Regenerative potential of platelet-rich plasma as an adjuvant to scaffolds in the repair of critical bone tissue defects

Background: A critical-size bone defect is defined as damage that exceeds the body’s intrinsic regenerative capacity for repair. The restoration of critical-size bone defects remains a major challenge in regenerative medicine and tissue engineering. Recent research emphasizes the importance of combining structural scaffolds with cellular and biologically active components to enhance bone regeneration. Objective: to develop and evaluate the structural and functional effects on bone repair and neoangiogenesis of a collagen-based scaffold implanted into a critical-size bone defect with platelet-rich plasma (PRP) in combination with stromal vascular fraction (SVF) cells. Methods: Forty Wistar rats were divided into groups: Group I (n = 10) received a collagen sponge (CS); Group II (n = 15) received a CS + SVF; Group III (n = 15) received a CS/SVF scaffold + PRP. Foreign material was received locally at the site of a critical-size bone defect. Micro-CT, haematological (clinical blood analyses), and histological (haematoxylin and eosin staining) analyses were performed. All animals were euthanized three months after implantation. Results: Micro-CT and histological evaluation revealed enhanced scaffold osteointegration, increased bone formation, and vascularisation in the CS+SVF+PRP group compared to controls. PRP significantly improved bone volume, surface area, and material density in the defect zone. Histological scoring confirmed more pronounced osteogenesis and neovascularisation in experimental groups. Haematological data indicated increased hemoglobin without signs of systemic inflammation. Local inflammatory response was minimal in the PRP group. Conclusion: The combination of collagen matrix, SVF, and PRP exhibits high biocompatibility and pronounced regenerative potential, providing a synergistic effect that promotes osteogenesis and angiogenesis. This approach shows promise for future applications in bone tissue engineering and warrants further molecular-level investigation.