Design, Synthesis, Radiolabeling, and Biologic Evaluation of Three 18F-Fdg-Radiolabeled Targeting Peptides for the Imaging of Apoptosis Publisher Pubmed



Khoshbakht S¹ ; Beiki D² ; Geramifar P² ; Kobarfard F³ ; Sabzevari O⁴ ; Amini M⁵ ; Bolourchian N⁶ ; Shamshirian D⁷ ; Shahhosseini S⁸
Source: Cancer Biotherapy and Radiopharmaceuticals Published:2019

Abstract

Background: Early detection of apoptosis is very important for therapy and follow-up treatment in various pathologic conditions. Annexin V interacts strongly and specifically with phosphatidylserine, specific biomarkers of apoptosis with some limitations. Small peptides are suitable alternatives to annexin V. A reliable and noninvasive in vivo technique for the detection of apoptosis is in great demand. Based on our previous studies, three new peptide analogs of LIKKPF (Leu-Ile-Lys-Lys-Pro-Phe) as apoptosis imaging agents were developed. Materials and Methods: Aoa-LIKKP-Cl-F, Aoe-LIKKP-Pyr-F, and Aoe-LIKKP-Nap-F were synthesized, functionalized with aminooxy, and radiolabeled with 18F-FDG. Their biologic properties were evaluated in vitro using apoptotic Jurkat cells. 18F-FDG-Aoe-LIKKP-Pyr-F peptide was injected into normal and apoptotic mice models for biodistribution and in vivo positron emission tomography/computed tomography imaging studies. Results: 18F-FDG-Aoe-LIKKP-Pyr-F peptide showed higher affinity for apoptotic cells. The localization of peptide in apoptotic liver mice was confirmed in biodistribution and imaging studies. Conclusion: The results showed that Aoe-LIKKP-Pyr-F peptide is an auspicious agent for molecular imaging of apoptosis. © Copyright 2019, Mary Ann Liebert, Inc., publishers 2019.