A self-consistent theory of non-specific and specific interactions of membranes and vesicles with hard, soft polymeric, and fluctuating substrates

• Applicant: Professor Dr. Udo Seifert
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 26845722

Our aim is to provide a quantitative theoretical framework for the problem of adhesion and de-adhesion of fluctuating lipid membranes and vesicles interacting with different types of substrates. This will be achieved by constructing a self-consistent theory for the effective potential of interactions that includes the temperature-dependent fluctuations which renormalize the direct interactions. For vesicles, the relation between the tension, geometrical constraints, and the shape will have to be determined. We will consider the interaction with (i) hard substrates that exhibit complex direct interactions (ii) soft compressible substrates that are analogous to a thick layer of polymers, (iii) \substrates which consist of a fluctuating bilayer connected to the other membrane with an array of elastic springs and (iv) elastic fluctuating substrates. Using the concept of an effective adhesion or repulsion strength, we will model discrete interactions, taking into account the statistical nature of the ensemble and of the single bond. Direct collaboration with several groups where the relevant measurements are currently performed will enable the comparison with appropriate experimental data.

• DFG Programme: Research Grants