UV-enhanced cytotoxicity of thiol-capped CdTe quantum dots in human pancreatic carcinoma cells

Quantum dots (QDs) have been gaining popularity due to their potential application in cellular imaging and diagnosis, but their cytotoxicity under light illumination has not been fully investigated. In this study, green and red mercaptopropionic acid capped CdTe quantum dots (MPA-CdTe QDs) were employed to investigate their cytotoxicity in human pancreatic carcinoma cells (PANC-1) under UV illumination. MPA-CdTe QDs exhibited excellent photostability, under UV illumination and could be easily ingested by cells. The cytotoxicity of MPA-CdTe QDs was significantly enhanced under UV illumination, which was determined by changes in cell morphology as well as by decreases in the metabolic activity and cell counting. Our results indicated that green and red QDs had different cellular distribution and exhibited distinct UV-enhanced cytotoxicity. UV illumination enhanced the generation of reactive oxygen species (ROS) in cells containing QDs, and NAC antioxidant could reduce their damage to cells under UV illumination. Moreover, the influences of different UV illumination conditions on the viability of cells containing QDs were examined and discussed in detail. (C) 2009 Elsevier Ireland Ltd. All rights reserved.