核酸功能化纳米探针在细胞荧光成像中的应用

核酸是携带遗传信息的物质,既存在于自然界中也能够通过成熟技术人工合成。通过体外筛选技术还可以筛选出具有特殊功能的核酸序列,例如核酸适体和脱氧核酶。核酸通过沃森-克里克碱基互补配对原则进行杂交,具有很强的专一性。无论是通过序列设计还是体外筛选,核酸探针在生物标志物的分析与成像应用方面都发挥着重要作用。纳米材料辅助构建核酸功能化纳米探针,可以保护负载的核酸探针不被核酸酶降解,并且无需转染试剂就能进入细胞,在细胞荧光成像应用上具有很大优势。为解决细胞内有些生物标志物含量低、难于检测的问题,目前已构建多种适用于细胞水平的成像信号放大方法来实现对低丰度生物标志物的高灵敏成像。本文主要综述了核酸功能化纳米探针在细胞荧光成像中的应用进展,包括反义寡核苷酸功能化纳米探针、核酸适体功能化纳米探针、脱氧核酶功能化纳米探针等,同时介绍了他们在成像信号放大中的应用。

Application in nucleic acid functionalized nanoprobe in cellular fluorescence imaging

Nucleic acid is a substance that carries genetic information. It exists either in nature or can be synthesized by established techniques. Nucleic acid sequences with special functions, such as aptamers and DNAzymes, can also be selected using in vitro techniques. Nucleic acids hybridize according to the principle of Watson-Crick base pairing, and have strong specificity. Whether through sequence design or in vitro screening, nucleic acid probes play an important role in the analysis and imaging applications of biomarkers. In addition, nanomaterials can be used to construct nucleic acid functionalized nanoprobes, which can protect the loaded nucleic acids from being degraded by nucleases and can enter cells without the aid of the transfection reagents. Therefore, nanomaterials have great advantages in the application of cell fluorescence imaging. In order to solve the problem of low intracellular biomarker content and thus difficult to detect, a variety of imaging signal amplification methods suitable for the cellular level have been developed to achieve highly sensitive imaging of low-abundance biomarkers. In this paper, the application of nucleic acid functionalized nanoprobes in cellular fluorescence imaging, including antisense oligonucleotide functionalized nanoprobes, aptamer functionalized nanoprobes and DNAzyme functionalized nanoprobes and that in imaging signal amplification are reviewed.