The Effect of Poloxamer Coating on the Toxicity of Carbon Dots in Glioblastoma and Embryonic Kidney Models In Vitro

Carbon dots (CDs), produced by microwave or hydrothermal synthesis, are low-toxic, carbon-based semiconductor nanoparticles that can be used for imaging of biological objects and antitumor therapy. To impart new functional properties to the CDs for biomedical purposes, they are coated with surfactants, such as poloxamers or pluronics. These are block copolymers of polyoxyethylene and polyoxypropylene. We assessed the cytotoxicity of CDs with and without surfactant coatings in in vitro experiments conducted on mouse glioblastoma M6 and human kidney embryonic HEK293 cell lines. The cell viability evaluated in MTT test and morphological study showed that CDs at concentrations of 0.45 and 0.88 mg/ml without a surfactant coating did not significantly inhibit the growth of HEK293 or M6 cells. However, CDs coated with surfactant (1% poloxamer solution) at a concentration of 0.65 mg/ml significantly reduced the metabolic activity of both cell lines. Thus, the use of a surfactant-coated CDs reduced the metabolic activity of cells. This, combined with their luminescent properties, can be used for both the simultaneous therapy and diagnosis of tumors.