Construction of enzyme-encapsulated fibermats from the cross-linkable copolymers poly(acrylamide)-co-poly(diacetone acrylamide) with the bi-functional cross-linker, adipic acid dihydrazide

Herein, we describe the successful construction of novel electrospun fibermats from the cross-linkable copolymer poly (acrylamide)-co-poly (diacetone acrylamide) (PAM-co-PDAAM) with the molar ratio of acrylamide and diacetone acrylamide units 8:2 (PAM-co-PDAAM(8:2)) by in situ cross-linking during electrospinning with the bifunctional cross-linker adipic dihydrazide (ADH). As the cross-linking reactions between the ketone groups in PAM-co-PDAAM(8:2) and the hydrazide groups in ADH (in pH 6-8 aqueous buffer) is one of the bio-orthogonal reactions that are inert for various functional groups in biomacromolecules, stable encapsulation of green fluorescent protein and alpha-chymotrypsin at the inside of constituent nanofibers was successfully achieved without losing the original biological activities. Aqueous buffer is the only solvent through all process of fibermat construction, and combination of bioorthogonal reactions is optimum for the construction of fibermats that encapsulate biomacromolecules. The examples presented in this study should provide fascinating insight for future biomacromolecule-encapsulated fibermat research. (C) 2017 Elsevier Ltd. All rights reserved.