Characterization Of Macromolecular Carboxymethyl Chitosan And The Study Of Its Hemostatic And Woundhealing Functions

Objective:Rapid and effective hemostasis has become one hot research point in medical field. The development and application of rapid hemostatic materials are undoubtly central to this research. The mechanisms of conventional rapid hemostatic materials, including porous zeolite, fibrin glue, cellulosic hemostat and chitosan hemostat, are different from each other. They have their own defects in actual application and thus cannot meet the demand of ideal rapid hemostatic materials. Carboxymethyl chitosan is a novel derivative of chitosan and besides better biocompatibility and degradability, carboxymethyl chitosan has hemostatic function and the capability of bacteriostasis and woundhealing, which enable it to be variously applied in the absorbable and degradable biomedical materials field. However, its application has been greatly limited because of its low molecular weight, strong water-solubility. Macromolecular carboxymethyl chitosan is used as the subject of this research and its physicochemical properties are studied. The swelling capacity and the biosafety of M-CM-Chitosan are studied and the hemostatic function and woundhealing function of M-CM-Chitosan are investigated through the experiments of carotid hemorrhage and hepatic hemorrhage of New Zealand white rabbits. The results above will provide theoretical basis for the development of rapid hemostatic materials and the research of carboxymethyl chitosan.Methods:1. Examine the physicochemical properties of macromolecular carboxymethyl chitosan. The indexes include moisture content, ash content, deacetylation degree, carboxymethyl degree, rotational viscosity and FTIR. The swelling capacity of M-CM-Chitosan at different time, temperature, pH and ionic strength is also studied.3. Evaluate the biosafety of M-CM-Chitosan by the hemolysis ratio test, intradermal irritation test, acute toxicity test and cytotoxicity test.4. Establish the models of carotid hemorrhage and hepatic hemorrhage of New Zealand white rabbits. In the former model, chitosan styptic powder is used as the control material and the hemostatic and woundhealing functions of M-CM-Chitosan are evaluated by the hemostatic time and the observation after the surgery at the7th,14th and21st day. In the latter model, Surgicel (oxidized regenerated cellulose) is used as the control material and the hemostatic and woundhealing functions of M-CM-Chitosan are evaluated by the hemostatic time and the anatomy as well as the histological observation after the surgery at the7th,14th and21st day.Results:1. M-CM-Chitosan has excellent swelling capacity. The swelling ratio will decrease with the increment of time and temperature.2. M-CM-Chitosan has no hemolytic reaction, acute toxicity, intradermal irritation or cytotoxicity. It has a good biosafety3. M-CM-Chitosan could magnificently shorten the hemostatic time (P<0.05) and enhance the hemostasis compared with chitosan styptic powder and Surgicel. C-CM-Chitosan has better degradability and it could also reduce local inflammation reactions and promote the healing of wound surface.Conclusion:M-CM-Chitosan has excellent swelling capacity and biosafety. Compared with conventional hemostatic agents, M-CM-Chitosan could magnificently shorten the hemostatic time in the hemostasis of carotid hemorrhage and hepatic hemorrhage of rabbits (P<0.05). Woundhealing effect of M-CM-Chitosan was also detected in the postoperative observation. This work provides experimental basis for the study of novel rapid hemostatic materials and the application of carboxymethyl chitosan.