文摘
125I-Radiolabeled F56 peptide was designed as a radioactive analogue of F56 (peptide WHSDMEWWYLLG) to bind with VEGFR1 receptor. It was synthesized in high radiochemical yield and specific activity. The in vitro stability of 125I–F56 was tested, and the bioactivity of 125I–F56 was confirmed by both cell uptake and binding affinity measurement in VEGFR1 positive BGC-823 cells. The time–radioactivity relationship and biodistribution of 125I–F56 tracer were conducted using nude mice bearing human gastric carcinoma BGC-823, by noninvasive micro-SPECT/CT imaging. The tracer’s tumor uptake was further confirmed by autoradiography and HE stain of 125I–F56 in tumor tissues ex vivo. Those results demonstrated that 125I–F56 holds great potential as a diagnostic agent in both molecular imaging and radioanalysis probe for gastric cancer.