A hierarchical bilayer sponge dressing based on QCMCS@GO/PLA for synergistic wound healing via hemostasis and...

To address the challenges of inefficient hemostasis, high risk of bacterial infection, and biofilm formation in wound management, this study developed a bilayered sponge dressing composed of quaternized carboxymethyl chitosan@ graphene oxide/polylactic acid (QCMCS@GO/PLLA) with triple functionalities: coagulation, antibacterial activity, and anti-adhesion. A hierarchical structure was constructed using freeze-drying and electrospinning techniques: the bottom layer is a QCMCS@GO composite sponge, where graphene oxide (GO) enhances mechanical strength and enriches coagulation factors, while the quaternized carboxymethyl chitosan (QCMCS) promotes platelet activation and intrinsic coagulation pathway via its cationic properties; the top layer consists of electrospun polylactic acid (PLLA) nanofibers that serve as a superhydrophobic physical barrier to effectively inhibit bacterial adhesion. The material exhibits high porosity (>92%) and rapid liquid absorption (≥95% within 40 ms). In vitro experiments demonstrated that the dressing significantly accelerated whole blood coagulation (time reduced by 52.3%), optimized the blood clotting index (BCI = 4.7%), and enhanced thrombus formation through FXII contact activation. It achieved bacterial eradication rates of 99.94% against Staphylococcus aureus and 99.61% against Escherichia coli, while reducing bacterial adhesion on the surface by 91.8%. The dressing showed excellent biocompatibility (hemolysis rate 2.3%, cell proliferation rate 138%). In a rat liver injury model, it shortened hemostatic time by 63.2% and reduced blood loss by 76.5% compared to commercial gelatin sponges. This study provides a novel strategy for developing multifunctional wound dressings.