Facile fabrication of carboxymethyl chitosan/paraffin coated carboxymethylated cotton fabric with asymmetric wettability for hemostatic wound dressing

Achieving effective hemostasis is significant to ensure the survival of the people with acute massive bleeding in the battlefield or daily life in pre-hospital care. In this work, modified cotton fabric with asymmetric wettability (Janus) was prepared using a fast and simple spray-coating strategy, where, one side of the fabric was sprayed with carboxymethyl chitosan solution to achieve hydrophilicity (0°) while the other side with hydrophobicity (152°) was built using paraffin. The hydrophilic surface could provide blood absorption and promote hemostasis, while the hydrophobic surface prevented the excessive blood absorption. The hemostatic efficiency of fabrics was tested in vitro and in vivo. Here, the carboxymethyl chitosan coated carboxymethylated cotton (CS-MCF) and Janus showed better hemostatic capacity than the cotton fabric (CF) in vitro with the lower blood clotting index. Furthermore, the Janus had better hemostatic performance than CF in rat liver animal model, and prolonged the survival time of the rats in carotid artery animal model. Therefore, Janus, with superior hemostatic efficiency over the cotton fabric, has a bright application prospect as hemostatic wound dressing.