Carbon dots as a potential therapy for breast cancer

Abstract

Carbon nanoparticles (CD) are fluorescent carbon-based nanomaterials and have been the subject of research since 2004. CD are characterized by their size between 2 and 100 nm and the presence of polar carbonyl and carboxyl groups on their surface. The major advantages of CD are their photoluminescence and excellent chemical and physical properties such as their solubility in water. Their manipulation is accomplished by synthesis techniques through the decomposition of organic material called top-down or the growth and agglomeration of atoms and molecules called bottom-up, in the formation of nanoparticles1. After synthesis, the surface groups enable the functionalization with various compounds. The success of these applications depends on the surface chemical composition of the CD. These nanostructures have good biocompatibility and low toxicity, which allows good interaction with biological systems and have onco-therapeutic potential1. These properties have allowed CD to be introduced as potential therapeutics for breast cancer mainly in drug transport systems, bioimaging, biosensor, microbial, photothermal and photodynamic therapy. Breast cancer (CaM) is the most prevalent cancer with the highest mortality rate in the female population worldwide. In this study, we tested the use of fructose-derived DCs for antitumor therapy of breast cancer. CD were synthesized from fructose using microwave irradiation by bottom-up method. After purification, CD were characterized for their morphology, size, structure, fluorescence and functional groups with the aid of transmission electron microscopy (TEM), dynamic light scattering (DLS), fluorescence spectrophotometer and Fourier transform infrared spectroscopy (FTIR), respectively. As expected, fructose-derived CD are composed of carbon, oxygen and hydrogen. As is also characteristic of CD, they are fluorescent with an absorption maximum at 360 nm and an emission spectrum with a broad emission band (maximum 520 nm). They have a round morphology with sizes between 2 and 6 nm (average particle size 3.1±1.8 nm), a hydrodynamic diameter of less than 2 nm and a crystalline structure. Regarding assays with breast cancer and breast epithelial cells, our results demonstrated the ability of CD to cross the cell membrane. Furthermore, they exhibited higher cytotoxicity and lower cell proliferation in breast tumor cells compared to breast epithelial cells.