title: Long-distance energy transfer photosensitizers arising in hybrid nanoparticles leading to fluorescence emission and singlet oxygen luminescence quenching.
abstract: This paper presents energy transfer occurring in small organically modified core-shell nanoparticles (core lanthanide oxide, shell polysiloxane) (diameter < 10 nm) conjugated with photosensitizers designed for photodynamic therapy applications. These nanoparticles covalently encapsulate a photosensitizing PDT drug in different concentrations. Stable dispersions of the nanoparticles were prepared and the photophysical properties of the photosensitizers were studied and compared to those of the photosensitizers in solution. Increasing the photosensitizer concentration in the nanoparticles was not found to cause any changes in the absorption properties while fluorescence and singlet oxygen quantum yields decreased. As a possible explanation, we have suggested that both long distance energy transfer such as FRET and self-quenching could occur into the nanoparticles. A simple "trend" model of this kind of energy transfer complies with results of experiments on steady state fluorescence and singlet oxygen luminescence.
authors.affiliation: LRGP, Laboratoire Réactions et Génie des Procédés, UPR 3349 CNRS, Nancy, France.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Sève
authors.forename: Pierre
authors.initials: P
authors.lastname: Couleaud
authors.forename: François
authors.initials: F
authors.lastname: Lux
authors.forename: Olivier
authors.initials: O
authors.lastname: Tillement
authors.forename: Philippe
authors.initials: P
authors.lastname: Arnoux
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: André
authors.forename: Céline
authors.initials: C
authors.lastname: Frochot
mesh_terms: D004337:Drug Carriers / Q000737:chemistry; D004735:Energy Transfer; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D007811:Lanthanum / Q000737:chemistry; D049449:Luminescence; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry*; D009369:Neoplasms / Q000188:drug therapy; D010087:Oxides / Q000737:chemistry; D055668:Photochemical Processes; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D004337:Drug Carriers; D010087:Oxides; D017319:Photosensitizing Agents; D012833:Siloxanes; D026082:Singlet Oxygen; C103829:lanthanum oxide; D007811:Lanthanum