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Cancerous Cell Death from Sensitizer Free Photoactivation of Singlet Oxygen
Author(s) -
Anquez François,
El YazidiBelkoura Ikram,
Randoux Stéphane,
Suret Pierre,
Courtade Emmanuel
Publication year - 2011
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2011.01028.x
Subject(s) - singlet oxygen , photosensitizer , photodynamic therapy , reactive oxygen species , photochemistry , oxygen , chemistry , oxidative stress , reactivity (psychology) , programmed cell death , biophysics , apoptosis , biochemistry , biology , organic chemistry , medicine , alternative medicine , pathology
Singlet oxygen ( 1 O 2 ) is an electronic state of molecular oxygen which plays a major role in many chemical and biological photo‐oxidation processes. It has a high chemical reactivity which is commonly harnessed for therapeutic issues. Indeed, 1 O 2 is believed to be the major cytotoxic agent in photodynamic therapy. In this treatment of cancer, 1 O 2 is created, among other reactive species, by an indirect transfer of energy from light to molecular oxygen via excitation of a photosensitizer (PS). This PS is believed to be necessary to obtain an efficient 1 O 2 production. In this paper, we demonstrate that production of 1 O 2 is achieved in living cells from PS ‐free 1270 nm laser excitation of molecular oxygen. The quantity of 1 O 2 produced in this way is sufficient to induce an oxidative stress leading to cell death. Other effects such as thermal stress are discriminated and we conclude that cell death is only due to 1 O 2 creation. This new simplified scheme of 1 O 2 activation can be seen as a breakthrough for phototherapies of malignant diseases and/or as a noninvasive possibility to generate reactive oxygen species in a tightly controlled manner.