Acrylate-based poly-high internal phase emulsions for effective enzyme immobilization and activity retention: from computationally-assisted synthesis to pharmaceutical applications

This paper focuses on the synthesis of innovative functional materials prepared by the polymerization of high internal phase emulsions (HIPEs) for the bioconjugation of active molecules. By applying a computational method, this paper demonstrates how to produce materials with tailored features, such as pore dimensions (on the nano–micro scale), swelling in water and organic solvents and bulk densities. To this aim, starting from different emulsion compositions, ten materials are synthesised and fully characterized. Six different outputs (i.e. swelling in water and THF, mass loss in water and THF, throat and void diameters) are modeled using D-optimal mixture experimental designs. A clear correlation between the applied synthetic conditions and the final properties of the materials is demonstrated. The responses allow the selection of a single material for the development of a bioreactor prototype. Thus, the selected material is loaded into a glass column and polymerized in situ. An in-column procedure is also used for the covalent binding of horseradish peroxidase (HRP) as a model enzyme. A standard substrate is selected to test the activity of the immobilized enzyme. To conclude, the experimental design models allow one to obtain different materials with different features that could find applications in the fields such as biocatalysis/biochromatography, drug delivery or diagnostics. To the best of our knowledge, for the first time, an acrylate based polyHIPE material is used for the binding of enzymes in the active form and successfully applied under flow conditions.