~(99)Tc~m标记VEGFR-3高亲和融合多肽在荷人卵巢癌裸鼠体内的分布和显像研究

目的 研究~(99)Tc~m标记VEGFR-3高亲和融合肽(phage-SHSWHWLPNLRHYAS)在荷人卵巢癌裸鼠体内分布和放射免疫定位显像.方法 用NHS-MAG3为双功能鳌合剂,固相法合成多肽.~(99)Tc~m预亚锡直接标记法进行标记,纸层析法测定标记率.经尾静脉注射于荷瘤鼠体内,取不同时相进行SPECT显像,测定标记物在体内的分布情况并进行分析.结果 融合多肽的~(99)Tc~m标记率为95.27%,放射化学纯度为96%,放射性浓度24.6 MBq/ml.经鼠尾静脉注射后1 h,植瘤部位开始出现放射性浓集,肾脏、肝脏及膀胱组织也可见显像;注射后3 h肿瘤显像最清晰,每克组织注射百分剂量率(%ID/g)为(30.20±6.89).其余大部分脏器的T/NT值均达最高,最高为肌肉(13.13);注射后4 h肿瘤部位显像逐渐消退.对照组裸鼠的肿瘤部位始终未见显像.结论 筛选获得的VEGFR-3高亲和融合肽能够靶向荷瘤鼠体内肿瘤组织,实现肿瘤的靶向受体显像.

Imaging and biodistribution of ~(99)Tc~m labeled peptide high-binding VEGF receptor 3 in nude mice with ovarian cancer

Objective To investigate the imaging and biodistribution of ~(99)Tc~m labeled peptide (phage-SHSWHWLPNLRHYAS) high-binding VEGF receptor 3 in nude mice with ovarian cancer. Methods We used NHS-MAG3 as the bifunctional chelating agent and synthesized the peptide above. It was completed with pre-stannous direct labeling by ~(99)Tc~m and then the labeling efficiency was determined by paper chromatography. The tumor bearing mice were injected via tail veins with radiolabeled peptide. The tumors were imaged with single photon emission computed tomography (SPECT). We measured and calculated the biodistribution of the radiolabeled peptide. Results The labeled rate was 95. 27% and the radiochemical purity was 96%. Under a SPECT apparatus, we observed tumor location image at 1 h post injection and the tumor images was the clearest at 3 h post injection, with the injected dose per gram of tissue (%ID/g) of (30. 20±6. 89) at the tumor sites. The tumor/muscle ratio was 13.13. Conclusion Our peptide can accumulate in the tumor masses. It is hope-ful to be used as an ovarian cancer targeting vector for diagnosis and therapy of the cancer.