Structure of polymer-capped gold nanorods binding to model phospholipid monolayers
Structure of polymer-capped gold nanorods binding to model phospholipid monolayers
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DOI：
10.1088/2515-7639/abedcd
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Peiyu Quan;W. Bu;Liming Wang;Chunying Chen;Xiaochun Wu;Charles T. R. Heffern;Ka Yee C. Lee;M. Meron;B. Lin
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文献类型：
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作者：
Peiyu Quan;W. Bu;Liming Wang;Chunying Chen;Xiaochun Wu;Charles T. R. Heffern;Ka Yee C. Lee;M. Meron;B. Lin
我们报道了一项聚合物封端的金纳米棒(AuNRs)与模型磷脂单分子膜结合的实验研究，以阐明推动AuNRs插入磷脂膜的机制。实验体系由四种不同的AuNRs与脂单分子膜相互作用组成：阳离子和阴离子聚合物封端的AuNRs分别悬浮在两性和阴离子磷脂的Langmuir单分子膜的纯水亚相中。利用液体表面X射线反射率，以亚纳米分辨率原位测量了气-水界面的脂类和AuNRs的结构，定量给出了AuNr在单分子膜中的插入数量、取向和深度。在由1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine，阳离子聚二烯丙基二甲基氯化铵(PDC)封端的AUNR(PDC-AUNR)组成的两性离子膜中，封端的AUNR(PDC-AUNR)外围吸附在水脂界面，而阴离子聚4-苯磺酸钠(PSS-AUNR)封端的AUNR(PSS-AUNR)深入脂单分子膜。在由1-stearoyl-2-oleoyl-sn-glycero-3-phospho-(1‘-rac-glycerol)(SOPG)组成的阴离子单分子膜的情况下，PDC-AuNR插入到单层中，而PSS-AuNRs甚至不被吸引到单层上。结果表明，AuNRs在模型膜上的吸附过程可能通过不同的机理进行。在带电膜的存在下，静电相互作用驱动AuNRs进入或离开膜，这取决于脂膜和AuNRs的电荷性质；而在两性离子膜的存在下，静电相互作用和疏水相互作用都介导了AuNRs插入膜的过程。
We report an experimental study of the structure of polymer-capped gold nanorods (AuNRs) binding to model phospholipid monolayers to elucidate the mechanism that drives the insertion of the AuNRs into phospholipid membranes. The experimental system consists of four different cases of AuNRs interacting with lipid monolayers: cationic and anionic polymer-capped AuNRs suspended in the pure water subphase of Langmuir monolayers of zwitterionic and anionic phospholipids, separately. Liquid surface x-ray reflectivity was used to measure in situ the structure of the lipids and AuNRs at the air-water interface with sub-nanometer resolution, yielding quantitatively the amount, orientation, as well as depth of AuNR insertion into the monolayer. In the case of a zwitterionic monolayer composed of 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine, cationic Poly-diallyldimethylammonium chloride (PDC) capped AuNRs (PDC-AuNRs) adsorbed peripherally at the water-lipid interface whereas the anionic Poly-sodium 4-styrenesulfonate (PSS) capped AuNRs (PSS-AuNRs) penetrated deeply into the lipid monolayer. In the case of an anionic monolayer composed of 1-stearoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (SOPG), PDC-AuNRs inserted into the monolayer whereas PSS-AuNRs were not even attracted to the monolayer. The results suggest that the adsorption process of AuNRs to model membranes may proceed through different mechanisms. In the presence of a charged membrane, electrostatic interactions drove the AuNRs to or away from the membrane depending on the nature of the charge of the lipid film and the AuNRs, while in the presence of a zwitterionic membrane, both electrostatic interactions and hydrophobic interactions mediated the insertion of the AuNRs into the membrane.