A method for coating a surface of a cell culture article includes dissolving a polymer having a covalently attached polypeptide in an aqueous solution to produce a polymer solution. The polymer is formed from monomers selected to form a polymer having a linear backbone, wherein the polymer is crosslink free. The weight percentage of the polypeptide relative to the polymer conjugated to the polypeptide is sufficiently high to render the polymer conjugated to the polypeptide water soluble. The aqueous solution is substantially free of organic solvents. The method further includes (i) disposing the polymer solution on the surface of the cell culture article to produce a coated article; and (ii) subjecting the coated article to sufficient heat or electromagnetic radiation to attach the polymer conjugated to a polypeptide to the surface of the cell culture article.