核素干细胞活体示踪

Radiolabeled molecular imaging and in vivo tracking of stem cells

活体示踪干细胞是干细胞移植治疗疾病进入临床应用的重要步骤。在现有的技术中,核医学分子显像不但灵敏性高,而且可以利用细胞内多种分子进行显像而具有灵活性、多样性,成为移植后在体追踪干细胞最具潜力的技术。本文结合各种策略核素分子显像近年来的发展和特点,分别简述各种方法活体示踪干细胞的前景。其中,受体显像方法简便,最有可能首先进入干细胞示踪领域,但其稳定性和普遍性较低;而利用寡聚核苷酸为探针的反义显像特异性高、普遍性好,配合以指数富集的配基系统进化技术(简称SELEX技术)寻找到干细胞特异的适合体寡核苷酸,将成为干细胞活体示踪的最终途径。

One of necessary steps before stem cell transplantation can be pushed on into clinic is finding a non-invasive method to track stem cells implanted inside human body. For high sensitivity and possibility of imaging various molecules within the cells as targets, molecular imaging with SPECT or PET has the most powerful potential to monitor stem cells transplanted in vivo among all the other imaging techniques. The possibility of in vivo tracking of stem cells with various strategies of radionuclide imaging was discussed respectively according to their characteristics and recent development. Receptor imaging may be firstly utilized to solve the problem for its simplicity but poor in its stability and universality. Screening with SELEX techniques, aptamer oligonucleotides specifically targeted to stem cells will be found. Combining antisense imaging with SELEX, the problem of tracing stem cells in vivo would be eventually and thoroughly solved.