Drug–biomolecule interactions in the excited state are relevant from a photobiological point of view as they can be correlated with a number of photosensitization disorders such as photocarcinogenicity, photoallergy, phototoxicity, etc. Nonsteroidal antiinflammatory 2-arylpropionic acids and antibacterial fluoroquinolones have been selected as typical examples of photoactive drugs. Protein phot...

OBJECTIVES It has been demonstrated that the efficiency of lethal photosensitization can be improved by covalently binding photosensitizing agents to bacteriophage. In this study we have investigated whether a bacteriophage requires the capacity to infect the bacterium to enhance lethal photosensitization when linked to a photosensitizer. METHODS Tin (IV) chlorin e6 (SnCe6) was conjugated to ...

The bacterium Propionibacterium acnes is light-sensitive due to porphyrin-induced photosensitization. The light sensitivity increases with incubation of 5-aminolevulinic acid, ALA. For the first time, 1H magic angle spinning NMR spectroscopy is used to describe the photoinduced changes in the bacterium after ALA incubation. Successful photosensitization was performed with light-emitting diodes ...

Reactive oxygen species (ROS) have been implicated in skin tumor promotion. Earlier, we showed that porphyrin-mediated cutaneous photosensitization results in the in situ generation of ROS. Recently, we have provided the first in situ evidence for the involvement of ROS in stage I tumor promotion. In this study we further show that in situ-generated ROS act as weak complete tumor promoters in 7...

The Friend virus complex was used as a model to study the effects of merocyanine 540 (MC 540)-mediated photosensitization on enveloped viruses. Simultaneous exposure to the lipophilic dye MC 540 and white light inactivated cell-free virus, cell-associated virus, and virus-transformed cells. When used under experimental conditions that are known to preserve most mature blood cells, at least some...

Certain drugs are known to elicit photosensitivity side effects. A satisfactory understanding of the involved mechanistic aspects is necessary to anticipate the photosensitizing potential. We have used tiaprofenic acid (TPA), a photosensitizing nonsteroidal antiinflammatory drug, to illustrate the methodology followed to address this problem. After studying the photophysical and photochemical p...

The aromatic amino acid tryptophan is the most susceptible protein residue involved in various photosensitized adverse effects. Of these processes, the tryptophan photosensitization induced by methylene blue has been well studied. A predominant type II photosensitizing activity, mediated by singlet oxygen, has been already demonstrated on various models. The purpose of this study is to compare ...