Photoexcited TiO2 nanoparticles through .OH- radicals induced malignant cells to necrosis

Photoexcited TiO2 nanoparticles have been used to cause oxidative stress in SPC-A1 lung adenocarcinoma cells in this study. It is commonly considered that hydroxyl free radicals can oxidatively stress cells to apoptosis, but through this experiment, we found that oxidative stress produced by photoex cited TiO2 nanoparticles in the malignant cells led to cell necrosis, not, as it is thought, apoptosis. This was confirmed by TEM observation and DNA electrophoresis analysis. The possible mechanism of oxidative-stress-induce d necrosis by photoexcited TiO2 nanoparticles was discussed. The research r evealed a novel possible way to kill tumor cells in the future. (C) 1998 El sevier Science Limited. All rights reserved.