Cellular Response to 3-D Printed Bioactive Silicate and Borosilicate Glass Scaffolds.

The repair and regeneration of loaded segmental bone defects is a challenge for both materials and biomedical science communities. Our recent work demonstrated the capability of bioactive glass in supporting bone healing and defect bridging using a rabbit femur segmental defect model without growth factors or bone marrow stromal cells (BMSCs). Here in the current work, a comprehensive in vitro evaluation of bioactive silicate (13-93) and borosilicate (2B6Sr) glass scaffolds was conducted to provide further understanding of their biological performances and to establish a correlation between in vitro and in vivo behaviors. Our in vitro evaluation using a murine MC3T3-E1 cell line confirmed the capability of both scaffolds to support cell attachment, vascular endothelial growth factor (VEGF) formation, and to stimulate mineral deposition and osteoblast marker gene expression. In particular, borosilicate (2B6Sr) glass showed a better capability in supporting the mineralization and gene expression than silicate (13-93) glass, consistent with a faster bone healing ability in vivo. The current in vitro results, combined with our previous in vivo findings, provide a strong basis for the further translational evaluation of bioactive glass scaffolds and for potential preclinical practice.