The effect of irradiance on virus sterilization and photodynamic damage in red blood cells sensitized by phthalocyanines.

E. Ben-Hur, Nicholas Geacintov, B. Studamire, M. E. Kenney, B. Horowitz

Research output: Contribution to journalArticle

Abstract

Phthalocyanines are being studied as photosensitizers for virus sterilization of red blood cells (RBC). During optimization of the reaction conditions, we observed a marked effect of the irradiance on production of RBC damage. Using a broad-band light source (600-700 nm) between 5 and 80 mW/cm2, there was an inverse relationship between irradiance and rate of photohemolysis. This effect was observed with aluminum sulfonated phthalocyanine (AlPcSn) and cationic silicon (HOSiPc-OSi[CH3]2[CH2]3N+[CH3]3I- phthalocyanine (Pc5) photosensitizers. The same effect occurred when the reduction of RBC negative surface charges was used as an endpoint. Under the same treatment conditions, vesicular stomatitis virus inactivation rate was unaffected by changes in the irradiance. Reduction in oxygen availability for the photochemical reaction at high irradiance could explain the effect. However, theoretical estimates suggest that oxygen depletion is minimal under our conditions. In addition, because the rate of photohemolysis at 80 mW/cm2 was not increased when irradiations were carried out under an oxygen atmosphere this seems unlikely. Likewise, formation of singlet oxygen dimoles at high irradiances does not appear to be involved because the effect was unchanged when light exposure was in D2O. While there is no ready explanation for this irradiance effect, it could be used to increase the safety margin of RBC virucidal treatment by employing exposure at high irradiance, thus minimizing the damage to RBC.

Original languageEnglish (US)
Pages (from-to)190-195
Number of pages6
JournalPhotochemistry and Photobiology
Volume61
Issue number2
StatePublished - Feb 1995

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erythrocytes
viruses
Viruses
irradiance
Blood
Erythrocytes
Cells
damage
Photosensitizing Agents
Oxygen
oxygen
Virus Inactivation
Light
Singlet Oxygen
Vesicular Stomatitis
Photochemical reactions
Silicon
Surface charge
Aluminum
Atmosphere

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biophysics

Cite this

The effect of irradiance on virus sterilization and photodynamic damage in red blood cells sensitized by phthalocyanines. / Ben-Hur, E.; Geacintov, Nicholas; Studamire, B.; Kenney, M. E.; Horowitz, B.

In: Photochemistry and Photobiology, Vol. 61, No. 2, 02.1995, p. 190-195.

Research output: Contribution to journalArticle

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