Immunoresponses and cytotoxicity induced by cutaneous exposure to nanoparticles: Implications and insights

Nanoscience, often termed “big science,” profoundly impacts daily life through applications across diverse fields, including biomedicine. Nanoparticles (NPs), typically sized between 1 and 100 nm, possess unique properties due to their high surface area-to-volume ratio, making them highly promising in therapeutic, diagnostic, and delivery applications in medicine. However, concerns about nanotoxicity arise from their interactions with biological systems. The skin, a primary exposure route via products like sunscreens and cosmetics, acts as a critical barrier, though some NPs can breach outer layers without deeply penetrating the dermis. NPs exposure triggers innate and adaptive immune responses, influencing inflammation and immune cell recruitment. Metallic NPs (MNPs), widely utilized, pose risks such as membrane damage, oxidative stress, DNA damage, and autophagy. These mechanisms underscore potential health hazards, including skin cancer risks, emphasizing the need for safer nanomaterials through comprehensive mechanistic understanding.