Fiber-based HIC capture loop for coupling of protein A and size exclusion chromatography in a two-dimensional separation of monoclonal antibodies

Interfacial modification of recombinant protein for immunoglobulin G adsorption with spindle-shaped MOF as nano molecular containers

Development of fresh solid phase extractant is critical for selective separation and purification of special proteins. Herein, we demonstrated a recombinant Staphylococcal Protein G (rSPG) with a His-tag modified the novel single-metal organic framework (rSPG@Ni-MOF-74). The proposed solid-phase extraction material possessed a uniform spindle-shaped structure, large surface area (709.60 m2 g-1) and pore volume (0.08 m3 g-1), high metal content (22.57 wt%), which facilitated the interaction between host and guest. As results, the composite displayed outstanding selective recognition and adsorption of IgG, due to synergistic effect of the binding ability of rSPG with the Fc region of IgG, maintained through hydrogen bonding and electrostatic attraction, as well as hydrophobic interaction. The adsorption performance and mechanism of rSPG@Ni-MOF-74 have been fully investigated. Additionally, the rSPG@Ni-MOF-74 composite could effectively separate IgG from serum obtained from healthy humans, with the purity of the separated IgG verified through SDS-PAGE analysis. Furthermore, LC-MS/MS analysis identified a high content of IgG (55.3 %) in the eluate from rSPG@Ni-MOF-74, suggesting the great potential of rSPG@Ni-MOF-74 in IgG separation and enrichment from complex matrix.

Quantitative Recoveries of Exosomes and Monoclonal Antibodies from Chinese Hamster Ovary Cell Cultures by Use of a Single, Integrated Two-Dimensional Liquid Chromatography Method

Cultured cell lines are very commonly used for the mass production of therapeutic proteins, such as monoclonal antibodies (mAbs). In particular, Chinese hamster ovary (CHO) cell lines are widely employed due to their high tolerance to variations in experimental conditions and their ability to grow in suspension or serum free media. CHO cell lines are known for their ability to produce high titers of biotherapeutic products such as immunoglobulin G (IgG). An emergent alternative means of treating diseases, such as cancer, is the use of gene therapies, wherein genetic cargo is "packaged" in nanosized vesicular structures, referred to as "vectors". One particularly attractive vector option is extracellular vesicles (EVs), of which exosomes are of greatest interest. While exosomes can be harvested from virtually any human body fluid, bovine milk, or even plants, their production in cell cultures is an attractive commercial approach. In fact, the same CHO cell types employed for mAb production also produce exosomes as a natural byproduct. Here, we describe a single integrated 2D liquid chromatography (2DLC) method for the quantitative recovery of both exosomes and antibodies from a singular sample aliquot. At the heart of the method is the use of polyester capillary-channeled polymer (C-CP) fibers as the first dimension column, wherein exosomes/EVs are captured from the supernatant sample and subsequently determined by multiangle light scattering (MALS), while the mAbs are captured, eluted, and quantified using a protein A-modified C-CP fiber column in the second dimension, all in a 10 min workflow. These efforts demonstrate the versatility of the C-CP fiber phases with the capacity to harvest both forms of therapeutics from a single bioreactor, suggesting an appreciable potential impact in the field of biotherapeutics production.

Two-dimensional separation of water-soluble polymers using size exclusion and reversed phase chromatography employing capillary-channeled polymer fiber columns

Polymeric materials are readily available, durable materials that have piqued the interest of many diverse fields, ranging from biomedical engineering to construction. The physiochemical properties of a polymer dictate the behavior and function, where large polydispersity among polymer properties can lead to problems; however, current polymer analysis methods often only report results for one particular property. Two-dimensional liquid chromatography (2DLC) applications have become increasingly popular due to the ability to implement two chromatographic modalities in one platform, meaning the ability to simultaneously address multiple physiochemical aspects of a polymer sample, such as functional group content and molar mass. The work presented employs size exclusion chromatography (SEC) and reversed-phase (RP) chromatography, through two coupling strategies: SEC x RP and RP x RP separations of the water-soluble polymers poly(methacrylic acid) (PMA) and polystyrene sulfonic acid (PSSA). Capillary-channeled polymer (C-CP) fiber (polyester and polypropylene) stationary phases were used for the RP separations. Particularly attractive is the fact that they are easily implemented as the second dimension in 2DLC workflows due to their low backpressure (<1000 psi at ∼70 mm sec^-1) and fast separation times. In-line multi-angle light scattering (MALS) was also implemented for molecular weight determinations of the polymer samples, with the molecular weight of PMA ranging from 5 × 10⁴ to 2 × 10⁵ g mol^-1, while PSSA ranges from 10⁵ to 10⁸ g mol^-1. While the orthogonal pairing of SEC x RP addresses polymer sizing and chemistry, this approach is limited by long separation times (80 min), the need for high solute concentrations (PMA = 1.79 mg mL^-1 and PSSA = 0.175 mg mL^-1 to yield comparable absorbance responses) due to on-column dilution and subsequently limited resolution in the RP separation space. With RP x RP couplings, separation times were significantly reduced (40 min), with lower sample concentrations (0.595 mg mL^-1 of PMA and 0.05 mg mL^-1 of PSSA) required. The combined RP strategy provided better overall distinction in the chemical distribution of the polymers, yielding 7 distict species versus 3 for the SEC x RP coupling.

Two-Dimensional Liquid Chromatography (2D-LC): Analysis of Size-Based Heterogeneities in Monoclonal Antibody–Based Biotherapeutic Products

Monoclonal antibodies (mAbs) dominate the pipelines in the biopharmaceutical industry today. Being complex products, this class of molecules has numerous critical quality attributes (CQAs). Their thorough characterization is a necessary and critical component of biopharmaceutical product development. One CQA is size-based heterogeneity. Aggregates are widely considered a CQA because of their likely impact on the immunogenicity of the product. There is no single analytical tool that can accurately characterize aggregates because of the significant diversity that they exhibit with respect to size, structure, and morphology. As a result, it is common practice to use multiple, orthogonal analytical tools for aggregate characterization. This article reviews efforts targeting the use of two-dimensional liquid chromatography (2D-LC) and mass spectrometry (MS) for aggregate characterization.

Recent trends in sorbents for bioaffinity chromatography

Isolation or enrichment of biological molecules from complex biological samples is mostly a prerequisite in proteomics, genomics, and glycomics. Different techniques have been used to advance the efficiency of the purification of biological molecules. Bioaffinity chromatography is one of the most powerful technique that plays an important role in the isolation of target biological molecules by the specific interactions with ligands that are immobilized on different support materials. This review examines the recent developments in bioaffinity chromatography particularly over the past 5 years in the literature. Also properties of supports, immobilization techniques, types of binding agents, and methods used in bioaffinity chromatography applications are summarized.

Charge variant analysis of protein-based biopharmaceuticals using two-dimensional liquid chromatography hyphenated to mass spectrometry

The profile of charge variants represents an important critical quality attribute of protein-based biopharmaceuticals, in particular of monoclonal antibodies, and must therefore becontrolled. In this work, 2D-LC methods for charge variant analysis were developed using a strong cation-exchange chromatography (SCX) as first dimension (¹D) separation. Non-porous SCX (3 µm) particle columns and different mobile phases were evaluated using a test mixture of some standard proteins of different size and pI (comprising myoglobin, bovine serum albumin, cytochrome c, lysozyme and β-lactoglobulin) and two monoclonal IgG1 antibodies (NIST mAb and Secukinumab). The most promising ¹D eluent for SCX was a salt-mediated pH-gradient system using a ternary mobile phase system with 2-(N-morpholino)ethanesulfonic acid, 1,3-diamino-2-propanol and sodium chloride. For the second dimension (²D), a desalting reversed-phase liquid chromatography (RP-LC) was chosen to enable the hyphenation of the charge variant separation with mass spectrometric (MS) detection. While for intact mAbs the ²D just served for desalting without additional selectivity, the ²D contributed some orthogonal selectivity for the mAb fragment separation. Various core-shell and monolithic columns were tested and variables such as gradient time and flow rate systematically optimized. Unexpectedly, a C4 400 Å column (3.4 µm diameter with 0.2 µm porous shell) provided higher peak capacities compared to the same 1000 Å column (2.7 µm diameter with 0.5 µm porous shell). A thinner shell appeared to be more advantageous than wider pores under high flow regime. An ultra-fast RP-LC method with a run time of one minute was developed using trifluoroacetic acid which was later replaced by formic acid as additive for better MS compatibility. The successful hyphenation of the two orthogonal separation modes, SCX and RP-LC, could be demonstrated in the multiple heart-cutting and the full comprehensive mode. MS analysis using a high-resolution quadrupole time-of-flight instrument enabled to identify different glycoforms and some major charge variants of the antibody at the intact protein level as well as on the subunit level (Fc/2, Lc, Fd') in a middle-up approach by 2D-LC-ESI-MS analysis.