Multicolorful Carbon Dots for Tumor Theranostics

Background: Cancer is a great threat of human health worldwide due to the uncontrollable spread of malignant cells throughout the body. Accurate diagnosis and targeted therapy approaches are critical factors for cancer treatment. Combination of therapeutic and diagnostic agents in a single nanocarrier enables to simultaneously monitor the cancer progression and tune disease therapy with minimum side effect. Objective: Carbon dots are a novel class of small fluorescence carbon nanostructures with size less than 10 nm at least in one dimension, which exhibit excellent optical properties, larger surface area to volume ratio and low toxicity. The unique properties of carbon dots make it as an ideal carrier for incorporation of cancer targeting moieties, bio-imaging agents and antineoplastic agents in one delivery system. Methods: An literature search was conducted using Web of Science to find out articles related to carbon dots and tumor theranostics. Results: Numerous applications of carbon dots in cancer theranostics have been reported during the past 10 years. This review introduces a brief history and basic fluorescent properties of carbon dots, and then discusses synthesis strategies and applications of carbon dots in biological imaging, targeted anti-cancer drug delivery, photodynamic therapy, photothermal therapy as well as gene delivery for cancer theranostics. Future directions of carbon dots in cancer theranostics are also highlighted.