Study On The Preparation And Application Of Chitosan-based Materials For Hemostasis

In wars,traffic accidents,natural disasters and other situations,uncontrolled bleeding is the main cause of death.Traditional hemostatic materials are not ideal for uncontrolled bleeding,so it is necessary to develop novel hemostatic materials to achieve better hemostatic effect.Chitosan is a kind of biomaterial with good biocompatibility,biodegradability,non-immunity,which is widely used in biomedical field.However,the hemostatic effect of a single chitosan component is limited,so it is considered to mix chitosan with other organic or inorganic hemostatic materials to prepare composite hemostatic materials to improve the hemostatic performance.In this paper,two novel chitosan based hemostatic materials were prepared,and their physicochemical properties and hemostatic effects were studied.(1)A mixed solution of carboxymethyl chitosan and gelatin was mixed with oxidized sodium alginate solution.The injectable gel was prepared by Schiff base reaction to stop bleeding for irregular wound.By optimizing the preparation conditions,the gel can be formed in 30 s,the freeze-dried gel showed three dimensional porous structure under scanning electron microscope.Meanwhile,the gel has good adhesion properties.Cytotoxicity tests showed no obvious toxicity of gels.The gel loaded with levofloxacin has good antibacterial activity against Escherichia coli and Staphylococcus aureus.The gel's hemostasis effect was tested with the rat liver injury model.Compared with untreated wounds,the bleeding time of the wound treated with gel was shortened by 84.2% and bleeding volume was reduced by 82.2%.(2)The glycidyl methacrylate functionalized quaternized chitosan and the iron oxide-kaolin nanosheet was fabricated,respectively.Then the composite sponge with different formulations were prepared by free radical polymerization.The composite sponge has three-dimensional porous structure.The swelling ratio of the composite sponge decreased gradually with the addition of kaolin nanosheets.The hemostatic performance of the composite sponge was tested with the rat tail amputation model.The results showed that the hemostatic time increased first and then decreased with the addition of kaolin nanosheets.When the loading amount of kaolin was 3 / 10 of the mass of quaternized chitosan,the hemostatic time was the shortened to 59 s,which was 84.2% less than the blank control.Cytotoxicity tests showed no obvious toxicity of gels.The results showed that the composite sponge was suitable for hemostasis.