Effect of methylene blue photodynamic therapy on human neutrophil functional responses

Publication date: Available online 25 August 2019Source: Journal of Photochemistry and Photobiology B: BiologyAuthor(s): E. Trevisan, R. Menegazzi, G. Zabucchi, B. Troian, S. Prato, F. Vita, V. Rapozzi, M. Grandolfo, V. BorelliAbstractPhotodynamic therapy (PDT) has become an emerging novel therapeutic approach for treating localized microbial infections, particularly those sustained by multidrug-resistant strains. Given the irreplaceable role played by professional phagocytes in limiting infections, such as polymorphonuclear neutrophils, any newly designed antimicrobial therapeutic approach must not interfere with their function. The present investigation presents a detailed analysis of the effect of PDT on the viability and several functional responses of human polymorphonuclear neutrophils loaded with methylene blue (MB), one of the more commonly used photosensitizers in antimicrobial PDT. Taking advantage of the use of a specifically-designed optical LED array for illuminating MB-loaded human polymorphonuclear neutrophils, a number of cell functions have been assayed under miniaturized, strictly controlled and reproducible experimental conditions. The major findings of this study are the following: (1) MB-PDT increases human neutrophils adhesion and does not modify myeloperoxidase release; (2) MB-PDT markedly enhances reactive oxygen species generation that is independent of superoxide-forming phagocytic oxidase and very likely ascribable to LED-dependent excitation of acc...
Source: Journal of Photochemistry and Photobiology B: Biology - Category: Speech-Language Pathology Source Type: research