With the development of nanotechnology, silver nanoparticles (Ag-NPs) have become one of the most in-demand nanoparticles owing to their exponential number of uses in various sectors. The increased use of Ag-NPs-enhanced products may result in an increased level of toxicity affecting both the environment and living organisms. Several studies have used different model cell lines to exhibit the cytotoxicity of Ag-NPs, and their underlying molecular mechanisms. This review aimed to elucidate different properties of Ag-NPs that are responsible for the induction of cellular toxicity along with the critical mechanism of action and subsequent defense mechanisms observed in vitro. Our results show that the properties of Ag-NPs largely vary based on the diversified synthesis processes. The physiochemical properties of Ag-NPs (e.g., size, shape, concentration, agglomeration, or aggregation interaction with a biological system) can cause impairment of mitochondrial function prior to their penetration and accumulation in the mitochondrial membrane. Thus, Ag-NPs exhibit properties that play a central role in their use as biocides along with their applicability in environmental cleaning. We herein report a current review of the synthesis, applicability, and toxicity of Ag-NPs in relation to their detailed characteristics.

Keywords: Ag+, silver ions; Ag-NPs, silver nanoparticles; Cytotoxicity; DNA, deoxyribonucleic acid; GSH, glutathione; LDH, lactate dehydrogenase; Mechanism; NPs, nanoparticles; PVP, polyvinylpyrrolidone; Physiochemical properties; ROS, reactive oxygen species; Silver nanoparticles; TMRE, tetramethylrhodamine ethyl ester; TT, toxicity threshold; ppm, parts per million.