Superior biological performance and osteoinductive activity of Si-containing bioactive bone regeneration particles for alveolar bone reconstruction

Bone grafting materials for repair of alveolar bone deficits have improved markedly in recent years, increasing the applicability and success of oral implantology. The long-term success rate of dental implant surgery is strongly dependent on the quality and stability of residual bone tissue. Therefore, reconstruction of resorbed alveolar bone is a challenge for clinicians. In the present study, we have developed bioactive bone regeneration particles (BRPs) using amorphous calcium phosphate and 58S bioglass as raw materials. The structural characteristics, biocompatibility, and osteoinductivity of these BRPs were compared to commercially available bovine spongy bone (BSB) without organic components. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) showed that BRPs were composed of beta-tricalcium phosphate (beta-TCP) and calcium silicate in the form of hexagonal crystals, while BSB was mainly hydroxyapatite (HA) arranged in orderly nano-sized crystals. The viability of human bone marrow mesenchymal stem cells (hBMSCs) cultured in BRP-containing medium was roughly equal to that of hBMSCs in control medium. Moreover, hBMSCs in BRP medium exhibited greater proliferation rates, substrate attachment, alkaline phosphatase (ALP) activity, alizarin red staining intensity, and expression levels of osteogenic-related genes (COL-I, OCN, Runx-2, ALP, BSP) than hBMSCs in BSB medium, indicating the superior osteoinductivity of BRPs. Silicon ions released from BRPs during cell culture were crucial for these enhanced biological properties. BRPs also demonstrated superior osteoconduction and osteoinduction properties for bone defect repair, suggesting promise for alveolar bone repair surgery.