Use of recombinant and synthetic peptides as attachment factors for cells on microcarriers.

Polystyrene culture dishes and polystyrene microcarriers were coated with Pronectin-F and poly-L-lysine (polylysine), either alone or in combination. Pronectin-F is a recombinant peptide containing repeats of the RGD cell-attachment sequence from fibronectin. Polylysine is a polymer of L-lysine. Pronectin-F supported attachment of Madin-Darby Canine Kidney (MDCK) cells at concentrations as low as 0.025 micrograms/cm2 of surface area. The cells rapidly spread after attachment. Polylysine at concentrations of 0.05-0.5 micrograms/cm2 also supported cell attachment but cells did not rapidly spread after attachment to this substrate. Higher concentrations of polylysine could not be used because of toxicity. When the two peptides were used in conjunction, MDCK cells attached and spread at lower peptide concentrations than they did when either substrate was used alone. These findings suggest that recombinant Pronectin-F alone or in conjunction with a cationic polymer could be a useful replacement for materials such as gelatin or collagen which are currently used as microcarrier surfaces.