Institute of Macromolecular Compounds, 31, Bolshoy pr., Saint-Petersburg 199004, Russia.
J Chem Phys. 2013 Aug 14;139(6):064903. doi: 10.1063/1.4817337.
Poly-L-lysine (PLL) dendrimers are promising systems for biomedical applications due to their biocompatibility. These dendrimers have a specific topology: two spacers of different lengths come out of each branching point and thus the branching is asymmetric. Because of this asymmetry terminal groups are located at branches of different lengths, unlike dendrimers with a symmetric branching. This paper presents the results of the first systematic molecular dynamics simulation of such asymmetric PLL dendrimers. It is shown that PLL dendrimers are porous molecules with all terminal groups equally accessible to water. We have found that in spite of an asymmetry of branching the general structural characteristics of PLL dendrimers are rather similar to those of dendrimers with symmetric branching. We have also found that the structural characteristics of PLL dendrimers obey the general laws for dendrimers and that their electrostatic properties agree with the predictions of a general analytic theory.
多聚-L-赖氨酸（PLL）树状聚合物由于其生物相容性，是有前途的生物医学应用系统。这些树状聚合物具有特定的拓扑结构：每个分支点伸出两个不同长度的间隔物，因此分支是不对称的。由于这种不对称性，末端基团位于不同长度的分支上，与具有对称分支的树状聚合物不同。本文介绍了首次对这种不对称 PLL 树状聚合物进行的系统分子动力学模拟的结果。结果表明，PLL 树状聚合物是具有多孔结构的分子，所有末端基团都能同等程度地与水接触。我们发现，尽管分支不对称，但 PLL 树状聚合物的一般结构特征与具有对称分支的树状聚合物非常相似。我们还发现，PLL 树状聚合物的结构特征遵循树状聚合物的一般规律，其静电特性与一般分析理论的预测一致。
