Use of riboflavin for photoinactivation of pathogens in blood components

Abstract

Riboflavin is a naturally occurring compound and an essential human nutrient. Studies in the 1960s and 1970s showed that it could be effective, when exposed to visible or UV light, in inactivating viruses and bacteria [1]. Other studies showed that the principal mode of action is through electron transfer reactions, most importantly in nucleic acids, and not through the production of active oxygen species [2]. This suggested to us that it could act as a photosensitizer useful in the inactivation of pathogens found in blood products, because of its nucleic acid specificity and its limited tendency toward indiscriminate oxidation. The riboflavin molecule is a planar, conjugated ring structure with a sugar side chain that confers water solubility. The planar portion is capable of intercalating between the bases of DNA or RNA in a pathogen and absorbing light in the visible and near UV regions. Light activated riboflavin oxidizes guanine in nucleic acids, preventing replication of the pathogen's genome [3]. Gambro BCT is developing processes using riboflavin and light to inactivate pathogens in plasma, platelet, and red cell products. We call these pathogen eradication technology (PET) processes.