Secretome from prolonged high‐density human Wharton's jelly stem cell culture accelerates wound healing in both in vitro and in vivo models

The complex of biofactors secreted by mesenchymal stem cells, termed the secretome, can promote wound healing. Studies using this secretome often utilise material collected from short term and sub-confluent lab-scale cultures. Secretome was derived from prolonged culture of high-density industrial scale human Wharton's jelly stem cells and its effects on wound healing was assessed. In vitro cell proliferation and scratch closure assays showed that secretome treatment dose-dependently increased cell proliferation and promoted scratch closure. Subsequently, using biopsy punch, circular wounds were created on three-dimensional de-epidermised dermis human skin equivalent (in vitro) where secretome-treated wounds showed accelerated wound closure, and enhanced epithelial proliferation and differentiation were observed and quantified. In an in vivo rat acute wound model, secretome applied to the back of test animals greatly enhanced wound healing by promoting re-epithelialisation, vascularisation and granulation maturation. In conclusion, secretome derived from prolonged culture of high-density industrial scale two-dimensional human Wharton's jelly stem cells possesses potent wound healing properties. This could greatly lower the cost of production and facilitate development of highly efficacious secretome-based wound healing products.