Phototoxicity of Vascular Endothelial Cells Caused by Contact with Talaporfin Sodium for 15-120 Min: In Vitro and In Vivo Studies.

Phototoxicity of Vascular Endothelial Cells Caused by Contact with Talaporfin Sodium for 15-120 Min: In Vitro and In Vivo Studies.

Photomed Laser Surg. 2017 Feb 22;:

Authors: Hamada R, Ogawa E, Arai T

Abstract
OBJECTIVE: To reveal the mechanism of vascular patency in the myocardium after photosensitization immediately after talaporfin sodium (TS) injection in a canine model, we investigated acute injury to vascular endothelial cells (VECs) in vitro and in vivo.
BACKGROUND DATA: There are many reports of vascular shutdown within the target region in photodynamic therapy with TS. Vascular patency within healthy canine myocardium in which a photosensitization reaction starts immediately after injection of TS has been reported.
MATERIALS AND METHODS: TS fluorescence in human umbilical vein endothelial cells and cell lethality were measured with drug contact time (DCT) up to 120 min at 20 μg/mL. Dependence of radiant exposure on cell lethality with 60 min DCT was investigated using two albumin concentrations that corresponded to those in plasma and interstices. Irradiation (21 mW/cm) outside the adventitia of canine cervical veins for 167 or 667 sec was emitted through a diffuser probe 30 min after intravenous injection of TS (2.5 mg/kg). Veins were extracted ∼30 min after the reaction and stained with von Willebrand factor.
RESULTS: Intracellular fluorescence increased, but not cell lethality, with increasing DCT. Cell lethality increased gradually and reached 100% over 20 J/cm(2) in the albumin concentration in the interstices. Normal VECs were found at the acute phase over 20 J/cm(2) with a TS concentration in plasma of ∼14 μg/mL in vivo.
CONCLUSIONS: VEC injury after a photosensitization reaction to healthy tissue shortly after TS injection might be low enough for the blood vessels to be patent.

PMID: 28437192 [PubMed - as supplied by publisher]

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