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World J Gastroenterol. Aug 7, 2007; 13(29): 4011-4014
Published online Aug 7, 2007. doi: 10.3748/wjg.v13.i29.4011
Nano-cerium-element-doped titanium dioxide induces apoptosis of Bel 7402 human hepatoma cells in the presence of visible light
Long Wang, Jian Mao, Gao-Hua Zhang, Ming-Jing Tu
Long Wang, Jian Mao, Ming-Jing Tu, College of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan Province, China
Long Wang, Mechanical Department, Zhongshan Torch Polytechnic, Zhongshan 528436, Guangdong Province, China
Gao-Hua Zhang, State Key Laboratory of Biotherepy, Chengdu 610041, Sichuan Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Jian Mao, College of Materials Science and Engineering, Chengdu 610064, Sichuan Province, China. maojianemail@163.com
Telephone: +86-28-85404370 Fax: +86-28-85404370
Received: March 8, 2007
Revised: April 15, 2007
Accepted: April 4, 2007
Published online: August 7, 2007
Abstract

AIM: To investigate the apoptotic effect of photoexcited titanium dioxide (TiO2) nanoparticles in the presence of visible light on human hepatoma cell line (Bel 7402) and to study the underlying mechanism.

METHODS: Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L CO2 at 37°C. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells.

RESULTS: The Ce (IV)-doped TiO2 nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 μg/cm3 Ce (IV)-doped TiO2 induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33 258 staining of the fixed cells revealed typical apoptotic structures (apoptotic bodies), agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones.

CONCLUSION: Ce (IV) doped TiO2 nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.

Keywords: Nano titanium dioxide; Cerium; Photocatalysis; Apoptosis; Hepatoma cells