Laser dyes for experimental phototherapy of human cancer: comparison of three rhodamines.
Laryngoscope
; 102(1): 81-7, 1992 Jan.
Article
em En
| MEDLINE
| ID: mdl-1731162
ABSTRACT
The mitochondrial dye Rhodamine 123 (Rh-123) has been shown to be an effective photosensitizer for argon-laser irradiation of some types of human cancer cells in vitro. We reported that 514.5-nm laser illumination of Rh-123 sensitized human melanoma, and squamous carcinoma cells strongly inhibited tumor-cell proliferation as measured by decreased 3H-thymidine (3H-T) uptake in vitro and may eradicate some tumors when grown as transplants in nude mice. However, several other human tumors were resistant to Rh-123 laser therapy in vitro and in vivo. In the current study, it was possible to obtain 100- to 1000-fold increased sensitivity to 514.5-nm laser illumination by replacement of Rh-123 with the cationic rhodamine dyes Rh-3G and Rh-6G. Cell viability was decreased over 95% and 3H-T incorporation reduced at least 80% by laser phototherapy after sensitizing tumor cells with 1 micrograms/mL Rh-123, 0.01 microgram/mL Rh-3G, or 0.001 microgram/mL Rh-6G. However, Rh-123 alone did not decrease 3H-T uptake significantly unless present at over 10- to 100-fold higher levels than Rh-3G, respectively. The tumor cell dye uptake level was measured by N-butanol extraction and absorption scans at 400 to 600 nm. The results revealed that dye uptake was more rapid, and retention of Rh-3G and Rh-6G was 5- to 10-fold higher than for Rh-123 in the human tumor cells. The data suggest that Rh-3G and Rh-6G may be highly sensitive chromophores for laser phototherapy of human cancer cells.
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Base de dados:
MEDLINE
Assunto principal:
Fotoquimioterapia
/
Rodaminas
/
Terapia a Laser
/
Corantes Fluorescentes
/
Neoplasias
/
Antineoplásicos
Idioma:
En
Ano de publicação:
1992
Tipo de documento:
Article