Enhancing fibroblast-based bone regeneration by harnessing nanosecond pulsed electric field

Despite their terminally differentiated state, human dermal fibroblasts (HDFs) can undergo osteogenic differentiation in vivo under certain pathological conditions, making them promising candidates for bone tissue engineering—though replicating this in vitro would be difficult. Building on prior findings that low-intensity (5 kV/cm) nanosecond pulsed electric fields (nsPEF) can partially reprogram HDFs toward pluripotency and boost their osteogenic capacity, an in vivo bone regeneration complex was fabricated by encapsulating nsPEF-treated cells in a self-healing hydrogel composed of oxidized hyaluronic acid and hydroxypropyl chitosan. In nude mice, these HDFs produced more robust ectopic bone both subcutaneously and within cranial defects, with significantly higher histological scores than untreated controls. RNA sequencing linked this enhanced osteogenesis to activation of the p38 MAPK/YAP pathway and accelerated endochondral ossification, findings that were validated by Western blot, qPCR, and immunofluorescence. The results in this study confirm that nsPEF stimulation markedly improves HDF osteogenic transformation in vitro and in vivo, highlighting its potential as a tool for advancing HDF-based bone regeneration strategies.