99mTc-HYNIC-Duramycin的制备及凋亡显像研究

Preparation and Apoptosis Imaging Study of 99mTc-HYNIC-Duramycin

  • 摘要: 细胞凋亡早期可出现特征性细胞膜磷酯酰乙醇胺(PE)外翻,耐久霉素(Duramycin)可高选择性、高特异性与PE结合,利用放射性核素标记耐久霉素后进行显像可实现体内细胞凋亡的早期监测。本研究中的显像剂99mTc-HYNIC-Duramycin是用放射性核素99mTc与标记前体HYNIC-Duramycin通过一步反应制备获得,标记反应时间约为20 min,放化纯度>95%。99mTc-HYNIC-Duramycin具有良好的水溶性和体外稳定性,LogP为−1.73±0.06(n=3),在生理盐水中放置6 h内的放化纯度>95%。生物分布结果表明,99mTc-HYNIC-Duramycin主要通过肝脏代谢,肾脏和脾脏摄取也较高,血和肌肉的摄取较低。SPECT/CT显像表明,与对照组和空白组相比,99mTc-HYNIC-Duramycin在经化疗药物治疗后的NCI-H460荷瘤鼠肿瘤部位的摄取明显增加,显示出较好的特异性。以上结果表明,该显像剂可以早期监测化疗后肿瘤细胞的凋亡情况,具有用于肿瘤疗效早期评估的潜力。

     

    Abstract: Phosphatidylethanolamine (PE) is externalized to the cell surface during the early stages of apoptosis. Duramycin is a peptide that can bind to PE with high selectivity and specificity. Radionuclide labeled Duramycin enables in vivo imaging to monitor apoptosis at an early stage. In this study, the imaging agent 99mTc-HYNIC-Duramycin was obtained by one-step reaction between 99mTc and the precursor HYNIC-Duramycin. The radiolabeling process takes approximately 20 min, and the radiochemical purity is above 95%. 99mTc-HYNIC-Duramycin is water-soluble, with a LogP value of −1.73±0.06 (n=3), and the radiochemical purity remains above 95% in saline for up to 6 h, indicating excellent stability in vitro. Biodistribution studies showed that 99mTc-HYNIC-Duramycin is primarily metabolized by the liver, with higher radioactive accumulation observed in the kidneys and spleen, and lower uptake in blood and muscle. Compared with the control group and the blank group, 99mTc-HYNIC-Duramycin has significantly higher uptake in NCI-H460 tumor after cisplatin treatment by SPECT/CT imaging. These results demonstrate the good specificity of the imaging agent and its ability to monitor chemotherapy-induced apoptosis in tumors at an early stage. In conclusion, 99mTc-HYNIC-Duramycin is a promising SPECT/CT radiotracer for early treatment evaluation following chemotherapy.

     

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