Synthesis of Positively and Negatively Charged CeO2 Nanoparticles: Investigation of the Role of Surface Chargeon Growth and Development of Drosophila melanogaster

摘要

Monodispersed cerium oxide nanoparticles (CeO2 NPs) with positive and negative surface potential were synthesized by co-precipitation method using hexamethylenetetramine (HMT) and poly(vinylpyrrolidone) (PVP), respectively, as precipitating agents. Synthesized NPs were characterized with scanning electron microscopy (SEM), UV–Visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and powder X-ray diffraction (XRD). Positively charged NPs of about 30 ± 10 nm in size formed within 5 h, aggregated in number, and resulted in larger-sized NPs as a function of time. The CeO2 NPs were administered to Drosophila as a part of their diet to study the effects on the growth and development of Drosophila. While the positively charged NPs did not affect the growth of the third instar larvae, the negatively charged NPs delayed the growth of larvae by about 7 days. It required 7 more days to reach the stage of adult fly. TEM imaging of the larvae gut showed that positively charged NPs were found to be smaller, whereas the size of negatively charged NPs remained unchanged. This biodegradability could be the reason for the delayed larvae growth in the case of negativelycharged particles. The distance covered by such second instar larvaefed with diet containing negatively charged CeO2 NPs wassignificantly lower, and their size was significantly smaller whencompared to the crawling activity and size of the third instar larvaeof the control group. Such positively charged NPs have high potentialfor use as drug delivery carriers for the treatment of disease, andnegatively charged NPs may play a rather detrimental role.