Green Synthesis of Hydroxyapatite Nanoparticles Using Semecarpus anacardium Linn leaf Extract: Examination of Anticancer Activity and its Apoptosis Induction

Nanotechnology and biomedical sciences enable diverse molecular and cellular applications. Plant-mediated biosynthesis of nanoparticles, a green chemistry approach, offers a cost-effective, eco-friendly alternative to traditional methods. This study focuses on developing hydroxyapatite nanoparticles (HA-NPs) using Semecarpus anacardium Linn (SAL) leaf extract (termed SAL@HA-NPs) as a capping agent and reducing agent. The presence of needle-shaped nanostructures was verified using SEM and TEM investigation. The presence of well-defined rings in the selected area electron diffraction (SAED) patterns provided evidence for the polycrystalline nature of the SAL@HA-NPs). The XRD spectrum exhibited clear peaks that closely corresponded to the hexagonal patterns of HA, indicating a mean crystalline diameter of 54.25 nm. The FTIR analysis revealed the presence of biomolecules from Semecarpus anacardium Linn leaves on the surface of the nanoparticles. The suspension of SAL@HA-NPs displayed a polydispersity index of 0.445 and demonstrated excellent stability, as indicated by the zeta potential of -32.2 mV, as observed in the DLS tests. The SAL@HA-NPs exhibited a harmful effect on the HeLa cervical and HepG2 liver cancer cells, with an IC₅₀ value of 52 µg/mL. Fluorescence microscopy revealed the deformation of the damaged cell membrane, fragmentation, and cell death following treatment with SAL@HA-NPs. The Annexin V-FITC and PI staining confirmed the mode of apoptosis by flow cytometric analysis. Thus, the SAL@HA-NPs acquired in this study could have a crucial impact on the biomedical domain of cancer treatment.