Development of the cytodetachment technique to quantify mechanical adhesiveness of the single cell

Adhesion of cells to biomaterials or to components of the extracellular mat rix is fundamental in many tissue engineering and biotechnological processe s, as well as in normal development and tissue maintenance. Many cells on a dhesive molecules will spread and form an organized actin cytoskeleton and complex transmembrane signaling regions called focal adhesions. Focal adhes ions appear to function as both signaling and stabilizing components of nor mal adherent cell activity. To better understand adhesion formations betwee n cells and their underlying substrata, we have designed, developed, and ut ilized a novel 'cytodetachment' methodology to quantify the force required to displace attached cells. We allowed bovine articular chondrocytes to att ach and spread on a substratum of either fibronectin, bovine serum albumin, or standard microscope glass. The cytodetacher was then employed to displa ce the cells from the substratum. Our results demonstrate that a significan tly greater force is required to detach cells from fibronectin versus the t wo other substrata, suggesting that a cell's actin cytoskeleton and perhaps focal adhesions contribute significantly to its mechanical adhesiveness. T he cytodetacher allows us to directly measure the force required for cell d etachment from a substratum and to indirectly determine the ability of diff erent substrata to support cell adhesion. (C) 1999 Elsevier Science Ltd. Al l rights reserved.