Carbon Dots as Promising Tools for Cancer Diagnosis and Therapy

Abstract

Carbon Dots (CDs) are the latest members of carbon-based nanomaterials, which since their discovery have attracted notable attention due to their chemical and mechanical properties, brilliant fluorescence, high photostability, and good biocompatibility. Together with the ease and affordable preparation costs, these intrinsic features make CDs the most promising nanomaterials for multiple applications in the biological field, such as bioimaging, biotherapy, and gene/drug delivery. This review will illustrate the most recent applications of CDs in the biomedical field, focusing on their biocompatibility, fluorescence, low cytotoxicity, cellular uptake, and theranostic properties to highlight above all their usefulness as a promising tool for cancer diagnosis and therapy.

Keywords: bioimaging; cancer diagnosis cancer therapy; carbon dots; drug delivery; photodynamic therapy; photothermal therapy.

Figure 1

(A) Schematic representation of bottom-up CDs formation from molecules precursors and doping agent. (B) Excitation spectrum of CDs in water and (C) Representation of CDs wavelength-dependent photoluminescence (PL).

Figure 2

Illustration of CDs cellular internalization for bioimaging. Left part: sketch of a cell depicting CDs penetrating the cell membrane and accumulating in the cytosol (gray circles on the left); right part: sketch of representative fluorescent green staining by intracellular CDs (cell nuclei in the image are stained with DAPI (blue)).

Figure 3

Schematic diagram of photodynamic therapy (PDT). CDs penetrate the cell membrane and accumulate in the cytosol. Light irradiation activates CDs and induces the production of reactive oxygen species (ROS) leading to the cell lysis and death.