Patent ID: 7534860

Claim:
A thin film, comprising a plurality of layers of polypeptides, wherein adjacent layers are oppositely charged wherein a first layer comprises a first layer polypeptide and a second layer comprises a second layer polypeptide, wherein the first layer polypeptide and the second layer polypeptide are unbranched polypeptides, wherein the first layer polypeptide is not a homopolymer, is at least 15 amino acid residues long, has a balance of charge at pH 7 greater than or equal to approximately one-half of its total length and comprises one or more first amino acid sequence motifs, wherein each of the first amino acid sequence motifs has a length of 5 to 15 amino acid residues, and a balance of charge at pH 7 greater than or equal to approximately one-half of its length, wherein the second layer polypeptide is at least 15 amino acid residues long, has a balance of charge at pH 7 greater than or equal to approximately one-half of its total length and of opposite polarity to that of the first layer polypeptide, and comprises one or more second amino acid sequence motifs, wherein each of the second amino acid sequence motifs has a length of 5 to 15 amino acid residues, and a balance of charge at pH 7 greater than or equal to approximately one-half of its length.