Mesoporous bioactive glass-coated 3D printed borosilicate bioactive glass scaffolds for improving repair of bone defects

Background: In the field of tissue engineering, there is currently increasing interest in new biomedical materials with high osteogenic ability and comparable mechanical function to repair bone defects. Three-dimensional (3-D) bioactive borosilicate glass (BG) scaffolds exhibit uniform interconnected macro-pores, high porosity and high compressive strength. In this study, we fabricated 3-D BG scaffolds by the 3D printing technique, then coated the surface of the 3-D BG scaffolds with mesoporous bioactive glass (MBG) (BG-MBG scaffold). Methods: The biocompatibility of the BG-MBG scaffolds was evaluated by assessing biodegradability, cell proliferation, alkaline phosphatase (ALP) activity and by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis of osteogenic gene expression with human bone marrow stromal cells (hBMSCs). Moreover, the BG-MBG scaffolds were used to repair rat femoral defects and their performance was evaluated using microcomputed tomography (micro-CT), fluorescence labeling, histological analysis and immunohistochemical (IHC) analysis.