Cognizing the crystallization aspects of NaCaPO4 concomitant 53S bioactive-structures and their imprints in in vitro bio-mineralization

Abstract

Compositional and bio-physico-chemical characteristics of bioactive glasses are of great importance for their applications in medicine. For the first time, herein we report the single crystalline phase NaCaPO₄ in 53S bioglass which is mainly achieved by sol–gel chemistry and processing parameters. The bioactive material sintered at 700 °C revealed a NaCaPO₄ crystalline phase with nominal deviation. Dominance of bridging oxygen is observed in 53S-700 through high resolution XPS spectroscopy which supports the XRD results in terms of exact crystal structure formation (NaCaPO₄). The dominant Q⁴ Si–O–Si stretching in the 700 °C heat treated bioglass exhibits bonding with bridged oxygen confirmed through functional group analysis. A triangular platelet-like structure and spherical morphology are visible in the synthesized bioactive materials. A comparatively elevated mechanical stability is achieved in the 700 °C sintered bioglass with respect to compactness in the crystal structure. The spiky rod-like apatite precipitation and dominant Ca₅(PO₄)₃(OH) phase symbolize the prominent mineralization behavior of the bioglass heat treated at 750 °C due to the rapid ionic release from the material. On the whole, development of pristine NaCaPO₄ in the 53S bioglass matrix encourages researchers to analyze the bio-chemical features of this material focusing on bone regeneration.