BiodegradablePolymeric Microspheres with EnhancedHemostatic and Antibacterial Properties for Wound Healing

Hemostasis is the initial step in wound healing, yet significant challenges, such as massive bleeding and infection, often arise. In this study, we developed amphiphilic biodegradable polyester-based segmented polyurethane (SPU) microspheres modified with epigallocatechin gallate (EGCG)-Ag nanoparticles and calcium-alginate cross-linking shell, combining blood absorption with the pro-coagulation properties of Ca²⁺ and the negative charge of EGCG for synergistic hemostatic effects across various stages of the coagulation cascade. The in vitro blood clotting time of the SPU@EAg@CaAlg microsphere (328.7 s) was reduced by half compared to the SPU microsphere (685.0 s). SPU@EAg@CaAlg exhibited a reduced hemostatic time and blood loss in three rat hemostatic models. Additionally, EGCG-Ag nanoparticles imparted strong antibacterial and anti-inflammatory properties both in vitro and in vivo. In vivo infected wound model demonstrated that SPU@EAg@CaAlg effectively eliminated bacteria and reduced the levels of pro-inflammatory factors, thereby promoting wound healing. Thus, the modified SPU microspheres present a promising candidate for effective hemostatic applications.