Regenerative effects of PRP-impregnated collagen-gelatin sponge in a full-thickness skin defect model

Artificial dermis is an essential biomaterial for reconstructing full-thickness skin defects. Pelnac G Plus® is a collagen-gelatin sponge (CGS) that can be impregnated with basic fibroblast growth factor (bFGF), offering sustained release and proven clinical efficacy. However, the off-label use of bFGF by impregnation remains restricted under current pharmaceutical regulations in Japan. In this study, we evaluated the wound healing potential of autologous platelet-rich plasma (PRP) as an alternative bioactive substance when impregnated into CGS.

Full-thickness skin defect models were created in nude rats and treated with artificial dermis alone (CGS group), artificial dermis + PRP (CGS + PRP group), or artificial dermis + bFGF (CGS + FGF group). Wounds were evaluated on postoperative day 14.

On postoperative day 14, the CGS + PRP group exhibited significantly greater collagen thickness and vascular density than the CGS group. Furthermore, the CGS + PRP group showed a smaller wound area than the CGS + FGF group (20.9 ± 14.3 mm² vs. 51.5 ± 18.0 mm², p < 0.001). The CGS + PRP group also demonstrated higher α-SMA expression compared to the CGS + FGF group (36.6 % ± 4.3 % vs. 23.9 % ± 8.1 %, p < 0.001), and immunohistochemical analysis revealed higher expression of VEGF and α-SMA, suggesting enhanced angiogenesis and fibroblast activity. PRP preserved the expression of TGF-β1 and α-SMA, supporting balanced tissue regeneration.

Our findings demonstrate that bFGF and PRP exert distinct effects on wound healing in a secondary-intention model. bFGF effectively promoted dermis-like granulation tissue regeneration without accelerating contraction, supporting its use in anatomical sites where scar contracture must be avoided. In contrast, PRP enhanced wound contraction and ulcer area reduction, suggesting clinical utility in non-healing ulcers where delayed secondary healing is a major concern.