Synthesis and characterization of innovative silica-based bioactive glasses doped with tellurium

In the last decades the research on innovative materials and technologies for applications in medicine improved considerably the quality of life and reduced the social costs of several diseases. Among materials for biomedical applications, bioactive glasses have been widely studied, since the 1970s, as third generation bone substitutes and biomaterials for tissue regeneration. The term “bioactive” is related to the ability of these glasses to stimulate bone regeneration trough a peculiar reactivity that induces the formation of a hydroxyapatite layer on their surface. A further peculiar property of bioactive glasses is the possibility of being doped with ions of therapeutic interest. Among them, tellurium is still under investigation and very few works report its introduction into bioactive glasses. The purpose of this work is to investigate the effect of the introduction of tellurium oxide in the composition of a silica-based bioactive glass in two different ratios. The tellurium-doped glasses have been synthesized by traditional melt and quenching route. The obtained glasses have been subsequently characterized in terms of their characteristic temperatures by Differential Thermal analysis (DSC), phase analysis by X-ray diffraction (XRD) and structural analysis by means of spectroscopic techniques (Raman and Fourier-transform infrared spectroscopy - FTIR). In addition, the obtained bioactive glasses were immersed in solutions similar to biological body fluid in order to investigate their bioactivity, evaluating pH evolution over time in solution, ion release and hydroxyapatite formation. In addition, cell viability assay and reactive oxygen species evaluation tests are in progress in order to investigate the role of tellurium as a biologically relevant ion. The findings suggested that the addition of tellurium oxide into a bioactive glass does not affect negatively the bioactivity and potentially may play a helpful role in the realization of a new class of bioactive materials with antimicrobial and antioxidant activities.