Disclosed herein are films, coatings and microcapsules comprising polypeptides. A thin film, for example, comprises a plurality of layers of polypeptides, the layers comprising alternating oppositely charged polypeptides. A first layer comprises a first layer polypeptide comprising one or more amino acid sequence motifs, wherein the first layer polypeptide is not a homopolymer, is at least 15 amino acid residues long, and has a balance of charge at pH 7 greater than or equal to approximately one-half of the total length of the first layer polypeptide.