A robust polyacrylic acid/chitosan cryogel for rapid hemostasis

Currently, it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs. A series of polyacrylic acid/chitosan (PAA/CS) cryogels were prepared by a cryostructurization technique to improve mechanical performance and hemostatic efficiency of chitosan (CS). In this system, the chemically cross-linked PAA network was used as a framework to improve water absorption behaviors and mechanical strength. The CS network was co-blended by hydrogen bonding and electrostatic interactions, both of which synergistically promoted hemostasis. These cryogels had high porosity (>94%), rapid water absorption rate (<3 s), high blood absorption capacity (>2000%), outstanding mechanical strength, and fatigue resistance. Moreover, the results of cytotoxicity and hemolysis demonstrated that the cryogels had good biocompatibility. Notably, the PAA/CS cryogels exhibited superior whole blood coagulation ability and red blood cell and platelet adhesion ability compared to those of commercial hemostatic dressing (gauze, gelatin sponges, and CS sponges). Based on these results, mouse femoral artery hemorrhage models and liver hemorrhage models were prepared to investigate the hemostatic ability of the prepared PAA/CS cryogels. Results suggested that the hemostatic ability of PAA 5 /CS cryogels was superior to that of commercial hemostatic materials. Therefore, the PAA/CS cryogels showed potential application in preventing massive hemorrhage from arteries and visceral organs.