Bioactive Borosilicate Glasses for Bone Tissue Engineering Applications

In the field of regenerative medicine and tissue engineering, there is a pressing need to develop synthetic alternatives to tissue grafts for reconstruction of bone defects. Bioactive glasses are a promising group of materials due to their ability to form active bonds with bone tissue and stimulate osteogenesis. While a limited number of bioactive glass products have been successfully utilized in clinicals, there is considerable potential to enhance bioactive glasses properties by controlling their
compositions.

During this dissertation, a borosilicate glass series with additional incorporations of magnesium and strontium was developed and characterized. The potential for thermal processing and crystallization mechanism of the glasses were studied. 3D structures were then prepared using both the porogen burn-off method and additive manufacturing. Further, glasses in vitro reactivity was studied in simulated body fluid, and cytotoxicity was evaluated with human mesenchymal stem cells.

These studies revealed that replacing a portion of the glass's calcium content with magnesium and/or strontium enhanced the hot forming capabilities without undesirable crystallization. The produced 3D-printed scaffolds possessed suitable porosity (pore size and interconnectivity) for tissue infiltration. In addition, the incorporation of Mg and Sr in the composition slowed the reactivity of the glasses, allowing for the customization of the degradation rate. Moreover, the studied glasses degradation products were found beneficial for both osteogenesis and angiogenesis.

In conclusion, the studied bioactive glasses demonstrate significant promise for applications in bone tissue engineering.