Tetrac-Conjugated Quantum Dots for Diagnosis and Treatment of Pancreatic Cancer: An In Vitro Evaluation

We report a preliminary investigation of the use of pegylated quantum dots (PEG-QDs) conjugated to tetraiodothyroacetic acid (tetrac), a thyroid hormone antagonist and anti-proliferative agent, as a luminescent probe for live cell imaging and treatment of human pancreatic cancer. PEG-QDs were conjugated to epoxyactivated tetrac through primary amino groups present on the PEG-QDs. Cellular entry of tetrac-conjugated PEG-QDs (tetrac-PEG-QDs) in vitro was examined by confocal microscopy and effects of PEG-QDs on cell proliferation were examined by CyQUANT® Cell Proliferation Assay. Tetrac-PEG-QDs exhibited a higher level of entry into pancreatic cancer (PANC-1) cells than unconjugated PEG-QDs. In addition, pre-incubation of cells with the thyroid hormone analogue L-thyroxine (T4) increased fluorescent intensity, indicating enhanced uptake of tetrac-PEG-QDs. Proliferation of PANC-1 cells was significantly inhibited by treatment with tetrac-PEG-QDs.