Polydopamine-modified collagen sponge scaffold as a novel dermal regeneration template with sustained release of platelet-rich plasma to accelerate skin repair: A one-step strategy.

Although employed to release growth factors (GFs) for regenerative medicine, platelet-rich plasma (PRP) has been hindered by issues like burst effect. Based on collagen sponge scaffolds (CSSs) modified with polydopamine (pDA), a novel dermal regeneration template (DRT) was designed. However, whether it could efficiently deliver PRP and even foster wound healing remained unclear. In this work, after PRP was prepared and pDA-modified CSSs (pDA-CSSs) were fabricated, microscopic observation, GFs release assay and in-vitro biological evaluations of pDA-CSSs with PRP (pDA-CSS@PRP) were performed, followed by BALA-C/nu mice full-thickness skin defects implanted with pDA-CSS@PRP covered by grafted skins (termed as a One-step strategy). As a result, scanning electron microscope demonstrated more immobilized platelets on pDA-CSS' surface with GFs' controlled release via enzyme-linked immunosorbent assay, compared with CSSs. In line with enhanced in-vitro proliferation, adhesion and migration of keratinocytes & endothelial cells, pDA-CSS@PRP were histologically revealed to accelerate wound healing with less scar via rapid angiogenesis, arrangement of more mature collagen, guiding cells to spread, etc. In conclusion, pDA-CSSs have potential to serve as a novel DRT capable of delivering PRP, which may foster full-thickness skin defect healing by means of a One-step strategy.