AVS 53rd International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI-WeA

Paper BI-WeA2
Micro-Three-dimensional Structuring Platform for Cell Culturing

Wednesday, November 15, 2006, 2:20 pm, Room 2014

Session: Bio-Interfacial Modification and Bio-Immobilization II (Honoring Marcus Textor, ETH-Zürich for Substantial Contributions to the Field)
Presenter: M. Ochsner, Federal Institute of Technology Zurich (ETHZ), Switzerland
Authors: M. Ochsner, Federal Institute of Technology Zurich (ETHZ), Switzerland
M. Dusseiller, Federal Institute of Technology Zurich (ETHZ), Switzerland
M. Grandin, Federal Institute of Technology Zurich (ETHZ), Switzerland
M. Textor, Federal Institute of Technology Zurich (ETHZ), Switzerland
Correspondent: Click to Email
Studies have shown differences in cell behavior when cells are cultured in a 3-dimensional matrix as compared with flat surfaces. Therefore, next to the physical and chemical microenvironment, the structural environment of a cell plays a crucial role in its shape and function. We have developed a set of tools which combines 2-dimensional chemical patterning with topographical microstructuring, thus presenting to the cells a controlled microenvironment that mimics the in vivo environment. The technique combines master fabrication in Si and replication techniques which allows us to create polydimethylsiloxane (PDMS) chips that display defined microwells of various shapes with a dimension on the order of single cells. By making use of different cross linking densities of the PDMS, tailoring of the mechanical properties of the surrounding material is possible. In addition to geometry, we are also able to control the chemistry of the microenvironments such that the surface inside the wells can present specific chemical functionality, e.g.: adhesion proteins, while the plateau surface between the wells is passivated against protein adsorption. The passivation is critical for a controlled microenvironment and we are developing a method for the wet-printing of a protein resistant graft-co-polymer, poly(L-lysine)-g-poly(ethylene glycol) using an inverted microcontact printing technique. As many proteins of interest in cell studies are membrane proteins, wherein mobility may also play an important role, we are also working toward coating the inside of the wells with protein functionalized lipid bilayers. In comparison to coating the wells with functionalized PLL-g-PEG-X,where X is some protein or peptide, we can provide an interesting platform to investigate the influence of ligand mobility. This work aims at the optimization of this technique, focusing on future applications in cell biology such as monitoring focal adhesion and actin dynamics in response to stress exposure.