Biocompatible Gradient Chitosan Fibers with Controllable Swelling and Antibacterial Properties

This study developed a partially water-soluble carboxymethyl chitosan (PWCS) fibers by ethanol-water exhaustion method. Sodium carboxylate was successfully introduced into chitosan fibers, as evidenced by FTIR, which enhanced natural chitosan water solubility. SEM-EDS revealed that the sodium carboxylate groups presented in a gradient distribution from the exterior to the interior of the PWCS fibers, which leads to a controllable swelling performance. Moreover, the PWCS fibers had excellent antibacterial ability against S. aureus and E. coli bacteria comparing with origin CS fibers. The cytotoxicity assay (CCK-8) and fluorescence staining confirmed that all developed samples showed non-toxicity towards MRC-5 and exhibited a surprising promoting effect on cell proliferation, corroborating their biocompatibility. Besides, due to its excellent controllable water selling ability and protonated amine groups, the PWCS fibers possessed an efficient hemostatic performance. In conclusion, PWCS fibers could become a promising material in hemostatic and wound healing applications.