This new book presents the authors' biomedical studies of natural degradable biopolymers (polyhydroxyalkanoates [PHAs]) and discusses the demand for medical-grade materials and modern trends, focusing on the present status and future potential of PHAs. The authors present and summarize their most important results and findings obtained during the last few years in experimental studies and clinical trials of PHAs at the Institute of Biophysics Siberian Branch of Russian Academy of Science.