Effect of graphene oxide nanoparticles on apoptosis of T-lymphocytes and Jurkat cells

Graphene and its derivatives are materials with unique physicochemical properties. A detailed study of these materials allows to consider them prospective biomedical agents for targeted drug and gene delivery, photothermal therapy of cancer, bioimaging, etc. However, this requires a comprehensive studies of their effects on the body tissues, including cells of the immune system. The aim of our research was to stydy the effects of nanoparticles based on pegylated graphene oxide (GO) upon apoptosis of T lymphocytes derived from blood of healthy donors and Jurkat 5332 cell line. Comparison of these cells will extend our knowledge of the effects of nanomaterials on the cells, and to respond the question, what results obtained with continuous cell lines are valid for normal non-malignant cells. In this work, we used GO nanoparticles (100-200 nm, 1-5 m) coated with linear (LP-GO) and branched (BP-GO) polyethylene glycol (PEG). The cells were cultured for 24 hours at 37 C and 5% CO2with nanoparticles at concentrations of 5 and 25 g/mL. Viability and early and late apoptosis of incubated Jurkat cells and CD3+cells from healthy donors were assessed by flow cytometry. It was found that the small nanoparticles coated with linear PEG at high concentrations (25 g/mL) could significantly reduce the number of live cells and increase the number of cells in late apoptosis. At the same time, large nanoparticles coated with branched PEG at high concentrations (25 g/mL) increased the percentage of T cells in early apoptosis. Meanwhile, the GO nanoparticles at both concentrations did not affect the viability and apoptosis of Jurkat cells, regardless of the size, concentration, and type of surface function of the particles. The obtained results suggest that GO nanoparticles exert different effects upon normal and malignant lymphocytes of T lineage. One may assume that these discrepancies could be explained by greater resistance of tumor cells compared to normal T cells. These findings suggests that studies of nanomaterials upon living cells should not be limited to experiments on cell lines, since their properties may significantly differ from those of non-malignant cells.