elastinlike

Elastin-like polypeptides (ELPs) are a class of synthetic biopolymers inspired by mammalian elastin, typically composed of repeats of the pentapeptide sequence Val-Pro-Gly-X-Gly, where X is a guest residue chosen to tune properties. These repeats mimic elastin’s elasticity and biocompatibility while allowing genetic encoding and precise control over composition and length. ELPs are often produced via recombinant DNA in prokaryotic hosts, enabling scalable manufacturing. Purification commonly uses inverse transition cycling, a nonchromatographic method that exploits the temperature-dependent phase behavior of ELPs to selectively precipitate the polypeptide and release contaminants.

The hallmark physical property of ELPs is the inverse temperature transition: they are soluble below a certain transition temperature and undergo reversible phase separation into coacervates above it. The transition temperature depends on sequence, length, concentration, salt, and pH; more hydrophobic guests and longer chains generally promote phase separation at lower temperatures. This tunable thermoresponsiveness makes ELPs attractive as building blocks for temperature-triggered drug delivery systems, injectable depots, and self-assembling hydrogels.

Applications include fusion to therapeutic proteins to enable simple purification or targeted delivery, surface coatings with tunable adhesion, and the formation of nanoparticle or hydrogel systems for controlled release or tissue engineering. While generally regarded as biocompatible and biodegradable, practical use requires careful sequence design to control immunogenicity, stability, and degradation. Elastin-like materials thus provide a versatile platform for stimulus-responsive biomaterials and protein engineering.