In situ cross-linked and highly carboxylated poly(vinyl alcohol) nanofibrous membranes for efficient adsorption of proteins

Creating adsorptive materials for the fast, efficient, and high-throughput adsorption and purification of proteins is critical to meet the great demands for highly purified proteins, yet it has proven to be a highly challenging task. Here, we report that cross-linked and highly carboxylated poly(vinyl alcohol) (PVA) nanofibrous membranes were fabricated by a combination of electrospinning and the in situ graft polymerization of PVA and maleic anhydride (MAH) under mild conditions. Taking advantage of the large surface area available for protein binding, the highly tortuous porous structure, and the robust mechanical properties, the resultant PVA/MAH nanofibrous membranes exhibited a good integrated adsorption performance towards lysozyme, including a superior adsorption capacity of 177 mg g(-1), fast adsorption equilibrium within 4 h, good selectivity, and good reversibility. Moreover, the saturation dynamic adsorption amount towards lysozyme reached 159 mg g(-1) under 750 Pa driven solely by gravity, which conformed to the specified requirements for high adsorption capacity under relatively low pressure drops. Furthermore, the adsorption performance towards a protein mixture was analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and the resultant PVA/MAH nanofibrous membranes retained excellent stability under depyrogenation conditions. The successful fabrication of such fascinating nanofibrous materials by using this simple and intriguing approach may provide new insights into the design and development of adsorptive materials for the purification of proteins with superior adsorption performance.