Nanofiber‐based Multifunctional Microspheres for Rapid Hemostasis and Microorganism Removal of Water

Abstract Constructing hemostats capable of effectively controlling severe hemorrhage from irregular wounds presents significant challenges and imperatives. In this study, a novel approach is introduced using nanofibrous chitin microspheres (NCM) that are compressed to 60% strain (NCM‐60%) to amplify their water‐initiated expansion performance. This unique capacity allows NCM‐60% to efficiently conform to and fill irregular bleeding cavities, even those of varying depths and curvatures, thereby promoting rapid blood coagulation at deep hemorrhage sites. NCM‐60% exhibits effective control of severe femoral artery and “J”‐shaped liver hemorrhages in 151 ± 6 s and 68 ± 15 s, respectively, revealing its exceptional hemostatic efficacy. Furthermore, NCM‐60% exhibited promising capabilities in removing microbes from water, achieving removal rates of over 96% of bacteria. Blood compatibility assessments and cytotoxicity tests further confirmed the favorable biocompatibility of NCM‐60%. Importantly, NCM‐60% is found to biodegrade and be absorbed in vivo within 12 weeks. This study represents the first instance of leveraging chitin nanofiber‐based biomaterials to design water‐initiated expansion micro‐hemostat, and integrate hemostatic functions with waterborne microorganism removal, thereby expanding the potential applications of micro‐nanostructural materials in emergency first‐aid scenarios.