Functionalized Biomaterials: Polyesters, Polyethers, and Polycarbonates from Diene-Based Monomers

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

The need for heteroatom functionalized biomaterials with tunable thermal, mechanical and solubility properties that also meet biocompatibility and biodegradation requirements is significant. The utility of functionality in these materials is evident in a number of applications ranging from drug delivery to gene therapy where the ability to attach targeting groups, cell fusion promoters, fluorescent labels, mechanical property-enhancing groups, etc. would significantly advance performance. While there are a variety of new materials that have been proposed to address the lack of functionality in synthetic polymeric biomaterials, many of them fall short because of poor biocompatibility, poor biodegradability or limited design capability and control. The development of a methodology to incorporate these needed functional groups into classes of materials that already meet many of these criteria is a viable approach. As such, the proposed research effort has three goals: 1) the design of synthetic routes that yield monomers capable of being polymerized via step growth reactions, 2) the synthesis of a variety of functionalized polyester, polyether and polycarbonate homopolymers and copolymers, and 3) the derivation of the structure-property relationships for these functionalized polymers, examining thermal, mechanical, processing, biocompatibility, biodegradation and structure-function characteristics of the materials. Intellectual Merit. The success of these materials will have a significant impact on this area of advanced biomaterials by providing a method of tailoring chemical functionality and optimizing physical, mechanical and biological properties. The approach is a rational one with significant potential as the work will focus on classes of materials that are FDA approved. Moreover, the starting materials used, disubstituted dienes, for example, are routinely produced in 85% overall yield on a 100 gram scale with greater than 99% purity, making them excellent starting materials for derivatization. While the initial thermal and mechanical property analysis will be conducted in laboratories at UNC, further analysis of these materials will be accomplished in collaboration with Professor Robert Langer's group at MIT. Collaborations with colleagues at MIT and UNC will combine expertise in polymer synthesis, polymer characterization and biomaterials to make significant contributions to the field. Broader Impact: This project will advance the understanding of the role of various functional groups in well-known aliphatic biomaterials, while promoting teaching and training. Graduate students will learn how to solve problems by starting with monomer synthesis moving to the polymer synthesis then to the material properties and applications. Undergraduates and high school student researchers will be presented with intriguing, relevant problems that can be answered in the laboratory using organic synthesis and analytical chemistry. The multidisciplinary interaction will also be an educational opportunity for all students, as they will be active participants in the collaborative research. Additionally, it is expected that the research results will be incorporated, where appropriate, into the teaching of undergraduate organic chemistry and of graduate polymer chemistry to help students appreciate the utility of basic concepts.