Photodynamic efficiency of macrophage activity using a photosensitizer, lumin, with near-IR laser light for photoimmunotherapy of a cancer
Mito, K.
Frontiers of Medical and Biological Engineering the International Journal of the Japan Society of Medical Electronics and Biological Engineering 7(2): 81-92
1996
ISSN/ISBN: 0921-3775 PMID: 8803558 Document Number: 459181
This study was carried out to determine the efficacy of photoimmunotherapy using a photosensitizer, lumin, and near-IR laser light irradiation for cancer therapy. Lumin is a potent cell-activating agent and a photosensitizer characterized by typical absorption peaks at 670 and 770 nm. To clarify that ingestion activity is enhanced by lumin administration with different light irradiation, He-Ne laser light (632.8 nm) and near-IR laser light (780 nm) were used. The results showed that a small dose of lumin (5 ng/ml) with near-IR laser light dramatically enhanced the ingestion activity. A human lung cancer grafted onto nude mice was used in this study. After the tumor hypertrophied, lumin was injected into it six times. Then, it was exposed to near-IR laser light (2 mW, 1 min) every other day for 2 weeks. The whole tumor was strongly cicatrized by collagen fiber from the stroma. It was removed 15 weeks after the treatment. Immunological function was investigated using a two-color flow cytometric assay method based on immunofluorescence labeling with specific monoclonal antibodies of 10(4) cell samples harvested from mouse peripheral blood. At 40 weeks, the ratio of T cells to B cells in untreated mice was 0.23, whereas that in treated mice was 0.58. These results demonstrated that photoimmunotherapy with lumin administration and laser light irradiation is a reliable method of cancer therapy.