Carbon Dots Induce Epithelial-Mesenchymal Transition for Promoting Cutaneous Wound Healing via Activation of TGF-β/p38/Snail Pathway

Skin lesions, as a relatively common clinical manifestation, not only damage the skin's barrier function, but also affect the skin's ability to feel temperature, pain and touch. However, a highly efficient method to restore the morphology and function of damaged skin remains an unmet goal. In this work, carbon dots (CDots) with excellent biocompatibility are synthesized via microwave-assisted heating ascorbic acid and polyethyleneimine. The synthesized CDots can induce the epithelial-mesenchymal transition (EMT) process by activating transforming growth factor-beta/p-38 mitogen-activated kinase/Snail signaling pathway, leading to an increase of cell motility. Further, by assessing a series of in vivo wound healing assays and histological examinations, it is demonstrated that CDots can accelerate the migration of epithelial cells in the full-thickness cutaneous wounds through EMT. As a result, a rapid re-epithelialization covers the granulation tissue and epidermal barrier formed, leading to a block of the external stimuli, reduction of the inflammatory reaction and the granulation tissue area, and finally the promotion of the wound healing with fewer scars.