Poly(glycidyl methacrylate)-grafted hydrophobic charge-induction agarose resins with 5-aminobenzimidazole as a functional ligand

Benzotriazole-5-carboxylic as a mixed-mode ligand for chromatographic separation of antibody with enhanced adsorption capacity

Mixed-mode chromatography provides a promising strategy for industrial protein purification for its potential merit of balancing efficiency and cost-effectiveness. However, mixed-mode media with satisfactory selectivity and binding capacity towards antibody are still urgently needed. A new type of mixed-mode chromatography resin was prepared using benzotriazole-5-carboxylicas as ligand (BTA MM), and its application in antibody separation was explored. A typical pH-dependent protein binding was observed, and the neutral condition was favorable for antibody adsorption. Dynamic binding capacity of human immunoglobulin G (hIgG) was 57.7 mg/mL at pH 7.4 (10 mM phosphate buffer, containing 150 mM NaCl), while elution with acidic solutions (pH 3-4) could achieve a recovery of more than 85%. Protein adsorption on the resin showed a salt-independent manner, thus it could work under physiological solution conditions, with satisfied antibody selectivity. One-step purification of antibody components from human serum samples could obtain a product with the purity more than 84%. Satisfied performance was also observed when the adsorbent was used for purifying a IgG1-type monoclonal antibody (mAb) from cell culture supernatant. In addition, the benzotriazole adsorbent has been found stable enough to withstand autoclave sterilization and other harsh conditions, including 1 M NaOH, 1 M HCl, and 75% ethanol. The results proved the potential of this type of mixed-mode chromatography medium for industrial antibody purification.

Recent advances in protein chromatography with polymer-grafted media

The strategy of using polymer-grafted media is effective to create protein chromatography of high capacity and uptake rate, giving rise to an excellent performance in high-throughput protein separation due to its high dynamic binding capacity. Taking the scientific development and technological innovation of protein chromatography as the objective, this review is devoted to an overview of polymer-grafted media reported in the last five years, including their fabrication routes, protein adsorption and chromatography, mechanisms behind the adsorption behaviors, limitations of polymer-grafted media and chromatographic operation strategies. Particular emphasis is placed on the elaboration and discussion on the behaviors of ion-exchange chromatography (IEC) with polymer-grafted media because IEC is the most suitable chromatographic mode for this kind of media. Recent advances in both the theoretical and experimental investigations on polymer-grafted media are discussed by focusing on their implications to the rational design of novel chromatographic media and mobile phase conditions for the development of high-performance protein chromatography. It is concluded that polymer-grafted media are suitable for development of IEC and mixed-mode chromatography with charged and low hydrophobic ligands, but not for hydrophobic interaction chromatography with high hydrophobic ligands and affinity chromatography with ligands that have single binding site on the protein.

Emerging biomaterials for downstream manufacturing of therapeutic proteins

Downstream processing is considered one of the most challenging phases of industrial manufacturing of therapeutic proteins, accounting for a large portion of the total production costs. The growing demand for therapeutic proteins in the biopharmaceutical market in addition to a significant rise in upstream titers have placed an increasing burden on the downstream purification process, which is often limited by high cost and insufficient capacities. To achieve efficient production and reduced costs, a variety of biomaterials have been exploited to improve the current techniques and also to develop superior alternatives. In this work, we discuss the significance of utilizing traditional biomaterials in downstream processing and review the recent progress in the development of new biomaterials for use in protein separation and purification. Several representative methods will be highlighted and discussed in detail, including affinity chromatography, non-affinity chromatography, membrane separations, magnetic separations, and precipitation/phase separations. STATEMENT OF SIGNIFICANCE: Nowadays, downstream processing of therapeutic proteins is facing great challenges created by the rapid increase of the market size and upstream titers, starving for significant improvements or innovations in current downstream unit operations. Biomaterials have been widely used in downstream manufacturing of proteins and efforts have been continuously devoted to developing more advanced biomaterials for the implementation of more efficient and economical purification methods. This review covers recent advances in the development and application of biomaterials specifically exploited for various chromatographic and non-chromatographic techniques, highlighting several promising alternative strategies.

Recent advances in mixed-mode chromatographic stationary phases

Mixed-mode phases have become very popular in the last decade, and the number of new mixed/multi-mode sorbents is growing fast. Unlike single-mode stationary phases, perfectly suited for the separation of the analytes possessing similar physicochemical properties, for instance reversed-phase chromatography for hydrophobic solutes, mixed-mode sorbents providing multimodal interactions can render better separation selectivity for complex mixtures of solutes differing significantly in their physicochemical characteristics. The most frequent modern mixed-mode stationary phases are di/tri-mode sorbents embracing the following interactions, hydrophobic, electrostatic (coulombic), and hydrophilic. According to their structures, it is possible to distinguish silica-based, polymer-based, hybrid, and monolithic mixed-mode stationary phases. Herewith, newly synthesized mixed-mode sorbents developed within the last two and half years are categorized, discussed, and summarized. The main attention is devoted to the description of the synthetic routes and characterization methods applied for the new stationary phases.