Renally Excretable Silver Telluride Nanoparticles as Contrast Agents for X-ray Imaging

The use of nanoparticles in the biomedical field has gained much attention due to their applications in biomedical imaging, drug delivery, and therapeutics. Silver telluride nanoparticles (Ag₂Te NPs) have been recently shown to be highly effective computed tomography (CT) and dual-energy mammography contrast agents with good stability and biocompatibility, as well as to have potential for many other biomedical purposes. Despite their numerous advantageous properties for diagnosis and treatment of disease, the clinical translation of Ag₂Te NPs is dependent on achieving high levels of excretion, a limitation for many nanoparticle types. In this work, we have synthesized and characterized a library of Ag₂Te NPs and identified conditions that led to 3 nm core size and were renally excretable. We found that these nanoparticles have good biocompatibility, strong X-ray contrast generation, and rapid renal clearance. Our CT data suggest that renal elimination of nanoparticles occurred within 2 h of administration. Moreover, biodistribution data indicate that 93% of the injected dose (%ID) has been excreted from the main organs in 24 h, 95% ID in 7 days, and 97% ID in 28 days with no signs of acute toxicity in the tissues studied under histological analysis. To our knowledge, this renal clearance is the best reported for Ag₂Te NP, while being comparable to the highest renal clearance reported for any type of nanoparticle. Together, the results herein presented suggest the use of GSH-Ag₂Te NPs as an X-ray contrast agent with the potential to be clinically translated in the future.