Preparation Of N-alkyl Chitosan Fibers And Their Coagulation Properties

Fast and effective hemostasis is a key link in the process of care patients during traffic accident,earthquake disaster and war.Therefore,good coagulation effect and biocompatibility of hemostatic materials have been the research hotspot in the related field.Chitosan are widely used in the hemostatic materials because of good biocompatibility,degradation in vivo and promoting wound healing,etc;and chitosan derivatives with good coagulation capability have a good solubility and processability as hemostatic materials research hotspot.Different carbon chain length of N-alkyl chitosan(alkyl chitosan(CS6),dodecyl chitosan(CS12)and octadecyl(CS18))was prepared with the reaction of the schiff base in this paper,its structure was studied by FTIR and 1HNMR;the alkyl substitution degree(DS)law was researched by the dosing ratio of aldehydes and chitosan.Chitosan(SCS)fiber and n-alkyl chitosan fiber were prepared by wet spinning technology.The structure and mechanical properties of fiber were characterized by single fiber strength meter,TG and XRD,the results showed that the surface of n-alkyl chitosan fiber had more groove than the surface of chitosan fiber;the thermal stability of n-alkyl chitosan fiber was improved compared with that of chitosan fiber.Using whole blood coagulation process,coagulation and platelet intracellular Ca2+ concentration method studied the clotting hemorrhagic of fiber,the results showed that N-alkyl chitosan fiber materials for platelet intracellular Ca2+concentration had no significant effect;it had good coagulation effect for the shorter coagulation time(33s and 35s),in vitro,when the DS was 19.22%of N-hexane chitosan fiber(SCS6b)and 33.57%of N-dodecane chitosan(CS12c).In order to study the effect of fiber diameter on coagulation effect,the electrostatic spinning technology was further used to prepare chitosan and n-alkyl chitosan nanofiber film(NM)in the paper.The surface morphology,crystallization performance and thermal stability of the fiber membrane were characterized by SEM,contact angle,XRD and TG,etc,the results showed that the diameter of nanofibers was between 120nm and 280nm,its hydrophobicity was increased with the increase of the graft chain length.Using whole blood coagulation,thromboela-stogram,material on the function of platelet and intracellular Ca2+ in platelet concentration method,the results showed that the DS of 8.98%octadecyl chitosan nanofiber membrane(CS18a-NM)had better clotting capability(83s of clotting time)in vitro;it could activate most coagulation factors in plasma and had a strong adhesion and aggregation effect on platelets.