Genetic engineering of protein-based polymers:: The example of elastinlike polymers

In spite of the enormous possibilities of macromolecules as key elements in developing advanced materials with increased functionality and complexity, the success in this development is often limited by the randomness associated with polymer synthesis and the exponential increase in technical difficulties caused by the attempt to reach a sufficiently high degree of complexity in the molecular design. This paper describes a new approach in the design of complex and highly functional macromolecules, the genetic engineering of protein-based macromolecules. The exploitation of the efficient machinery of protein synthesis in living cells opens a path to obtain extremely well-defined and complex macromolecules. Different molecular designs are presented, with increasing degree of complexity, showing how the controlled increase in their complexity yields (multi) functional materials with more select and sophisticated properties. The simplest designs show interesting properties already, but the adequate introduction of given chemical functions along the polymer chain presents an opportunity to expand the range of properties to enhanced smart behavior and self-assembly. Finally, examples are given where those molecular designs further incorporate selected bioactivities in order to develop materials for the most cutting-edge applications in the field of biomedicine and nano (bio)technology.