Structure and properties of biologically and medically relevant interfaces

Structure and properties of biologically and medically relevant interfaces Here, we investigate the interfacial structure of model systems that are used to mimic some biological function or induce some medical effect. Typically such research is more meaningful if it is carried out with medical or biological specialists, which is what we strive to do. Since most biologically relevant molecules have a secondary and tertiary structure we have started with designing equipment that could be used to measure surface vibrational modes in the fingerprint region of the IR spectrum. This allows us to measure low frequency modes that are characteristic of e.g. phospholipid head groups, or sugar or peptide backbone modes. Using our new instrument, we have, in collaboration with researchers from the Nuclear Medicine department of the Utrecht Medical Center (NL), investigated the chemical properties of Holmium loaded biodegradable polymer microspheres that are proposed as a new treatment for secondary liver cancer. In order to have a better understanding of the materials effect on the human body we have also investigated the 3 dimensional structure of the biodegradable polymer itself. In collaboration with a biologist (Dr T. Wolfram, University of Heidelberg) we have investigated the attachment of the extracellular domain of the cell adhesion proteins L1 and N-Cadherin to selfassembled surfaces with the aim of understanding of the binding process. In another collaborative project we are studying the binding of Annexin (a protein that may play a role in the Alzheimers decease process) to supported lipid membranes in order to find out if the binding is indeed reversible, and if not, how the membrane structure is affected. This project is a collaboration with Prof. A Brisson from the University of Bordeaux (Fr). Additionally, we have managed to detect the interfacial signal of vesicles, which means that for studying membrane processes we no longer have to rely on model monolayers or supported lipid membranes.

Recent publications

Cell adhesion proteins

J. Fick, T. Wolfram, F. Belz and S. Roke, Surface binding of transmembrane protein L1 to nitrilotriacetic acid terminated self-assembled monolayers, Langmuir 25 (2009), 1051-1056.

Biodegradable polymers

A. B. Sugiharto, C. M. Johnson, I. E. Dunlop and S. Roke, Delocalized surface modes reveal 3- dimensional structure of complex bio-molecules, J. Phys. Chem. C. 221 (2008), 7531-7535.

A. B. Sugiharto, C. M. Johnson, H. B. de Aguiar, L. Alloatti and S. Roke, Generation and application of high power femtosecond pulses in the vibrational fingerprint region, App. Phys. B 91 (2008) 315-318.

C. M. Johnson, A. B. Sugiharto and S. Roke, Surface and bulk structure of poly(lactic acid) films studied by vibrational sum frequency spectroscopy, Chem. Phys. Lett., 449 (2007), 191-195.