Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 3...

Time-dependent UV/visible absorption changes are observed on photolysis of aerated solutions of monodisperse, vinyl end-capped 2,5-diheptyloxyl substituted PV-oligomers (OPV, n = 1, 2, 3). In all cases, photolysis occurs in at least two distinct stages. Evidence for the intermediacy of singlet oxygen comes from pulse radiolysis and time-resolved luminescence studies, which confirm formation of ...

By using an anthryl-substituted 2,2'-bipyridine as a singlet oxygen-reactive ligand, a new class of Ru(II)-bipyridine complex derivatives that can specifically respond to singlet oxygen with remarkable phosphorescence enhancements have been successfully developed.

The autofluorescent pigments that accumulate in retinal pigment epithelial cells with aging and in some retinal disorders have been implicated in the etiology of macular degeneration. The major constituent is the fluorophore A2E, a pyridinium bisretinoid. Light-exposed A2E-laden retinal pigment epithelium exhibits a propensity for apoptosis with light in the blue region of the spectrum being mo...

Cyanobacteria have developed a photoprotective mechanism that decreases the energy arriving at the photosynthetic reaction centers under high-light conditions. The photoactive orange carotenoid protein (OCP) is essential in this mechanism as a light sensor and energy quencher. When OCP is photoactivated by strong blue-green light, it is able to dissipate excess energy as heat by interacting wit...

The autofluorescent pigments that accumulate in retinal pigment epithelial cells with aging and in some retinal disorders have been implicated in the etiology of macular degeneration. The major constituent is the fluorophore A2E, a pyridinium bisretinoid. Light-exposed A2E-laden retinal pigment epithelium exhibits a propensity for apoptosis with light in the blue region of the spectrum being mo...

We have recently demonstrated that singlet oxygen-mediated photooxidation can cause an increase in blue fluorescence and covalent cross-linking in bovine lens crystallins in vitro. Because these changes closely parallel modifications known to occur in human crystallins during aging and cataractogenesis, it was suggested that singlet oxygen may play an important role in these processes in vivo. ...

The reactivity of a trisubstituted alkene surfactant (8-methylnon-7-ene-1 sulfonate, 1) to airborne singlet oxygen in a solution containing E. coli was examined. Surfactant 1 was prepared by a Strecker-type reaction of 9-bromo-2-methylnon-2-ene with sodium sulfite. Submicellar concentrations of 1 were used that reacted with singlet oxygen by an "ene" reaction to yield two hydroperoxides (7-hydr...

The photosensitized generation of reactive oxygen species, and particularly of singlet oxygen [O2 (a(1) Δg )], is the essence of photodynamic action exploited in photodynamic therapy. The ability to switch singlet oxygen generation on/off would be highly valuable, especially when it is linked to a cancer-related cellular parameter. Building on recent findings related to intersystem crossing eff...