Detailed in vitro study of the photosensitization reaction of extracellular talaporfin sodium in rat myocardial cells

Abstract

This in vitro system for the extracellular photosensitization reaction may reflect the situation in live myocardial tissue. We found that the extracellular photosensitization reaction progressed in two distinctive phases; the first phase depended upon dissolved oxygen, and the second upon the molar density ratio between Talaporfin sodium and albumin. Cell lethality due to the extracellular photosensitization reaction was influenced by both of these factors in our in vitro system. We suggest that a photosensitizer concentration of 25 µg/ml might be necessary to treat myocardial tissue with therapies involving the extracellular photosensitization reaction.

Immediate response and cytotoxicity effect on myocardial cells by extracellular photosensitization reaction varying irradiance

“…The extracellular photosensitization reaction continuity was confirmed with this irradiance in previous study [8]. Fig.…”

Immediate response of Ca2+concentration in myocardial cells against oxidation stress by extracellular photosensitization reaction using Talaporfin sodium for the arrhythmia treatment application

“…We have studied the photocytotoxicity effect on myocardial cells by extracellular photosensitization reaction measuring cell lethality using in vitro experimental system. This experimental system was confirmed the continuity of the photosensitization reaction occurrence measuring photosensitizer fluorescence and dissolved oxygen pressure [8][9][10]. The cell killing effect behavior 2 h after the laser irradiation was understood by these studies but the immediate cell response of myocardial cells by the extracellular photosensitization reaction has not been investigated yet before.…”

“…The laser irradiation area was 5.1×10 -3 mm 2 . The emitted laser power from the objective lens was measured by a power meter (Coherent, Japan) to regulate the laser irradiance at 0.29 W/cm 2 that was confirmed the extracellular photosensitization reaction continuous occurrence [9][10]. …”

Comparison of an <i>in vivo</i> Model with an <i>in vitro</i> Model Based on the Electrical Potential Decrease in the Myocardium or Myocardial Cells by an Extracellular Photosensitization Reaction

“…Basic research during in vivo animal studies on arrhythmia ablation by applying an extracellular photosensitization reaction has led to successful blockade of electrical conduction in the myocardium [12][13][14] . The oxidation targets of the extracellular photosensitization reaction in these studies are cellular ion channels, which can be purposely damaged to achieve the electrophysiological effect of inducing electrical conduction blockade in the myocardium and cellular membranes to induce necrotic cell death [15][16][17] . Although myocardial cell damage caused by extracellular photosensitization reaction mediated by oxidation has been investigated from the perspective of cellular respiration activity and cellular morphology in in vitro studies [15][16][17] , our knowledge of dosimetry in terms of the electrophysiological effects by extracellular photosensitization reaction mediated oxidation is still insufficient.…”