Synthesis, radiolabeling, biodistribution and fluorescent imaging of histidine-coupled hematoporphyrin

Introduction: Hematoporphyrin (Hp) and hematoporphyrin derivatives (HpDs) have been widely used as photosensitizers in photodynamic therapy (PDT). Radiolabeling of HpDs is helpful for preclinical and clinical studies of PDT. Methods: The histidine-coupled hematoporphyrin (His-Hp) was synthesized and radiolabeled with [Tc-99m(CO)(3)(H2O)(3)](+). Biodistribution of the radioligand and fluorescent imaging of His-Hp in mice bearing S180 tumor were investigated. Results: [Tc-99m(CO)(3)](+)-labeled His-Hp was electrically neutral, hydrophilic and stable. The biodistribution of the radioligand in S180 tumor-bearing mice was similar with that of nonlabeled HpD in the literature. The uptake of His-Hp in tumors and livers was confirmed by fluorescent imaging. Conclusions: The complex [Tc-99m(CO)(3)](+)-His-Hp might be suitable for in vivo dose evaluation of HpD in PDT. (C) 2012 Elsevier Inc. All rights reserved.Radiology, Nuclear Medicine & Medical ImagingSCI(E)PubMed4ARTICLE4579-5853