Preparation And Application Research Of High-viscosity Chitosan Hemostatic Material

Chitosan is an abundant and renewable polymer biomaterial. It has many excellent physical and chemical properties, biodegradability, biocompatibility and other advantages, so that it is wildly used in bio-medical field. However, chitosan as absorbable hemostatic wound dressing, the effects of DD and viscosity on the application is not fully studied. Based on this reasons, this paper studied preparation of the high viscosity, high DD chitosan and the preparation of composite chitosan hemostatic film, at last decided its safety and practicability. The results are as follows:1. According to the following methods of deacetylation can obtain high viscosity and high DD chitosan. Put60~80mesh chitin in40%NaOH solution, in proportion to1:12, after stirring10min under40℃, immediately conduct800W,2450MHz microwave pretreatment3min, after filtering the products added to50%NaOH solution, in proportion to1:12, mix and heat it to90℃for40min, use pure water to wash to pH7.2-7.5, dried3h at105℃. Finally, obtaining chitosan which DD is85.32%, the apparent viscosity is1271mPa·s, the viscosity average molecular weight is1.16x1062. According to the following methods of preparation of chitosan composite film, the film will has excellent hemostatic properties, flexibility and water absorption.①The chitosan gel preparation:take4g chitosan, into200mL2%acetic acid solution at room temperature(20~25℃), stirring until completely dissolved, after filtering, to clarify the chitosan solution, drying1h at70℃, then put the chitosan solution into a Petri dish, and the in the precipitation liquid overnight (precipitation solution by ethanol,8%glycerol,5%NaOH, in ratio of100:10:1), until chitosan completely precipitation formation of chitosan gel, wash with deionized water to neutral.②he chitosan surface carboxylation:put chlorination of acetic acid, isopropyl alcohol (ratiol:10)in an airtight container, heating to70℃, then put the chitosan gel into and reaction30min, wash with a sufficient amount of ethanol5~6times.③The cross-linking reaction and introducing of the coagulation factor:put the chitosan gel in1%of calcium chloride reaction30min, and wash by deionized water.④The plasticizing reaction:put the chitosan gel into30%glycerol solution for plasticizing reaction6h, dry at70℃for3h, last obtain the high viscosity chitosan hemostatic composite film.3. The hemolysis experiment and the acute systemic toxicity experiment prove, this method for the preparation of high viscosity chitosan composite film has the advantages of biological safety. The hemolysis experiment results show that, the hemolysis rate is0.74%, it proves this material will not cause hemolysis, with blood compatibility; The acute systemic toxicity experiment results show that, the injection dose not cause metabolic disorders of mice, so the film does not cause acute systemic toxicity reaction.4. The vitro degradation experiment and the coagulation experiments show that, under the same conditions preparing hemostatic material, the method of preparation of high viscosity chitosan in contrast to other DD and viscosity of chitosan, the biodegradation is faster, the coagulation effect is better. The vitro degradation experiment results show that, the materials about85%DD contribute to accelerated degradation; The vitro coagulation experiment and rabbit ear artery coagulation experiment results show that, the material with1000mPa·s viscosity speed up the coagulation, better than other chitosan materials, and chitosan hemostatic materials promote coagulation effect on anti-coagulated blood equally.