Modulation of adhesive properties of DEAE‐dextran with laminin

Human squamous epithelial cells produce lower amounts of laminin and fibronectin when cultured on DEAE‐dextran than when cultured on gelatin‐coated polystyrene ( Biotechnol. Bioeng. , 33:1235). The epithelial cells also spread much more slowly on DEAE‐dextran than they do on gelatincoated polystyrene. To determine if the low level of matrix production by cells grown on DEAE‐dextran contributed to the slowness of cell spreading on this substrate, microcarriers made from DEAE‐dextran were treated with exogenous laminin (10 μg/cm 2 of surface area) and then examined for ability to support cell adhesion. Squamous epithelial cells spread as rapidly on the laminin‐treated DEAE‐dextran as they did on gelatin‐coated polystyrene (much more rapidly than on untreated DEAE‐dextran). This indicates (1) that laminin can bind to DEAE‐dextran in a fashion that is biologically usable by anchorage‐dependent cells, and (2) that when laminin is bound to DEAE‐dextran, the failure of squamous epithelial cells to rapidly spread is overcome. These data support the hypothesis that failure of the cells to synthesize an intact extracellular matrix on DEAE‐dextran is responsible, at least in part, for the slowness with which cells spread on this substrate. © 1995 John Wiley & Sons, Inc.