Quantitative methods for studying the role of free radicals in biology

Judit Jakus, Tamas Kriska, Tatjana K. Maximova, Andras Nemeth, Laszlo Korecz, Dezso Gal

Research output: Contribution to journalConference article

1 Citation (Scopus)


The mechanism of the primary sensitization steps in Photodynamic Therapy could be of essential importance concerning the efficiency of the treatment. Besides the well known mechanisms there is a possibility that the interaction between the excited triplet state sensitizer and the doublet state free radicals generated by the cells adds a significant contribution to the overall photodynamic effect. To support this hypothesis the quantification and identification of free radicals would be required. For this purpose chemiluminescence studies and spin trapping seemed to be the most suitable methods due to the extremely short lifetime of free radicals in biological systems. We present data on the kinetics of accumulation of free radicals: by measuring luminol-dependent chemiluminescence of stimulated macrophages both in the absence and in the presence of a free radical inhibitor 3,5 di-tert-butyl-4-hydroxyphenyl propionic acid; by following the production of primary, secondary and tertiary radical adducts using DMPO (5,5-dimethyl-1-pyrroline N-oxide) as spin trapping agent in chemical model systems. The measured data are used to determine the effect of the excited sensitizers on the kinetics of accumulation of free radicals under biological conditions. These results would serve to design new and more effective sensitizers used for therapy based on the triplet-doublet mechanism of action.

Original languageEnglish
Pages (from-to)100-111
Number of pages12
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - Jan 1 1999
EventProceedings of the 1998 Photochemotherapy of Cancer and Other Diseases - Stockholm, SWE
Duration: Sep 9 1998Sep 11 1998


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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