Adhesion and detachment of biological cellsin vitro

Adhesion between biological cells and various surfaces is explained in terms of various models, including coagulation at primary or secondary minima of free energy, macromolecular bridges or matrices, and specialized structures at the surfaces of some cells. These models are used to predict the magnitudes of force necessary to detach a cell in the limiting cases of peeling and simultaneous separation over finite areas of contact. Diverse experimental assays of cellular adhesiveness are reviewed and the forces applied to individual cells are estimated. A very wide range of the forces applied to cells in different assays suggests that different mechanisms of bonding are dominant for different types of cells and surfaces under various conditions of growth and chemical environment. The peeling mode of separation is most consistent with the magnitudes of applied force used experimentally in the detachment of cells.