AVS 51st International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI+NS-TuM

Paper BI+NS-TuM6
Micro- and Nanopatterns of DNA-Tagged Vesicles

Tuesday, November 16, 2004, 10:00 am, Room 210D

Session: The Nano-Bio Interface
Presenter: B. Städler, Laboratory for Surface Science and Technology, Switzerland
Authors: B. Städler, Laboratory for Surface Science and Technology, Switzerland
D. Falconnet, Laboratory for Surface Science and Technology, Switzerland
F Höök, Chalmers University of Technology, Sweden
I Pfeiffer, Chalmers University of Technology, Sweden
H Solak, Paul Scherrer Institute, Switzerland
J. Vörös, Laboratory for Surface Science and Technology, Switzerland
Correspondent: Click to Email
A new approach for the creation of vesicular micro-and nanoarrays is presented based on a novel patterning approach termed Molecular Assembly Patterning by Lift-off (MAPL) in combination with the immobilization of DNA-tagged intact vesicles. This technique is shown to be a promising platform for future studies of enzyme and membrane protein activity in a controlled, native nanoenvironment. Fabrication of DNA microarrays by spotting is state-of-the-art today. This arraying technology, however, cannot be directly applied to membrane-based microarrays because the contact with the ambient environment damages the membranes. Our approach starts with conventional single stranded DNA arrays, which are subsequently converted into a membrane protein array by using phospholipidic vesicles tagged with the complementary DNAs. These functionalized vesicles specifically couple to the surface through hybridization of the DNA strands. The MAPL process was used to provide a surface with a background resistant to the nonspecific adsorption of vesicles and active spots (diameter between 1 and 200 µm) for the immobilization of the single stranded DNAs. The surface chemistry of the active spots and background consisted of biotinylated PEG and non-functionalized PEG, respectively. Complexes of biotin-terminated DNA and neutrAvidin, preformed in solution, were immobilized to the biotinylated, active spots. POPC vesicles tagged with complementary cholesterol-terminated DNA could then be specifically coupled to the surface through the hybridization of the DNA strands. Quartz crystal microbalance and optical waveguide technique were used to monitor in situ and optimize the multistep surface modification process. The micropatterns of DNA-tagged, fluorescently labeled vesicles were investigated by fluorescence microscopy. X-ray Interference Lithography was successfully used to downscale the patterning process to the nanometer scale in order to produce single vesicle arrays.