AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP13
Force Spectroscopy of Mechanically Stretched Fibronectin

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: K.L. De Jong, The University of Western Ontario, Canada
Authors: K.L. De Jong, The University of Western Ontario, Canada
P.R. Norton, The University of Western Ontario, Canada
N.O. Petersen, The University of Western Ontario, Canada
Correspondent: Click to Email
Cell motility is a delicate balance between adhesion and detachment. Identifying key proteins involved (for example, fibronectin, Fn) and understanding the mechanisms employed to find this balance, will provide new insight into the means by which motility can be controlled. Mechanical forces play a key regulatory role in biological cells, and therefore to understand how cells move and adhere, ultimately relies on knowledge of how forces are generated and propagated or in essence, how the cell interacts with the surface. The stress on Fn fibres may be the deciding factor in determining the attachment of the cell to the matrix, and the adhesion of the matrix to the substrate. Studies geared toward understanding fibronectin structure, organization, and binding affinity under mechanical stretching, are providing information crucial to the understanding of the effect of mechanical forces on cell function. To test the prediction that stretching Fn reduces integrin-binding activity, an AFM compatible device is designed to apply a mechanical force to fibronectin while the change in intermolecular interactions that result is monitored. The force required to rupture the interaction between an integrin mimic and fibronectin is determined to be approximately 100 pN. After stretching fibronectin, a trend towards fewer rupture events characterized by smaller pull-off forces in each force curve is observed; this implies a decrease in potential binding sites available to the integrin mimic and concomitant weaker interactions.