C-X-C 趋化因子受体 4 型 (CXCR4) 通常在不同类型和阶段的癌症疾病中过度表达或过度激活。因此，它被认为是原发肿瘤和转移的成像和早期检测的有前途的靶标。在本研究中，基于 99mTc 放射性标记的新环肽 99mTc-Cyclo [D-Phe-D-Tyr-Lys (HYNIC)- D-Arg-2-Nal-Gly-Lys(iPr)] 被设计出来。亲本LY251029肽作为CXCR4表达肿瘤的潜在体内显像剂。采用Fmoc固相肽合成方法成功制备了放射性配体，并进行了生物学评估。分子对接结果显示 Cyclo [D-Phe-D-Tyr-Lys (HYNIC)-D-Arg-2-Nal-Gly-Lys(iPr)] 具有高亲和力（结合能为 -9.7 kcal/mol）和有效相互作用CXCR4受体（PDB代码：3OE0）的结合口袋中也有。通过反相高效液相色谱（RP-HPLC）和质谱评估合成的肽及其纯度。在人血清中具有高稳定性（95%，n = 3），在 B16-F10 细胞系中具有良好的亲和力（Kd = 28.70 ± 13.56 nM 和 Bmax = 1.896 ± 0.123 fmol/mg 蛋白质）。小鼠的生物分布评估结果和平面图像解释均显示放射性示踪剂对 CXCR4 受体具有高亲和力和选择性。因此，研究结果表明这种设计的放射性配体可用作高度增殖的 CXCR4 受体肿瘤的潜在 SPECT 成像剂。版权所有© Bentham科学出版社；如有任何疑问，请发送电子邮件至 epub@benthamscience.net。

C-X-C Chemokine receptor type 4 (CXCR4) is often overexpressed or overactivated in different types and stages of cancer disease. Therefore, it is considered a promising target for imaging and early detection of primary tumors and metastasis. In the present research, a new cyclo-peptide radiolabelled with 99mTc, 99mTc-Cyclo [D-Phe-D-Tyr-Lys (HYNIC)- D-Arg-2-Nal-Gly-Lys(iPr)], was designed based on the parental LY251029 peptide, as a potential in vivo imaging agent of CXCR4-expressing tumors.The radioligand was successfully prepared using the method of Fmoc solid-phase peptide synthesis and was evaluated in biological assessment. Molecular docking findings revealed high affinity (binding energy of -9.7 kcal/mol) and effective interaction of Cyclo [D-Phe- D-Tyr-Lys (HYNIC)-D-Arg-2-Nal-Gly-Lys(iPr)] in the binding pocket of CXCR4 receptor (PDB code: 3OE0) as well.The synthesized peptide and its purity were assessed by both reversed-phase high-performance liquid chromatography (RP-HPLC) and mass spectroscopy. High stability (95%, n = 3) in human serum and favorable affinity (Kd = 28.70 ± 13.56 nM and Bmax = 1.896 ± 0.123 fmol/mg protein) in the B16-F10 cell line resulted. Biodistribution evaluation findings and planar image interpretation of mice both showed high affinity and selectivity of the radiotracer to the CXCR4 receptors.Therefore, the findings indicate this designed radioligand could be used as a potential SPECT imaging agent in highly proliferated CXCR4 receptor tumors.Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.