Effect of Grafted Chain Length on Hemostatic Activity of N-Alkylated Chitosan

This study aimed to synthesize N-alkylated chitosan derivates with similar degree of substitution (DS) and alkyl groups of different carbon chain lengths via reductive alkylation, and then to compare their coagulation properties. Structural properties of the N-alkylated chitosan derivates were characterized by Fourier transform infrared spectroscopy, elemental analysis and H-1 nuclear magnetic resonance spectroscopy. Their pro-coagulant properties were evaluated by detecting whole blood clotting time and performing TEG test. Pro-coagulant mechanisms of the N-alkylated chitosan derivates were explored by detecting intracellular Ca2+ concentration in platelets and P-selectin expression on platelets. We successfully prepared N-alkylated chitosan derivates with a DS of 32.88%-39.78%, including NACS6, NACS12 and NACS18. Our experimental findings showed that all N-alkylated chitosan derivates (NACS6, NACS12, NACS18) have outstanding procoagulant effects, and the longer alkyl chain, the better procoagulant ability. However, N-alkylated chitosan cannot activate platelets, and its procoagulant mechanism remains to be further studied in future. Based on the above results, this paper makes a conjecture about the coagulation mechanism of N-alkylation chitosan.