Flow Cytometry Analysis of Cytotoxicity In Vitro and Long‐Term Toxicity of HA‐40 wt% BaTiO3 Nanoparticles In Vivo

The development of new implantable biomaterials requires bone‐mimicking physical properties together with desired biocompatible property. In continuation to our earlier published research to establish compositional dependent multifunctional bone‐like properties and cytocompatibility response of hydroxyapatite (HA)‐BaTiO₃ composites, the toxicological property evaluation, both in vitro and in vivo, were conducted on HA‐40 wt% BaTiO₃ and reported in this work. In particular, this work reports in vitro cytotoxicity of mouse myoblast cells as well as in vivo long‐term tissue and nanoparticles interaction of intra‐articularly injected HA‐40 wt% BaTiO₃ and BaTiO₃ up to the concentration of 25 mg/mL in physiological saline over 12 weeks in mouse model. The careful analysis of flow cytometry results could not reveal any statistically significant difference in terms of early/late apoptotic cells or necrotic cells over 8 d in culture. Extensive histological analysis could not record any signature of cellular level toxicity or pronounced inflammatory response in vital organs as well as at knee joints of Balb/c mice after 12 weeks. Taken together, this study establishes nontoxic nature of HA‐40 wt% BaTiO₃ and therefore, HA‐40 wt% BaTiO₃ can be used safely for various biomedical applications.