AVS 47th International Symposium
    Biomaterial Interfaces Friday Sessions
       Session BI-FrM

Paper BI-FrM3
Adhesion of Mammalian Cells Modeled by Functionalized Vesicles

Friday, October 6, 2000, 9:00 am, Room 202

Session: Biomolecular Recognition at Surfaces
Presenter: A. Janshoff, WWU Muenster, Germany
Authors: A. Janshoff, WWU Muenster, Germany
J. Wegener, WWU Muenster, Germany
H.-J. Galla, WWU Muenster, Germany
Correspondent: Click to Email
Specific molecular recognition between cell-surface receptors and extracellular matrix proteins immobilized on a growth substrate are the most relevant interactions that allow cells to actively spread on a surface. We applied the quartz crystal microbalance technique (QCM) to follow the time course of cell attachment and spreading on artificial substrates. The shift of the sensor´s resonance frequency provides a direct measure for the fractional surface coverage of the piezoelectrically active area. Frequency shifts associated with the establishment of confluent cell layers were found to be dependent on the cell species, reflecting their individual impact on the displacement of the resonator. In order to learn more about the mechanisms that govern the response of shear wave resonators to the attachment of mammalian cells, we modeled the cellular system with unilamellar liposomes doped with biotinylated lipids. Liposome adhesion to avidin/streptavidin coated surfaces was monitored using the QCM technique. Increasing fractions of the biotinylated lipid in the liposome shell resulted in enhanced shifts of the resonance frequency. Concomitant shape analysis of the surface-attached vesicles using SFM revealed an extended contact area between liposome and surface. We conclude, that an increasing number of bonds between the liposome and the surface induces the extended contact areas and that a similar mechanism may be applicable to explain the individual response of the QCM to different cell species.