Preparation And Performance Investigation Of Composite Hemostatic Material Of Oxidized Cellulose Nanocrystal And Alginate

TEMPO-oxidized cellulose nanocrystal(TOCN) has the structure and properties of oxidized cellulose, and the properties of nanomaterials, as a natural material nanoscale, which has the special shape and geometry, high crystallinity, high surface area, high mechanical strength, surface chemistry, biocompatibility, biodegradability, etc. Meanwhile, Sodium alginate(SA) has excellent physical and chemical properties, such as mild gel condition, biodegradable, biocompatible, etc. They have become the focus of medical polymer material science. In this study, we attempted a novel approach to design TOCN/SA composite hemostatic material by preparation of TOCN and SA with the divalent calcium, and hemostatic properties, hemostatic and biodegraded mechanism of composite hemostatic materials have also been investigated.The reactions of Oxidized nanocellulose with TEMPO-NaClO-NaBr for different oxidation time, and the selectivity of oxidation at C6 of Nanocellulose was proved by FTIR, 1C NMR, XRD and XPS technology, producing TEMPO-Oxidized Nanocellulose. The results revealed an increase in carboxyl content as the oxidation time increased, 3h is the optimum oxidation time. Carboxyl content TEMPO-oxidized nanocellulose is above approximately 17.8%.The TOCN/SA composite hemostatic material obtained through different drying methods. The TOCN/SA composite film that prepared by solution casting-solvent evaporation is homogeneous and transparent, which has better water absorption, and the average thickness of film is about 40μm. The TOCN/SA composite sponge that prepared by freeze drying is regularly shaped, which has higher porosity and water absorption. What’s more, the structures of the materials have been characterized by FTIR, XRD, AFM, SEM and EDS, which revealed that TOCN can occur with SA by Ca2+ crosslinking reaction, and the replacement rate of Na+ was 100%. The roughness of composite film decreased and the pore size of the composite sponge increased with the increasing additive amount of TOCN. When the amount of TOCN further increased, agglomeration of TOCN occurred, and leaded to increasing of the roughness of composite film and sponge.Through acute skin irritation, intradermal irritation test, hemolysis and acute systemic toxicity test,etc. biological security evaluation test, TOCN/SA composite film and sponge were able to match IOS 10993 standard. Antibacterial test showed that antimicrobial properties of TOCN/SA composites enhanced with the increasing additive amount of TOCN. The hemostatic efficiency of TOCN/SA composite film and sponge materials were studied through rabbit ear artery and hepatic trauma models. The hemostatic time of TOCN/SA shortened as increase of TOCN content, however, the tine of TOCN-50/SA sharply raised. The hemostatic time of TOCN-30/SA film is 172 s, and the hemostatic time TOCN-30/SA sponge is 159 s. And TOCN/SA hemostatic mechanism was provided that included adsorbing red blood cells and white blood cells and assembling blood platelets to achieve the purpose of hemostasis. Implantation test showed that TOCN/SA composite film and sponge was completely biodegraded in 14 d, and hasn’t caused any pathological response.