Positively charged porphyrins: a new series of photosensitizers for sterilization of RBCs

Transfusion. 2004 Aug;44(8):1186-96. doi: 10.1111/j.1537-2995.2004.03275.x.

Abstract

Background: Photodynamic treatment could be a way to inactivate pathogens in RBCs. The objective of this study was to characterize the virucidal activity and RBC-damaging activity of a series of cationic porphyrins. Using the most efficacious photosensitizer, various in-vitro human RBC quality variables and in-vivo RBC survival in Rhesus monkeys were evaluated.

Study design and methods: RBCs, spiked with 5 log of extracellular VSV, were treated with porphyrins (25 micro mol/L) and red light (100 W/m2) and essayed for virucidal activity. In-vitro RBC quality variables were assessed during 5 weeks of storage in various ASs. In-vivo survival was investigated with autologous RBCs in Rhesus monkeys.

Results: Tri-P(4) was by far the best sensitizer of a series tested, giving the least hemolysis under conditions that resulted in 5 log-kill of extracellular VSV. Under our experimental conditions, the percentage hemolysis in treated cells was 5.1 +/- 1.1 percent after 5 weeks of storage in SAG-M compared to 1.9 +/- 1.1 percent in the untreated control. Storage in AS-3 resulted hemolysis of 2.3 +/- 1.9 percent. With the exception of IgG binding and potassium leakage, RBC quality variables remained unchanged after photodynamic treatment. Addition of reduced glutathione (GSH) during treatment reduced IgG binding. The 24-hour recovery and T50 of treated RBCs in Rhesus monkeys were satisfactory.

Conclusion: Porphyrin Tri-P(4) may be a suitable photosensitizer for sterilization of RBCs. However, further exploration to optimize the method is necessary to reach clinically acceptable goals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Erythrocytes / drug effects*
  • Erythrocytes / virology*
  • Hemagglutination
  • Hemolysis / drug effects
  • Humans
  • Immunoglobulin G / metabolism
  • Macaca mulatta
  • Photosensitizing Agents / pharmacology*
  • Porphyrins / pharmacology*
  • Potassium / blood
  • Sterilization*
  • Vesicular stomatitis Indiana virus / drug effects*

Substances

  • Immunoglobulin G
  • Photosensitizing Agents
  • Porphyrins
  • Potassium