Modeling the Hydrophobicity of Nanoparticles and Their Interaction with Lipids and Proteins.
Modeling the Hydrophobicity of Nanoparticles and Their Interaction with Lipids and Proteins.
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DOI：
10.1021/acs.langmuir.6b01963
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发表时间：
2016-12
期刊：
影响因子：
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通讯作者：
A. Ramazani;T. Mandal;R. Larson
中科院分区：
文献类型：
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作者：
A. Ramazani;T. Mandal;R. Larson
我们提出了一种使用粗粒度分子动力学（CG MD）模拟模拟纳米颗粒（NP）疏水性的方法，并将其应用于脂质与纳米颗粒的相互作用。为了在粗粒度水平上对给定材料的润湿性或疏水性进行建模，我们选择 MARTINI 粗粒度力场，并通过模拟确定位于由各种 MARTINI 珠类型（C1、C2 等）组成的平坦规则表面上的 MARTINI 水滴的接触角。每个表面均由具有三种晶体对称性（FCC、BCC 和 HCP）的单一珠子类型组成。虽然这种方法将多个原子（例如，一个铈和两个 CeO2 氧原子）组合成一个 CG 珠子，但我们仍然可以通过选择与实际材料的接触角最佳拟合的 MARTINI 珠子类型来捕获实际材料的整体疏水性，如通过实验或全原子模拟确定的。对于不同的 MARTINI 珠类型，宏观接触角是通过将八种不同尺寸的液滴（包含 Nw = 3224-22978 水分子）的微观接触角外推到无限液滴尺寸而获得的。对于每个液滴，接触角是根据外推到表面第一层的液滴界面的圆形曲线的最佳拟合来计算的。然后，我们研究了不同润湿性的小纳米颗粒如何与马丁尼二棕榈酰磷脂酰胆碱 (DPPC) 脂质和 SP-C 肽（肺表面活性剂的一种成分）相互作用。 DPPC 显示出从涂覆纳米粒子的尾部到涂覆水润湿纳米粒子的半胶束的转变，因为表面上水滴的接触角降低到～60°以下。这些结果与开发描述纳米颗粒与肺部成分相互作用的潜在纳米毒性的分类法相关。
We present a method of modeling nanoparticle (NP) hydrophobicity using coarse-grained molecular dynamics (CG MD) simulations, and apply this to the interaction of lipids with nanoparticles. To model at a coarse-grained level the wettability or hydrophobicity of a given material, we choose the MARTINI coarse-grained force field, and determine through simulation the contact angles of MARTINI water droplets residing on flat regular surfaces composed of various MARTINI bead types (C1, C2, etc.). Each surface is composed of a single bead type in each of three crystallographic symmetries (FCC, BCC, and HCP). While this method lumps together several atoms (for example, one cerium and two oxygens of CeO2) into a single CG bead, we can still capture the overall hydrophobicity of the actual material by choosing the MARTINI bead type that gives the best fit of the contact angle to that of the actual material, as determined by either experimental or all-atom simulations. For different MARTINI bead types, the macroscopic contact angle is obtained by extrapolating the microscopic contact angles of droplets of eight different sizes (containing Nw = 3224-22978 water molecules) to infinite droplet size. For each droplet, the contact angle was computed from a best fit of a circular curve to the droplet interface extrapolated to the first layer of the surface. We then examine how small nanoparticles of differing wettability interact with MARTINI dipalmitoylphosphotidylcholine (DPPC) lipids and SP-C peptides (a component of lung surfactant). The DPPC shows a transition from tails coating the nanoparticle to a hemimicelle coating the water-wet NP, as the contact angle of a water droplet on the surface is lowered below ∼60°. The results are relevant to developing a taxonomy describing the potential nanotoxicity of nanoparticle interactions with components in the lung.