In Vitro Evaluation of Cytotoxicity of Colloidal Amorphous Silica Nanoparticles Designed for Drug Delivery on Human Cell Lines

Silica nanoparticles are being developed and tested vigorously in drug delivery systems to treat various diseases. There are many advantages of using silica nanoparticles as a nanodelivery system because they are relatively inexpensive to produce, chemically inert, thermally stable and can be tailored to contain porous structures for drug encapsulation and to be hydrophilic for higher solubility in the human body. Despite these tremendous benefits, one of the pivotal requirements of these drug delivery systems is to be biocompatible with the human body. In this study, the cytotoxicity of colloidal amorphous silica nanoparticles synthesized using the micelle formation method has been tested against normal human foreskin fibroblast cell line (Hs27) as well as selected human bone carcinoma (U-2 OS), human breast cancer (MCF-7), and human cervical carcinoma (HeLa) and (Ca Ski) cell lines to determine the IC50 values. Two different sizes of silica nanoparticles, 20 nm and 40 nm, were used to study the relationship between their size and the level of toxicity exerted on the different cells being tested. The cytotoxicity results indicated that 20 nm and 40 nm silica nanoparticles significantly reduce cell viability in a dose-and cell-type-dependent manner in the normal and cancerous cells tested.