Regular Article
Elaborate design of ethylene vinyl alcohol (EVAL) nanofiber-based chromatographic media for highly efficient adsorption and extraction of proteins

https://doi.org/10.1016/j.jcis.2019.07.065Get rights and content

Abstract

The development of chromatographic media with superb adsorption capacity and large processing throughput is of great importance for highly efficient protein adsorption and separation, yet still faces a huge challenge. Herein, a new kind of butane tetracarboxylic acid (BTCA) functionalized ethylene vinyl alcohol (EVAL) nanofibrous membranes (BTCA@EVAL NFM)-based chromatographic media is fabricated, for the first time, by combining blend electrospinning technique with in-situ modification technology. The resulting BTCA@EVAL NFM possesses an enhanced equilibrium protein adsorption capability (716 mg g−1), a high saturated dynamic protein binding capacity (490 mg g−1), and a distinctive selectivity towards positively charged proteins, which are attributed to the synergistic effects of the hydrophilic EVAL nanofibrous matrix and the plentiful carboxyl groups introduced by BTCA. Besides, benefiting from its stable physical and chemical structures, the membrane also presents excellent acid and alkaline resistance as well as good reusability. Significantly, the BTCA@EVAL NFM can directly extract lysozyme from egg white with a relatively large capture capability of 353 mg g−1, highlighting its superb potential practicability. We sincerely hope that this new design concept and the highly effective nanofiber-based chromatographic media can provide some guidance for the further development of bio-separation and purification.

Introduction

Nowadays, our human beings are suffering from increasingly serious health problems, such as cancer, tumors, and pandemic virus, which are caused by environmental pollution, heavy workload, and life pressure [1], [2], [3], [4]. Biological pharmaceuticals, especially protein drugs, play a critical role in preventing and treating those diseases due to their high activity, strong specificity, and low toxicity [5], [6], [7]. Thus, a highly efficient and large-scale manufacture technology for producing high-purity proteins is highly desired. Generally, during the manufacturing of protein products, the isolation and purification of proteins are regarded as the most critical steps, which directly decided the quality and cost of the protein products [8], [9]. To date, various methods have been developed to separate and purify proteins, mainly including precipitation, electrophoresis, sedimentation, extraction, and chromatography [10], [11], [12], [13]. Among these techniques, chromatography has been applied most widely due to its high separation precision and large capacity [14], [15]. Currently, the most commonly used chromatographic media are functionalized porous resin or polysaccharide gel particles-based chromatographic media with high adsorption capacity, which can be ascribed to their ultra-large specific surface area (SSA) arising from the internal porous structure. However, the inner-pore feature also causes those particle-based chromatographic materials suffering from some shortcomings, such as relatively slow molecular mass-transfer, long retention time, high fluid flow resistance, and large elution liquid consumption, which seriously restrict the further development of chromatography technique [16], [17], [18].

Alternatively, the newly developed fiber-based chromatographic media have presented promising potentials to make up the disadvantages of the porous particle-based media due to their convective mass-transfer of protein molecules on the fiber surface, thus have attracted widespread attention. Accordingly, a variety of membrane-based chromatographic media have been developed, such as functionalized collagen, polyamide, cellulose, silica, and synthetic polymers membranes [19], [20], [21], [22]. Although certain progress in fibrous chromatographic media has been obtained, the main challenges in aspects of relatively low static protein binding capability and unsatisfactory dynamic breakthrough capacity are still unresolved, which are caused by their relatively insufficient adsorption surface area and functional groups [23]. Alternatively, nanofibrous membrane-based chromatographic media have presented broad prospects to address the above problems effectively, yet needs to be further explored.

Currently, as compared with the traditional preparation methods of nanofiber (e.g., melt blowing, island spinning, and template synthesis), electrospinning has been perceived as the most promising technique to massively fabricate nanofibers due to its advantages of abundant raw materials, excellent tunability of fiber aggregating structure, and ease of combination with other technologies [24]. Owing to the structural features of nanofibrous membranes (e.g., high SSA, interconnected pore channels, and controllable interface properties) and the technical features of electrospinning, electrospun nanofibers have obtained widespread applications including filtration, biomedical treatment, functional clothing, and oil-water separation [25], [26], [27], [28], [29], [30]. Recently, electrospun nanofibers also have received increasing attention from researchers engaged in the development of bio-separation and purification materials. Up to now, several kinds of electrospun nanofiber-based chromatographic materials have been reported. For instance, the diacetate nitrate-based ion-exchange membrane with a bovine serum albumin (BSA) adsorption capacity of 300 mg g−1, the protein A/G functionalized regenerated cellulose-based affinity membrane with an IgG adsorption capacity of 18.8 mg g−1, the Cibacron blue F3GA grafted polyacrylonitrile-based affinity membrane with a bromelain adsorption capacity of 161.6 mg g−1, and the hydroxyapatite nanoparticles decorated cellulose triacetate-based membrane with a BSA adsorption capacity of 176 mg g−1 [31], [32], [33], [34]. Although the fabrication of electrospun nanofiber-based chromatographic materials has made certain progress, some bottleneck problems still exist, such as the complicated functionalization processes, unsatisfactory adsorption performance, relatively poor chemical resistance, and weak mechanical properties. Consequently, it is highly urgent to exploit a simple and robust approach for fabricating highly effective nanofiber-based chromatographic media.

In the present work, we demonstrate a facile, versatile, and scalable methodology to fabricate a new kind of butane tetracarboxylic acid (BTCA) modified ethylene vinyl alcohol (EVAL) nanofibrous membranes (BTCA@EVAL NFM)-based cation-exchange chromatographic media, for the first time, by subtly combining blend electrospinning method with fruitful in-situ modification technology (as exhibited in Scheme S1). The morphologies, pore structures, surface wettability, mechanical properties, and protein adsorption performance of the membranes were finely controlled by regulating the BTCA loading amount. Moreover, the static and kinetic adsorption properties, dynamic breakthrough adsorption performance, acid and alkaline resistance, selectivity, and reusability of the obtained membranes were systemically studied. Additionally, the effects of properties of the buffer solution (e.g., pH value, ionic strength, and ion species) on the protein binding capability of the resultant membranes were also thoroughly investigated. Furthermore, the potential practical application properties of the resultant membranes were evaluated by testing their capability of extracting lysozyme from the fresh egg white.

Section snippets

Materials

EVAL (ethylene content of 44 mol% and density of 1.14 g cm−3) was brought from Kuraray Co., Ltd., Japan. BTCA, isopropyl alcohol (IPA), catalyst of polyphosphoric acid (PPA, P2O5 content of >85 wt%), disodium hydrogen phosphate (Na2HPO4), phosphoric acid (H3PO4), sodium hydroxide (NaOH), sodium dihydrogen phosphate (NaH2PO4), anhydrous sodium sulfate (Na2SO4), lithium chloride (LiCl), potassium chloride (KCl), sodium chloride (NaCl), and magnesium chloride (MgCl2) were bought from Aladdin

Preparation, surface morphologies, and chemical structures

This work aimed to fabricate a new kind of nanofiber-based chromatographic media with enhanced efficiency. Therefore, we elaborately designed the materials based on the following three principles: (1) the membranes should possess high SSA, fine hydrophilicity, abundant adsorption groups, and interconnected pore structure; (2) the physicochemical structure of the membrane should be stable to ensure the long-term application; (3) the fabrication process should be convenient and conducted under

Conclusions

In summary, we have successfully fabricated a new type of butane tetracarboxylic acid (BTCA) functionalized ethylene vinyl alcohol (EVAL) nanofibrous membranes (BTCA@EVAL NFM)-based chromatographic media, for the first time, by subtly combining blend electrospinning technique with in-situ modification technology. The above results showed that the BTCA loading amount possessed great influences on the physicochemical structure and application performance of the resultant membranes, which mainly

Author contributions

The manuscript was written through the contributions of all authors. All authors have approved the final version of the manuscript.

Acknowledgement

This work is supported by the National Natural Science Foundation of China (Nos. 51673037 and 51773033).

References (53)

  • Y.S. Chen et al.

    Protein adsorption separation using glass fiber membranes modified with short-chain organosilicon derivatives

    J. Membrane Sci.

    (2007)
  • R. Ghosh

    Protein separation using membrane chromatography: opportunities and challenges

    J. Chromatogr. A

    (2002)
  • X. Li et al.

    Electreted polyetherimide-silica fibrous membranes for enhanced filtration of fine particles

    J. Colloid Interface Sci.

    (2015)
  • Y. Arima et al.

    Effect of wettability and surface functional groups on protein adsorption and cell adhesion using well-defined mixed self-assembled monolayers

    Biomaterials

    (2007)
  • T. Jiang et al.

    Electrospinning of polymer nanofibers for tissue regeneration

    Prog. Polym. Sci.

    (2015)
  • Z. Ma et al.

    Electrospun regenerated cellulose nanofiber affinity membrane functionalized with protein A/G for IgG purification

    J. Membrane Sci.

    (2008)
  • T. Lan et al.

    Electrospun nanofibrous cellulose diacetate nitrate membrane for protein separation

    J. Membrane Sci.

    (2015)
  • Q. Fu et al.

    Electrospun nanofibrous composite materials: a versatile platform for high efficiency protein adsorption and separation

    Comp. Comm.

    (2018)
  • H.T. Zhang et al.

    Surface modification of electrospun polyacrylonitrile nanofiber towards developing an affinity membrane for bromelain adsorption

    Desalination

    (2010)
  • B.B. Sauer et al.

    Temperature modulated DSC studies of melting and recrystallization in polymers exhibiting multiple endotherms

    Polymer

    (2000)
  • J.H. Zhou et al.

    Characterization of surface oxygen complexes on carbon nanofibers by TPD, XPS and FT-IR

    Carbon

    (2007)
  • Z. Zhou et al.

    Sorption performance and mechanisms of arsenic(V) removal by magnetic gelatin-modified biochar

    Chem. Eng. J.

    (2017)
  • M.N. Sarvi et al.

    Development of functionalized mesoporous silica for adsorption and separation of dairy proteins

    Chem. Eng. J.

    (2014)
  • T. Do et al.

    A rapid method for determining dynamic binding capacity of resins for the purification of proteins

    Protein Expres. Purif.

    (2008)
  • V. Orr et al.

    Recent advances in bioprocessing application of membrane chromatography

    Biotechnol. Adv.

    (2013)
  • F. Dismer et al.

    Effects of ionic strength and mobile phase ph on the binding orientation of lysozyme on different ion-exchange adsorbents

    J. Chromatogr. A

    (2008)
  • Cited by (20)

    • PNIPAm hydrogel composite membrane for high-throughput adsorption of biological macromolecules

      2022, Separation and Purification Technology
      Citation Excerpt :

      The separation process of protein needs to ensure not only the stability of its physical and chemical properties, but also its good biological activity, which brings great difficulties to the separation of protein [11,12]. There are deficiencies in the traditional protein separation methods [13], which can not meet the development of modern society. Until now, the adsorption separation of proteins has made great progress on the effective separation materials [14].

    • Biotextile-based adsorbents for medical applications

      2022, Medical Textiles from Natural Resources
    View all citing articles on Scopus
    View full text