Key Laboratory of Longevity and Aging-Related Diseases of Chinese Ministry of Education, Key Laboratory of Biological Molecular Medicine Research, Education Department of Guangxi Zhuang Autonomous Region, School of Basic Medical Sciences, Guangxi Medical University, Nanning, 530021, P.R. China.
CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P.R. China.
J Nanobiotechnology. 2024 Oct 18;22(1):636. doi: 10.1186/s12951-024-02927-1.
DNA walkers have attracted considerable attention in biosensing and bioimaging. Compared with the conventional single leg-based DNA walker, the bipedal DNA walker has remarkable advantages, with improved sensitivity and fast kinetics, and can work efficiently in a crowded cellular environment. However, most reported bipedal DNA walkers are powered by exogenous supplementation, and elaborate DNA sequence designs, auxiliary additives or extra carriers are often needed. A highly integrated bipedal DNA walker that can address robustness, sensitivity and consistency issues in a single system is highly desirable but remains a great challenge. We herein report a novel bipedal DNA nanowalker system through simple assembly of a DNA substrate, hairpin functionalized-AuNPs (AuNPs-H2), and a blocked Mn-dependent DNAzyme hairpin (H1) on degradable MnO nanosheets, which holds great potential for living cell operation. Highly integrated features enable the simultaneous delivery of core components of the bipedal DNA walker, including a walking track (AuNPs-H2), a walking strand (H1 cleaved by APE1), and a driving force (Mn-dependent DNAzyme cleavage) as a whole, thereby enhancing the control of the spatiotemporal distribution of these components at the intracellular target sites. The redox reaction between the MnO nanosheets and GSH inside the cells not only consumed the intracellular GSH to improve the biostability of the walking track but also generated abundant Mn as a cofactor of the DNAzyme. As a proof of concept, the developed nanowalker was demonstrated to work efficiently for monitoring base excision repair (BER)-related human apurinic/apyrimidinic endonuclease 1 (APE1) in living cells, highlighting the great potential of the bipedal DNA nanowalker in biological systems.
DNA walker 在生物传感和生物成像领域引起了广泛关注。与传统的基于单腿的 DNA walker 相比，双足 DNA walker 具有显著的优势，具有更高的灵敏度和更快的动力学，并且可以在拥挤的细胞环境中高效工作。然而，大多数报道的双足 DNA walker 都是由外源性补充剂驱动的，通常需要精心设计 DNA 序列、辅助添加剂或额外的载体。一个高度集成的双足 DNA walker，能够在单个系统中解决稳健性、灵敏度和一致性问题，是非常需要的，但仍然是一个巨大的挑战。我们在此报告了一种新型的双足 DNA 纳米 walker 系统，通过简单地将 DNA 底物、发夹功能化的金纳米粒子 (AuNPs-H2) 和被阻断的 Mn 依赖性 DNA 酶发夹 (H1) 组装在可降解的 MnO 纳米片上，该系统具有在活细胞中操作的巨大潜力。高度集成的特点使双足 DNA walker 的核心组件能够同时递送到细胞内目标部位，包括行走轨道 (AuNPs-H2)、被 APE1 切割的行走链 (H1) 和驱动力 (Mn 依赖性 DNA 酶切割)，从而增强了对这些细胞内目标部位的时空分布的控制。细胞内 MnO 纳米片和 GSH 之间的氧化还原反应不仅消耗了细胞内的 GSH，以提高行走轨道的生物稳定性，而且还产生了丰富的 Mn 作为 DNA 酶的辅因子。作为概念验证，所开发的纳米 walker 被证明可以有效地用于监测活细胞中碱基切除修复 (BER) 相关的人类脱嘌呤/脱嘧啶内切核酸酶 1 (APE1)，突出了双足 DNA 纳米 walker 在生物系统中的巨大潜力。
