UV-enhanced toxicity of water-stable quantum dots in human pancreatic carcinoma cells

Abstract

Zn-based (capped with thioglycolic acid (TGA) or 3-mercaptopropionic acid (MPA)) and Cd-based quantum dots (QDs) (capped with TGA or L-glutathione), were synthesised and used to investigate their cytotoxicity to human pancreatic carcinoma cells (PANC-1) in absence and presence of UV irradiation. Zn-based QDs exhibited less intrinsic cytotoxicity than the Cd-based QDs, however, the excitation of 50 mg/mL-QDs using UV lamp significantly enhanced the cytotoxicity of both QDs. After 15 min of UV irradiation, the viability for cells exposed to Cd-based QDs capped with TGA or glutathione was 49% AE 6% or 56% AE 3%, respectively. The corresponding cell viability in the control test was 83% AE 8% after 15 min of UV irradiation. In turn, the viability for cells exposed to Zn-based QDs capped with 3-MPA or TGA was 64% AE 3% and 52% AE 3%, respectively, after 30 min of UV irradiation; the cell viability in the control test was 80% AE 7% for the same UV irradiation time. Laser scanning confocal analyses evidenced that QDs can be easily ingested by PANC-1. Based on their good compositional stability, Zn-based QDs capped with 3-MPA can be considered a promising material for nanomedicine applications until concentrations of 200 mg/mL.

Engineering of relevant photodynamic processes through structural modifications of metallotetrapyrrolic photosensitizers

“…Release of Cd 2+ and subsequent generation of radicals damages the plasma membrane and organelles [239][240][241]. Several groups have reported the cytotoxicity of QDs under UV irradiation [242,243]. However, the proper choice of QD components or their wrapping with a biocompatible shell structure may significantly reduce the toxic effect [244].…”