Iron-based driven chitosan quaternary ammonium salt self-gelling powder: Sealing uncontrollable bleeding and...

Uncontrollable bleeding poses a significant risk of death and cost in wars, vehicle accidents, and first aid. Hence, in order to seal uncontrollable bleeding and promote wound healing, the Fe³⁺-driven chitosan quaternary ammonium salt self-gelling powder (QPF) was prepared using 5%QCS/AA/Fe³⁺ with the 52.72 % ± 0.30 % yield. As demonstrated by the results, the QPF had a high liquid absorption rate, mechanical properties, reactive oxygen species scavenging capacity, and bacteriostatic ability. Furthermore, QPF has excellent self-healing characteristics and underwater adherence, making it appropriate for a wide range of wound types. Importantly, this property is influenced by variations in Fe³⁺ concentration. In the in vitro coagulation experiment, QPF can rapidly capture blood cells, resulting in coagulation within 30s. After applying the QPF to different bleeding models, it immediately formed the self-gel (<2 s) that adheres securely to the hemorrhage site. Subsequently, the bleeding site could be promptly closed within 30s, and no blood leaking occurred within 10 min. Compared to CS, QPF (200 mg) improves wound healing by closing the wound gap, activating M2-type macrophage polarization, increasing neovascularization, and hastening granulation tissue proliferation (1046.0 μm ± 41.9 μm). In conclusion, iron-based driven self-gelling powders offer significant promise for limiting uncontrolled bleeding and promoting wound healing.