Preparation, Characterization and Antiradical Activity of Zinc Oxide Nanoparticles

Abstract

Zinc oxide nanoparticles (ZnO NPs) have recently been studied as a multi-functional and multi-target nanomedicine for cancer treatment. They can be used not only as a nanocarrier for delivery of the chemotherapy drug but also as an antiradical agent due to their photo-catalytic and photo-oxidizing abilities. Our previous work showed a potential use of commercial-available ZnO NPs without and with carboplatin for the treatment of retinoblastoma. The aim of this work was to synthesize ZnO NPs having smaller particle size than the commercial ones, i.e., 100 nm average diameter, in order to improve the reaction time. ZnO NPs were prepared by a sol-gel technique and calcined with different calcination conditions. The structure and particle size of ZnO powders were characterized using an x-ray diffractometer and a particle size analyzer. Average nanoparticle sizes of 16.32 ± 1.64 nm were achieved at a calcination temperature of 300 degree Celsius and 1 hour holding time. The antiradical activity of prepared ZnO NPs in cooperation with ultraviolet irradiation was assessed using a putative model of cancer cells, i.e., 2,2(diphenyl-1-picryhydrazyl) radicals (DPPH*). An optical spectroscopy was used to detect the decrease in peak absorbance of the antiradical solution at a wavelength of 515 nm, which in turn can be used to calculate the percent remaining of DPPH*. The disappearance of DPPH* with respect to the reaction time revealed that prepared ZnO NPs (16.32 ± 1.64 nm) improved response time as compared with ZnO NPs (100 nm). Moreover, the effective ZnO concentrations to reduce the initial DPPH* concentration by 50%, also known as the EC50 value in the present study, is lower indicating the improvement of anti-proliferative activity when compared to the commercial ZnO NPs.