Facile fabrication of nanofibrous ion-exchange chromatography membrane with aminated surface for highly efficient RNA separation and purification

Abstract

Construction of ion-exchange chromatography membrane with appropriate pore size and high-density ligands is essential to improve its working efficiency and service life for the separation and purification of biomacromolecules such as RNA. Herein, surface aminated ethylene vinyl alcohol copolymer (EVOH) ion-exchange chromatography nanofibrous membrane (PEI-NFM) with 0.7 µm pore size was fabricated by sea-island spinning and in situ crosslinking (EVOH nanofibers reacted with glutaraldehyde (GA) and polyethyleneimine (PEI) in dispersion). Morphological and chemical characterization of PEI-NFM indicated that GA and PEI crosslinked on the surface of nanofibers uniformly. Benefiting from the 3D network scaffold structure stacked by nanofibers and high-density amine groups, PEI-NFM exhibits high saturated capacity toward RNA (191.16 mg/g), and still possesses more than 93% of its initial adsorption capacity after ten times cyclic adsorption-elution. Moreover, PEI-NFM packed syringe-driven filter shows high water flux of 10.38 L/h at 0.1 MPa and a high dynamic adsorption performance toward RNA (144.07 mg/g at 1 mm/min). Besides, PEI-NFM exhibits high-recognition binding property toward RNA mixed with other biomacromolecules by adjusting pH of mixed solution to make other biomacromolecules positively charged. This work provides a facile strategy for the preparation of high performance and long service life ion-exchange chromatography membrane.