Abstract
BACKGROUND: Bone regeneration often relies on biomaterials to promote osteogenesis and modulate inflammation. Growth-factor-rich matrices and xenogeneic bone scaffolds have been reported to influence bone formation, vascularisation, and immune responses in vivo. This study therefore compared four biomaterials for their bone-regenerative potential in a rabbit non-critical tibial defect model: (1)Deproteinized porcine bone mineral (DPBM) (2)APRF (Advanced Platelet-Rich Fibrin) (3)Sticky Bone (STB, formed by combining DPBM and APRF) (4)Bovine collagen scaffolds (CS). METHODS: Thirty 15-week-old male New Zealand White rabbits were assigned to five groups: empty control (EC), DPBM, APRF, STB, and CS. Bilateral tibial defects (2.2 mm in diameter, 6 mm in depth) were filled with the respective materials and covered with porcine collagen membranes. Assessments at 2 and 6 weeks included micro-CT, histology, and immunohistochemistry (Runx2, ALP, CD31, TNF-α) to evaluate bone formation, vascularization, and inflammation. RESULTS: STB exhibited consistently greater new bone fill and a stronger trabecular framework, alongside elevated Runx2 and ALP levels, indicating enhanced osteogenic capacity. Concurrently, higher CD31 expression and lower TNF-α suggested improved vascularization and attenuated inflammation. By contrast, collagen alone showed limited osteoinduction, whereas APRF alone provided mild early bone promotion. Taken together, these findings highlight STB's enhanced bone-regenerative capacity. However, no statistically significant differences in new bone formation were observed between STB and DPBM at all time points. Notably, at the 2-week mark, STB demonstrated a more pronounced anti-inflammatory effect than DPBM, reflected by significantly lower TNF-α levels. CONCLUSIONS: STB demonstrated a pronounced capability for promoting bone formation and reducing inflammation, suggesting its potential as an effective biomaterial for clinical bone regeneration. Nonetheless, differences between STB and DPBM were not statistically significant at all time points, warranting further investigation into their comparative efficacy.