Trithiol chelates are suitable for labeling radioarsenic (72As: 2.49 MeV β+, 26 h; 77As: 0.683 MeV β–, 38.8 h) to form potential theranostic radiopharmaceuticals for positron emission tomography (PET) imaging and therapy. A trithiol(b)-(Ser)2-RM2 bioconjugate and its arsenic complex were synthesized and characterized. The trithiol(b)-(Ser)2-RM2 bioconjugate was radiolabeled with no-carrier-added 77As in over 95% radiochemical yield and was stable for over 48 h, and in vitro IC50 cell binding studies of [77As]As-trithiol(b)-(Ser)2-RM2 in PC-3 cells demonstrated high affinity for the gastrin-releasing peptide (GRP) receptor (low nanomolar range). Limited biodistribution studies in normal mice were performed with HPLC purified 77As-trithiol(b)-(Ser)2-RM2 demonstrating both pancreatic uptake and hepatobiliary clearance.
三
硫醇配合物适用于标记放射性
砷(72As:β+ 2.49 MeV,26小时;77As:β– 0.683 MeV,38.8小时),形成潜在的正电子发射断层扫描(PET)成像和治疗用放射性药物。合成并表征了一种三
硫醇(b)-(Ser)2-RM2
生物偶联物及其
砷配合物。该
生物偶联物在无载体添加的77As标记下,放射
化学产率超过95%,稳定性超过48小时,并且[77As]As-三
硫醇(b)-(Ser)2-RM2在PC-3细胞中的体外IC50细胞结合研究表明,对胃泌素释放肽(GRP)受体具有高亲和力(低纳摩尔范围)。在正常小鼠中进行了有限
生物分布研究,通过HPLC纯化的77As-三
硫醇(b)-(Ser)2-RM2显示胰腺摄取和肝胆清除。