Project

Nanoparticles: physical-chemical interaction with biomembranes and membrane permeation

Nanosized particulate matter is present in natural aquatic environments. In many cases these particles have a natural origin, but more and more situations occur that these are introduced by man.

We do not precisely know all risks that such systems present for various ecosystems. One of the aspects is to understand how particles interact with biological matter. The working hypothesis is that particles have to interact with or pass through a biological membrane before they can exert a biological response.  In this project we zoom in on an even more fundamental aspect, that is, we study how model particles interact with model membranes. We choose  SiO2 particles interact with DOPC vesicles.

In a set of experiments we like to understand how the interaction of these particles with vesicles can be modulated by pH, ionic strength, or some polymeric additives. Our methods are reflectometry, light scattering, fluorescence essays, confocal microscopy.

The experimental data are compared to theoretical modelling. We have a self-consistent field model for the lipid bilayer membrane and are keen  to see if this model can be used to evaluate how particles interact with membranes. In the viewgraph we give an example of a small particle (blue sphere) interacting with a supported bilayer (the white regions are the head groups of the lipids that form the PC bilayer). Both the position of the particle and the support (lower blue rectangle) are specified. As  you can see the membrane likes to interact with both and therefore deforms toward the particle.

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