School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China.
Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, China.
Anal Bioanal Chem. 2022 Aug;414(20):6157-6166. doi: 10.1007/s00216-022-04182-5. Epub 2022 Jun 22.
Long-term and continuous monitoring of the microRNA (miRNA) expression in living cells is essential in biomedical research, but it is currently limited by fast consumption and easy digestion of probes in the intracellular environment. Herein, we report polydopamine-modified gold nanoparticles (AuNPs@PDA) as protective and efficient nanocarriers for DNA hairpin probes (hpDNA), achieving long-term monitoring (48 h) of the miRNA (let-7a) levels in living cells after drug treatments. This method enabled excellent sensitivity and high selectivity toward let-7a with a limit of detection of 0.51 nM (n = 3) and a linear range from 1 to 100 nM. More importantly, AuNPs@PDA can not only efficiently improve the loading of hpDNA on each nanoparticle, but also effectively protect hpDNA from hydrolysis in the cell microenvironment, finally realizing the continuous monitoring of let-7a in living cells for 48 h. This simple method would be of great significance for drug screening and precision medicine.
长期且连续监测活细胞中的 microRNA (miRNA) 表达在生物医学研究中至关重要，但目前受到细胞内环境中探针快速消耗和易被消化的限制。在此，我们报告了聚多巴胺修饰的金纳米粒子 (AuNPs@PDA) 作为 DNA 发夹探针 (hpDNA) 的有效保护纳米载体，实现了药物处理后活细胞中 miRNA (let-7a) 水平的长期监测 (48 h)。该方法对 let-7a 具有出色的灵敏度和高选择性，检测限低至 0.51 nM（n = 3），线性范围为 1 至 100 nM。更重要的是，AuNPs@PDA 不仅可以有效地提高每个纳米颗粒上 hpDNA 的负载量，还可以有效地保护 hpDNA 免受细胞微环境中水解的影响，最终实现了 48 h 内活细胞中 let-7a 的连续监测。这种简单的方法对于药物筛选和精准医学具有重要意义。
