In vivo toxic studies and biodistribution of near infrared sensitive Au-Au2S nanoparticles as potential drug delivery carriers

Near infrared (NIR) sensitive Au-Au2S nanoparticles are intensively being developed for biomedical applications including drug and gene delivery. Although all possible clinical applications will require compatibility of Au-Au2S nanoparticles with the biological milieu, their in vivo capabilities and limitations have not yet been explored. Au-Au2S nanoparticles and cisplatin-loaded Au-Au2S nanoparticles were successfully synthesized by the reduction of tetrachloroauric acid (HAuCl4) using sodium sulfide (Na2S), and cisplatin was loaded onto NIR sensitive Au-Au2S nanoparticles via an MUA (11-mercaptoundecanoic acid) layer. In this work, acute systemic toxicity in vivo, blood biochemistry assay, and tissue distribution in mice were carried out to further investigate the biocompatibility and biodistribution of these nanoparticles. The results from these studies demonstrated that both of nanoparticles (< 200 mu g/mL) might have a great advantage in biocompatibility and good biological safety.