Poly-4-hydroxybutyrate (P4HB) is a resorbable, thermoplastic homopolyester with a linear chain structure of 4-hydroxybutyrate monomers. High molecular weight P4HB is difficult to synthesize chemically but can be produced via a recombinant bacterial fermentation process through biologic catalysis using enzymes from the
polyhydroxyalkanoate biosynthetic pathway. Due to its biocompatibility and biodegradability, as well as its unique mechanical properties, P4HB has emerged during the last decade as a promising biomaterial for various biomedical applications including tissue engineering (congenital heart defects, heart valves and vascular grafts), suture materials, and surgical textiles. In 2007, the TephaFLEX® absorbable monofilament suture was the first medical device derived from P4HB cleared for clinical use by the Food and Drug Administration (FDA) in the United States. Since then, additional regulatory clearances in the US and Europe have expanded the applications of P4HB products to include devices for hernia repair, tendon and ligament repair, and plastic and reconstructive surgery. This chapter will review the unique characteristics of P4HB polymer for use in resorbable medical evices, its processing into various forms, together with strategies that can be used to tailor the material properties for a variety of clinical applications. A number of exciting tissue engineering products based on P4HB that are
currently in development, including vascular grafts and heart valves, will be presented as well as examples of potential future medical applications of P4HB in regenerative medicine.