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

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).

It is believed from these results that the BG-MBG scaffolds possess excellent osteoinductive and osteogenic properties which will make them appealing candidates for bone defect repair. The novelty of our research is to provide a new material to treat bone defects in clinic.

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.

The results showed that the BG-MBG scaffolds possessed ordered nearly 4nm meso-pores and regular macro-pores, as well as good biodegradability, and that they stimulated the proliferation and osteogenic differentiation of hBMSCs. In in vivo studies, the result of micro-CT reconstructed images (BG-9M group, 0.63 ± 0.02 g/cm3 and BG group 0.13 ± 0.02 g/cm3 ) and van Gieson staining (BG-9M groups, 62.67 ± 3.39% and BG group, 12.33 ± 2.58%) showed that the BG-MBG scaffolds could significantly enhance new bone formation in both inner and peripheral scaffolds in defects, in and in without the presence of growth factors or stem cells (P < 0.05). Conclusions: It is believed from these results that the BG-MBG scaffolds possess excellent osteoinductive and osteogenic properties which will make them appealing candidates for bone defect repair. The novelty of our research is to provide a new material to treat bone defects in clinic.