Project
Protein block copolymers as novel biomaterials
Fibrillar proteins such as collagen, silk and elastin are promising materials with broad medical and pharmaceutical application.
However, the extraction from their natural sources (as they are mainly obtained from animals) is often difficult, expensive and gives potential risk with respect to transmittable diseases. That is why, the challenge is to produce safe, recombinant proteins that can be highly expressed and form nanostructured gels under desirable conditions, are able to self-assemble and form cross-linked systems (hydrogels).
In principle, genetic engineering provides the tool to design protein-based polymers with precisely defined block structure, monomer sequence and molecular weight, and thereby control physicochemical properties and biological fate needed for biomedical applications. Depending on the individual interest protein-based polymers can be constructed that form hydrogel structures, react to different environmental stimuli, form complexes with drugs, etc.
The aim is (1) to construct stable genes encoding polymer blocks with highly repetitive sequence and (2) to investigate the physical behavior of the protein-based polymers that result from such gene expression. The research is focused on the production of hydrogel-forming triblock copolymers with pH and temperature responsive blocks which can be separately addressed. Two types of polymers were designed A-B-A and B-A-B, were A stands for elastin-like protein (ELP) that is known to phase separate upon increase of temperature, and B is silk-like motifs (S) that can fold into sheet-like configuration upon changing the pH. The properties of these polymers will be investigated. This will involve rheology, self-assembly triggered by pH and temperature, and co-assembly caused by suitable additives in order to develop new hybrid materials.
