Seminar: On the Interplay Between Hydration Water and Headgroup Dynamics in Lipid Bilayers and Biomechanical Effects of Nanoparticles on Human Airway Cells

Speaker:

Peter Berntsen, Chalmers University of Technology Sweden

Abstract:

One of the hallmark features of cellular life is the presence of membranes that separate a cell from the rest of the world and its compartments from each other. There is, however, some fluidity in the cellular environment that is possible due to the presence of water. The first part of this seminar is about the close association and dynamical interplay between lipid membranes and the surrounding water. We will show that the molecular motions of the lipids are similar to the molecular motions of glass forming liquids at low temperatures and the exact dynamical behavior is strongly dependent on the amount of water in the lipid systems. The hydration water in lipid membranes modulates the motions of the lipid head groups and vice-versa; there are also local lipid motions that influence the water dynamics at low hydration levels.
Thus, in lipid membranes there is a strong interplay between water and lipid dynamics. In many critical biological processes, cells both exert and respond to forces in their surroundings; the mechanical properties of cells are intimately related to their viscoelastic character. In the second part of this seminar we will show that the cellular mechanical function of human lung cells is susceptible to particulate exposure in a manner that is dependent upon particle material, size and dose. Thus, direct exposures of the airway smooth muscle cells toparticulates may initiate or aggravate respiratory diseases.