Genetically encoded “smart” peptide polymers for biomedicine

Drug delivery systems are becoming increasingly sophisticated, with the ability to target and penetrate specific tissues and release drugs based upon the local environment. While these advanced systems often offer advantages over their less sophisticated counterparts, the final product may be more complex and require additional manufacturing steps. In this article, we review a body of work based on genetically encoded elastin-like polypeptides (ELPs) that offer a route to modular, multifunctional delivery systems that are simple to manufacture. ELPs are temperature-sensitive biopolymers that can be designed on the genetic level and expressed in cell-based protein production systems. The tools of molecular biology and versatility of proteins are used to engineer polymers with precise composition and molecular weight that self-assemble to form drug delivery systems with an impressive variety of features and functions. Due to their versatility and ease of production, ELPs are likely to contribute to the goal of designing simple and effective “smart” delivery systems.