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

Invited Paper BI+NS-TuM8
Activation of Integrin Function by Nanopatterned Adhesive Interfaces

Tuesday, November 16, 2004, 10:40 am, Room 210D

Session: The Nano-Bio Interface
Presenter: M. Arnold, University of Heidelberg, Germany
Authors: J.P. Spatz, University of Heidelberg, Germany
M. Arnold, University of Heidelberg, Germany
Correspondent: Click to Email
To study the function behind molecular arrangement of single integrins in cell adhesion, we designed a hexagonally close-packed rigid template of cell adhesive gold nano-dots coated with cyclic RGDfK peptide by lithographic means of diblock copolymer self-assembly. The diameter of the adhesive dots is <8nm, which allows the binding of one integrin per dot. These dots are positioned with high precision at 28, 58, 73 and 85 nm spacing at interfaces. A separation of >= 73nm between the adhesive dots results in limited cell attachment and spreading and dramatically reduces the formation of focal adhesion and actin stress fibers. We attribute these cellular responses to restricted integrin clustering rather than insufficient number of ligand molecules in cell-matrix interface since "omicro-nanopatterned" substrates consisting of alternating fields with dense and no nano-dots support cell adhesion. We propose that the range between 58-73 nm is a universal length scale for integrin clustering and activation, since these properties are shared by a variety of cultured cells.