Structural characterization and in vitro anticancer activity of biogenic NiFe₂O₄ nanoparticles

Nickel ferrite (NiFe₂O₄) Nanoparticles were prepared using a green co-precipitation method with a natural reducing and stabilizing agent of Crocus sativus flower petal extract. The synthesis was performed by the controlled co-precipitation of nickel and iron precursors with the plant extract, followed by drying and calcination to obtain NiFe₂O₄ nanoparticles. The green synthesis method minimizes the use of toxic chemicals and offers an environmentally friendly method to synthesize nanoparticles. The synthesized nanoparticles were highly crystalline with an average crystallite size of about 29.8 nm and predominantly cubic spinel NiFe₂O₄ structure. The morphological analysis showed that the nanoparticles were almost spherical and moderately aggregated. The synthesized nanoparticles exhibited concentration-dependent in-vitro anticancer activity against human lung carcinoma (A549) cells with an IC₅₀ value of 51.23 µg/mL as determined using the MTT assay. In comparison, relatively high viability (> 85%) was maintained in normal HEK293 cells at 100 µg/mL, which is evidence of good cytocompatibility and selective biological response. The exact mechanism of anticancer activity was not directly studied in the present study, and further mechanistic studies are needed. Overall, the study demonstrates the successful green preparation of nanocrystalline NiFe₂O₄ nanoparticles with potential anti-cancer activity.