Nanostructured Vanadates as Janus-faced Redox-active Nanomaterials: Biological Effects and Molecular Mechanisms

Recent advances in the field of nanotechnology have paved the way for novel biomedical applications of nanomaterials. Nanoscale vanadates possess unique properties and have been reported to elicit anti-aging, antibacterial, anti-cancer and antioxidant effects. Likewise, they are potentially applied as bioimaging, drug delivery, theranostic or would healing agents, as well as biosensors. In this review, we highlight and critically discuss biomedical applications of vanadate nanostructures. This review article aims at identifying molecular hallmarks of vanadate nanomaterial-mediated cytotoxicity. Our analysis reveals that depending on size, morphology, composition, concentration, and external conditions (pH, irradiation, etc.) nanoscale vanadates induce oxidative stress, mitochondrial dysfunction, and lysosomal damage, culminating in cell death. Notably, besides apoptosis, nanosized vanadates trigger immunogenic non-apoptotic cell death pathways (ferroptosis and necroptosis) primarily due to overproduction of reactive oxygen species (ROS). Thus, our review demonstrates that nanostructured vanadates are multifaceted pharmacological agents with a wide spectrum of diverse biological applications. Our analysis demonstrates that redox activity of nanostructured vanadates is a key factor determining biological responses to them. Thus, more studies should focus on elucidating the biologically-relevant redox mechanisms of nanosized vanadates.