Amphiphilic polymer conetworks with defined nanostructure and tailored swelling behavior for exploring the activation of an entrapped lipase in organic solvents

Amphiphilic polymer conetworks (APCNs) are nanomaterials that greatly activate entrapped enzymes in organic solvents. We have designed two novel APCNs with similar nanostructure, but different swelling behavior in toluene and n-heptane to explore the true origin of enzyme activation. They were realized by copolymerization of telechelic methacrylamide terminated poly(2-methyl oxazoline) (PMOx) with butyl acrylate (BuAc) and 2-ethylhexyl acrylate (EhAc), respectively. While the first APCN swells in toluene but not in n-heptane, the latter swells in both solvents. Lipase Cal B entrapped in the conetworks is most active at a composition that contains some 50 wt% PMOx in all cases. Further, the maximal activation of Cal B with respect to the suspended powder is some 20-fold independent on the solvent as long as the APCN is swellable. (C) 2015 Elsevier Ltd. All rights reserved.