ABSTRACT
Proteins are essentially polymers of amino acids folded into three-dimensional shapes. Proteins are a major structural or mechanical component of many tissues and are also biochemically important as directive substrates for cell adhesion and migration, signaling molecules, enzymes, active regulators of cellular differentiation and function, and more. Because the structure and properties of natural tissues depend so strongly on constituent proteins, proteins and industrially created polymers containing amino acids have been developed as biomaterials for tissue repair and replacement. Since the amino acids that comprise proteins are produced by the human body, one would expect protein-based biomaterials to undergo naturally controlled degradation processes (Lu et al. 2004) into products less toxic than those produced by some synthetic polymers and to perhaps elicit lower immune responses than some synthetic polymeric biomaterials (Meinel et al. 2005). The chemical and mechanical properties of protein-based biomaterials can be tailored for speci c applications, depending on the amino acid composition and on any further chemical modications added by a biomaterials scientist or engineer. This chapter will focus on a select set of proteins and amino acid-derived matrices, which are broadly studied and/or commonly used as biomaterials, presenting fundamental and overview information, which should be helpful in understanding the general eld of research and the specialized chapters on different types of protein/ amino acid-based polymeric biomaterials presented elsewhere in this book. See Chapter 14 for additional details on brin, Chapter 21 for collagen, and Chapter 24 on silk. These chapters explore the topics in more details.
