Morphomechanical and organelle perturbation induced by silver nanoparticle exposure

The unique physico-chemical properties of silver nanoparticles (AgNPs) make them a powerful tool in many fields, ranging from cosmetics, biomedicals, household products, and wound dressing. Several evidences suggest the strong toxicity of AgNPs both in vitro and in vivo, but few data are available to full understanding of their adverse effects on cellular components and cytoskeleton. In this work, we assessed the toxicity of citrate-capped AgNPs on cortical actin and organelles, namely mitochondria and lysosomes, on epithelial breast cancer cells (MCF-7). The impact of AgNPs on cells was firstly evaluated in term of viability, oxidative stress, mitochondria membrane potential alteration, and apoptosis activation. Afterwards, we carefully estimated the qualitative and quantitative morphological alterations of cortical F-actin and organelles by confocal microscopy and specific software tools, coupled with a biomechanical analysis by atomic force microscopy (AFM). This multidisciplinary approach, which combines the standard biological assays with systematic morphometric and biomechanical analysis on cells, permits to understand at different levels the intracellular response elicited by AgNPs in order to provide new scenarios in toxicity assessment.