• Busila, Mariana

Abstract

<jats:p>Surface modification of zinc oxide nanoparticles (ZnO NPs) is a strategy to tune their biocompatibility. Herein we report on the synthesis of a series of fluorescent ZnO NPs modified with 2–10% (3-glycidyloxypropyl)trimethoxysilane (GPTMS) to investigate the fluorescence propertiesand to explore their applications in microbiology and biomedicine. The obtained ZnO NPs were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). Size reduction occurred from ca. 13 nm in unmodifiedZnO to 3–4 nm in silane-modified samples and fluorescence spectra showed size-dependent variation of the photoemission bands' intensity. The antibacterial and cytotoxic activities were investigated on Gram-negative (<jats:italic>Escherichia coli</jats:italic>) and Gram-positive (<jats:italic>Staphylococcus aureus</jats:italic>)bacteria, and in ovarian (A2780) and prostate (PC3) cancer cells by tetrazolium/formazan-based methods. The antibacterial effect was higher for <jats:italic>E. coli</jats:italic> than <jats:italic>S. aureus</jats:italic>, while the cytotoxic activity was similar for both cancer cells and varied with the particle size. Cell deathby apoptosis, and/or necrosis versus autophagy, were explored by flow cytometry using an Annexin V based-method and transmission electron microscopy (TEM). The main mechanism of ZnO NPs toxicity may involve the generation of reactive oxygen species (ROS) and the induction of apoptosis or autophagy.This work revealed the potential utility of GPTMS-modified ZnO NPs in the treatment of bacterial infection and cancer.</jats:p>

Topics

• nanoparticle
• impedance spectroscopy
• surface
• x-ray diffraction
• Oxygen
• zinc
• reactive
• transmission electron microscopy
• toxicity
• Fourier transform infrared spectroscopy
• biocompatibility