School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K.
School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, U.K.
Langmuir. 2022 May 10;38(18):5372-5380. doi: 10.1021/acs.langmuir.1c03155. Epub 2022 Apr 26.
The interaction of amorphous silica nanoparticles with phospholipid monolayers and bilayers has received a great deal of interest in recent years and is of importance for assessing potential cellular toxicity of such species, whether natural or synthesized for the purpose of nanomedical drug delivery and other applications. This present communication studies the rate of silica nanoparticle adsorption on to phospholipid monolayers in order to extract a heterogeneous rate constant from the data. This rate constant relates to the initial rate of growth of an adsorbed layer of nanoparticles as SiO on a unit area of the monolayer surface from unit concentration in dispersion. Experiments were carried out using the system of dioleoyl phosphatidylcholine (DOPC) monolayers deposited on Pt/Hg electrodes in a flow cell. Additional studies were carried out on the interaction of soluble silica with these layers. Results show that the rate constant is effectively constant with respect to silica nanoparticle size. This is interpreted as indicating that the interaction of hydrated SiO molecular species with phospholipid polar groups is the molecular initiating event (MIE) defined as the initial interaction of the silica particle surface with the phospholipid layer surface promoting the adsorption of silica nanoparticles on DOPC. The conclusion is consistent with the observed significant interaction of soluble SiO with the DOPC layer and the established properties of the silica-water interface.
近年来，无定形二氧化硅纳米颗粒与磷脂单层和双层的相互作用引起了极大的关注，对于评估此类物质（无论是天然的还是为了纳米医学药物输送和其他应用而合成的）的潜在细胞毒性非常重要。本通讯研究了二氧化硅纳米颗粒在磷脂单层上的吸附速率，以便从数据中提取非均相速率常数。该速率常数与从分散体中的单位浓度在单位面积的单层表面上生长的纳米颗粒吸附层的初始速率有关。实验是在 Pt/Hg 电极上沉积的二油酰基磷脂酰胆碱（DOPC）单层的流动池中进行的。还对可溶性二氧化硅与这些层的相互作用进行了额外的研究。结果表明，速率常数与二氧化硅纳米颗粒的尺寸基本保持不变。这表明水合 SiO 分子物种与磷脂极性基团的相互作用是分子引发事件（MIE），定义为二氧化硅颗粒表面与磷脂层表面的初始相互作用，促进了 DOPC 上二氧化硅纳米颗粒的吸附。这一结论与可溶性 SiO 与 DOPC 层的显著相互作用以及二氧化硅-水界面的特性一致。
