Highly flexible platform for tuning surface properties of silica nanoparticles and monitoring their biological interaction

摘要

The present work offers a simple, reliable and scalable seeding-growth methodology to prepare silica nanoparticles (SiO2 NPs) (20, 30, 50 and 80 nm) directly in aqueous phase, both as plain- as well as fluorescent-labelled silica. The amount of fluorescent label per particle remained constant regardless of size, which facilitates measurements in terms of number-based concentrations. Dispersions of SiO2 NPs were functionalized with an epoxysilane, thus providing a flexible platform for the covalent immobilization of wide variety of molecules under mild experimental conditions. This approach was validated with ethylenediamine and L-Serine to generate positive and negatively charged particles, respectively. Accurate characterization of particle size, size distributions, morphology and surface chemistry is provided, both for as-synthesized particles and after incubation in cell culture medium. The impact of physico-chemical properties of SiO2 NPs was investigated with human alveolar basal epithelial cells (A549) such as the effect in cytotoxicity, cell internalization and membrane interaction.