Biostability of a non-ether polyurethane

A new type of medical grade polyurethane elastomer, based upon an ether-free macroglycol, has been developed by VASCOR, Inc. Prior research conducted by others has indicated that an ether-free urethane should be inherently immune to biodegradation and environmental stress cracking. Specimens of the experimental polyurethane, along with positive and negative control materials, were formed into tubing, mounted on mandrels, and implanted in rabbits. After being exposed to the in vivo environment for six months, the specimens were explanted and examined with scanning electron microscopy. No indication of degradation was observed in the experimental polymer or negative control specimens, whereas severe microcracking was seen in most of the positive control specimens.