Amphiphilic polymer conetworks derived from aqueous solutions for biocatalysis in organic solvents

Activating enzymes in organic solvents is of great interest in current biotechnology. Amphiphilic conetworks have been shown to activate entrapped enzyme molecules in such media. Although successful, the loading of such conetworks is limited by the diffusion of protein molecules. In order to overcome this, we designed a new polyoxazoline-based polymer conetwork that allows the enzyme entrapment during the preparation. To this end, new polymer conetwork soft scaffolds derived from more hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) and more hydrophobic, telechelic poly(2-ethyl-1,3-oxazoline) (PEtOx) were prepared as free-standing membranes. The transparent, nanophasic polymer conetworks showed a selective swelling in aqueous and organic solvents. The enzyme lipase was entrapped by dissolving it in the prepolymer mixture followed by photopolymerization. Compared to the literature known PHEA-l-PDMS systems a 6-fold higher specific activity and a 8-fold higher conetwork activity in organic solvents were obtained. Thus, the novel PHEA-l-PEtOx conetworks are outstanding materials for entrapping and activating enzymes in organic solvents.