of Example 1 will be described.

  Chitosan having a deacetylation degree of 75% and 1.8 g of Daichitosan P (VL) manufactured by Dainichi Seika Kogyo Co., Ltd. were dissolved in a dilute hydrochloric acid aqueous solution to obtain a chitosan solution having a solid content concentration of 2% and a pH of 2. While stirring, 1.4 g of sodium chitouronic acid salt prepared in Production Example 4 was added as a 2% aqueous solution. When 2N hydrochloric acid was added to this mixed solution to adjust the pH to 1.5, a transparent solution was obtained. Further, when the pH was adjusted to 6.5 with a 1N-NaOH aqueous solution, the gel was precipitated. When the stirring was stopped and the mixture was allowed to stand for a while, the gel was deposited and bound on the bottom surface of the container to form a wet gel sheet. The supernatant was discarded and the polysaccharide complex of Example 1 was obtained. The wet polysaccharide complex exhibited clay or resinous plasticity. When this polysaccharide complex was once agglomerated and then pulled in a uniaxial direction, it exhibited characteristic physical properties that stretched like a thread.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a dilute hydrochloric acid solution to obtain a chitosan solution having a solid concentration of 2% and a pH of 1. To this, 1 g of sodium chitouronic acid salt prepared in Production Example 4 was added with stirring, and then the pH was adjusted to 7 with 1N-NaOH aqueous solution to precipitate a gel. When stirring was stopped and the mixture was allowed to stand for a while, the gel was deposited on the bottom surface of the container and bound to form a wet gel sheet. The supernatant was discarded and the polysaccharide complex of Example 2 was obtained. The wet polysaccharide complex exhibited clay or resinous plasticity.
<Comparative Example 1>
2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a dilute hydrochloric acid solution to obtain a chitosan solution having a solid concentration of 2% and a pH of 1. While stirring, 1 g of sodium celouronic acid salt prepared in Production Example 8 was added, and then the pH was adjusted to 7 with 1N-NaOH aqueous solution to precipitate a gel. When stirring was stopped and the mixture was allowed to stand for a while, the gel was deposited on the bottom of the container. The supernatant was discarded and the polysaccharide complex of Comparative Example 1 was obtained. This polysaccharide complex had a weak binding force, and when deforming stress was applied, the form was broken into pieces.
<Comparative example 2>
2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a dilute hydrochloric acid solution to obtain a chitosan solution having a solid concentration of 2% and a pH of 1. To this, while stirring, carboxymethylcellulose sodium salt MLD = 250,000 DS = 0.7 1 g made from ALDRICH was added as a 1% aqueous solution, and then the pH was adjusted to 7 with 1N-NaOH aqueous solution. Precipitated. When stirring was stopped and the mixture was allowed to stand for a while, the gel was deposited on the bottom of the container. The supernatant was discarded and the polysaccharide complex of Comparative Example 2 was obtained. This polysaccharide complex had a weak binding force and easily collapsed into a tattered form.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. To this, 1 g of sodium chitouronic acid salt prepared in Production Example 4 was added with stirring, and then the pH was adjusted to 7 with 1N-NaOH aqueous solution to precipitate a gel. After stirring for 1 minute as it was, the mixture was quickly poured into a polystyrene container having a bottom area of 127.5 cm ² and allowed to stand overnight. The deposited gel was deposited and bound on the bottom of the container to form a wet gel sheet. The supernatant was discarded, and after air drying, the gel sheet was thoroughly washed with deionized water to obtain the polysaccharide complex of Example 3. This polysaccharide complex is a tan transparent sheet with a film thickness of 100 to 200 μm when dried, and the sheet shape does not collapse even when washed with deionized water, and is NaCl, which is a salt of counterions It was possible to remove.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. To this, 1 g of chitouronic acid sodium salt prepared in Production Example 5 was added while stirring, and then the pH was adjusted to 7 with a 1N-NaOH aqueous solution to precipitate a gel. After stirring for 1 minute as it was, the mixture was quickly poured into a polystyrene container having a bottom area of 127.5 cm ² and allowed to stand overnight. The deposited gel was deposited and bound on the bottom of the container to form a wet gel sheet. The supernatant was discarded, and after air drying, the gel sheet was thoroughly washed with deionized water to obtain the polysaccharide complex of Example 4. This polysaccharide complex is a tan transparent sheet with a film thickness of 100 to 200 μm when dried, and the sheet shape does not collapse even when washed with deionized water, and is NaCl, which is a salt of counterions It was possible to remove.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. To this, 1 g of sodium chitouronic acid salt prepared in Production Example 6 was added with stirring, and then the pH was adjusted to 7 with 1N-NaOH aqueous solution to precipitate a gel. After stirring for 1 minute as it was, the mixture was quickly poured into a polystyrene container having a bottom area of 127.5 cm 2 and allowed to stand overnight. The deposited gel was deposited and bound on the bottom of the container to form a wet gel sheet. The supernatant was discarded, and after air drying, the gel sheet was thoroughly washed with deionized water to obtain the polysaccharide complex of Example 5. This polysaccharide complex is a tan transparent sheet with a film thickness of 100 to 200 μm when dried, and the sheet shape does not collapse even when washed with deionized water, and is NaCl, which is a salt of counterions It was possible to remove.
<Comparative Example 3>
2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. To this, 1 g of sodium alginate 500 to 600 cP manufactured by Wako Pure Chemical Industries, Ltd. was added as a 1% aqueous solution with stirring, and then the pH was adjusted to 7 with a 1N-NaOH aqueous solution, whereby the whole became a gel. This highly swollen gel was transferred to a polystyrene container having a bottom area of 127.5 cm ² and allowed to stand overnight, but a slight amount of supernatant was produced, but it was in a highly swollen state. This gel was air-dried to obtain the polysaccharide complex of Comparative Example 3. Although this polysaccharide composite became a sheet having a film thickness of 50 to 300 μm when dried, it was uneven and did not swell and remain in the sheet shape when poured into water.

The dried polysaccharide composite sheet of Example 3 was freeze-ground and powdered. 1 g of this powder was added to 100 g of distilled water with stirring. After stirring for 3 minutes, the mixture was immediately poured into a polystyrene container having a bottom area of 36.3 cm ² and allowed to stand overnight. The wet gel deposited on the bottom of the container was bound to form a wet gel sheet having tensile strength.

The polysaccharide composite dry sheet of Example 4 was freeze-ground and powdered. 1 g of this powder was added to 100 g of distilled water with stirring. After stirring for 3 minutes, the mixture was immediately poured into a polystyrene container having a bottom area of 36.3 cm ² and allowed to stand overnight. The wet gel deposited on the bottom of the container was bound to form a wet gel sheet having tensile strength.
<Comparative Examples 4-6>
The dried gels of the polysaccharide complexes of Comparative Examples 1 to 3 were freeze-ground and powdered. In each case, 1 g of powder was added to 100 g of distilled water with stirring. After stirring for 3 minutes, the mixture was immediately poured into a polystyrene container having a bottom area of 36.3 cm ² and allowed to stand overnight. The wet gel deposited on the bottom of the container did not bind and did not become a sheet in the wet state.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. While stirring, 0.7 g of sodium chitouronic acid salt prepared in Production Example 5 and 0.3 g of sodium cellouronic acid salt prepared in Production Example 8 were dissolved in 20 g of distilled water, and then added with a 1N-NaOH aqueous solution. When the pH was adjusted to 7, the gel was precipitated. After stirring for 1 minute as it was, the mixture was quickly poured into a polystyrene container having a bottom area of 127.5 cm ² and allowed to stand overnight. The deposited gel was deposited and bound on the bottom of the container to form a wet gel sheet. The supernatant was discarded, and after air drying, the gel sheet was thoroughly washed with deionized water to obtain the polysaccharide complex of Example 8. This polysaccharide complex is a yellow-brown sheet having a thickness of 100 to 200 μm when dried, and the sheet shape does not collapse even when washed with deionized water, and removes NaCl, which is a salt between counter ions. Was possible.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. While stirring, 0.3 g of chitouronic acid sodium salt prepared in Production Example 5 and 0.7 g of ceurouronic acid sodium salt prepared in Production Example 8 were dissolved in 20 g of distilled water, and then added with 1N-NaOH aqueous solution. When the pH was adjusted to 7, the gel was precipitated. After stirring for 1 minute as it was, the mixture was quickly poured into a polystyrene container having a bottom area of 127.5 cm ² and allowed to stand overnight. The deposited gel was deposited and bound on the bottom of the container to form a wet gel sheet. The supernatant was discarded, and after air drying, the gel sheet was thoroughly washed with deionized water to obtain the polysaccharide complex of Example 9. This polysaccharide complex is a yellow-brown sheet having a thickness of 100 to 200 μm when dried, and the sheet shape does not collapse even when washed with deionized water, and removes NaCl, which is a salt between counter ions. Was possible.

2 g of N-acetylated chitosan prepared in Production Example 3 was dissolved in a diluted hydrochloric acid solution to obtain a chitosan solution having a solid content concentration of 3% and a pH of 1. While stirring, 0.5 g of sodium chitouronic acid prepared in Production Example 5 and 0.5 g of sodium amyluronate prepared in Production Example 7 were dissolved in 20 g of distilled water, and then added with 1N-NaOH aqueous solution. When the pH was adjusted to 7, the gel was precipitated. After stirring for 1 minute as it was, the mixture was quickly poured into a polystyrene container having a bottom area of 127.5 cm ² and allowed to stand overnight. The deposited gel was deposited and bound on the bottom of the container to form a wet gel sheet. The supernatant was discarded, and after air drying, the gel sheet was thoroughly washed with deionized water to obtain the polysaccharide complex of Example 9. This polysaccharide complex is a tan transparent sheet with a film thickness of 100 to 200 μm when dried, and the sheet shape does not collapse even when washed with deionized water, and is NaCl, which is a salt of counterions It was possible to remove.
<Test Example 2>
The dried gel sheets of the polysaccharide complexes of Examples 3 to 10 were used as 1 cm square test pieces and immersed in 10 ml of phosphate buffered saline in 20 ml glass bottles. After storage at 37 ° C. for 3 days, morphological changes were observed. Even if all swollen, the sheet shape was maintained. Furthermore, when the container was vigorously stirred during storage at 37 ° C., the gel sheets of Examples 3 and 6 were broken and fragmented, but other than that, the sheet was maintained without breaking.
<Test Example 3>
The dried gel sheets of the polysaccharide complexes of Examples 3 to 10 were used as 1 cm square test pieces and immersed in 10 ml of phosphate buffered saline in 20 ml glass bottles. Here, 10 μg of lysozyme (derived from egg white) manufactured by Wako Pure Chemical Industries, Ltd. was added and stored at 37 ° C. for 2 days, and morphological changes were observed. Thereafter, the remaining gel sheet was taken out, washed and dried, and weight loss (%) = (100−dry weight after test / dry weight before test × 100) was determined.

  In all of the gel sheets of Examples 3 to 7, only fragments remained, and the weight loss was almost decomposed to 90 to 98%, whereas Examples 8 to containing seurouronic acid or amylouronic acid as anionic polysaccharides. The gel sheet of No. 10 maintained the sheet shape, and the weight reduction was 80% in Example 8, 50% in Example 9, and 40% in Example 10.

  The polysaccharide complex of the present invention has excellent biodegradation, high safety and biocompatibility, and can be designed for materials that meet various required physical properties. Applications in various fields such as cosmetics and functional fibers can be expected. For example, in the form of a pharmaceutical or medical device that is required to maintain the form for several days without being dissolved or disintegrated in the living body, and then eventually decomposes and absorbs and disappears. Application is expected as a material that is supplied to the affected tissue and wet-gelled on the affected tissue surface to form a film.

It is a ¹ H-NMR spectrum measured by dissolving N-acetylated chitosan of Production Example 3 in a deuterated aqueous solution of deuterated hydrochloric acid. It is the spectrum of ¹³ C-NMR measured by dissolving chitouronic acid sodium salt of Production Example 4 in heavy water. It is the spectrum of ¹³ C-NMR measured by dissolving chitouronic acid sodium salt of Production Example 5 in heavy water. It is a ¹³ C-NMR spectrum measured by dissolving the sodium chitouronic acid salt of Production Example 6 in heavy water. FIG. 6 is a ¹³ C-NMR spectrum measured by dissolving sodium amylouronate of Production Example 7 in heavy water. It is a ¹³ C-NMR spectrum measured by dissolving the celluloronic acid sodium salt of Production Example 8 in heavy water. It is a graph which shows the biodegradation degree measured according to Test Example 1 of oxidation polysaccharide, chitosan, and carboxymethylcellulose.

Claims (5)

A polysaccharide complex in which an anionic polysaccharide and a cationic polysaccharide form a polyion complex structure, and at least chitin / chitosan is oxidized as the anionic polysaccharide to form N- It contains an oxidized polysaccharide introduced with a carboxyl group or a salt thereof at the 6-position of acetyl-D-glucosamine, and further oxidizes polysaccharides other than chitin / chitosan to a carboxyl group or a salt thereof at the 6-position of the pyranose ring of the polysaccharide. A polysaccharide complex comprising amyloulonic acid or seurouronic acid into which is introduced, and at least chitosan as the cationic polysaccharide.   The oxidized polysaccharide is obtained by a method in which an alkali-regenerated chitin or N-acetylated chitosan having reduced crystallinity is used as a raw material and is oxidized in an aqueous system using an oxidizing agent in the presence of an N-oxyl compound catalyst. The polysaccharide complex according to claim 1, wherein The polysaccharide complex according to claim 1 or 2, wherein the oxidized polysaccharide has a chemical structure represented by the following general formula (1).
In the anionic polysaccharide, an oxidized polysaccharide obtained by oxidizing chitin / chitosan and introducing a carboxyl group or a salt thereof at the 6-position of N-acetyl-D-glucosamine, which is a constituent monosaccharide, and other than chitin / chitosan The ratio of amylouronic acid or ceurouronic acid obtained by oxidizing a polysaccharide and introducing a carboxyl group or a salt thereof at the 6-position of the pyranose ring of the polysaccharide is from 8: 2 to 1: 9 by weight. Item 4. The polysaccharide complex according to any one of Items 1 to 3. A biocompatible material using the polysaccharide complex according to any one of claims 1 to 4.