M.G. DeGroote Institute for Infectious Disease Research Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, Canada.
Chembiochem. 2020 Jun 2;21(11):1547-1566. doi: 10.1002/cbic.202000003. Epub 2020 Mar 31.
Circular nucleic acids (CNAs) are nucleic acid molecules with a closed-loop structure. This feature comes with a number of advantages including complete resistance to exonuclease degradation, much better thermodynamic stability, and the capability of being replicated by a DNA polymerase in a rolling circle manner. Circular functional nucleic acids, CNAs containing at least a ribozyme/DNAzyme or a DNA/RNA aptamer, not only inherit the advantages of CNAs but also offer some unique application opportunities, such as the design of topology-controlled or enabled molecular devices. This article will begin by summarizing the discovery, biogenesis, and applications of naturally occurring CNAs, followed by discussing the methods for constructing artificial CNAs. The exploitation of circular functional nucleic acids for applications in nanodevice engineering, biosensing, and drug delivery will be reviewed next. Finally, the efforts to couple functional nucleic acids with rolling circle amplification for ultra-sensitive biosensing and for synthesizing multivalent molecular scaffolds for unique applications in biosensing and drug delivery will be recapitulated.
环状核酸（CNAs）是具有闭环结构的核酸分子。这一特征带来了一些优势，包括完全抵抗核酸外切酶的降解、更好的热力学稳定性，以及能够以滚环方式被 DNA 聚合酶复制。环状功能性核酸是指至少包含核酶/DNA 酶或 DNA/RNA 适体的 CNAs，它们不仅继承了 CNAs 的优势，还提供了一些独特的应用机会，例如拓扑控制或功能分子器件的设计。本文首先总结了天然存在的 CNAs 的发现、生物发生和应用，然后讨论了人工构建 CNAs 的方法。接下来将综述环状功能性核酸在纳米器件工程、生物传感和药物输送中的应用。最后，将总结将功能性核酸与滚环扩增相结合用于超灵敏生物传感和合成多价分子支架的研究进展，这些支架在生物传感和药物输送方面具有独特的应用。
