title: Synthesis of a photostable near-infrared-absorbing photosensitizer for selective photodamage to cancer cells.
abstract: A new class of near-infrared (NIR)-absorptive (>900 nm) photosensitizer based on a phenothiazinium scaffold is reported. The stable solid compound, o-DAP, the oxidative form of 3,7-bis(4-methylaminophenyl)-10H-phenothiazine, can generate reactive oxygen species (ROS, singlet oxygen and superoxide) under appropriate irradiation conditions. After biologically evaluating the intracellular uptake, localization, and phototoxicity of this compound, it was concluded that o-DAP is photostable and a potential selective photodynamic therapy (PDT) agent under either NIR or white light irradiation because its photodamage is more efficient in cancer cells than in normal cells and is without significant dark toxicity. This is very rare for photosensitizers in PDT applications.
authors.affiliation: Graduate Institute of Biomedical Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan (R.O.C.).
authors.forename: Tung-Sheng
authors.initials: TS
authors.lastname: Hsieh
authors.forename: Jhen-Yi
authors.initials: JY
authors.lastname: Wu
authors.forename: Cheng-Chung
authors.initials: CC
authors.lastname: Chang
mesh_terms: D002460:Cell Line; D005347:Fibroblasts / Q000187:drug effects / Q000528:radiation effects; D006367:HeLa Cells; D006801:Humans; D010084:Oxidation-Reduction; D010640:Phenothiazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D055668:Photochemical Processes; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry
chemical_list: D010640:Phenothiazines; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D026082:Singlet Oxygen
keywords: near infrared; phenothiazinium; photodamage; photosensitizers; reactive oxygen species