Green-synthesised cerium oxide nanostructures (CeO2-NS) show excellent biocompatibility for phyto-cultures as compared to silver nanostructures (Ag-NS)

Abstract

The use of nanostructures (NS) in plant tissue culture can be beneficial only if we have their complete bio-safety and biocompatibility profile. In the recent past, increasing rate of NS-cytotoxicity has alarmed the plant biotechnologist to think critically. Keeping this in view, our current study represents a comparative cytotoxicity examination of green fabricated highly potent CeO₂-NS and Ag-NS. Phyto-reductants from O. europaea extract simultaneously acted as reducing as well as capping agent in tuning the shape of CeO₂-NS and Ag-NS to as small as 18 nm and 26 nm respectively. High-performance liquid chromatography (HPLC) analysis of O. europaea extract supplemented by thermo-gravimetric analysis (TGA) findings further validates the capping action of bioactive agents from the plant extract. X-ray diffraction (XRD) testing confirms the phase purity and crystalline nature of prepared CeO₂-NS and Ag-NS. Fourier transform infrared (FTIR) spectroscopy shows typical Ce–O bond vibrations at 457 cm⁻¹ and Ag around 563 cm⁻¹ to 641 cm⁻¹. Moreover, the optimized NS shows differential cytotoxicity when tested on callogenesis and organogenesis of Lycopersicon esculentum. Findings from DPPH assay shows that CeO₂-NS are biocompatible and have tremendously enhanced the antioxidant potential of L. esculentum with greater biomass, contrastingly Ag-NS are found phyto-toxic with lower antioxidant potential and have a negative impact when added during plant tissue culture.