title: Photosensitizer drug delivery via an optical fiber.
abstract: An optical fiber has been developed with a maneuverable mini-probe tip that sparges O(2) gas and photodetaches pheophorbide (sensitizer) molecules. Singlet oxygen is produced at the probe tip surface which reacts with an alkene spacer group releasing sensitizer upon fragmentation of a dioxetane intermediate. Optimal sensitizer photorelease occurred when the probe tip was loaded with 60 nmol sensitizer, where crowding of the pheophorbide molecules and self-quenching were kept to a minimum. The fiber optic tip delivered pheophorbide molecules and singlet oxygen to discrete locations. The 60 nmol sensitizer was delivered into petrolatum; however, sensitizer release was less efficient in toluene-d(8) (3.6 nmol) where most had remained adsorbed on the probe tip, even after the covalent alkene spacer bond had been broken. The results open the door to a new area of fiber optic-guided sensitizer delivery for the potential photodynamic therapy of hypoxic structures requiring cytotoxic control.
authors.affiliation: Department of Chemistry and Graduate Center, City University of New York, Brooklyn College, Brooklyn, New York 11210, USA.
authors.forename: Matibur
authors.initials: M
authors.lastname: Zamadar
authors.forename: Goutam
authors.initials: G
authors.lastname: Ghosh
authors.forename: Adaickapillai
authors.initials: A
authors.lastname: Mahendran
authors.forename: Mihaela
authors.initials: M
authors.lastname: Minnis
authors.forename: Bonnie I
authors.initials: BI
authors.lastname: Kruft
authors.forename: Ashwini
authors.initials: A
authors.lastname: Ghogare
authors.forename: David
authors.initials: D
authors.lastname: Aebisher
authors.forename: Alexander
authors.initials: A
authors.lastname: Greer
mesh_terms: D016503:Drug Delivery Systems; D055100:Optical Fibers; D017319:Photosensitizing Agents / Q000008:administration & dosage*
chemical_list: D017319:Photosensitizing Agents