Collagen-rich porcine acellular dermal matrix-eggshell membrane sponge promotes programmed healing of diabetic wounds through the sustained release of Cu/Zn.

Eggshell membrane (ES) is a low-cost, high-value extracellular matrix biomaterial. However, natural ES has disadvantages, such as poor water solubility and difficulty in controlling its shape and size, which limit its application as a biomaterial. In this study, we prepared an eggshell membrane drug-loaded sponge (PES@Cu-Zn) with haemostatic, anti-inflammatory, and healing properties for managing diabetic wounds. CuO/ZnO was introduced into the three-dimensional structure of PES by electrostatic adsorption to form PES@Cu-Zn sponges with good exudate absorption capacity and shape memory. The slow and coordinated release of Cu/Zn (32 % released in 7 days) promotes the proliferation and migration of wound repair cells and angiogenesis. In a rat haemostasis model, the haemostatic effect of the PES@Cu-Zn sponge was 1.5 times greater than that of the control. When the PES@Cu-Zn sponge was applied to diabetic wounds in rats, the results showed that the sponge accelerated wound healing by reducing wound inflammation and promoting collagen deposition, angiogenesis, and re-epithelialisation. In conclusion, this eggshell membrane sponge dressing is a promising strategy for promoting programmed healing of diabetic wounds using green and renewable eggshell membranes.