Artificial Protein Block Polymer Libraries Bearing Two SADs: Effects of Elastin Domain Repeats

We have generated protein block polymer E(n)C and CE(n) libraries composed of two different self-assembling domains (SADs) derived from elastin (E) and the cartilage oligomeric matrix protein coiled-coil (C). As the E domain is shortened, the polymers exhibit an increase in inverse transition temperature (T(t)); however, the range of temperature change differs dramatically between the E(n)C and CE(n) library. Whereas all polymers assemble into nanoparticles, the bulk mechanical properties of the E(n)C are very different from CE(n). The E(n)C members demonstrate viscolelastic behavior under ambient conditions and assemble into elastic soft gels above their T(t) values. By contrast, the CE(n) members are predominantly viscous at all temperatures. All library members demonstrate binding to curcumin. The differential thermoresponsive behaviors of the E(n)C and CE(n) libraries in addition to their small molecule recognition abilities make them suitable for potential use in tissue engineering and drug delivery.