Nucleolus Targeted Photodynamic Anticancer Therapy Using Carbon Dots

Photodynamic therapy(PDT)is a strategy that uses photosensitizer under the excitation of specific wavelength light to generate reactive oxygen species(ROS)that kills diseased cells or tissues.In view of its unique advantages,such as non-invasiveness,minimal side effects,etc.,PDT has attracted widespread attention in recent years,and has been successfully used for clinical application.In order to improve the effect of PDT,organelle-targeted PDT,such as mitochondrial-targeted,is realized by functionalization of photosensitizers.The latest research shows that nucleolus is a more effective and safer tumor treatment target.Therefore,nucleolus-targeted PDT can provide a new strategy for enhanced PDT.Here,we synthesized carbon dots(C-dots)by hydrothermal method and applied C-dots to nucleolus-targeted PDT for the first time.The C-dots have high fluorescence quantum yield and ROS quantum yield.At the cellular level,the ability of C-dots specifically bind to RNA to target nucleoli is verified.The C-dots based PDT has an excellent therapeutic effect even under conditions of low light dose and low photosensitizer dose in in vitro and in vivo experiments.At the same time,C-dots could be quickly cleared out via the renal route into urine within one hour.Considering its excellent photodynamic efficacy,good biocompatibility,and rapid renal clearance,C-dots have great potential for clinical treatment of tumors.