Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC, 27695, USA.
Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, 55455, USA.
Macromol Rapid Commun. 2017 Oct;38(20). doi: 10.1002/marc.201700422. Epub 2017 Sep 12.
A comprehensive study is reported on the effect of salt concentration, polyelectrolyte block length, and polymer concentration on the morphology and structural properties of nanoaggregates self-assembled from BAB single-strand DNA (ssDNA) triblock polynucleotides in which A represents polyelectrolyte blocks and B represents hydrophobic neutral blocks. A morphological phase diagram above the gelation point is developed as a function of solvent ionic strength and polyelectrolyte block length utilizing an implicit solvent ionic strength method for dissipative particle dynamics simulations. As the solvent ionic strength increases, the self-assembled DNA network structures shrinks considerably, leading to a morphological transition from a micellar network to worm-like or hamburger-shape aggregates. This study provides insight into the network morphology and its changes by calculating the aggregation number, number of hydrophobic cores, and percentage of bridge chains in the network. The simulation results are corroborated through cryogenic transmission electron microscopy on the example of the self-assembly of ssDNA triblocks.
本文报道了盐浓度、聚电解质嵌段长度和聚合物浓度对 BAB 单链 DNA（ssDNA）三嵌段聚合物自组装形成纳米聚集体的形态和结构特性的影响，其中 A 代表聚电解质嵌段，B 代表疏水性中性嵌段。利用耗散粒子动力学模拟的隐式溶剂离子强度方法，作为凝胶化点以上的形态相图，作为溶剂离子强度和聚电解质嵌段长度的函数进行了开发。随着溶剂离子强度的增加，自组装 DNA 网络结构明显收缩，导致从胶束网络到蠕虫状或汉堡状聚集体的形态转变。通过计算网络中的聚集数、疏水核数和桥链的百分比，这项研究深入了解了网络形态及其变化。通过对 ssDNA 三嵌段自组装的实例进行低温透射电子显微镜观察，验证了模拟结果。
