Heterogeneous Rate Constant for Amorphous Silica Nanoparticle Adsorption on Phospholipid Monolayers

Abstract

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 2 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 2 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 2 with the DOPC layer and the established properties of the silica–water interface.

A Facile Method to Coat Nanoparticles with Lipid Bilayer Membrane: Hybrid Silica Nanoparticles Disguised as Biomembrane Vesicles by Particle Penetration of Concentrated Lipid Layers

“…It has also been previously suggested that this interaction may involve the layer of water between the lipid membrane and the silica nanoparticles. [ 46 ] . However, there are considerably fewer studies on vesicle fusion on silica nanoparticles, so further investigation is needed to elucidate the mechanism.…”

Exploiting Mass Spectrometry to Unlock the Mechanism of Nanoparticle-Induced Inflammasome Activation

“…Overall, the propensity of silica NPs to interact with phospholipids, , and the capacity for hydroxyl radical formation, may explain the membrane damage evidenced in silica NP-exposed cells. However, it is important to consider whether cellular ROS also play a role, as several previous studies have shown that silica NPs provoke ROS production. , One conundrum is that such effects are thought to require the active uptake of the NPs through endocytosis.…”

Key Role of Choline Head Groups in Large Unilamellar Phospholipid Vesicles for the Interaction with and Rupture by Silica Nanoparticles

“…[18][19][20] Several types of binding forces have been postulated, including: 1) ionic interactions of negatively charged silanol groups with positively charged amino groups or quaternary ammonium ions; 2) hydrogen bonding with electron donor atoms such as nitrogen or oxygen; 3) hydrophobic bonding between the siloxane surface and biopolymers; and 4) van der Waals forces. [21][22][23][24] As SiO 2 -NPs increase the permeability of lipid bilayers, phospholipids, in addition to proteins, are direct targets. [25] Anionic NPs, including silica, also induce local gel formation in liposomes, resulting in less fluidic membranes at the site of interaction.…”