Preliminary Evaluation of Median Lethal Concentrations of Stöber Silica Particles with Various Sizes and Surface Functionalities Towards Fibroblast Cells

The application of silica particles in the biomedical field has experienced a great development in recent years, especially in the design of nanoparticles having homogeneous size, structure and amenable to specific grafting. In this way, it becomes possible to control the interaction of nanoparticles with cells in order to meet the requirements for desired applications. This work explores the cytotoxicity of silica particles of various sizes and surface functionality towards L929 fibroblast cells. In particular, the median lethal concentration of the different silica particles has been established. Preliminary investigations of silica nanoparticles prepared by the Stöber method with sizes ranging from 100 nm to 500 nm showed that the largest particles are less harmful for the cells. Moreover, cytotoxicity towards L929 fibroblasts was mainly observed for bare particles, whereas sulfonate-, amine- and thiol-grafted particles had less detrimental effects. This shows the key influence of particle surface curvature and chemistry on nanomaterials cytotoxicity.