The Design, Synthesis, And Characterization Of Poly(Carbonate-Ester)S Based On Dihydroxyacetone For Use As Potential Biomaterials.

The creation of new devices and materials with desirable biomedical characteristics, such as biocompatibility and easily tunable physico-chemical parameters, has played a key role in the advancement of the biomedical industry. In recent years, the combination of classical engineering principles with polymer chemistry has led to a wide range of materials that influence the manner in which drugs are delivered, tissues are engineered, and surgery is performed. The work presented in this thesis is focused on the design, synthesis, and characterization of a poly(carbonate-ester) biomaterial based on lactic acid (LA) and a carbonate form of dihydroxyacetone (DHAC) as vehicles for controlled release. The goal of this work was to synthesize a variety of pLAx-co-DHACy copolymers and characterize their behavior to better understand their structure/function relationships. The results show that random copolymers based on dihydroxyacetone and lactic acid are easily and reliably producible, with unique characteristics. In vitro degradation studies showed that the poly(carbonate-ester)s had an unexpected degradation pattern, in that the carbonate bond was more labile to hydrolysis than that of the ester bond. The resulting degradation pattern made from these biomaterials did not appear to have an acidic interior environment, due to a lack of i visible viscous core commonly seen with bulk degrading lactic acid based polymers. Due to the insolubility of the poly(carbonate-ester)s, exploration of copolymer degradation was determined by the development of a newly discovered technique to quantify dihydroxyacetone release from the matrix using the bicinchoninic acid assay. Finally, the release kinetics and mechanism from these poly(carbonate-ester)s was studied following the incorporation of two different model proteins, bovine serum albumin and lysozyme. Their release behaviors and activities were analyzed to explore the controlled release capabilities of these materials and to identify their potential for the effective release of proteins. i