Synthesis and Structural Characterization of Strontium-Substituted 45S5 Bioactive Glasses for Potential Bone Regeneration Applications

​Bone tissue possesses an intrinsic capacity for regeneration, yet severe trauma or degenerative diseases often require osteoinductive biomaterials for functional recovery. This work explores bioactive glasses based on the classical 45S5 composition, synthesized via the melt-quenching route, where calcium oxide (CaO) was progressively substituted with strontium oxide (SrO) at 0, 25, 50, 75, and 100 mol% to leverage Sr²⁺ in enhancing bone metabolism. Differential Scanning Calorimetry (DSC) revealed a systematic decrease in glass transition temperature (T_g) from 518 °C to 468 °C with increasing SrO, indicating structural network modifications. X-ray Diffraction (XRD) confirmed the amorphous nature of all compositions, showing a characteristic halo that progressively shifted toward lower 2θ angles, reflecting network expansion. Ongoing in vitro studies aim to elucidate how strontium substitution influences dissolution kinetics and surface reactivity. Preliminary expectations include hydroxyapatite (HAp) layer formation, confirming these materials' potential for bone tissue regeneration.