Molecularly imprinted bioartificial membranes for the selective recognition of biological molecules

Membranes of a synthetic (poly(ethylene-co-vinyl alcohol), Clarene(R)) and a biological (dextran) polymer, imprinted with alpha-amylase, of different compositions were prepared by the phase-inversion process. Membrane morphologies were shown to be dependent on the synthetic-biological components composition. The removal of the template from the membranes was performed by extraction with water, while an aqueous solution of a-amylase was permeated across the membranes under pressure to obtain the rebinding of the template. The selectivity of alpha-amylase-imprinted membranes was investigated by the same uptake experiment using pepsin, albumin and amyloglucosidase, and the rebinding of these proteins was compared with that of the print molecule. Before and after template extraction and after the rebinding experiment, kinetic measurements of the imprinting molecule were conducted to estimate the activity of the enzyme immobilised in the polymer matrix. Results obtained revealed that the immobilised enzyme maintains a good functionality while in the membrane compared to the free enzyme and the imprinted 'bioartificial' dextran and Clarene(R) membranes, obtained by the phase-inversion method, can establish efficient interaction with alpha-amylase as template molecule, as confirmed by the fair selectivity in rebinding tests.