Effects of aloe-emodin nanoliposome-induced photodynamic therapy on human gastric cancer cells

Abstract:

Objective：To investigate the effects of aloe-emodin nanoliposome-induced photodynamic therapy（PDT） on the prolifera－tion and apoptosis of human gastric cancer cells. Methods：Human gastric cancer cells SGC-7901 were cultured in vitro with aloe-e－modin nanoliposome at the concentration of 16 μg/ml for 1，2，4，6，8 h and the uptake of aloe-emodin nanoliposome in the gastric cancer cells was detected by confocal laser scanning. The SGC-7901 were treated by different concentrations of aloe-emodin（0，2，4，8，16，32 μg/ml） for 4 h and then were given blue uv（wavelength of 430 nm，continuous output mode，power density of 40 mW/cm2） illumination with different energy densities（0.0，0.8，1.6，3.2，6.4，12.8，25.6 J/cm2）. Survival rate of gastric cancer cells was tested by MTT assay. Human gastric cancer cells SGC-7901 were dealt with aloe-emodin nanoliposome（16 μg/ml） for 4 h，and then received the blue uv（wavelength of 430 nm，continuous output mode，power density of 40 mW/cm2） illumination with 6.4 J/cm2 energy density. Cell apoptosis and apoptosis rate were analyzed by using Hoechst33342 and flow cytometry respectively. Results：Uptake time of aloe-emodin nanoliposome in gastric cancer cells peaked at 4 h. No significant difference was found in the cell survival rate when the human gastric cancer cells being dealt with aloe-emodin nanoliposome（concentration<8 μg/ml） for 4 h（P=0.945，P=0.074）. There was no significant difference in the inhibition of gastric cancer cells between single light irradiation group and nanoliposome group（P=0.125）. After gastric cancer cells being dealt with aloe-emodin nanoliposome（16 μg/ml） and blue uv illumination with the energy density of 6.4 J/cm2 for 4 h，the apoptosis rate in PDT group was higher than that in single light irradiation group and nanoliposome group based on results of flow cytometry. Karyopyknosis，fragmentation and apoptotic body were also found by Hoechst33342. Conclusions：Apoptosis of gastric cancer cells can be induced by aloe-emodin nanoli－posome-PDT significantly. Aloe-emodin nanoliposome-induced PDT may be used as a novel effective treatment for gastric can－cer.