Biodistribution and in vivo toxicity of aptamer-loaded gold nanostars

This paper reports an in vivo evaluation of toxicology and biodistribution of a highly anisotropic Au nanoconstruct composed of a gold nanostar (AuNS) core and a ligand shell of a G-quadruplex DNA aptamer AS1411 (Apt) supporting both targeting and therapy capabilities. We examined the toxicity of the nanoconstructs (Apt-AuNS) at four different injected concentrations. At the highest dose tested (48mg/kg), maximal tolerated dose was not reached. Clinical pathology showed no apparent signs of acute toxicity. Interestingly, the nanoconstructs circulated longer in female rats compared to male rats. In two different tumor models, the biodistribution of Apt-AuNS, especially tumor accumulation, was different. Accumulation of Apt-AuNS was 5 times higher in invasive breast cancer tumors compared to fibrosarcoma tumors. These results provide insight on identifying a tumor model and nanoconstruct for in vivo studies, especially when an in vitro therapeutic response is observed in multiple cancer cell lines.