Study on the mechanism of killing HeLa cells caused by photoexcitation of folic acid-modified titanium dioxide particles

• Main Authors: Tzu-Ying Lai, 賴紫盈
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/35972677658196105405

碩士 === 國立中正大學 === 化學工程所 === 96 === Titanium dioxide photocatalyst can produce reactive oxygen species (ROS) such as hydroxyl radical and superoxide anion under UV illumination. These reactive oxygen species are useful for photodegradating organic compounds. Therefore titanium dioxide nanoparticles have a very wide range of application. In this research, we utilized this characteristics of titanium dioxide to kill cancer cells. In order to increase the specifility of titanium dioxid to cancer cells, we used the chemical adsorption method to modify titanium dioxide particles with folic acid. After the conjugation of folic acid and titanium dioxide particles, zeta-potential and FT-IR always were used to confirmed the succsess of folic aicd modification. Besides, we used flow cytometry to detect the specifility of the modified titanium dioxide particles. In the experiment of photo-killiing of cancer cells, we found that the best titanium dioxide-to-folic acid ratio was 5 to 1. After the illumination of UV lamp for 15 minutes, the survival rate of cells incubated with modified titanium dioxide particles decreased to 17%, while the non-modified titanium dioxide particles resulted in a survival rate of 48%. The difference between data from modified and non-modified titanium dioxide particles was about 30%. Finally, we used Annexin V apoptosis assay to investigate that the mechanism of photokilling of cacer cells. It was found both apoptosis and necrosis were present.