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 one or more first amino acid sequence motifs consists of n amino acids, wherein a balance of charge in the amino acid sequence motif is greater than or equal to approximately one-half of n, and wherein n is 5 to 15.