N-Succinimidyl 4-[18F]-fluoromethylbenzoate-labeled dimeric RGD peptide for imaging tumor integrin expression

摘要: RGD peptides, radiolabeled with 18F, have been used in the clinic for PET imaging of tumor angiogenesis cancer patients. peptides are typically labeled using a prosthetic group such as N-succinimidyl 4-[18F]-fluorobenzoate ([18F]SFB) or 4-nitrophenyl 2-[18F]-fluoropropionate ([18F]NPFP). However, complex radiosynthetic procedures impeded their broad application clinical studies. We previously proteins and group, 4-[18F]-fluoromethylbenzoate ([18F]SFMB), which was prepared simple one-step procedure. In this study, we PEGylated cyclic peptide dimer, PEG3-E[c(RGDyK)]2 (PRGD2), [18F]SFMB evaluated αvβ3 integrin expression positron emission tomography (PET). one step [18F]fluoride displacement nitrobenzenesulfonate leaving under mild reaction conditions followed by HPLC purification. The 18F-labeled peptide, [18F]FMBPRGD2 coupling PRGD2 pH 8.6 borate buffer purified HPLC. direct labeling on BMBPRGD2 also attempted. A Siemens Inveon to image uptake into U87MG xenograft mouse model. [18F]FMBPRGD2, 15% overall radiochemical yield (uncorrected) total synthesis time 90 min, considerably shorter than preparation [18F]SFB- [18F]NPFP-labeled peptides. labeling, however, not successful. High quality microPET images clearly visualized tumors 15 min good target background ratio. Early tracer accumulation bladder suggests fast renal clearance. No obvious bone can be detected even at 4-h point indicating that fluorine attachment is stable mice. conclusion, ([18F]SFMB) alternative other