Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130023, China.
Phys Chem Chem Phys. 2012 Jun 21;14(23):8348-59. doi: 10.1039/c2cp40700k. Epub 2012 May 15.
Dissipative particle dynamics simulations are used to study the specific binding structures of polyamidoamine (PAMAM) dendrimers on amphiphilic membranes and the permeation mechanisms. Mutually consistent coarse-grained (CG) models both for PAMAM dendrimers and for dimyristoylphosphatidylcholine (DMPC) lipid molecules are constructed. The PAMAM CG model describes correctly the conformational behavior of the dendrimers, and the DMPC CG model can properly give the surface tension of the amphiphilic membrane. A series of systematic simulations is performed to investigate the binding structures of the dendrimers on membranes with varied length of the hydrophobic tails of amphiphiles. The permeability of dendrimers across membranes is enhanced upon increasing the dendrimer size (generation). The length of the hydrophobic tails of amphiphiles in turn affects the dendrimer conformation, as well as the binding structure of the dendrimer-membrane complexes. The negative curvature of the membrane formed in the dendrimer-membrane complexes is related to dendrimer concentration. Higher dendrimer concentration together with increased dendrimer generation is observed to enhance the permeability of dendrimers across the amphiphilic membranes.
利用耗散粒子动力学模拟研究了聚酰胺-胺（PAMAM）树枝状大分子在两亲性膜上的特异结合结构和渗透机理。分别构建了 PAMAM 树枝状大分子和二肉豆蔻酰磷脂酰胆碱（DMPC）脂质分子的相互一致的粗粒化（CG）模型。PAMAM CG 模型正确描述了树枝状大分子的构象行为，DMPC CG 模型可以正确给出两亲性膜的表面张力。进行了一系列系统模拟，以研究具有不同疏水性尾部长度的两亲性分子在膜上的结合结构。随着树枝状大分子尺寸（代）的增加，树枝状大分子穿过膜的渗透性增强。两亲性分子的疏水性尾部长度反过来影响树枝状大分子的构象以及树枝状大分子-膜复合物的结合结构。在树枝状大分子-膜复合物中形成的膜的负曲率与树枝状大分子的浓度有关。观察到较高的树枝状大分子浓度和增加的树枝状大分子代数会增强树枝状大分子穿过两亲性膜的渗透性。
