AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Tuesday Sessions
       Session NS+BI-TuA

Paper NS+BI-TuA2
Surface Nanopatterning for the Control of Cell Behavior

Tuesday, November 1, 2005, 2:20 pm, Room 210

Session: Molecular and Biological Applications of Nanostructures
Presenter: C.M. Dekeyser, Université Catholique de Louvain, Belgium
Authors: C.M. Dekeyser, Université Catholique de Louvain, Belgium
J. Marchand-Brynaert, Université Catholique de Louvain, Belgium
A.M. Jonas, Université Catholique de Louvain, Belgium
Ch.C. Dupont-Gillain, Université Catholique de Louvain, Belgium
P.G. Rouxhet, Université Catholique de Louvain, Belgium
Correspondent: Click to Email
Cell adhesion is mediated by proteins of the extracellular matrix, called adhesion proteins. RGD (arginine-glycine-aspartic acid) is the most widely spread peptide sequence responsible for these recognition events. It has been shown that a surface covered by adhesion proteins or grafted with the RGD sequence can induce different cell behaviors, depending on the distribution of the ligands. The aim of the work is to get a better insight into the influence on cell behavior of the distribution of ligands at the nanometer scale. This involves four aspects: creating a nanostructured surface, grafting a RGD ligand or adsorbing an adhesion protein according to defined motifs, passivating the rest of the surface with respect to protein adsorption and evaluating the cell behavior. The nanopatterns are created by means of electron-beam lithography. The challenge here is to draw small motifs (100 nm) on an area (500*500 µm@super 2@), large enough to allow cell adhesion to be studied. This was realized by juxtaposition of patterns (143*143 µm@super 2@) on which electron-beam lithography allowed continuous and regular lines to be drawn. In order to minimize non specific protein adsorption, the passivation of the surface is realized by self-assembly of oligo(ethylene glycol)-terminated silanes on silicon. The influence of various parameters has been examined in order to optimize the treatment in terms of cleanliness, thickness and density (AFM, X-ray reflectometry, XPS) of the obtained layer. Adsorption of different proteins is used to evaluate the inertness of the background and the selective adsorption on the patterns. RGD immobilization is realized by photografting an azide which bears an active ester able to react with the NH@sub 2@ groups of the ligand. The influence of the nanopatterned surfaces on the adhesion and spreading of neural cells will be examined.