CNR-Istituto per l'Energetica e le Interfasi, UOS Genova, Genoa, Italy.
Colloids Surf B Biointerfaces. 2013 May 1;105:284-93. doi: 10.1016/j.colsurfb.2013.01.020. Epub 2013 Jan 18.
Langmuir monolayers of Cholesterol (Chol) and a mixture of Chol with 1,2-Dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC), at a ratio of 17:83 in weight, spread on pure water and on silica nanoparticle dispersions, have been investigated measuring the compression isotherms as well as the surface pressure response to harmonic area variation of the monolayer. Aim of this study was to evaluate the effects of the interaction of silica nanoparticles with Chol and the conditions for the incorporation in the monolayer. In previous works on different kind of lipid monolayers, it has been shown that hydrophilic silica nanoparticles dispersed in the sub-phase may transfer into the monolayer, driven by the interaction with the lipid molecules that make them partially hydrophobic. The results here obtained indicate that also for Chol and Chol-DPPC mixtures the presence of silica nanoparticles may have important effects on the phase behaviour and structural properties of the monolayer. As confirmed by complementary structural characterisations, BAM, AFM and ellipsometry, the principal effect of the nanoparticle incorporation is the disruption of the monolayer packing, owing to the alteration of the cohesive interactions of lipid components.
胆固醇（Chol）和胆固醇与 1,2-二棕榈酰-sn-甘油-3-磷酸胆碱（DPPC）的混合物的 Langmuir 单层，按重量比 17:83 在纯水上和二氧化硅纳米颗粒分散体上展开，通过测量压缩等温线以及单层对表面压力响应的谐波面积变化来进行研究。本研究的目的是评估二氧化硅纳米颗粒与 Chol 的相互作用以及它们在单层中掺入的条件的影响。在以前关于不同类型的脂质单层的研究中，已经表明，分散在亚相中亲水性的二氧化硅纳米颗粒可能会由于与使它们部分疏水的脂质分子的相互作用而转移到单层中。这里得到的结果表明，对于 Chol 和 Chol-DPPC 混合物，二氧化硅纳米颗粒的存在也可能对单层的相行为和结构性质产生重要影响。正如 BAM、AFM 和椭偏仪的补充结构特征所证实的那样，纳米颗粒掺入的主要影响是由于脂质成分的内聚相互作用的改变而破坏了单层的堆积。
