Multifunctional effects of Cys–CdTe QDs conjugated with gambogic acid for cancer cell tracing and inhibition

Abstract

We have studied the multifunctional effects of cysteamine-coated cadmium–tellurium quantum dots (Cys–CdTe QDs) conjugated with gambogic acid (GA) for cancer cell labeling and cancer treatment. Our results indicated that the Cys–CdTe QDs (about 3 nm) could readily bind on the cell plasma membranes and then be internalized into cancer cells for real-time tracing and treatment of human leukemia cancers. The positively charged surface of the self-assembled and conjugated GA with the Cys–CdTe QDs could significantly enhance the drug accumulation into leukemia K562 cells and the drug's cytotoxicity, to inhibit the cancer cell proliferation. The GA–Cys–CdTe nanocomposites improved the drug action to overcome the multidrug resistance of K562/A02 cells and facilitated the GA induced G0/G1 phase cancer cell cycle arrest to promote cell apoptosis. Moreover, the sensitive pH-triggered release behavior of the relevant nanocomposites, loaded with GA, greatly reduced the side effects of the anticancer agents to the normal cells/tissues in the blood circulation and facilitated an efficient drug release and accumulation in the target tumor cells. Thus, the combination of an active compound from Traditional Chinese Medicine (TCM), GA, with Cys–CdTe QDs can afford a new strategy for the potential multimode cancer therapy.