AVS 49th International Symposium
    Biomaterials Thursday Sessions
       Session BI-ThA

Paper BI-ThA1
Analysis of Cell Adhesion Strengthening Using Micropatterned Substrates

Thursday, November 7, 2002, 2:00 pm, Room C-201

Session: Cell Patterning to Engineer Function
Presenter: N.D. Gallant, Georgia Institute of Technology
Authors: N.D. Gallant, Georgia Institute of Technology
A.J. García, Georgia Institute of Technology
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Cell adhesion to fibronectin (FN) involves integrin receptor binding and subsequent adhesion strengthening, which includes integrin clustering, interactions with cytoskeletal and signaling components to form focal adhesions (FAs), and cell spreading. We applied micropatterning methods to control FA size and position and decouple FA formation from gross changes in cell morphology in order to analyze the contributions of FA assembly to adhesion strength. Microcontact printing was used to pattern alkanethiol self-assembled monolayers into arrays of circular adhesive islands (2, 5, 10 µm dia.) within a non-adhesive background.@footnote 1@ NIH3T3 fibroblasts adhered to FN-coated islands and remained constrained to the patterns presenting a nearly spherical morphology. Cells assembled robust adhesive structures that localized to the micropatterned islands and contained typical components of FA. Cell adhesion strength to FN-coated micropatterned islands was quantified using a spinning disk device that applies a well-defined range of hydrodynamic forces to adherent cells.@footnote 2@ Adhesion strength exhibited significant time- and adhesive area-dependent increases. Comparison of experiments for equivalent contact areas showed a 9-fold increase in adhesion strength over time, independently of cell spreading. These results demonstrate that FA assembly, independently of changes in cell morphology, contributes significantly to adhesion strengthening. This work provides an experimental framework for the functional analysis of FA components in adhesive interactions. @FootnoteText@ @footnote 1@N.D. Gallant et al., "Micropatterned surfaces to engineer focal adhesions for analysis of cell adhesion strengthening," Langmuir (in press).@footnote 2@A.J. García et al., "Force required to break @alpha@@sub 5@@beta@@sub 1@ integrin-fibronectin bonds in intact adherent cells is sensitive to integrin activation state," J. Biol. Chem. Vol. 273, pp. 1098-10993, 1998.