Assessing the toxicity of nanostructures requires a multidisciplinary approach combining physicochemical characterization, in vitro assays, and in vivo studies. In vitro assays help evaluate cellular uptake, cytotoxicity, and genotoxicity by using various cell lines. In vivo studies provide insights into the biodistribution, metabolism, and potential long-term effects of nanostructures in animal models. Advanced techniques such as high-throughput screening and omics technologies are also employed to enhance the understanding of nanostructure-biological interactions.