Abstract
Promising work on bioactive glasses (BAGs) in bone defect regeneration has led to their clinical implementation. However, the effects of the ionic dissolution products of different types and the physical interaction modalities of BAGs on the behavior and function of mesenchymal stromal cells (MSCs) of human patients have not received sufficient attention. Recently, we showed that the in vitro response of hMSC to micron-sized, monodispersed BAGs is dependent on dosage, composition, and mode of interaction1. Two commercially available and widely used types of BAGs, namely the silicate BAGs 45S5 and 1393, were used to study hMSC cell behavior. Interestingly, exposure to 1393 BAG resulted in superior metabolic activity, proliferation, and cell spreading compared to 45S5 BAG in similar dosage, suggesting that additional cellular functions could also be differentially modulated by both glasses1. In the context of bone regeneration, the hMSCs’ potential to secrete angiogenic factors as well as deposit mineralized matrix upon exposure to BAG dissolution products was investigated in the present study. Aside from dose-dependent effects of both glasses, 45S5 BAG induced a significant pro-angiogenic response, demonstrated by robust tube formation in HUVECs in the presence of MSC conditioned media. 1393 BAG, on the other hand, stimulated osteogenesis by upregulating osteogenic gene expression and mineralized matrix deposition. Based on these results, combining the pro-angiogenic 45S5 BAG and the pro-osteogenic 1393 BAG might be an attractive strategy to target the multiple processes underlying bone regeneration. These results highlight how different BAGs can be utilized to promote MSC-mediated bone regeneration.
