Temperature Responsive Polyesters

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.




  1. Swanson, J. P., Monteleone, L. R., Haso, F., Costanzo, P. J., Liu, T., Joy, A; A library of thermoresponsive, coacervate-forming biodegradable polyesters; Macromolecules2015, 48, 3834
  2. 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