CDK1-loaded extracellular vesicles promote cell cycle to reverse impaired wound healing in diabetic obese mice.

Small extracellular vesicles (sEVs) mediate intercellular signaling to coordinate the proliferation of cell types that promote re-epithelialization of skin following injury. Cyclin-dependent kinase 1 (CDK1) drives cell division and is a key regulator of entry to the cell cycle. To understand the potential of sEV-mediated delivery of CDK1 to reverse impaired wound healing, we generated CDK1-loaded sEVs (CDK1-sEVs) and evaluated their ability to mediate cell proliferation, re-epithelialization, and downstream signaling responses in the wound bed. We found that treatment of human keratinocytes with CDK1-sEVs increased phosphorylation of the CDK1 target, eukaryotic translation inhibition factor 4E-binding protein 1 (4E-BP1), and histone H3 within 24 h via AKT and ERK phosphorylation, driving increased proliferation and cell migration. Treatment of the wound bed of diabetic obese mice, a model of delayed wound healing, with a single dose of CDK1-sEVs accelerated wound closure, increased re-epithelialization, and promoted the proliferation of keratinocytes. These studies show that delivery of CDK1 by sEVs can stimulate selective and transient proliferation of cell types that increase re-epithelialization and promote proliferation of keratinocytes to accelerate wound healing.