Toxicological assessment of intraperitoneal administration for Au nanorods with ultra-small Pt nanoparticles on surface (Au@pt NRs) in mice

Ultra-small Pt NPs on Au nanorods (Au@Pt NRs) is a typical bimetallic nanomaterial. Due to their superior optical and catalytic ability, they are widely investigated in biomedical fields. However, the toxicity has not been fully studied.
Based on previous intravenous injection studies, this work evaluated the tissue distribution, histopathological characteristics, hematology, and serum biochemical indicators of Au@Pt NRs in C57BL/6 mice through intraperitoneal injection.
Within 16 days, it mainly accumulated in the liver and spleen, exhibiting time-dependent redistribution. On Day 1, catalase (CAT) activity and superoxide dismutase (SOD) expression in liver and kidney slightly decreased, then returned to normal. Blood cell counts changed more significantly after intraperitoneal injection, but within normal range. H&E staining revealed inflammatory cell infiltration and changes in liver lobule structure. Levels of liver and kidney function indicators, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and uric acid (UA), decreased within 16 days. Liver injury marker cytokeratin18 (CK18) and kidney injury marker alpha-smooth muscle actin (α-SMA) showed no significant changes.
In summary, Au@Pt NRs administered via different routes show slightly different distributions and histological changes, and their safety was acceptable, confirming their potential for biomedical applications via the intraperitoneal route.