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Study on the Preparation and Biocompatibility of N-Carboxymethyl Chitosan

Author: HuangPan
Tutor: LiuWanShun
School: Ocean University of China
Course: Marine biology
Keywords: N - carboxymethyl chitosan Structural characterization Biocompatible wins
CLC: R318.08
Type: Master's thesis
Year: 2009
Downloads: 208
Quote: 2
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Abstract

Objective: Chitosan (CTS) is chitin by deacetylation to give the poly-(1,4) -2 - amino-2 - deoxy-beta-D-glucose, rich source is the nature of the only obvious alkaline natural polysaccharide with a positive charge, with a wide range of applications in medicine and other fields. However, chitosan is soluble only in the nature of the acidic solution, largely limiting its development and utilization. Carboxymethyl chitosan (CMC) is 600 chitin derivatives reported so far, the most studied a water-soluble chitosan derivatives. Studies have shown that the CMC has good biocompatibility, biodegradability, degradation controlled and bacteriostatic its unique physical and chemical properties, it has become a hot topic in the medical profession and the field of biomedical research. Chitosan molecule C6 hydroxyalkyl, C3 hydroxyl group and C2 the amino can occur carboxymethylation substituted, therefore, control of reaction conditions can be prepared by the O-carboxymethyl chitosan (O-CMC), N-carboxymethyl chitosan sugar (N-CMC) and N, O-carboxymethyl chitosan (O, N-CMC) three products. Current research and applications are mostly concentrated in the O, N-CMC, obtained N-CMC little research on the N bits of carboxymethylation system. O, N-CMC in the preparation process to go through a long time high temperature reaction conditions such as concentrated alkali, the product prepared is the relative molecular weight and viscosity will be decreased significantly degraded and absorbed in the body too quickly, as medical polymer materials, it is difficult to meet the biological the requirements of the polymer material. The relatively mild conditions of the preparation of the N-CMC, a larger molecular weight of the product can be obtained. This study were prepared by different degree of substitution of the N-CMC, and carried out a preliminary study of its physical and chemical properties and biological properties of significance to broaden the application of the chitosan. METHODS: The experiment is divided into two parts: 1, glyoxylic acid and CTS as raw material, the preparation and purification of N-CMC reaction in acidic conditions, physical and chemical properties of the different degrees of carboxylation product, infrared scanning characterized substitutable positions, and Determination of its crystalline, acid-base titration of the degree of carboxylation (DC), and moisture content, ash content, viscosity, molecular weight, isoelectric point, and moisture absorption properties were studied by X-RAY diffraction. 2, on the degree of N-CMC of two carboxylated biocompatibility study of mouse fibroblasts L929 cytotoxicity test performed with New Zealand rabbit blood hemolysis test and coagulation tests of the material, the depyrogenation N-CMC prepared as the two forms of colloidal formulations and film formulations rats implanted test, evaluation of its tissue compatibility and biodegradability. Results: 1, N-CMC prepared DC between 25% to 78%. The characteristic absorption peaks FITR spectra at 1590cm ^{-1 at the presence of sodium carboxymethyl carboxymethylation occur in the 2 N of the CTS. X-RAY diffraction curve at 2θ of 20 ° and 10 °, the diffraction peak is greatly reduced, and that reduces the degree of crystallinity of the product after the carboxymethylation. 2 into the fiber cell lines L929 evaluation material cytotoxicity in mice, the set within 62.5μg/mL, to 5000μg/mL concentration, the high degree of carboxylation N-CMC has good cell compatibility, but low-carboxymethyl The degree of N-CMC at a concentration of> 500μg/mL demonstrated the role of inhibition of cell growth. The hemolytic tests showed five kinds carboxylation degree sample hemolysis rate of less than 5%, to meet the requirements of the biomedical material; coagulation tests showed no effect of N-CMC on clotting time; animal tissue compatibility experiments show that the same quality N- CMC colloidal solution is absorbed more easily than film formulations organization degradation; degraded and absorbed faster than subcutaneous tissue in the muscle tissue. N-CMC is an excellent biomedical materials. Conclusion: N-CMC prepared by the present method can avoid the the CTS in carboxymethyl process a large number of molecular chains of the phenomenon of fracture, to get a relatively stable molecular weight of the product. It was determined, N-CMC has good biocompatibility, blood compatibility and tissue compatibility. The results for the N-CMC provides a theoretical basis for research and applications in biomedical materials.}

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