The Background and Scope of Polyphosphazenes as Biomedical Materials

Abstract

Although many traditional organic polymers have been evaluated for uses in biology and medicine, relatively few have proved to be satisfactory for crucial uses such as surgical sutures or mesh, tissue engineering substrates, controlled drug delivery, or soft matter. A reason for this is that most large-volume commercial polymers are optimized for some mechanical engineering purpose, and biomedical compatibility or bioerodibility is not one of the target properties. Thus, biomedical scientists and engineers have been forced to improvise and compromise by using widely available non-biological polymers, mainly because those materials are already available in commercial quantities. Polyphosphazenes offer an opportunity to solve many of these problems. A crucial need exists for new polymers that can be utilized in orthopedics, cardiovascular, dental, neural, or drug delivery applications, yet very few long-existing polymers have properties that are ideal for these medical uses. Our research seeks to design and find methods to synthesize polymeric materials that are specifically designed to solve a range of medical challenges. In our program, we make use of an unusual polymer backbone comprised of alternating phosphorus and nitrogen atoms to which are attached a wide range of organic side groups. This system is unique in the wide range of different property combinations that can be generated, and many of these combinations can be matched precisely to the needs of medical materials.