聚（酰胺胺）树枝状大分子对脂质双层破坏的直接观察。

Direct observation of lipid bilayer disruption by poly(amidoamine) dendrimers.

作者信息

Mecke Almut, Uppuluri Srinivas, Sassanella Timothy M, Lee Dong-Kuk, Ramamoorthy A, Baker James R, Orr Bradford G, Banaszak Holl Mark M

机构信息

Department of Physics, University of Michigan, 500 E. University Avenue, Ann Arbor, MI 48109, USA.

出版信息

Chem Phys Lipids. 2004 Nov;132(1):3-14. doi: 10.1016/j.chemphyslip.2004.09.001.

DOI:10.1016/j.chemphyslip.2004.09.001

PMID:15530443

Abstract

Atomic force microscopy (AFM) is employed to observe the effect of poly(amidoamine) (PAMAM) dendrimers on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayers. Aqueous solutions of generation 7 PAMAM dendrimers cause the formation of holes 15-40 nm in diameter in previously intact bilayers. This effect is observed for two different branch end-groups--amine and carboxyl. In contrast, carboxyl-terminated core-shell tectodendrimer clusters do not create holes in the lipid membrane but instead show a strong affinity to adsorb to the edges of existing bilayer defects. A possible mechanism for the formation of holes in the lipid bilayer is proposed. The dendrimers remove lipid molecules from the substrate and form aggregates consisting of a dendrimer surrounded by lipid molecules. Dynamic light scattering (DLS) measurements as well as 31P NMR data support this explanation. The fact that tectodendrimers behave differently suggests that their cluster-like architecture plays an important role in their interaction with the lipid bilayer.

摘要

采用原子力显微镜（AFM）观察聚酰胺-胺（PAMAM）树枝状大分子对1,2-二肉豆蔻酰-sn-甘油-3-磷酸胆碱（DMPC）脂质双层的影响。第7代PAMAM树枝状大分子的水溶液会在先前完整的双层膜中形成直径为15 - 40纳米的孔洞。对于两种不同的分支端基——胺基和羧基，均观察到了这种效应。相比之下，羧基封端的核壳结构树枝状大分子簇不会在脂质膜中形成孔洞，而是表现出强烈的吸附到现有双层膜缺陷边缘的亲和力。提出了脂质双层中孔洞形成的一种可能机制。树枝状大分子从底物中去除脂质分子，并形成由被脂质分子包围的树枝状大分子组成的聚集体。动态光散射（DLS）测量以及³¹P NMR数据支持这一解释。结构树枝状大分子表现不同这一事实表明，它们的簇状结构在其与脂质双层的相互作用中起着重要作用。