Riboflavin and UV‐Light Based Pathogen Reduction: Extent and Consequence of DNA Damage at the Molecular Level

Abstract

We are developing a technology based on the combined application of riboflavin (RB) and light for inactivating pathogens in blood products while retaining the biological functions of the treated cells and proteins. Virus and bacteria reduction measured by tissue culture infectivity or colony formation with UV light alone and in combination with RB yield equivalent results. The effects of RB as a sensitizing agent on DNA in white cells, bacteria and viruses in combination with UV light exposure have been evaluated. UV-mediated DNA degradation in Jurkat T cells and leukocytes in plasma as measured by the FlowTACS assay was significantly increased in the presence of RB. Agarose gel electrophoretic analysis of DNA in Escherichia coli and leukocytes in plasma demonstrated enhanced DNA degradation in the presence of RB. UV light in combination with RB prevented the reactivation of lambda phage compared with samples irradiated in the absence of RB. UV-mediated oxidative damage in calf thymus DNA was also enhanced in the presence of RB. These observations clearly demonstrate that the presence of RB and UV light selectively enhances damage to the guanine bases in DNA. These data also suggest that the type and extent of damage to DNA for virus in the presence of RB and light make it less likely to be repaired by normal repair pathways available in host cells.

Modern banking, collection, compatibility testing and storage of blood and blood components

“…In the Mirasol system, addition of riboflavin (vitamin B2) to platelet concentrate together with ultraviolet light exposure selectively enhances damage to the guanine bases in the DNA of pathogens, thus preventing their replication [19]. There is no removal step at the end of the process, so residual riboflavin and its photo-products remain in the platelet concentrate during storage.…”

Corneal Collagen Cross-linking for Treatment of Bacterial and Herpetic Keratitis

“…It has been demonstrated that combined application of Riboflavin and UV light could inactivate viruses and bacteria. These effects are the consequence of damage of DNA at the molecular level such as damage to the guanine bases in DNA induced by Riboflavin/UV light [15]. It has also been shown that riboflavin/UVlight induces a photochemical inactivation of viruses and bacteria in platelet concentrates, fresh frozen plasma and in red blood cells [15][16][17].…”

“…These effects are the consequence of damage of DNA at the molecular level such as damage to the guanine bases in DNA induced by Riboflavin/UV light [15]. It has also been shown that riboflavin/UVlight induces a photochemical inactivation of viruses and bacteria in platelet concentrates, fresh frozen plasma and in red blood cells [15][16][17]. Antimicrobial efficacy of riboflavin/UV-A combination for bacterial isolates has been tested in vitro [18].…”

PACK-CXL: Defining CXL for Infectious Keratitis

“…Damage to the pathogen's cell walls caused by massive amounts of reactive oxygen species. 14,15 3. Changes in the tertiary structure of the surrounding stromal collagen fibers, making it difficult for the collagenases to dock to their cleavage sites and exert their function.…”