Mesoporous Bioactive Glass Scaffold Delivers Salvianolic Acid B to Promote Bone Regeneration in a Rat Cranial Defect Model

Abstract

Background: Mesoporous Bioactive Glass (MBG) has been widely studied because of its excellent histocompatibility and degradability. However, due to the lack of good osteoinductive activity, the pure MBG scaffold is not effective in repairing large-scale bone defects.

Objective: To observe the repair effect of MBG scaffolds delivering Salvianolic acid B (SB) on critical bone defects in rats.

Methods: In this study, MBG scaffolds were used as delivery vehicle. SB, a small molecular active drug with good osteogenic differentiation ability, was loaded into the MBG scaffolds at low, medium and high doses. The effect of SB released from the MBG scaffolds on osteogenic differentiation of rat Bone Marrow Mesenchymal Stem Cells (rBMSCs) was investigated using alkaline phosphatase staining, alizarin red staining and real-time quantitative polymerase chain reaction. Moreover, 8 weeks after implantation of the scaffolds, the bone regeneration was evaluated by micro- CT, sequential fluorescence labeling and histological staining analysis.

Results: The in vitro results showed that different doses of SB had similar release rate from scaffolds and could be released from scaffolds continuously. The middle dose (MBG/MSB) and high dose (MBG/HSB) groups significantly promoted the osteogenic differentiation of rBMSCs when compared with a low dose (MBG/LSB) group. Moreover, SB produced significant increases in newly formed bone of calvarial bone defects in rats.

Conclusion: It is concluded that the use of MBG scffolds delivering SB is an effective strategy for the treatment of bone defects.

Keywords: Mesoporous bioactive glass; Salvianolic acid B; bone graft; bone regeneration; orthopedic; osteogenic differentiation.