The Effect Of Photodynamic Therapy On Rat C6 Glioma Cells In Vitro

Objectives: To evaluate the lethal effect of hepatoprophyrin derivative(HpD) mediated photodynamic therapy (PDT) on cultured C6 glioma cells so as to provide the further evidence for the clinical application of the technique.Methods: This study consists of two parts.Part one: Examination of cell survival rate and structure of C6 glioma cells after different HpD-PDT treatment:1. 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltertrazolium bromide(MTT) assay was used to determine the cell survival rate of C6 glioma cells 24 hrs after irradiation by Lumacare-051 irradiator as follows:1) C6 glioma cells were irradiated at 628 nm, 20 mW/cm2 for 5 min afrer being incubated with different concentration of HpD (0, 2, 5, 10, 20, 30 and 40 mg/L)respectively.2) C6 glioma cells were irradiated at 628 nm, 20 mW/cm2 for 5 min after being incubated with HpD for different times respectively (0, 5, 1, 3, 6, 12 and 24 hrs).3) After being incubated with HpD in different concentration, C6 gliomas cells were irradiated at 628 nm for 5 min at different light power output (10, 20 and 30 mW/cm2) respectively.The cell survival rate was calculated as follows: Survival(%)=(mean O.D. value of treated cell/mean O.D. value of control cell)×100%.2. Inverted phase contrast microscope was used to observe the changes of structure of C6 glioma cells of each group.3. Transmitted eletron microscope (TEM) was used to examine the ultrastructural characteristics of C6 glioma cells of each group.Part two: Primary examination on the possible pathway of HpD-PDT induced C6 glioma cell death:1) DNA agarose gel electrophoresis (AGE) was used to determine the DNA band of C6 glioma cells after HpD-PDT.