Temperature monitored low dose ICG-PDT treatment of neuroblastoma cell lines

Photodynamic therapy (PDT) is a noninterventional technique used for cancer treatment. It makes use of a chemical agent sensitive to a specific wavelength of light and corresponding laser exposure. In our study, the effect of PDT with low concentration (5 μg/ml) indocyanine green (ICG) on the neuroblastoma cell lines (SH-SY5Y) was investigated. The cell lines (n = 7) were incubated for 24 hours after the administration of ther ICG. PDT was achieved with continuous wave laser irradiation (λ = 809 nm, 100 mW/cm²) for a dose of 60 J/cm². An infrared thermocouple sensor was focused in one of the wells for thermal monitoring. Temperature increase was not observed in any group during the treatment. Cell viability was measured by XTT assay. Laser, ICG and ICG-PDT groups showed a statistically significant decrease in cell viability. The cell viability decrease in ICG-PDT group was determined as approximately 83% in comparison to the control group (p<;0.01). ICG-PDT treatment has cytotoxic effects on neuroblastoma cell lines. Further research on this subject should focus on determining the ideal ICG concentrations and laser parameters.