Keratinocytes-hair follicle bulge stem cells-fibroblasts co-cultures on a tri-layer skin equivalent derived from gelatin/PEG methacrylate nanofibers.

Generation of full thickness skin equivalent models is of increasing interest in tissue engineering because of the limitations inherent to current models. In recent years, considerable interest has been given to electrospun hybrid nanofibers prepared using natural and synthetic combinations of polymers. By blending two polymers, gelatin and PEG methacrylate we created a novel functional hydrogel-named GelMet. By adjusting the concentration of GelMet between 14 and 20wt%, three types of electrospun membranes were fabricated. Keratinocytes, hair follicle bulge stem cells (HFBSCs) and fibroblasts were successfully isolated and cultured in 14 wt%, 17 wt% and 20 wt% GelMet scaffolds respectively and generated a tri-layered electrospun construct. Characterization of GelMet electrospun membranes were compared with those of the pure gelatin nanofibers. Due to plasticity, by incorporating HFBSCs, it is expected to increase the cell content of skin substitute without the need to incorporate several different cell populations. The fiber diameter and pore size of the scaffold for each layer were fabricated in such a way to mimic the structural gradation of collagen matrix across the native skin. Good mechanical properties and dimensional stability of GelMet scaffold, combined with the ability to support cell growth in vitro , suggest its tremendous potential application in skin tissue engineering.