The past decade has witnessed a vigorous growth in activities toward the development of a variety of biomedical devices ranging from the simple A-V shunt to the complex artificial heart. Re­ search and development teams have been created comprising engi­ neers, material scientists and clinicians and, perhaps for the first time, such groups are collaboratively bringing their respec­ tive talents to bear on problems associated with defects in the human organism. These collaborations have resulted in a prolifera­ tion of new information and a rapid and continuing redefinition of the frontiers of progress. It was to keep pace with these changes, and provide an updated view of the state of the art that this meeting was conceived. The present volume marks the publication of the proceedings of the Johnson & Johnson Symposium held in Morristown, New Jersey, on July 11 and 12, 1974. It surveys the applications of polymers to medical and surgical problems and contains discus­ sions on the biocompatibility of polymers, polymers as biomate­ rials, and the use of polymers in prosthetic devices and drug re­ lease systems. In addition, the Symposium offers recent perspec­ tives on the critical problems of the material-tissue interface, the design criteria for silicone-based systems, and the varied use of polymers in artificial hearts, kidneys, eyes and lungs.