| Polymers have been used in biomedical applications for well over 50 years. Early applications involved using off-the-shelf materials that were designed for other uses, but appeared suitable for a particular situation. There were numerous problems associated with these off-the-shelf materials, including less than ideal material properties which resulted in long term failure and lack of purity and inertness which caused clotting and inflammation. Failure of off-the-shelf materials to meet the needs of biomedical applications has spawned a large body of research to design materials with properties that are tailored to the specific application.;A particularly challenging application is the development of materials suitable for load-bearing orthopedic applications. Three important limitations with respect to available biodegradable orthopedic materials are low initial strengths, rapid loss of strength as the materials degrade, and tedious methods for scaffold fabrication. New orthopedic materials, based on crosslinked polymer networks, can be rationally designed to address these problems based on a fundamental understanding of crosslinked polymer network development. Several variables are important to the development of crosslinked networks including monomer chemistry, functionality and the reaction conditions. Choosing the particular combination of these variables to achieve the desired macroscopic properties of the polymer is a daunting task unless one has a fundamental understanding of the underlying processes. These underlying processes currently are incompletely understood. As such, this work encompasses several fundamental studies of the kinetics and material properties of crosslinked polymers to further the understanding of crosslinked polymer network evolution. Novel biodegradable photopolymerizable crosslinking monomers have been developed using fundamental principles to guide the selection of monomer chemistry and functionality. The crosslinked polymer networks developed through photopolymerization of these novel monomers have been characterized in terms of their ability to provide greater initial strengths than those that have thus far been achieved and to provide a surface degrading polymer so that strength is not significantly affected by degradation of the material. Additionally, a novel device for creating 3-dimensional objects from photopolymerizable monomers, that promises to overcome the problem of scaffold preparation, has been developed. |
