Collagen-embedded hydroxylapatite-beta-tricalcium phosphate-silicon dioxide bone substitute granules assist rapid vascularization and promote cell growth

In the present study we assessed the biocompatibility in vitro and in vivo of a low-temperature sol-gel-manufactured SiO2-based bone graft substitute. Human primary osteoblasts and the osteoblastic cell line, MG63, cultured on the SiO2 biomatrix in monoculture retained their osteoblastic morphology and cellular functionality in vitro. The effect of the biomaterial in vivo and its vascularization potential was tested subcutaneously in Wistar rats and demonstrated both rapid vascularization and good integration within the peri-implant tissue. Scaffold degradation was progressive during the first month after implantation, with tartrate-resistant acid phosphatase-positive macrophages being present and promoting scaffold degradation from an early stage. This manuscript describes successful osteoblastic growth promotion in vitro and a promising biomaterial integration and vasculogenesis in vivo for a possible therapeutic application of this biomatrix in future clinical studies.