Structure, Properties, and Function in Periodically Sequenced Poly(lactic-co-glycolic acid)s*

Despite the deep understanding of the connection between sequence and properties in biological copolymers, synthetic challenges have inhibited the development of a sophisticated understanding of structure and function in non-biological systems. We have prepared a library of poly(lactic-co-glycolic acid)s and have investigated how properties, especially hydrolytic degradation, depend on sequence. Our studies have shown that while some properties depend only slightly on sequence (Tg, modulus), others are extremely sensitive (swelling, hydrolytic degradation). We are now beginning to explore how sequence errors affect properties. In particular, we will present data that demonstrate that some properties follow a dopant model, where even small error rates are meaningful, while other characterisitics are controlled by a dominant material model, where a threshold of contamination must be attained before property changes become significant.