In vitro cytotoxicity evaluation of green-synthesized nano-hydroxyapatite from eggshell waste using banana extract (Musa acuminata Cavendish)

Hydroxyapatite (HA) is a promising bioceramic material for biomedical applications due to its biocompatibility and bioactivity. In this study, nano-hydroxyapatite (nano-HA) was synthesized from chicken eggshell waste using banana ( Musa acuminata Cavendish) extracts as green templating agents. Three nano-HA variants derived from banana flower (NHA230B15), pseudostem (NHA230K15), and peel (NHA230P15) were evaluated for in vitro cytotoxicity against normal CV-1 cells using the resazurin reduction assay. NHA230K15 and NHA230P15 maintained cell viability above the ISO 10993-5 cytotoxicity threshold throughout the tested concentration range up to 1000 μg/mL, whereas NHA230B15 showed reduced viability at the highest concentration tested, approaching the cytotoxicity threshold. Morphological observations revealed that treated cells generally retained normal fibroblast-like morphology and membrane integrity without severe structural damage. Differences in cellular response may be associated with variations in the physicochemical characteristics of the synthesized materials. Overall, the banana-template-derived nano-HA materials demonstrated favorable cytocompatibility toward CV-1 cells under the tested in vitro conditions. These findings provide a preliminary assessment of the biological response of green-synthesized nano-HA materials and support further investigation of their potential biomedical relevance. Further studies involving additional cell models, mechanistic evaluation, long-term biocompatibility, and in vivo evaluation are still required.