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【目的】构建~(99m)Tc标记前列腺癌特异性膜抗原(PSMA)适配体(A10-3.2),并探讨其在体内外的生物特点。【方法】通过双功能螯合剂6-肼基烟酸琥珀酰亚胺酯盐酸盐(SHNH)对适配体A10-3.2进行~(99m)Tc标记(~(99m)Tc-SHNH-A10-3.2),并检测其在体外的稳定性,被前列腺癌LNCa P细胞(PSMA+)摄取的特异性,在移植瘤小鼠体内SPECT/CT成像及生物分布的特点。【结果】所构建~(99m)Tc-SHNH-A10-3.2的标记率和放化纯分别为(71.31±6.78)%和97.03%。~(99m)Tc-SHNH-A10-3.2对PSMA(+)的前列腺癌LNCa P细胞具有明显的靶向特异性,摄取率明显高于PSMA(-)的前列腺癌PC3细胞(P<0.01),在移植瘤体内具有一定的靶向特异性和较高的瘤/肌肉比值。【结论】成功构建~(99m)Tc标记的靶向PSMA的适配体A10-3.2,具有良好的体内外稳定性和靶向性,在小鼠体内具有较高的瘤组织/肌肉本底的比值,显示~(99m)Tc标记的适配体A10-3.2可能是一种具有潜力的PSMA阳性前列腺癌分子靶向显像剂。
【Objective】 To construct ~ (99m) Tc labeled PSMA aptamer (A10-3.2) and to explore its biological characteristics in vitro and in vivo. 【Method】 The ~ (99m) Tc-labeled 99m Tc-SHNH-A10-Tc was labeled with the bifunctional chelator 6-hydrazinyl nicotinic acid succinimidyl ester hydrochloride (SHNH) 3.2), and its in vitro stability, specificity of uptake by prostate cancer LNCa P cells (PSMA +), SPECT / CT imaging and biodistribution in xenografted mice were examined. 【Result】 The results showed that the labeling rate and radiochemical purity of (99m) Tc-SHNH-A10-3.2 were (71.31 ± 6.78)% and 97.03%, respectively. ~ (99m) Tc-SHNH-A10-3.2 has obvious targeting specificity to PSMA (+) prostate cancer LNCa P cells, and the uptake rate was significantly higher than that of PCMA PC3 cells (P <0.01) In the transplanted tumor body has a certain target specificity and high tumor / muscle ratio. 【Conclusion】 The aptamer targeting to 99mTc labeled PSMA has been successfully constructed and has good in vivo stability and targeting in vivo and high in vivo tumor tissue / muscle background Ratio, showing that ~ (99m) Tc-labeled aptamer A10-3.2 may be a potential PSMA positive prostate cancer molecular targeted imaging agent.