Effect of cell-substrate interaction time and shearing force on adhesion of L1210 cells to collagen and glass.

The early adhesive interaction of living cells with substrates was examined. L1210 cells were allowed to interact with collagen or glass in serum-containing medium (time of cell-substrate interaction, tint, under stationary conditions, was within 2-25 min) or in serum-free medium (tint was 5 s-15 min). The relative number A of cells adhering under stationary conditions, and remaining adherent to the substrate despite experiencing a shearing force F, was determined. The following was found for cells adherent to collagen and glass, both in the presence and absence of serum in the medium. The number A increases with the value of tint and tends to reach a plateau. The plateau value depends on adhesion conditions (presence or absence of serum). When adhesion occurred in serum-containing medium (F congruent to 0.1 X 10(-13)N), function A(tint) increased up to 15 min. The plateau values were in the ratio of 2:1 for cells adherent to collagen and glass, respectively. When adhesion took place in serum-free medium, the function A(tint) increased within the first 20 or 130s for cells adhering to glass or collagen, respectively. The value of A(tint) increased up to the effective interaction time, teff int, i.e. the time after which a plateau was reached at 100% adhesion. This meant that after tint greater than or equal to teff int all cells were in adhesion with glass and collagen despite the application of the greatest shearing force, F congruent to 2 X 10(-9)N. The values of teff int for cells adherent to collagen and glass were in the ratio of 6:1, respectively. The value of A decreases with the value of F for cells adherent to substrate in the absence of serum when tint less than teff int. The function A(F) for cells adherent to collagen and glass in the presence of serum, but not in the absence of serum, can be described by the equation: A = a/square root F + c, where a and c = constant greater than 0. The values of a were in the ratio of 2:1 for cells adherent to collagen and glass, respectively. The Brownian motion of cells interacting with both substrates in the absence of serum ceased. The times during which cell motion persisted for cells interacting with collagen and glass, respectively, were in the ratio of 2.5:1.