Janus Self‐Propelled Chitosan‐Based Hydrogel Spheres for Rapid Bleeding Control

Uncontrolled hemorrhage is a major cause of potentially preventable death in civilian trauma nowadays. Considerable concern has been given to the development of efficient hemostats with high blood absorption, self‐propelled property, and Ca(2+) release ability, for irregularly shaped and noncompressible hemorrhage. Herein, Janus self‐propelled chitosan‐based hydrogel with CaCO(3) (J‐CMH@CaCO(3)) is developed by partial ionic crosslinking of carboxylated chitosan (CCS) and Ca(2+), gravity settlement, and photopolymerization, followed by removing the shell of CCS. The obtained J‐CMH@CaCO(3) is further used as a hemostat powered by the internal CaCO(3) and coordinated protonated tranexamic acid (J‐CMH@CaCO(3)/T). Bubbles are generated and detached to provide the driving force, accompanied by the release of Ca(2+). The two aspects work in synergy to accelerate clot formation, endowing the J‐CMH@CaCO(3)/T with excellent hemostatic efficiency. The J‐CMH@CaCO(3)/T presents high blood absorption, favorable blood‐clotting ability, desired erythrocyte and platelet aggregation, and acceptable hemocompatibility and cytocompatibility. In rodent and rabbit bleeding models, the J‐CMH@CaCO(3)/T exhibits the most effective hemostasis to the best knowledge of the authors, wherein the hemorrhage is rapidly halted within 39 s. It is believed that the J‐CMH@CaCO(3)/T with self‐propelled property opens up a new avenue to design high‐performance hemostats for clinical application.