Ultrafast self-gelling, superabsorbent, and adhesive chitosan-based hemostatic powders for rapid hemostasis and wound healing.

Hemostatic powders are widely used for managing bleeding from wounds with various irregular shapes. However, their limited liquid absorption capacity and difficulty in removal after application remain significant clinical challenges. Herein, we introduce a multifunctional hemostatic powder composed of dually crosslinked poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride-co-acrylic acid) (pMATC-co-AA) and N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride (HTCC), which are integrated via electrostatic interactions and hydrogen bonding. This hemostatic powder exhibits superb liquid-absorbing capacity (94.5 times its own weight in water and 9.1 times in blood), sufficient adhesive properties (5.9 kPa on pig skin), and on-demand removability. It significantly reduces the number of viable Escherichia coli and Staphylococcus aureus by 4.61 and 4.04 orders of magnitude, respectively, thus providing an effective microbiological barrier for the wound. Furthermore, a series of in vivo and in vitro experiments confirm the powder's excellent hemostatic properties. The hydrogel formed on the wound after hemostasis can be removed by saline rinsing on demand, due to its superb liquid-absorbing capacity. Notably, the powder demonstrates good in vivo biocompatibility, with minimal risk of impeding wound healing, and it facilitates the healing process during the later stages. In sum, the hemostatic powder offers a promising solution for trauma bleeding control and acute wound treatment.