State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, P.R. China.
J Am Chem Soc. 2013 Sep 11;135(36):13282-5. doi: 10.1021/ja406532e. Epub 2013 Aug 29.
This work designs a telomerase-responsive mesoporous silica nanoparticle (MSN) to realize in situ "off-on" imaging of intracellular telomerase activity. In the wrapping DNA (O1) sealed MSN probe, a black hole fluorescence quencher is covalently immobilized on the inner walls of the mesopores, while fluorescein is loaded in the mesopores. In the presence of telomerase and dNTPs, the designed O1 can be extended and then moves away from the MSN surface via forming a rigid hairpin-like DNA structure. Thus the O1 can act as a "biogate" to block and release fluorescein for "off-on" switchable fluorescent imaging. The MSN probe exhibits good performance for sensitive in situ tracking of telomerase activity in living cells. The practicality of this protocol has been verified by monitoring the change of cellular telomerase activity in response to telomerase-related drugs.
本工作设计了一种端粒酶响应介孔硅纳米粒子（MSN），实现了细胞内端粒酶活性的原位“开-关”成像。在包裹 DNA（O1）密封的 MSN 探针中，将黑洞荧光猝灭剂共价固定在介孔的内壁上，而荧光素装载在介孔中。在端粒酶和 dNTPs 的存在下，设计的 O1 可以延伸，然后通过形成刚性发夹状 DNA 结构从 MSN 表面移动。因此，O1 可以作为“生物门”来阻断和释放荧光素，实现“开-关”可切换荧光成像。MSN 探针在活细胞中端粒酶活性的灵敏原位跟踪中表现出良好的性能。通过监测细胞中端粒酶活性对端粒酶相关药物的变化，验证了该方案的实用性。
