The effect of photodynamic therapy on cultured rat C6 glioma cells under different conditions

Abstract

Objective To evaluate the effect of hepatoprophyrin derivative (HpD) mediated photodynamic therapy (PDT) on cultured C6 glioma cells. Methods Cell survival rate examination after HpD-PDT treatment: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyhertrazolium bromide (MTr) assay was used to determine eell survival rate 24 hrs after irradiation by Lumaeare-051 as follows: (1) C6 cells were irradiated at 628 nm, 20 mW/cm2 for 5 rain afrer being incubated with different concentration of HpD (0, 2, 5, 10, 20, 30 and 40 mg/L) respectively; (2) Cells were irradiated at 628 nm, 20 mW/cm2 for 5 min after being ineubated with HpD for different time periods (0. 5, 1, 3, 6, 12 and 24 hrs); (3) After being incubated with HpD, Cells were irradiated at 628 nm for 5 min at different light output power (10, 20 and 30 mW/cm2). Cell survival rate was calculated as follows: Survival(%)=(mean O. D. value of treated cell/mean O. D. value of control cell) × 100%. Results The effect of HpD-PDT on C6 cells differed under different conditions: No cell death was seen in low HpD concentration (2 mg/L) or short time incubation (< 3 h) groups; Cell survival rate decreased as the concentraion of HpD, incubation time with HpD and light output power increased. Conclusions The effect of HpD-PDT differes under different conditions, which is correlated to the concentration of HpD, incubation time of C6 cells with HpD and also the light output power. Key words: Glioma; Photodynamic therapy (PDT); C6 glioma cell; Hematoporphyrin derivative(HpD)