Proteomics unite traditional toxicological assessment methods to evaluate the toxicity of iron oxide nanoparticles.

Iron oxide nanoparticles (IONPs) are the first generation of nanomaterials approved by the Food and Drug Administration for use as imaging agents and for the treatment of iron deficiency in chronic kidney disease. However, several IONPs-based imaging agents have been withdrawn because of toxic effects and the poor understanding of the underlying mechanisms. This study aimed to evaluate IONPs toxicity and to elucidate the underlying mechanism after intravenous administration in rats. Seven-week-old rats were intravenously administered IONPs at doses of 0, 10, 30, and 90 mg/kg body weight for 14 consecutive days. Toxicity and molecular perturbations were evaluated using traditional toxicological assessment methods and proteomics approaches, respectively. The administration of 90 mg/kg IONPs induced mild toxic effects, including abnormal clinical signs, lower body weight gain, changes in serum biochemical and hematological parameters, and increased organ coefficients in the spleen, liver, heart, and kidneys. Toxicokinetics, tissue distribution, histopathological, and transmission electron microscopy analyses revealed that the spleen was the primary organ for IONPs elimination from the systemic circulation and that the macrophage lysosomes were the main organelles of IONPs accumulation after intravenous administration. We identified 197 upregulated and 75 downregulated proteins in the spleen following IONPs administration by proteomics. Mechanically, the AKT/mTOR/TFEB signaling pathway facilitated autophagy and lysosomal activation in splenic macrophages. This is the first study to elucidate the mechanism of IONPs toxicity by combining proteomics with traditional methods for toxicity assessment.

High nitrogen stainless steel drug-eluting stent - Assessment of pharmacokinetics and preclinical safety in vivo.

Pharmacokinetic analyses were performed using 20 pigs for 120-days implantation, while one sirolimus-eluting stent was implanted into one of their coronary artery. At different time points, the residual sirolimus on the stent, delivered locally (to artery wall), regionally (to adjacent and downstream muscle) and systemically (to plasma and visceral organs), was detected throughout 120 days. Preclinical safety evaluation was performed using 32 pigs for 180-days implantation to study the safety of metal platform material and the effectiveness of sirolimus eluting coating on the HNS stent. The neointima area, restenosis rate and inflammatory grade for HNS and control group stents were detected and analyzed. Approximately 80% sirolimus was eluted from the sirolimus-eluting stents after 30-days implantation in vivo. Additionally, there was sustained sirolimus in the artery wall, cardiac muscle and heart throughout 120-days implantation, and sirolimus accumulated to the peak at 90-days implantation. It was inferred that the sirolimus eluting stent in this study was covered by neointima before 90-days implantation, indicating that the sirolimus eluting coating on the HNS stent was safe and effective. Very little sirolimus was distributed in visceral organs after 14-days implantation. HNS sirolimus-eluting stent exhibited lower restenosis rate and lower inflammatory grade than control group, which verified that the sirolimus-eluting coating design in this study was reasonable and practical. In addition, there were no significant difference in restenosis rate and inflammatory score between HNS bare-metal stent and drug-eluting stents, illustrating that HNS has good bio-compatibility and is suitable to use as coronary artery stent material.