Temperature responsive smart materials undergo a reversible hydrophilicity change at a lower critical solution temperature (LCST) which makes them particularly attractive for biomedical applications such as targeted drug delivery. However, the nondegradable backbone of many well-studied thermoresponsive polymers, such as poly(acrylamides) (PAs), ultimately limit their use for many applications. To date, few examples of thermoresponsive, biodegradable polymers exist. Our lab has developed a library of thermoresponsive polyesters (TR-PEs) inspired by PAs and thermoresponsive elastin-like peptides (ELPs). A modular synthetic design allows for polyesterification of a variety of N-substituted monomers, yielding a library of high molecular weight TR-PEs, with a range of LCSTs that can be tuned between 0‑100ºC.
Recently, work in our lab has focused on the development of ionic thermoresponsive polyesters (iTR-PEs) for the encapsulation of sensitive biomolecules. The hydrophilic nature of iTR-PEs prevents full dehydration above the LCST, resulting in the formation of viscous polymer-rich coacervates. The degradable polyester backbone facilitates quick hydrolytic degradation. These features make iTR-PEs ideal systems for the segregation of therapeutically useful biomolecules (i.e. nucleic acids and proteins), whose biological function is dependent on maintaining their native structure.
- Swanson, J. P., Monteleone, L. R., Haso, F., Costanzo, P. J., Liu, T., Joy, A; A library of thermoresponsive, coacervate-forming biodegradable polyesters; Macromolecules, 2015, 48, 3834
- Swanson, J.; Martinez,M.; Cruz, M.; Mankoci, S.; Costanza, P.; Joy, A., A Coacervate-forming Biodegradable Polyester with Elevated LCST based on Bis-(2-methoxyethyl)amine; Polym. Chem., 2016, 7, 4693