Self-assembled nano-bioreactor from block ionomers with elevated and stabilized enzymatic function

Core-cross-linked polyion complex (PIC) micelles entrapping trypsin in the core were prepared by mixing trypsin and poly(ethylene glycol)-block-poly(alpha,beta-aspartic acid) in aqueous medium, followed by the introduction of glutaraldehyde cross-linkages. Trypsin incorporated into the core-cross-linked micelles showed high storage stabilities, and the initial enzymatic activity of trypsin was maintained even after standing for one week at ambient temperature. Further, stable compartmentalization of trypsin into the core-cross-linked micelles led to a unique modulation in the enzymatic functions including an improved thermal tolerability with an increased maximum reaction rate compared to native trypsin.