Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States.
J Phys Chem B. 2013 Aug 22;117(33):9806-20. doi: 10.1021/jp4053049. Epub 2013 Aug 8.
We use polymer self-consistent field theory to study the physics involved in the permeation of charged dendrimer molecules across anionic lipid bilayer membranes. We specifically examine the influence of dendrimer shape deformations, neutral grafts, and pH conditions on the interactions between dendrimers and membranes. Our results indicate that the ability of the dendrimer to undergo conformational rearrangements plays a crucial role in influencing the interactions between the dendrimer and the membrane. At neutral pH, we observe that dendrimers with grafted chains are repelled by the anionic bilayers. However, decreasing the solution pH to endosomal conditions results in attractive dendrimer-membrane interactions under some parametric conditions. We observe that dendrimer insertion into the membrane results in a decreased value in membrane tension at which rupture occurs and, furthermore, that the rupture tension decreases with the addition of grafts to the dendrimer. Our results suggest that dendrimers grafted with neutral polymers can serve as effective pH sensitive delivery vectors.
我们使用高分子自洽场理论研究了带电荷的树枝状分子穿过阴离子脂质双层膜的渗透过程中的物理现象。我们特别研究了树枝状分子形状变形、中性接枝和 pH 值条件对树枝状分子与膜相互作用的影响。我们的结果表明，树枝状分子能够进行构象重排，这对于影响树枝状分子与膜之间的相互作用起着关键作用。在中性 pH 值下，我们观察到带有接枝链的树枝状分子被阴离子双层排斥。然而，将溶液 pH 值降低到内涵体条件下，在某些参数条件下会导致树枝状分子与膜之间产生吸引力。我们观察到，树枝状分子插入膜中会导致膜张力降低，从而导致破裂，而且，随着向树枝状分子中添加接枝物，破裂张力会降低。我们的结果表明，接枝有中性聚合物的树枝状分子可用作有效的 pH 敏感递药载体。
