Kidneys Toxicity and Biodistribution of Albumin-Based Gold and Silver Nanoclusters

The interaction of the kidneys with nanoparticles is a fundamental issue that accelerates the proper design of efficient and safe nanotherapeutics. The present study aimed to establish the kidney toxicity and the biodistribution profile of novel gold and silver nanocluster formulations.

Gold and silver nanoclusters were synthesized in an albumin template to probe their kidney- nano interaction. The interaction was performed on healthy animals to unveil the toxicity of nanoclusters on kidney tissue.

Albumin-based gold nanoclusters (BSA-AuNCs) and albumin-based silver nanoclusters (BSA-AgNCs), exhibited comparable core size (2.2±1.3 nm and 2.5±1.6 nm, respectively) and hydrodynamic diameter (11.3±2.1 nm for BSA-AuNC and 10.7±1.9 nm for BSA-AgNC) indicating similarity in their core and overall sizes. Zeta potential measurements demonstrated a comparable surface charge between BSA- AuNC (18.1±3.2 mV) and BSA- AgNC (20.1±3.6 mV), which closely resembled the surface charge of albumin in water (20.7±3.5 mV). Upon administration to rats via intravenous route, ICP-OES measurements showed a significant silver and gold nanocluster accumulation in various vital organs with unequal distribution patterns. BSA-AgNC exhibited higher concentrations in the liver and spleen, while BSA-AuNC showed predominant accumulation in the liver and kidneys. However, the administered BSA-AgNC induced more renal damage than BSA- AuNCs.

The identified renal toxicity linked to BSA-AgNCs, despite their lower kidney accumulation than BSA-AuNCs, illuminates the intricate interplay between nanoparticle biodistribution and toxicity. This underscores the significance of considering the core metal type in nanoparticle design and evaluation. Further investigation is needed to clarify the underlying molecular mechanisms of the observed biodistribution and toxicity.