Chitosan stabilized Prussian blue nanoparticles for photothermally enhanced gene delivery.

The lack of biosafety and insufficient delivery efficiency of gene-carriers are still obstacles to human gene therapy. This paper reported highly biocompatible chitosan (CS) functionalized Prussian blue (PB) nanoparticles (designated as CS/PB NPs) for photocontrollable gene delivery. The ultra-small size (∼3 nm), positive charge and high physiological stability of CS/PB NPs make it suitable to be a nonviral vector. In addition, CS/PB NPs could effectively convert the near infrared (NIR) light into heat due to its strong absorption in the NIR region, assisting the uptake of NPs by cells. Upon NIR light irradiation, CS/PB NPs showed superior gene transfection efficiency, much higher than that of free polyethylenimine (PEI). Both in vitro and in vivo experiments demonstrated that CS/PB NPs had excellent biocompatiblity. This work also encourages further exploration of the CS/PB NPs as a photocontrollable nanovector for combined photothermal and gene therapy.