Invited Review Building Fibrous Biomaterials From a-Helical and Collagen-Like Coiled-Coil Peptides

T he study of peptideand protein-based biomaterials is of interest in itself because it probes and advances basic understanding of how natural biomaterials are constructed and used in biology. In addition, the successful development of new biomaterials presents new possibilities for applications in biotechnology and synthetic biology, such as templating inorganic materials that might lead to new routes to nano-to-micron scale electronic components, through to the construction of smart scaffolds for 3D cell culture and tissue engineering. Although these are fascinating application areas, this brief review focuses on the more fundamental biomaterials science; specifically, how can polypeptides be programmed to assemble to prescribed structures faithfully and controllably. Broadly speaking, polypeptide-based biomaterials can be placed into one of four categories: (1) ex-vivo natural materials; for example, largely collagen-based extracts used in cell culture and tissue engineering. (2) Recombinantly produced, and often engineered, natural full-length proteins, including recombinant silks, collagens, and elastins. (3) Polypeptide-synthetic polymer hybrids, which combine the advantages of low cost and bulk of the synthetic systems with the precise biomolecular recognition and functional properties of proteins. (4) Peptides that self-assemble to materials that span the nanometer to micrometer scales. The latter, peptide-based biomaterials are often designed de novo (i.e., they are programmed for folding and assembly). Arguably, therefore, they are the most fundamental class of bioInvited Review Building Fibrous Biomaterials From a-Helical and Collagen-Like Coiled-Coil Peptides