<br/>In photodynamic therapy (PDT), the light of known wavelength is used to activate a photosensitizing agent, which generates reactive oxygen species (ROS) in cancerous tissue. The ROS damages DNA and other nearby macromolecules, causing targeted cells to die. As a result of its clinical success, PDT is considered a viable alternative solution to treat localized cancers for which surgery may not be an option. Most PDT agents absorb red light. However, a dye that is best suited for PDT should absorb 700 nm to 900 nm near-infrared light. This wavelength window allows the maximum transmission of the light deeply into targeted tissues. In this presentation, we report on a symmetrical carbocyanine dye with two 4-quinolinium rings that are attached by a central pentamethine bridge meso-substituted with bromine (ESS-2-4). UV-Visible spectra show that the dye not only absorbs near-infrared light but that it avidly interacts with DNA in aqueous solutions. Agarose gel electrophoresis demonstrates that the dye cleaves DNA when irradiated with 830 nm near-infrared light (pH 7.0, 10 degrees C). ESS-2-4 is additionally taken up by ES2 ovarian cancer cells, where it causes substantial levels of near-infrared photo-toxicity. Therefore, the preliminary data presented here, suggest that 4-quinolinium-based carbocyanine dyes may one day be useful in photodynamic cancer therapy.

A study of near infrared DNA damage and photo-cytotoxicity by a brominated 4-quinolinium dicarbocyanine dye (ESS-2-4)

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.