IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Thursday Sessions
       Session BI-ThA

Paper BI-ThA8
Improved Functionalization for Chemically Patterned Polystyrene Surfaces

Thursday, November 1, 2001, 4:20 pm, Room 102

Session: Cell-Surface Interaction
Presenter: K. Schröder, Institute of Non-thermal Plasma Physics, Germany
Authors: A.A. Meyer-Plath, Institute of Non-thermal Plasma Physics, Germany
K. Schröder, Institute of Non-thermal Plasma Physics, Germany
A. Ohl, Institute of Non-thermal Plasma Physics, Germany
Correspondent: Click to Email
Tight contact between living cells and polymeric materials is a key characteristic of implant materials, medical, pharmaceutical diagnostic devices, and in vitro cell culturing. To improve cell adhesion and growth, surface modification is required for almost all types of polymer. Plasma-chemically introduced functional groups are widely used for this purpose. Type and density of surface functionalities control adsorption behaviour of cell-signaling molecules. Also, selective immobilization of biologically active molecules (e.g. attachment factors) is possible. This way, the polymer surface provokes cell responses. Chemical patterns for different cellular responses are the basis for some advanced applications of biomaterials. They may directly induce selective cell adhesion. Plasma functionalization is the basis for pattern generation. Here, continuous wave and pulsed microwave and radio frequency plasmas in nitrogen-containing gas mixtures were studied for grafting of nitrogen functional groups on polystyrene. Plasma conditions were optimized in two respects: either to obtain a high selectivity for amino groups, or to maximize the overall density of nitrogen groups. The obtained functionalized surfaces were investigated by means of XPS, contact angles and cell culture. Specific plasma conditions lead to surfaces with high-density cultures of adherent cells after 24 hours of culturing, exceeding significantly densities on the untreated or oxygen-plasma-treated polymer. The highest level of nitrogen and amino functionalization was obtained using pulsed microwave plasmas. Patterning of the chemical functionalization was realized by a hydrogen plasma treatment using a laser-cut metal mask. The chemical pattern was verified by XPS with high local resolution.