The objective of this research is to develop a monofilament absorbable suture with a 50% retention of strength three months after implantation. This product is expected to meet an unmet need in the suture market for a device that can provide longer term wound support. Such a product could be used in the treatment of patients with diabetes, compromised immune systems, nutritional impairment, obesity, or conditions that compromise wound healing such as malignancy or infection. The suture is also expected to find application in fascia closure, and in orthopedic procedures for ligament and tendon repair. The approach involves the use of a new proprietary absorbable biomaterial known as poly-4-hydroxybutyrate (P4HB). The specific aims of the project are to: (1) produce an extrudable form of P4HB; (2) optimize the production of a monofilament of P4HB; (3) prepare sutures of P4HB; (4) characterize the P4HB suture properties; (5) determine the in vivo strength retention of P4HB; (6) develop an in vitro model for P4HB strength retention; (7) evaluate the suture's biocompatibility; (8) demonstrate the surgical functionality of the P4HB suture; (9) analyze the biodistribution and pharmacokinetics of P4HB; and (10) determine the suture stability and shelf life. In addition to developing a useful new product, the research is also expected to assist in the introduction of a new medical biomaterial that is expected to have application in other medical devices, such as surgical meshes, tissue engineering scaffolds and drug release matrices. [unreadable] [unreadable]