Folic acid Modified Prussian Blue/Polydopamine Nanoparticles as MRI Agent and Targeted Chemo/Photothermal Therapy
Fabricating multifunctional theranostic nanoparticles is highly pursued but still challenging for effective cancer treatment. Here was reported a new theranostic nanoagent as both MRI and targeted chemo/photothermal therapeutic agent. Prussian blue nanoparticles (PB) were first decorated with polydopamine (PDA), then conjugated with polyethylene glycol (PEG) and folic acid (FA), and loaded with doxorubicin (DOX) (denoted as PB@PDA@PEG-FA-DOX). The nanoagent was estimated at 40 nm in average size with DOX loading capacity of 36%, photothermal conversion efficiency of 45.7% and transverse relaxation rate of 0.366 mM-1s-1. In vitro release investigation showed the dual-responsive release by mild acid and near-infrared (NIR) laser irradiation. PB@PDA@PEG-FA illustrated the negligible cytotoxicity against HL-7702 cell line and 38.2% cell viability under NIR against HeLa cell line. PB@PDA@PEG-FA-DOX exhibited 45.2% cell viability. In contrast, the cell viability of PB@PDA@PEG-FA-DOX dramatically decreased 18.4% under NIR. Exclusive of folic acid, PB@PDA@PEG-DOX demonstrated 40.5% of cell viability. These results demonstrated the nanoagent integrated photothermal therapy (PTT) and chemotherapy, and embraced the FA targeting effect. In vivo MRI confirmed the effective nanoparticle accumulation and infrared thermal image revealed the dramatically increased temperature under NIR at tumor site. In vivo combination treatment induced tumors nearly completely destroyed without significant body weight loss after 14 days. H&E and Ki67 staining indicated remarkable necrosis and weak cell proliferation in the tumor area. Histologic examination revealed lower toxicity in vital organs. Therefore, this fabrication of the combination of chemo/photothermal therapy provided an efficient route in the cancer treatment.