Photodynamic treatment of acute vascular occlusion by using an iron-nitrosyl complex

Abstract

Retinal vascular occlusion (RVO) is a common cause of visual impair-ment. Although several approaches, including vasodilators, have been explored to treat retinal vascular occlusion, there is no proper method to treat this obstruction today. We report a strategy that aims to pierce clogged blood vessels with a spatiotemporally controllable nitric oxide transporter, [Fe(TBDAP)(NO)(H2O)]2+ (1), which was synthesized and precisely characterized by various phys-icochemical methods, including X-ray crystallography. In the animal model, normal retinal blood vessels were confirmed to be dilated by the photoresponsive iron-nitrosyl complex. Furthermore, occluded retinal blood vessels were effectively reperfused after the immedi-ate delivery of nitric oxide using light in animal disease models. These studies suggest an unprecedentedly selective and control-lable treatment option for acute vascular occlusive diseases, including cardiovascular and cerebrovascular diseases.