An effective and potentially safe blood disinfection protocol using tetrapyrrolic photosensitizers

• Published in: Future medicinal chemistry Vol. 9; no. 4; pp. 365 - 379
• Main Authors: Marciel, Lúcia, Teles, Luís, Moreira, Beatriz, Pacheco, Mário, Lourenço, Leandro MO, Neves, Maria GPMS, Tomé, João PC, Faustino, Maria AF, Almeida, Adelaide
• Format: Journal Article
• Language: English
• Published: England Future Science Ltd 01.03.2017
• Subjects: antimicrobial photodynamic therapy; aPDT; Blood - microbiology; blood disinfection techniques; blood products; Blood Safety; cationic phthalocyanines; cationic porphyrins; Disinfection; Erythrocytes - drug effects; Escherichia coli - drug effects; Humans; Indoles - pharmacology; Light; Photosensitizing Agents - pharmacology; Plasma - microbiology; Porphyrins - pharmacology; Staphylococcus aureus - drug effects; aPDT; blood products; blood disinfection techniques; cationic phthalocyanines; antimicrobial photodynamic therapy; cationic porphyrins
• ISSN: 1756-8919; 1756-8927
• DOI: 10.4155/fmc-2016-0217

Conventional disinfection techniques, considered safe for plasma, are usually associated with collateral damages on concentrated platelets and erythrocytes. Alternative methods are required and antimicrobial photodynamic therapy (aPDT) seems promising. In this study the effectiveness of two photosensitizers (PS), a porphyrin and a phthalocyanine, to disinfect blood products was evaluated. The cationic porphyrin was more effective in the photoinactivation of bacteria. Also, no significant osmotic stress was found for samples treated with PS at 5.0 µM in isotonic conditions after antimicrobial photodynamic therapy. Effective reduction of Gram-positive bacteria at 5.0 µM of PS provided promising indications toward its safe use to disinfect blood samples. For Gram-negative bacteria, lower PS concentrations, between 5.0 and 10 µM, must be tested.