title: Bioinhibition of human fibroblast cultures sensitized to Q-switch II dye and treated with the Nd: YAG laser: a new technique of photodynamic therapy with lasers.
abstract: Kodak Q-switch II dye has recently proven to be an effective biostimulative agent on normal human fibroblast cultures. The potential for this dye as a new chemosensitizing agent for the treatment of connective tissue diseases and wound healing with the Nd:YAG laser was examined. Two normal fibroblast cell lines were first sensitized to a nontoxic dose of Q-switch II dye, then subjected to treatment with an Nd:YAG laser at 1,060 nm, with varying levels of energy and temperatures determined by a reproducible method of dosimetry. The results indicate that Q-switch II dye at nontoxic doses of 0.1 micrograms/ml enhances the cytotoxic effects of the Nd:YAG laser at temperatures as low as 36 degrees C. Furthermore, at physiological temperature ranges as low as 24 degrees C to 34 degrees C, cell duplication was inhibited, but cell viability was not affected. Similar results were not observed when fibroblast cultures were treated with the laser alone. These observations suggest that Q-switch II dye is an effective chemosensitizing agent for the Nd:YAG laser and could potentially be used to reduce collagen deposits in conditions such as keloids and hypertrophic scars.
authors.affiliation: Division of Head and Neck Surgery (Otolaryngology), UCLA School of Medicine 90024.
authors.forename: D J
authors.initials: DJ
authors.lastname: Castro
authors.forename: R E
authors.initials: RE
authors.lastname: Saxton
authors.forename: H R
authors.initials: HR
authors.lastname: Fetterman
authors.forename: D J
authors.initials: DJ
authors.lastname: Castro
authors.forename: P H
authors.initials: PH
authors.lastname: Ward
mesh_terms: D001578:Benzopyrans / Q000494:pharmacology*; D002470:Cell Survival; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology; D005456:Fluorescent Dyes / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D010778:Photochemotherapy / Q000379:methods*
chemical_list: D001578:Benzopyrans; D005456:Fluorescent Dyes; C054228:Q-switch II dye