Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM 87185, USA.
Nanoscale. 2015 Jul 7;7(25):10998-1004. doi: 10.1039/c5nr00826c. Epub 2015 May 5.
We describe for the first time how biological nanomotors may be used to actively self-assemble mesoscale networks composed of diblock copolymer nanotubes. The collective force generated by multiple kinesin nanomotors acting on a microtubule filament is large enough to overcome the energy barrier required to extract nanotubes from polymer vesicles comprised of poly(ethylene oxide-b-butadiene) in spite of the higher force requirements relative to extracting nanotubes from lipid vesicles. Nevertheless, large-scale polymer networks were dynamically assembled by the motors. These networks displayed enhanced robustness, persisting more than 24 h post-assembly (compared to 4-5 h for corresponding lipid networks). The transport of materials in and on the polymer membranes differs substantially from the transport on analogous lipid networks. Specifically, our data suggest that polymer mobility in nanotubular structures is considerably different from planar or 3D structures, and is stunted by 1D confinement of the polymer subunits. Moreover, quantum dots adsorbed onto polymer nanotubes are completely immobile, which is related to this 1D confinement effect and is in stark contrast to the highly fluid transport observed on lipid tubules.
我们首次描述了生物纳米马达如何可用于主动自组装由两亲嵌段共聚物纳米管组成的介观网络。尽管相对于从脂质囊泡中提取纳米管而言，从由聚（氧化乙烯-嵌段-丁二烯）组成的聚合物囊泡中提取纳米管所需的力更大，但多个肌球蛋白纳米马达作用于微管丝上产生的集体力足够大，足以克服所需的能量势垒。尽管如此，这些马达仍能动态组装大规模的聚合物网络。这些网络显示出增强的稳健性，在组装后 24 小时以上仍能持续（相比之下，相应的脂质网络为 4-5 小时）。聚合物膜内和表面上的物质传输与类似的脂质网络上的传输有很大不同。具体而言，我们的数据表明，聚合物在纳米管状结构中的迁移率与平面或 3D 结构中的迁移率有很大不同，并且由于聚合物亚基的一维限制而受到阻碍。此外，吸附在聚合物纳米管上的量子点完全不移动，这与这种一维限制效应有关，与在脂质小管上观察到的高度流动的输运形成鲜明对比。
