Fabrication Of Highly Carboxylated Poly(vinyl Alcohol) Ultrafine Fibrous Membranes For Efficient Adsorption Of Proteins

Highly purified proteins are critical for addressing issues in immunodiagnostics, immunotherapy, and scientific research, thereby, the current biotechnological and biopharmaceutical industries have made tremendous efforts towards the purification 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. Among numerous protein purification technology, Chromatography is one of the most effective methods of protein separation, Taking advantage of the high efficiency, fast purification speed, and large throughput, Ion exchange chromatography has aroused widespread interest in scientific research, bio-technological and biopharmaceutical industries.Here, we report that cross-linked and highly carboxylated poly(vinyl alcohol)(PVA) ultrafine fibrous 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 ultrafine fibrous membranes exhibited a good integrated adsorption performance.In this article, we present an intriguing approach by creating carboxyl group-surface functionalized ultrafine fibrous membranes under mild conditions for protein adsorption by the combination of electrospun. Considering that the adsorption was driven by the mutual electrostatic attraction between the negatively charged group on the PVA/MAH ultrafine fibrous membranes and the positively charged lysozyme molecules, the carboxyl group content of the PVA/MAH ultrafine fibrous membranes was of great importance to the protein adsorption performance; consequently, the effect of MAH content on the adsorption capacity was intensively investigated. Notably, the addition of 30% MAH could guarantee the saturation of the concentration of carboxyl groups on the membranes, since further increasing the MAH content could not lead to a dramatic intensity change. The as-prepared PVA/MAH ultrafine fibrous membranes achieved a high distribution coefficient and an exceptional superior adsorption capacity of 177 mg/g within 4 h, which was significantly better than that of the PVA/MAH flat films. Additionally, the dynamic saturation adsorption capacity of the PVA/MAH nanofibrous membranes reached 159 mg/g under 750 Pa driven solely by gravity. Moreover, the PVA/MAH ultrafine fibrous membranes exhibited good reversibility after an extended number of regeneration/reuse cycles and excellent stability under depyrogenation conditions. Furthermore, the adsorption performance towards a protein mixture was analysed by SDS-PAGE.Considering the simplicity and cost-effectiveness of the fabrication process, and the excellent adsorption performance including a high adsorption capacity, fast adsorption equilibrium, and good reversibility, the PVA/MAH ultrafine fibrous membranes provide not only a promising method for the purification of lysozyme, but also a versatile platform for the further development of fibrous membrane-based purification systems towards various proteins.