Poly(acrylamide-allyl glycidyl ether) cryogel as a novel stationary phase in dye-affinity chromatography

Cryogels and Monoliths: Promising Tools for Chromatographic Purification of Nucleic Acids

The increasing demand for highly pure biopharmaceuticals has put significant pressure on the biotechnological industry to innovate in production and purification processes. Nucleic acid purification, crucial for gene therapy and vaccine production, presents challenges due to the unique physical and chemical properties of these molecules. Meeting regulatory standards necessitates large quantities of biotherapeutic agents of high purity. While conventional chromatography offers versatility and efficiency, it suffers from drawbacks like low flow rates and binding capacity, as well as high mass transfer resistance. Recent advancements in continuous beds, including monoliths and cryogel-based systems, have emerged as promising solutions to overcome these limitations. This review explores and evaluates the latest progress in chromatography utilizing monolithic and cryogenic supports for nucleic acid purification.

Impact of double cryogelation process on a macroporous dye-affinity hydrogel

Cryogels with interconnected channels allow high flow-through properties and mass transfer when dealing with complex mixtures such as non-clarified crude extracts. However, their mechanical strength can be challenged due to a large void volume inside the polymeric network. We have addressed this problem by forming a double-layer cryogel applied as a dye-affinity chromatography gel. In this study, poly(acrylamide-co-allyl glycidyl ether) cryogel was prepared at sub-zero temperature. The second layer was then prepared inside the primary cryogel under the same conditions to form a double-layer network. Cibacron Blue F3GA, a dye molecule, was immobilized on the surface of the cryogels. Bovine serum albumin was used as a model molecule to study the adsorption/elution procedure in batch and continuous modes. The maximum batch binding capacity and the dynamic binding capacity for the single-layer cryogel were 18 and 0.11, and for the double-layer cryogel were 7.5 and 0.9 mg/g of gel, respectively. However, the mechanical stability of the double-layer cryogel increased 7-fold (144 kPa). It was found that the kinetic and adsorption isotherms follow pseudo-second-order and Freundlich models, respectively. The regeneration of the columns after adsorption/elution cycles was evaluated, and no significant loss of capacity was observed after 10 cycles.

Affinity monolith chromatography: A review of general principles and recent developments

Affinity monolith chromatography (AMC) is a liquid chromatographic technique that utilizes a monolithic support with a biological ligand or related binding agent to isolate, enrich, or detect a target analyte in a complex matrix. The target-specific interaction exhibited by the binding agents makes AMC attractive for the separation or detection of a wide range of compounds. This article will review the basic principles of AMC and recent developments in this field. The supports used in AMC will be discussed, including organic, inorganic, hybrid, carbohydrate, and cryogel monoliths. Schemes for attaching binding agents to these monoliths will be examined as well, such as covalent immobilization, biospecific adsorption, entrapment, molecular imprinting, and coordination methods. An overview will then be given of binding agents that have recently been used in AMC, along with their applications. These applications will include bioaffinity chromatography, immunoaffinity chromatography, immobilized metal-ion affinity chromatography, and dye-ligand or biomimetic affinity chromatography. The use of AMC in chiral separations and biointeraction studies will also be discussed.

Cibacron blue F3GA incorporated immobilized metal chelate affinity sorbent as a high efficient affinity immobilization materials for catalase enzyme

Catalase is a metalloenzyme commonly found in almost all plant and animal tissues and catalyzes the conversion of hydrogen peroxide to less reactive molecules. It is used for the elimination of hydrogen peroxide in biological, biomedical, food and textile applications. For this purpose, a novel affinity sorbent [poly(methacrylic acid- N-isopropyl acrylamide-CB-Fe³⁺, (p(MAA-NIPAAM)-CB-Fe³⁺)] for the determination and it was first developed using MAA and NIPAAM monomers. After characterization with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), adsorption parameters were determined. Reusability of p(MAA-NIPAAM)-CB-Fe³⁺ sorbent was determined after by determining the appropriate desorption agent for desorption of adsorbed catalase in the developed sorbent. It was determined that catalase adsorption could be performed with 0.01 g of sorbent in 45 min. The maximum adsorption capacity for catalase adsorption was determined as 243.17 mg/g with the use of sorbent. The operational and storage stability of the immobilized catalase was found to be high as expected. The conversion of H₂O₂ can be successfully performed by the immobilized enzyme in the prepared sorbent. It has been proven that the affinity of catalase for its substrate is increased by immobilization.

Affinity Membranes and Monoliths for Protein Purification

Affinity capture represents an important step in downstream processing of proteins and it is conventionally performed through a chromatographic process. The performance of this step highly depends on the type of matrix employed. In particular, resin beads and convective materials, such as membranes and monoliths, are the commonly available supports. The present work deals with non-competitive binding of bovine serum albumin (BSA) on different chromatographic media functionalized with Cibacron Blue F3GA (CB). The aim is to set up the development of the purification process starting from the lab-scale characterization of a commercially available CB resin, regenerated cellulose membranes and polymeric monoliths, functionalized with CB to identify the best option. The performance of the three different chromatographic media is evaluated in terms of BSA binding capacity and productivity. The experimental investigation shows promising results for regenerated cellulose membranes and monoliths, whose performance are comparable with those of the packed column tested. It was demonstrated that the capacity of convective stationary phases does not depend on flow rate, in the range investigated, and that the productivity that can be achieved with membranes is 10 to 20 times higher depending on the initial BSA concentration value, and with monoliths it is approximately twice that of beads, at the same superficial velocity.

Biomedical Applications of Polymeric Cryogels

The application of interconnected supermacroporous cryogels as support matrices for the purification, separation and immobilization of whole cells and different biological macromolecules has been well reported in literature. Cryogels have advantages over traditional gel carriers in the field of biochromatography and related biomedical applications. These matrices nearly mimic the three-dimensional structure of native tissue extracellular matrix. In addition, mechanical, osmotic and chemical stability of cryogels make them attractive polymeric materials for the construction of scaffolds in tissue engineering applications and in vitro cell culture, separation materials for many different processes such as immobilization of biomolecules, capturing of target molecules, and controlled drug delivery. The low mass transfer resistance of cryogel matrices makes them useful in chromatographic applications with the immobilization of different affinity ligands to these materials. Cryogels have been introduced as gel matrices prepared using partially frozen monomer or polymer solutions at temperature below zero. These materials can be produced with different shapes and are of interest in the therapeutic area. This review highlights the recent advances in cryogelation technologies by emphasizing their biomedical applications to supply an overview of their rising stars day to day.

Overview of Albumin and Its Purification Methods

As the most frequent plasma protein, albumin constitutes more than 50% of the serum proteins in healthy individuals. It has a key role in oncotic pressure maintenance and it is known as a versatile protein carrier for transportation of various endogenous and exogenous ligands. Reduced amounts of albumin in the body will lead to different kinds of diseases such as hypovolemia and hypoproteinemia. It also has various indications in shocks, burns, cardiopulmonary bypass, acute liver failure and etc. Further applications in research consist of cell culture supplement, drug delivery carrier and protein/drug stabilizer. So, the demand for albumin increased annually worldwide. Due to different applications of albumin, many efforts have been accomplished to achieve albumin during a long period of time. In this review, an overview of serum albumin and different purification methods are summarized.

Introduction to macroporous cryogels

Cryogels are highly elastic three-dimensional materials consisting of a network of interconnected macropores. This unique morphology combined with high mechanical and chemical stability provides excellent mass flow properties. The matrices are synthesized at subzero temperatures from almost any gel-forming precursor. The main fields of application are in biotechnology as 3D-scaffold for cell cultivation, and tissue engineering, or bioseparation as chromatographic media for the separation and purification of biomolecules. This chapter briefly highlights the preparation, properties, and application of these materials.

Interpenetrating polymer network composite cryogels with tailored porous morphology and sorption properties

Cryogels, by their particular morphology and mechanical properties, proved to be invaluable materials in biomedicine and biotechnology as carriers for molecules and cells, chromatographic materials for cell separations and cell culture. Methods used in the characterization of porosity and sorption properties of cryogels are very needful tools, which assist the investigator in the decision on the performances of the gel. Herein, we describe the preparation of ionic interpenetrating polymer network composite cryogels and the characterization methods of their porous morphology, and then the methods used for testing their sorption properties for ionic dyes used as models for drugs.

A novel affinity disks for bovine serum albumin purification

The adsorption characteristics of bovine serum albumin (BSA) onto the supermacroporous poly(hydroxyethylmethacrylate)-Reactive Green 19 [p(HEMA)-RG] cryogel disks have been investigated in this paper. p(HEMA) cryogel disks were prepared by radical polymerization initiated by N,N,N',N'-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. Reactive Green (RG) 19 was covalently attached to the p(HEMA) cryogel disks. These disks were used in BSA adsorption studies to interrogate the effects of pH, initial protein concentration, ionic strength, and temperature. BSA adsorption capacity of the p(HEMA)-RG cryogel disk was significantly improved after the incorporation of RG. Adsorption capacity reached a plateau value at about 0.8 mg/mL at pH 4.0. The amount of adsorbed BSA decreased from 37.7 to 13.9 mg/g with increasing NaCl concentration. The enthalpy of BSA adsorption onto the p(HEMA)-RG cryogel disk was calculated as -58.4 kJ/mol. The adsorption equilibrium isotherm was fitted well by the Freundlich model. BSA was desorbed from cryogel disks (over 90 %) using 0.5 M NaSCN, and the purity of desorbed BSA was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The experimental results showed that the p(HEMA)-RG cryogel disks have potential for the quick protein separation and purification process.

Affinity-recognition-based polymeric cryogels for protein depletion studies

Supermacroporous cryogels can be used for the depletion of highly abundant proteins prior to proteome investigations.

Purification of alcohol dehydrogenase from Saccharomyces cerevisiae using magnetic dye-ligand affinity nanostructures

Reactive Green 19 was covalently immobilized onto magnetic nanostructures for purification of alcohol dehydrogenase from Saccharomyces cerevisiae. The Reactive Green 19 immobilized magnetic nanostructures were characterized by Fourier transform infrared spectroscopy, electron spin resonance, atomic force microscope, and energy dispersive X-ray analysis. Particle size of nanostructures was found to be roughly 70 nm. Alcohol dehydrogenase adsorption experiments were investigated under different conditions in batch system (i.e., medium pH, alcohol dehydrogenase concentration, temperature, and ionic strength). Maximum alcohol dehydrogenase adsorption capacity was found to be 176.09 mg/g polymer while nonspecific alcohol dehydrogenase adsorption onto plain magnetic nanostructures was negligible (19.4 mg/g polymer). Alcohol dehydrogenase molecules were desorbed by using 1.0 M NaCl with 98.4 % recovery. Alcohol dehydrogenase from S. cerevisiae was purified 45.63-fold in single step with dye-immobilized magnetic nanostructures, and purity of alcohol dehydrogenase was shown by silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Selective removal of 17β-estradiol with molecularly imprinted particle-embedded cryogel systems

The selective removal of 17β-estradiol (E2) was investigated by using molecularly E2 imprinted (MIP) particle embedded poly(hydroxyethyl methacrylate) (PHEMA) cryogel. PHEMA/MIP composite cryogel was characterized by FTIR, SEM, swelling studies, and surface area measurements. E2 adsorption studies were performed by using aqueous solutions which contain various amounts of E2. The specificity of PHEMA/MIP cryogel to recognition of E2 was performed by using cholesterol and stigmasterol. PHEMA/MIP cryogel exhibited a high binding capacity (5.32 mg/gpolymer) and high selectivity for E2 in the presence of competitive molecules, cholesterol (k(E2/cholesterol) = 7.6) and stigmasterol (k(E2/Stigmasterol) = 85.8). There is no significant decrease in adsorption capacity after several adsorption-desorption cycles.

Evaluation of in situ albumin binding surfaces: a study of protein adsorption and platelet adhesion

Surface modification strategies that take advantage of the passivation effects of albumin are important in the development of biomaterial surfaces. In this study, linear peptides (LP1, LP2) and a small chemical ligand (SCL) with albumin binding affinities were grafted onto silane functionalized silicon substrates. Surfaces were characterized with contact angle and ellipsometric measurements, and densities of immobilized ligands were assessed spectroscopically. Ellipsometrically measured thickness correlated with the predicted molecular lengths of grafted moieties. Contact angle analysis indicated that the LP1 and LP2 functionalized surfaces were hydrophilic compared to SCL functionalized and control surfaces. Adsorption of albumin from human serum was evaluated and quantified via specific enzyme-linked immunosorbent assays and 2D gel electrophoresis. The following trend was noted for surface adsorbed albumin: LP1 > LP2 > SCL > C, with LP1 derivatized surfaces having ~2.450 μg/cm(2) of bound albumin. LP1 derivatized surfaces possessed the least number of adsorbed platelets with rounded platelet morphology when compared to control surface.