Quantitative assessment of singlet oxygen production for the new cancer therapeutics (2013)

Undergraduate: Chuheng Ding

Faculty Advisor: Malcolm Forbes
Department: Chemistry

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My undergraduate research aims to develop a quantitative assess for the production of singlet oxygen, a reactive molecule used in a clinical cancer treatment called Photodynamic Therapy (PDT). PDT is a cancer treatment currently approved for the treatment of squamous cell carcinomas of the head and neck, basal cell carcinomas on the skin. This treatment uses visible light and a sensitizer molecule (usually a porphyrin such as the commercial product Photofrin¿) to create the highly reactive singlet oxygen, which initiates oxidative stress and can trigger cell death. Current PDT treatment protocol has been closely examined and can be improved with a better drug delivery system that increases local treatment intensity. Singlet oxygen production and topology at the treatment site is mimicked using hindered secondary amine that forms a stable nitroxide radical in competition with other singlet oxygen deactivation pathways. This radical is observable by electron paramagnetic resonance spectroscopy, allowing for indirect quantification of 1*O2. Further, hindered piperidine derived precursors ((secondary amine)used in these studies are easily modified to examine singlet oxygen production in heterogeneous environments such as vesicles, micelles and tissues.