Conduction block recovery by photosensitization reaction under extracellular talaporfin sodium existence in a cardiomyocyte electrical conduction wire

Abstract

s / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375 333 Conduction block recovery by photosensitization reaction under extracellular talaporfin sodium existence in a cardiomyocyte electrical conduction wire Mariko Kurotsu, Emiyu Ogawa, Tsunenori Arai Graduate School of Science and Technology, Keio University, Japan Westudied theelectrical conduction (EC)block recoverybyphotosensitization reaction (PR) under extracellular talaporfin sodium existence in a novel cardiomyocyte EC wire in vitro. Tachyarrhythmia can be cured by permanent block of abnormal EC. The EC block recovery sometimes occurs in the case of weak damage on myocardium. The pattern cultivation cover glass, which had 60 m width cultivation areas, was used to form the wires. The PR was operated to the wires for 600 s varying 3–120mW/cm2 in 663nm laser irradianceswith 20 g/ml talaporfin sodium. The cardiomyocyte ECwas evaluated by the cross correlation function of a fluorescence brightness of intracellular Ca2+ probe in a wire. In 30 and 60mW/cm2, the EC of 15min after the PR was blocked significantly faster than the reported cardiomyocyte necrosis occurrence timing of the same PR conditions. Despite the EC block probabilities of 15min and 2h after the PR were almost 90% in 60mW/cm2, those in 30mW/cm2 were approximately 90 and 60%, respectively. We think this temporary EC block might be caused by gap junction closure induced by intracellular Ca2+ increase. http://dx.doi.org/10.1016/j.pdpdt.2015.07.036 Light fractionation improves the response to BF-200 ALA-PDT in hairless mouse skin Henriette S. de Bruijn1, Sander Brooks2, Angelique van der Ploeg-van den Heuvel1, Ellen R.M. de Haas2, Dominic J. Robinson1 1 The Centre for Optical Diagnostics and Therapy, Department of Otolaryngology and Head & Neck Surgery, The Netherlands 2 Department of Dermatology, Erasmus MC, Rotterdam, The Netherlands Fractionated illumination significantly enhances the effectiveness of 5-aminolevulinic-acid based photodynamic therapy (ALAPDT) but not of Methyl-AminoLevulinate (MAL). BF-200 ALA is a recently approved novel formulation of 10% ALA in a lecithin-based nanoemulsion. Here we compare the fluorescence kinetics, distribution and PDT induced response in hairless mice using BF-200 ALA, MAL and ALA. Comparable fluorescence kinetics was determined forMAL, ALAandBF-200ALA. Cryo-sectionswere stained for CD31 and co-localization with PpIX fluorescence was significantly stronger after ALA and BF-200 ALA compared to MAL (p<0.01). Intra-vital confocalmicroscopy showed no difference betweenALA and BF-200 ALA at depth in skin. Vascular responses were not different as determined in the skin-fold chamber immediately after PDT or at day 1 in cryosections. Visual skin damage scored up to 14 days post PDT showed an significantly increased response to light fractionation for bothALAandBF-200ALA. BF-200ALAbehaves like ALA in normal mouse skin. While light fractionated ALA-PDT was successfully translated to a treatment modality for human lesions our results suggest that ALA can be replaced by BF-200 ALA, marketed as Ameluz® in Europe, for the treatment of superficial BasalCell-Carcinoma and other skin lesions using light fractionation. http://dx.doi.org/10.1016/j.pdpdt.2015.07.037 Parameter study of myocardial cell damage with photosensitization reaction under extracellular talaporfin sodium existence