Toxicity of Sol-Gel Synthesized Silica Nanoparticles: Insights from Cellular and Model Organism Studies

Silica nanoparticles (SiNPs) demonstrate exceptional properties that vary depending on their intended applications. It is imperative to comprehend the toxic effects associated with these nanoparticles, which have gained wider use due to diverse synthesis methods and application areas. The sol-gel method yields SiNPs with a radius ranging from 4 to 7 nm. The characterization of the synthesized nanoparticles involved capturing transmission electron microscopy images (TEM), employing Fourier transform infrared spectroscopy (FTIR), and conducting differential scanning calorimetry (DSC). The evaluation of their toxicity and cellular uptake was performed on human vein endothelial (HUVEC) cells. The impact on the model organism Cearnohabditis elegans (C. elegans) and bacterial growth was also investigated. The zeta sizer measurements confirmed the average size distribution of 7 nm, while also revealing a strong surface charge of the particles. The presence of Si-O-Si junctions was indicated by the peak observed at 1077 cm-(1) on the FTIR spectrum of the SiNPs. The thermogram obtained from the DSC measurement, conducted between 200 and 500 degree celsius, displayed a similar curve to polymer matrices containing SiNPs. The cytotoxicity experiments were focused on investigating the effects of low concentrations of SiNPs. Even at 10 mu g/mL, 50 mu g/mL, and 100 mu g/mL concentrations, increasing concentrations resulted in a decrease in cell proliferation. Antibacterial effects were confirmed by a real-time cell analyzer (xCELLigence) for 24 h. At a concentration of 10 mu g/mL, there were no observable effects on lifespan, reproduction, and body bending frequency; at a 50 mu g/mL, the nanoparticles accumulated in the nematode body affected the body bending frequency.