Photosynthetic and Self-Draining Biohybrid Dressing for Accelerating Healing of Diabetic Wound

Wound healing is a well-orchestrated progress associated with angiogenesis, epithelialization, inflammatory status, and infection control, whereas these processes are seriously disturbed in diabetic wounds. In this study, a biohybrid dressing integrating the inherent ability of Bromeliad leaf (photosynthesis and self-draining) with the therapeutic effect of artificial materials (glucose-degrading and ROS-scavenging) is presented. The dressing consists of double-layered structures as follows: 1) Outer layer, a Bromeliad leaf substrate full of alginate hydrogel-immobilized glucose oxidase (GOx@Alg@Bromeliad substrate, abbreviated as BGA), can generate oxygen to guarantee the GOx-catalyzed glucose oxidation by photosynthesis, reducing local hyperglycemia to stabilize hypoxia inducible factor-1 alpha (HIF-1α) for angiogenesis and producing hydrogen peroxide for killing bacteria on the surface of wound tissue. The sophisticated structure of the leaf drains excessive exudate away via transpiration-mimicking, preventing skin maceration and impeding bacterial growth. 2) Inner layer, microneedles containing catalase (CAT-HA MNs, abbreviated as CHM), reduces excessive oxidative stress in the tissue to promote the proliferation of fibroblasts and inhibits proinflammatory polarization of macrophages, improving re-epithelialization of diabetic wounds. Together, the biohybrid dressing (BGA-CHM, abbreviated as BCHM) can enhance angiogenesis, strengthen re-epithelialization, alleviate chronic inflammation, and suppress bacterial infection, providing a promising strategy for diabetic wound therapy.