Department of Chemical Engineering, Dankook University, Yongin, 448-701, South Korea.
Phys Chem Chem Phys. 2013 Oct 14;15(38):16334-40. doi: 10.1039/c3cp52747f. Epub 2013 Sep 3.
We performed coarse-grained (CG) molecular dynamics (MD) simulations of single-walled carbon nanotubes (SWNTs) with lipid bilayers to understand the effect of the SWNT diameter, length, and concentration on membrane curvature and penetration. Starting with different orientations of multiple SWNTs near lipid bilayers, simulations show that SWNTs insert into the bilayer and induce membrane curvature, which is much larger than that observed from previous simulations of a single SWNT. Longer and thicker SWNTs at higher concentration cause larger membrane curvature, indicating the effect of the SWNT size and concentration, in qualitative agreement with experiments. In particular, thicker SWNTs significantly increase the bilayer height and the difference of the projected and contour bilayer areas, decrease the area compressibility, and disorder lipids. When inserted into the bilayer, thinner SWNTs mainly contact the entire tails of lipids, while thicker SWNTs are wrapped mainly by the ending tail-carbons, leading to the larger membrane curvature. This indicates the effect of SWNT diameter on the SWNT-lipid interaction, yielding different extents of membrane curvature. These findings imply that the SWNT-induced membrane penetration and curvature are modulated by a combination of SWNT length, diameter, and concentration.
我们使用粗粒化（CG）分子动力学（MD）模拟方法研究了单壁碳纳米管（SWNTs）与脂质双层的相互作用，以了解 SWNT 的直径、长度和浓度对膜曲率和穿透的影响。在模拟中，我们从多个靠近脂质双层的 SWNTs 的不同取向开始，结果表明 SWNTs 会插入双层并诱导膜曲率，这比之前对单个 SWNT 的模拟观察到的要大得多。更长和更厚的 SWNTs 在更高的浓度下会导致更大的膜曲率，表明 SWNT 的尺寸和浓度的影响与实验定性一致。特别是，更厚的 SWNTs 会显著增加双层的高度以及投影和轮廓双层区域的差异，降低面积压缩性并使脂质无序化。当插入双层时，较薄的 SWNTs 主要与脂质的整个尾部接触，而较厚的 SWNTs 主要被尾部的末端碳原子包裹，从而导致更大的膜曲率。这表明 SWNT 直径对 SWNT-脂质相互作用的影响，导致膜曲率的程度不同。这些发现表明，SWNT 诱导的膜穿透和曲率是由 SWNT 的长度、直径和浓度的组合调制的。
