Photodynamic purging of leukemia cells by high-brightness light emitting diode and gallium-metal porphyrin

We applied a high-brightness light emitting diode (LED) and gallium-metal porphyrin (Ga-C10-P) for leukemia cell purging. The blue, blue-green, green, yellow-green, yellow, orange and red color LEDs were constructed in photo-irradiation equipment (BIOLED). We set up the BIOLED in a CO/sub 2/ incubator and cultured human chronic myelocytic leukemia cell line K562 in RPMI1640. We irradiated 525 nm green light, 612 nm orange light or 660 nm red fight on to the K562 cells in the presence of 0.1 /spl mu/M or 1 /spl mu/M Ga-C10-P. Surprisingly, the 525 nm photo-irradiation induced the suppression of proliferation of leukemia cells in the presence of 1 /spl mu/M Ga-C10-P. Our results suggest a possibility of eliminating leukemia cells in autologous bone marrow transplantation by photodynamic purging using LED light and Ga-C1O-P.