Quantifying Carbohydrate Based Ligand/Rezeptor Interaction at Soft Hydrogel Interfaces via Soft Colloidal Probe AFM

• Applicant: Professor Dr. Stephan Schmidt
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Biomaterials ; Biophysics ; Medical Physics, Biomedical Technology
• Term: from 2013 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 233437216

Quantifying Carbohydrate Based Ligand/Rezeptor Interaction at Soft Hydrogel Interfaces via Soft Colloidal Probe AFMLigand/receptor (l/r) interactions are crucial for almost all processes in cell biology, including signal transduction, recognition or immune response. Also material designs in biomedical applications make increased use of ligand functionalized surfaces to achieve a desired therapeutic effect. For biomedical material development and their application it is therefore imperative to achieve a fundamental understanding of l/r interactions at synthetic hydrogel interfaces. For example, theoretical work showed that soft, thermally fluctuating hydrogel interface may lead to cooperative binding events. However, this has not been experimentally shown yet. Therefore, this project aims at the development of a new force spectroscopy based method for the determination of binding energies between ligand functionalize soft hydrogel particles and receptor surfaces. The method is termed 'soft colloidal probe AFM' (AFM-SCP). The technical aim of the method development is to drastically enhance the sensitivity of the surface energy measurement in order to allow the characterization of low affinity l/r pairs. The overall scientific aim is the investigation of cooperative binding events between an assembly of binding partners presented at soft material interfaces. As specific biomolecular binding species we will study carbohydrate based interactions because they have been recently been show to be biologically highly active, however the molecular details are still not well understood. We will focus on the binding cooperativity as a function of the material parameters of the l/r- material matrix (hydrogel), i.e. stiffness, mesh size and density of binding pairs. The effect of these material parameters in biomolecular interactions was so far only a matter of theoretical work, experimental confirmations are still pending. Consequently, the effect of these material parameters on low affinity carbohydrate interactions will be experimentally studied via AFM-SCP in this project.

• DFG Programme: Research Grants