Recent Advances in AS101 and Tellurium-Based Nanoplatforms for Immunomodulation, Cancer Therapy, Antimicrobial...

Tellurium (Te), a metalloid historically associated with toxicity, has recently gained attention for its potential biomedical applications through advances in AS101-based pharmacology and tellurium nanotechnology. This review discusses the evolution of tellurium research from the immunomodulatory compound AS101 [ammonium trichloro-(dioxoethylene-O,O')-tellurate] to modern tellurium nanoparticles (TeNPs) and nanoheterojunctions. Experimental studies indicate that AS101 modulates cytokine signaling, inhibits integrin activation, and exerts immunomodulatory effects through thiol redox regulation. Preclinical evidence also suggests neuroprotective and anti-inflammatory effects in animal models of neurodegenerative and mood-related disorders. In parallel, TeNPs and Te-based heterostructures have been investigated in vitro and in animal models for applications in photothermal therapy (PTT), radiosensitization, and ROS-mediated anticancer activity. In addition, TeNPs demonstrated antimicrobial and antibiofilm effects against multidrug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). The review also highlights recent advances in tellurium speciation analysis, metabolism, and toxicity assessment using approaches such as LC-ICP-MS. Overall, current findings support tellurium-based compounds and nanoplatforms as emerging candidates for biomedical applications, although further pharmacokinetic, toxicological, and clinical studies remain necessary to establish their long-term safety and therapeutic efficacy.