Abstract
Nanoparticles (NPs) are a group of substances with characteristics that differ from their bulk and molecular counterparts. Different NPs have various size averages from 1 to 100 nanometers in two or three dimensions. NPs have been used for numerous industrial and domestic purposes, progressively increasing their production. Because of using NPs in different and multiple products, their presence in the environment around us has increased, raising the risk of potentially adverse effects of NPs in natural systems. NPs can enter the human body through different routes such as inhalation, ingestion, and skin contact. Applications of NPs in the medical field are variable; they are being utilized in diagnostic and therapeutic methods. The physico-chemical characteristics of NPs, such as size, shape, surface area, and dispersity, are considered crucial factors that significantly impact their safe or toxicological behaviors. Before clinical use, it is important to understand the characteristics of NPs, their effect on the body, and their toxicity mechanisms. This work aimed to summarize the studies that have described the great progression of nanotechnology and formulation of NPs in the last few years and its effects and toxicity on different human body systems.