Dosimetry of laser radiation for in vitro cancer cells inactivation using exogenous chlorophyll and protoporphyrin IX (PpIX)

Abstract

The aim of this research is to study dosimetry of red diode laser radiation for breast cancer cells MCF-7 inactivation with and without the addition of the photosensitizer. Chlorophyll and Protoporphyrin IX (PpIX) were used as exogenous photosensitizers in this research, each with a concentration of 0.25 mg/ml and 0.0006 mM based on the results of acytotoxicity assay. Energy doses of laser irradiation used in this research were between 0.68 to 6.80 J/cm2 with two different laser powers (10 mW and 20 mW). The results showed that the higher dose of laser energy, the greater the percentage of cancer cells death. At the same energy dose, the higher the laser power resulted in a higher percentage of deaths as well. The highest percentage of deaths produced by a laser with power 20 mW and irradiation time 10 minutes (energy dose of 6.80 J/cm2) was 68.75% for laser irradiation without photosensitizer, 83.15% for laser irradiation with the addition of chlorophyll, and 93.59% for the laser irradiation with the addition of PpIX. Based on these results, it could be concluded that the red laser irradiation with addition photosensitizer chlorophyll and PpIX can inactivate cancer cells and can be used as a candidate for photodynamic therapy.