Plantain peel extract–mediated synthesis of CuO nanoparticles: comprehensive characterization, bioinertness <i>in vitro</i> and <i>in vivo</i>, and anticancer evaluation

Background and purpose: Cancer is one of the leading causes of death worldwide, failing to identify a complete cure. Liver cancer is the sixth most frequent cancer worldwide, and its cure is still not assured. Nanoparticles, especially the metal oxide nanoparticles, have been explored as anticancer agents in recent times. In an attempt to make the best use of waste, plantain peel, a byproduct of agriculture, was used to synthesize copper oxide nanoparticles. Experimental approach: The plantain peel extract was evaluated for its chemical compo­sition by GC-MS analysis, which revealed a predominant presence of tetratetracontane. The copper oxide nanoparticles were characterized by UV-visible spectrophotometry, dynamic light scattering, zeta poten­tial, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX). Bio-inertness was assessed using an MTT assay of fibroblasts, a haemolysis assay, and zebrafish embryo analysis. The anticancer activity against HepG2 cells was estimated. Key results: The absorption peak was found at 402 nm, the hydrodynamic diameter was 323 nm, the zeta potential was +10.74 mV, and a band gap of 1.3 eV. The SEM images showed a size range of 54 to 85 nm with a chrysanthemum-petal-like morphology. EDAX showed the presence of Cu and O, and the XRD and FTIR peaks corroborated with that of CuO. The result showed that up to a dose of 50 μg mL-1, the nanoparticles did not induce any toxicity. Finally, the anticancer activity, evaluated using the HepG2 cell line, showed a dose-dependent cytotoxic effect with an IC50 of 26.20 μg mL-1. Conclusion: The outcome of this study suggested that the synthesized copper oxide nanoparticles can be used at controlled doses to kill cancer cells. Further studies are needed using other cancer cell lines and in vivo cancer models.