Dual responsive zein hydrogel membrane with selective protein adsorption and sustained release property

Drug-loaded hydrogels have been paid increasing attentions in biomedical fields. As a sort of natural plant protein, zein generally cannot form hydrogel with high water retention because of its predominant hydrophobicity, which will limit its application as biomaterial. In this paper, zein electrospun fibrous membranes (ZEFM) are fabricated through a chemical modification of zein using citric acid and acetic anhydride. The resulting ZEFM can be totally soluble in neutral phosphate buffer solution. After being crosslinked by sodium hexametaphosphate, the ZEFM can form a hydrogel membrane and displays stimuli-responsive behavior towards pH and ionic strength. The hydrogel membrane exhibits better protein adsorption, selectivity and sustained release profile for positively-charged proteins such as cytochrome C, compared with those unmodified ones, and also shows fast biodegradation behavior and qualified cytotoxicity, which all make it favourable for biomedical use.