Efficacy of the Controlled Release of Concentrated Platelet Lysate from a Collagen/Gelatin Scaffold for Dermis-Like Tissue Regeneration

Introduction: A collagen/gelatin scaffold (CGS) can provide a sustained release of basic fibroblast growth factor (bFGF), which promotes wound healing. However, bFGF is approved for clinical use in Japan and China only. One potential alternative to bFGF is platelet lysate (PL), a safe and easily attainable source of a wide range of growth factors necessary for tissue repair. In the present study, we investigated the use of PL with CGS to repair wounds and identified the optimal concentration of PL for wound healing. Materials and Methods: We generated PL from concentrated platelets harvested from individual healthy donors. We measured growth factors in PL. Transforming growth factor (TGF)-beta 1, platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF), and bFGF were selected because they were the major growth factors contained in platelets and showed the greatest ability to enhance the maturation of newly formed blood vessels. Pieces of CGS impregnated with PL solution (x1, x2, x3, or x4 concentrated) or normal saline solution (NSS) were implanted into full-thickness skin defects on the backs of mice. We evaluated the wound area, neoepithelium length, and total area of newly formed capillaries in the implanted CGS. Results: Our release experiments revealed that PDGF-BB and TGF-beta 1 were released from CGS incubated with collagenase in a sustained manner. CGS impregnated with concentrated PL was more effective than CGS impregnated with NSS in all evaluated items. The x2 concentrated PL accelerated wound healing and enhanced cell proliferation and vessel growth in granulation tissue. Conclusion: Our findings indicate that CGS can bind to TGF-beta 1 and PDGF-BB and release these growth factors in a sustained manner. x2 concentrated PL-impregnated CGS accelerates the formation of dermis-like tissue.