One-Pot To Synthesize Multifunctional Carbon Dots for Near Infrared Fluorescence Imaging and Photothermal Cancer Therapy

Abstract

It is an emerging focus to develop a simple and straightforward strategy to synthesize multifunctional nanomedicines for cancer imaging and treatment. In this work, a new carbon dot (named CyCD) with intrinsic theranostic properties was prepared from a hydrophobic cyanine dye [2-((E)-2-((E)-2-chloro-3-((E)-2-(1-(2-hydroxyethyl)-3,3-dimethylindolin-2-ylidene) ethylidene)cyclohex-1-en-1-yl)vinyl)-1-(2-hydroxyethyl)-3,3-dimethyl-3H-indol-1-ium iodide, CyOH] and poly(ethylene glycol) (PEG800) via a simple solvothermal process. The as-prepared CyCD is well dispersed in water media with an average diameter of 2.9 ± 0.5 nm; it possesses favorable hydrophilicity and excellent photostability. More importantly, the strong absorption and near-IR (NIR) emission within the range from 600 to 900 nm, along with preferential uptake at tumors and high photothermal conversion efficiency (η = 38.7%), facilitate CyCD to act as an ideal theranostic agent for NIR fluorescent imaging and photothermal therapy in vitro and in vivo. This work highlights theranostic CDs as an excellent candidate for efficient cancer imaging and therapy.