AVS 50th International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI+SS-WeM

Paper BI+SS-WeM4
Micrometer-scale Fibronectin Patterning for Control of Focal Adhesion Dynamics in Fibroblasts

Wednesday, November 5, 2003, 9:20 am, Room 307

Session: Cell Interactions with Patterned Surfaces
Presenter: D.S. Rhoads, Cornell University
Authors: D.S. Rhoads, Cornell University
R.N. Orth, Cornell University
M. Wu, Cornell University
B.A. Baird, Cornell University
J.L. Guan, Cornell University
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We have developed a new method for analyzing the processes of fibroblast adhesion and spreading using micro- and nanometer-scale fibronectin patterns. Fibronectin is an extracellular matrix protein that provides mechanical stability for cells and tissues, by being a ligand for integrin cell surface receptors which anchor the actin cytoskeleton to the plasma membrane. These anchor points are referred to as focal adhesions, and are composed of numerous scaffolding and signaling proteins in addition to forming focus points of the actin cytoskeleton. Here, we patterned fibronectin using a technique previously shown to produce feature sizes as small as 700nm. The fibronectin features are used to observe small focal adhesions and the morphological effects of minimal activation by fibronectin per cell area. For fabrication of patterned surfaces, polymer-coated silicon wafers were patterned using photolithography and reactive ion etching. Fibronectin was then deposited onto the wafer samples prior to polymer removal and cell application. The resulting patterns contained features ranging from 76 µm to > 1 µm, and were used in cell adhesion and spreading experiments. Cells adhering to the pattern were fixed, permeablized and analyzed by immunofluorescence, using antibodies to fibronectin, f-actin, paxillin, and focal adhesion kinase. Fluorescence microscopy was complemented with scanning electron microscopy to image focal adhesions, stress fibers, lamellipodia and filopodia. From this analysis, we propose that this method for analyzing cellular responses to subcellular cues from their surroundings is a model system for spatially isolating and studying focal adhesions.