Interaction of Particles with Langmuir Monolayers of 1,2-Dipalmitoyl-Sn-Glycero-3-Phosphocholine: A Matter of Chemistry?

Abstract

Lipid layers are considered among the first protective barriers of the human body against pollutants, e.g., skin, lung surfactant, or tear film. This makes it necessary to explore the physico-chemical bases underlying the interaction of pollutants and lipid layers. This work evaluates using a pool of surface-sensitive techniques, the impact of carbon black and fumed silica particles on the behavior of Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). The results show that the incorporation of particles into the lipid monolayers affects the surface pressure–area isotherm of the DPPC, modifying both the phase behavior and the collapse conditions. This is explained considering that particles occupy a part of the area available for lipid organization, which affects the lateral organization of the lipid molecules, and consequently the cohesion interactions within the monolayer. Furthermore, particles incorporation worsens the mechanical performance of lipid layers, which may impact negatively in different processes presenting biological relevance. The modification induced by the particles has been found to be dependent on their specific chemical nature. This work tries to shed light on some of the most fundamental physico-chemical bases governing the interaction of pollutants with lipid layers, which plays an essential role on the design of strategies for preventing the potential health hazards associated with pollution.

Investigation on the Interactions between Self-Assembled β-Sheet Peptide Nanofibers and Model Cell Membranes

“…These results indicate that EG 12 NFs and EG 6 NFs were retained in the plane of the monolayer without desorption, even in the range of higher π ( Figure 9 , left). A similar π– A isotherm in the presence of hydrophobic nanoparticles had been reported [ 21 , 25 , 26 ]. Third, the ε 0 -π plot demonstrated that NFs caused a significant decrease in the maximum ε 0 value irrespective of EG length ( Figure 5 ).…”

“…Typically, an increase in π upon injection of some additives, such as polymers and nanomaterials, to the subphase can be attributed to lipid molecules condensation due to lipid–additive interactions. Two possible scenarios in which phospholipid packing can be more condensed due to the interaction with additives are described as follows: (i) the additives interact electrostatically with phospholipid molecules, leading to reduction in the repulsive forces between the lipid molecules [ 11 , 12 ]; (ii) the additives incorporate to the water–air interface via hydrophobic interactions with the hydrophobic tail of the phospholipids [ 13 , 25 , 41 ]. These interactions can lead to a decrease in the phospholipids’ available area and an increase in π.…”

“…Using a simple membrane model, such as supported lipid bilayers [ 6 , 7 ], liposome membranes [ 8 ], and Langmuir lipid monolayers [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], is an effective approach. Among these, Langmuir monolayers containing lipids is one of the commonly used systems to study the interactions between nanomaterials and model cell membranes [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. The surface pressure of the Langmuir monolayer is related to the molecular lateral packing of lipids in the monolayer [ 29 ], and it is thus influenced by interactions between the nanomaterials and lipids.…”

The Influence of Polysaccharides/TiO2 on the Model Membranes of Dipalmitoylphosphatidylglycerol and Bacterial Lipids

“…Due to difficulties in studying the biological processes that take place on or within the natural membranes, resulting from the high complexity of such structures, research in this area is performed with the use of biomimetic model membranes [2]. It has been proven that their application allows the assessment of changes in the physicochemical properties of lipid layers caused by foreign substances [3].…”

Probing of Interactions of Magnetite Nanoparticles Coated with Native and Aminated Starch with a DPPC Model Membrane

“…However, the most important advantage of this method is the possibility of investigating not only a cell’s overall response but also a mechanism of nano–bio interactions at the molecular level. The Langmuir monolayers were extensively used as cell membrane models in studies on the interactions between different kinds of nanoparticles and phospholipids [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”