Comparison of PDT efficiencies for photooxidation of substrate (NADPH) using a photosensitizer (Photofrin II)

Paulo R. Bargo, Parmeswaran Diagaradjane, Steven L. Jacques

Research output: Contribution to journalConference article

Abstract

Photooxidation was studied during PDT (Photodynamic therapy) in a model system using NADPH as the target substrate and Photofrin II as the photosensitizer. The efficiency of NADPH oxidation per photon absorbed by photosensitizer was determined as a function of substrate concentration. The kinetics of changes in absorbance (340 nm) was measured to assay oxidation of NADPH. The efficiency of oxidation increased (.002; .004: .0049; .005) with increasing NADPH concentration (0.4; 1; 3.5; 10 mM) and approached a stable value of 0.0048. Using typical values for the quantum efficiency of the Photofrin triplet state generation and the efficiency of singlet oxygen production we obtained a value for the efficiency of interaction between singlet oxygen and NADPH (0.024). Efficiency of diffusion of singlet oxygen was modeled with molecular diffusion theory using typical values for the singlet oxygen lifetime and the diffusion coefficient in aqueous solutions.

Original languageEnglish (US)
Pages (from-to)97-103
Number of pages7
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume3909
StatePublished - Jan 1 2000
EventOptical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy IX - San Jose, CA, USA
Duration: Jan 22 2000Jan 23 2000

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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