Effective electrical stimulation by a Poly(L-lactic acid)/Vitamin B₂-Based piezoelectric generator promotes wound healing

Chronic wounds pose an increasing burden not only to patients, but also to the health system. Wound repair requires the timely and orderly migration of fibroblasts to the wound bed. In this respect, electrical stimulation by a piezoelectric generator (PEG) is an attractive approach to wound management because it is noninvasive and effective in promoting chronic wound healing. However, commonly used PEGs based on polyvinylidenefluoride (PVDF) and poly(L-lactic acid) (PLLA) suffer from low biocompatibility and low piezoelectric output, respectively. Herein, we developed a bio-based PEG composed of PLLA blended with vitamin B₂ (VB₂), leading to an improvement of crystallinity and β-phase orientation, which exhibited better biocompatibility than PVDF and a higher piezoelectric output than pure PLLA. Such piezoelectricity could serve as effective electrical stimulation and promoted in vitro cell migration and fibroblast proliferation, evidenced by significant higher gene expression levels of extracellular matrix proteins and growth factors. Moreover, it facilitated in vivo wound closure by enhancing the re-epithelialization, collagen deposition, neovascularization, and increase the concentration of growth factors in the wound bed, leading to a 1.4-fold higher wound closure rate than that in the control group. Thus, the PLLA/VB₂ PEG opens an avenue for the application of bio-based PEGs for wound healing.