Uptake of carbon nanodots into human acute myeloid leukemia (AML) cells in comparison to primary hematopoietic cells

Carbon nanodots (CNDs) are a promising class of nanoparticles. These carbon based, nanometer-sized particles offer a broad spectrum of potential biomedical applications like bioimaging, cancer diagnosis and drug delivery. In context of drug delivery, a selective uptake by malignant cells is crucial. Our aim was to investigate whether there is a differential uptake into AML cells compared to primary hematopoietic cells. CNDs prepared using citric acid and diethylenetriamine were incubated for 24 h with malignant cells from five patients with de novo AML and primary hematopoietic cells from three normal donors. The differential uptake of the CNDs was studied by flow cytometry and monoclonal antibodies. A significant CND uptake was observed in all cell types of the normal and leukemic cells. However, the uptake was significantly smaller for the CD34⁺ and CD33⁺ myeloid subsets of the malignant cell population. T- (CD3⁺) and B- (CD19⁺) lymphoid cells within the leukemic and healthy samples showed a similar uptake. The subcellular distribution was examined on HL-60 cells. Confocal microscopy images show perinuclear accumulation of CNDs in lysosomes. This particular localization could be useful for therapeutical targeting.