Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA.
Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA.
Nanoscale. 2019 Nov 14;11(42):19850-19861. doi: 10.1039/c9nr03761f. Epub 2019 Sep 27.
Controlling the dimensions of DNA nanotubes is of great interest as they can be used in different applications ranging from functional elements in nanodevices to carriers for drug delivery. ssDNA-amphiphiles composed of a ssDNA headgroup, a hydrophobic dialkyl tail and a polycarbon spacer between the tail and the headgroup, self-assemble into hollow DNA nanotubes by forming bilayer nanotapes that transition from twisted nanotapes, to helical nanotapes, to nanotubes. The presence of the DNA nanotubes is verified via cryo-TEM and SAXS. We further explore the effect of the ssDNA secondary structure and tail length on the assembly of the ssDNA-amphiphiles. We demonstrate that the presence of intermolecular G-quadruplexes in the ssDNA sequence dictates the nanotube length. The nanotube diameter is controlled by the hydrophobic tail length, and coarse-grained molecular dynamics simulations are employed to elucidate the tail design impact on assembly.
控制 DNA 纳米管的尺寸非常重要，因为它们可用于从纳米器件中的功能元件到药物输送载体等各种不同的应用。由 ssDNA 头基、疏水二烷基尾和尾与头基之间的聚碳酸酯间隔物组成的 ssDNA 两亲分子自组装成中空 DNA 纳米管，通过形成双层纳米带，从扭曲的纳米带、螺旋纳米带转变为纳米管。通过冷冻透射电镜和小角 X 射线散射来验证 DNA 纳米管的存在。我们进一步探讨了 ssDNA 二级结构和尾长对 ssDNA 两亲分子组装的影响。我们证明了 ssDNA 序列中分子间 G-四链体的存在决定了纳米管的长度。纳米管的直径由疏水尾的长度控制，并且使用粗粒化分子动力学模拟来阐明尾设计对组装的影响。
