State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology , Sichuan University , Chengdu 610065 , China.
ACS Appl Mater Interfaces. 2019 Aug 7;11(31):27588-27597. doi: 10.1021/acsami.9b09243. Epub 2019 Jul 24.
Recently, many researchers have reported that DNA nanostructures, such as tetrahedral framework nucleic acids (tFNAs), have great potential to be useful tools in clinical and laboratory applications due to their programmable shapes, functional sites, and biological responses. However, finite endocytosis and stability in cells and body fluids compromise the functions of DNA nanostructures as a result of various adverse factors. In this study, we successfully synthesized PEGylated protamine, and tFNAs were adsorbed to it in a proper ratio of nitrogen in protamine to phosphorus in tFNAs (N/P ratio) as the functional complex. Furthermore, we demonstrated that PEGylated protamine-adsorbed tFNAs show a more prominent positive effect on cell viability and proliferation than naked tFNAs do. An increase in endocytosis can be observed in three different tissue-derived cells with the PEG-protamine-tFNA (PPT) complex. The increased endocytic ability is mediated by multiple pathways; moreover, the stimulatory effect of the PPT complex on the endocytic ability is dramatically blocked by the inhibition of the caveola-dependent pathway. Consistently, when tFNAs are stabilized by PEGylated protamine, they often tend to escape from lysosomes and survive for a longer period in biological fluids rather than being rapidly eliminated from the kidneys. The in vitro and in vivo results of our study demonstrate that the PPT complex method is a feasible, potent, and low-cost strategy that improves tFNA biocompatibility, stability, and internalization. This study provides evidence supporting the possibility of implementing PPTs for use in drug delivery, bioimaging, and gene transfection in the future.
最近，许多研究人员报告称，由于 DNA 纳米结构（如四面体型核酸框架结构（tFNA））具有可编程形状、功能位点和生物响应等特性，因此在临床和实验室应用中具有很大的应用潜力。然而，由于各种不利因素的影响，DNA 纳米结构在细胞和体液中的有限内吞作用和稳定性会影响其功能。在本研究中，我们成功合成了聚乙二醇化鱼精蛋白，并以适当的鱼精蛋白中氮与 tFNA 中磷的比例（N/P 比）将 tFNA 吸附到其上作为功能复合物。此外，我们证明了与裸露的 tFNA 相比，吸附了聚乙二醇化鱼精蛋白的 tFNA 对细胞活力和增殖具有更显著的积极影响。在三种不同的组织来源的细胞中，可以观察到带有 PEG-鱼精蛋白-tFNA（PPT）复合物的内吞作用增加。内吞作用的增加是通过多种途径介导的；此外，通过抑制 caveola 依赖性途径可以显著阻断 PPT 复合物对内吞作用的刺激作用。一致地，当 tFNA 被聚乙二醇化鱼精蛋白稳定时，它们往往倾向于从溶酶体中逃逸，并在生物流体中存活更长时间，而不是从肾脏中迅速消除。我们的研究的体外和体内结果表明，PPT 复合物方法是一种可行、有效且低成本的策略，可以提高 tFNA 的生物相容性、稳定性和内化作用。本研究为未来在药物输送、生物成像和基因转染中实施 PPT 提供了证据支持。
