The long and winding nano-road: A review of toxicity, uncertainty, and regulation in nanomedicine

Nanomedicine has emerged as one of the most dynamic fields in contemporary biomedical research, driven by the unique physicochemical properties of nanoparticles that enable advanced therapeutic strategies. However, alongside these technological advances, growing evidence indicates that nanoparticles may induce adverse biological effects, raising significant concerns regarding their cytotoxicity, biodistribution, bioaccumulation, and long-term safety. Despite the rapid expansion of nanoparticle-based medical applications, regulatory frameworks and public policies addressing their safe use, disposal, and environmental impact remain limited and fragmented. This review provides a systematic analysis of the current scientific literature on nanotoxicology. In parallel, existing regulatory and policy frameworks related to the medical and industrial use of nanomaterials, with particular attention to the Colombian context, were examined. The results reveal a substantial imbalance between the volume of research devoted to developing nanoparticle-based medical technologies and the relatively scarce attention paid to regulatory and safety policies. This review highlights critical knowledge gaps in long-term toxicity, standardization of testing protocols, and regulatory oversight, and underscores the urgent need for integrated scientific and policy approaches to ensure the safe and responsible implementation of nanomedicine.