Laser micropatterned dermal templates support early rete ridge formation and basement membrane deposition when used with cultured epithelial autografts

The success of cultured epithelial autografts (CEAs) in treating large surface area burns is limited by their fragility and poor adhesion to the wound bed. Rete ridges, interdigitations at the dermal-epidermal junction, are stem cell niches critical to dermal-epidermal adhesion and distribution of mechanical forces within the skin, but are slow to develop in CEA-treated burn wounds. A porcine burn-excise-autograft model was used to investigate the efficacy of an allogeneic dermal template (DT), seeded with fibroblasts and laser micropatterned to have dermal papillae-like topography, in improving outcomes with CEA. Autologous CEAs were applied to full-thickness wounds alone or with DTs that were flat (CEA+Flat) or micropatterned (CEA+Ridged). The use of a DT improved graft handleability and integration at the wound margins, and restored epidermal barrier function two weeks faster than CEAs alone. In CEA+Ridged grafts, increases in keratinocyte proliferation and basement membrane deposition were observed at 2 weeks post-grafting. Rete ridges were only present in CEA+Ridged grafts at week 2, and developed less frequently and shallower in CEA and CEA+Flat grafts over the course of the study. These results suggest that laser micropatterned DTs are suitable for co-transplantation with CEAs and can significantly improve graft adhesion and development.