Monodisperse porous polymer particles with polyionic ligands for ion exchange separation of proteins

Application of deep eutectic solvents in protein extraction and purification

Deep eutectic solvents (DESs) are a mixture of hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) molecules that can consist, respectively, of natural plant metabolites such as sugars, carboxylic acids, amino acids, and ionic molecules, which are for the vast majority ammonium salts. Media such as DESs are modular tools of sustainability that can be pointed toward the extraction of bioactive molecules due to their excellent physicochemical properties, their relatively low price, and accessibility. The present review focuses on the application of DESs for protein extraction and purification. The in-depth effects and principles that apply to DES-mediated extraction using various renewable biomasses will be discussed as well. One of the most important observations being made is that DESs have a clear ability to maintain the biological and/or functional activity of the extracted proteins, as well as increase their stability compared to traditional solvents. They demonstrate true potential for a reproducible but more importantly, scalable protein extraction and purification compared to traditional methods while enabling waste valorization in some particular cases.

The study and application of biomolecules in deep eutectic solvents

Deep eutectic solvents offer stimulating possibilities for biomolecular stabilization and manipulation, biocatalysis, bioextraction, biomass processing, and drug delivery and therapy.

Development of different deep eutectic solvent aqueous biphasic systems for the separation of proteins

In this work, aqueous biphasic systems (ABSs) formed by different deep eutectic solvents (DESs) were prepared and applied to extract proteins. The five kinds of DESs comprised amino acids and polyols ([amino acids][polyols]). They were combined with another DES resulting from tetrabutylammonium chloride and polypropylene glycol 400 ([TBAC][PPG400]) to form ABSs. The phase-forming abilities of [TBAC][PPG400]/[amino acids][polyols] were compared with those of [TBAC][PPG400]/amino acids and [TBAC][PPG400]/polyols. The results exhibited that the biphasic formation ability of [amino acids][polyols] lies between those of amino acids and polyols when [TBAC][PPG400] acts as the other phase in ABSs. The systems comprising [TBAC][PPG400] and [l-proline][xylitol] ([Pro][Xyl]) were further investigated to optimize the extraction performance. It was found that 97.30% chymotrypsin tended to distribute into the [Pro][Xyl]-rich phase under optimum conditions. The practical application of the system was demonstrated by the extraction of chymotrypsin from porcine pancreas. Besides, UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and circular dichroism (CD) spectroscopy proved that the conformation of proteins remained unchanged during the extraction process. The extraction mechanism of the formation of DES-protein aggregates was investigated via conductivity, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The overall results suggest that the DES/DES-based ABSs have outstanding potential in the green extraction of proteins.

Vortex Fluidic Mediated Synthesis of Macroporous Bovine Serum Albumin-Based Microspheres

Macroporous bovine serum albumin (BSA) nanoparticles with controllable diameter were readily fabricated in a rapidly rotating angled glass tube in a vortex fluidic device (VFD). Systematically varying the rotational speed and the ratio of BSA, ethanol, and glutaraldehyde led to conditions for generating ca. 600 nm diameter macroporous particles that have intrinsic fluorescence emission at 520 nm when excited at 490 nm. The presence of the macropores increased the absorption efficiency of rhodamine B with potential applications for drug delivery purpose, compared with BSA nanoparticles having surfaces devoid of pores. Further control over the size of BSA nanoparticles occurred in the presence of C-phycocyanin protein during the VFD processing, along with control of their shape, from spheres to pockets, as established in exploring the parameter space of the microfluidic device.

Two-Stage Growth of Polymer Nanoparticles at the Liquid-Vapor Interface by Vapor-Phase Polymerization

In this article, we study the growth of polymer nanoparticles that are formed on the surface of silicone oils via initiated chemical vapor deposition. The average radius of the particles can be increased by decreasing the silicone oil viscosity, increasing the deposition time, or increasing the deposition rate. The time series data indicates that there are two stages for particle growth. Particle nucleation occurs in the first stage and the particle size is dependent on the liquid viscosity and deposition rate. Particle growth occurs in the second stage, during which the particle size is dependent only on the amount of deposited polymer. This two-step process allows us to make core-shell particles by sequentially depositing different polymers. The benefits of our nanoparticle synthesis process are that solvents and surfactants are not required and the size of the nanoparticles can be controlled over a wide range of radii with a relatively narrow distribution.

Use of specific polysaccharide-immobilized monodisperse poly(glycidyl methacrylate) core-silica shell microspheres for affinity purification of lectins

Immobilization of polysaccharides (yeast mannan and gum arabic) on the macroporous poly(glycidyl methacrylate) monodisperse microspheres coated with silica (SiO2 )-containing amino groups on the surface was used to prepare affinity sorbents for lectin purification. The efficiency of isolating mannose specific Pisum sativum lectin was demonstrated on sorbent with immobilized yeast mannan and that of galactose specific Glycine hispida lectin on sorbent with immobilized gum arabic. The microspheres with immobilized polysaccharides can be used for selecting an affinity sorbent for purification of other mannose- and galactose-specific lectins. In contrast to yeast mannan, the gum arabic immobilized on the microspheres possesses much narrower specificity and is suitable for purification of only those galactose specific lectins which interact well with l-rhamnose or l-arabinose. The synthesized macroporous particles are capable of immobilizing 50 mg of polysaccharide per 1 g of the matrix, which is 10 times higher than the capacity of epoxy-activated Sepharose 6B. That makes it possible to obtain the same lectin quantity using a column of 10 times smaller volume. Another advantage of novel affinity sorbents comparing corresponding Sepharose gels is the possibility of sorbent drying after use.

Macrocyclic receptors immobilized to monodisperse porous polymer particles by chemical grafting and physical impregnation for strontium capture: a comparative study

Separation of strontium is of great significance for radioactive waste treatment and environmental remediation after nuclear accidents. In this work, a novel class of adsorbent (Crown-g-MPPPs) was synthesized by chemical grafting a macrocyclic ether receptor to monodisperse porous polymer particles (MPPPs) for strontium adsorption. Meanwhile, a counterpart material (Crown@MPPPs) with the receptor molecules immobilized to the MPPPs substrate by physical impregnation was prepared. To investigate how the immobilization manner and distribution of the receptors influence the adsorption ability, a comparative study on the adsorption behaviour of the two materials towards Sr(II) in HNO3 media was accomplished. Due to the shorter diffusion path and covalently-bonded structure, Crown-g-MPPPs showed faster adsorption kinetics and better stability for cycle use. While Crown@MPPPs had the advantages of facile synthesis and higher adsorption capacity, owing to the absence of conformational constraint to form complexation with Sr(II). Kinetic functions (Lagergren pseudo-first-order/pseudo-second-order functions) and adsorption isotherm models (Langmuir/Freundlich models) were used to fit the experimental data and examine the adsorption mechanism. On this basis, a chromatographic process was proposed by using Crown@MPPPs for an effective separation of Sr(II) (91%) in simulated high level liquid waste (HLLW).

Hydroxyl functionalized thermosensitive microgels with quadratic crosslinking density distribution

N-isopropylacrylamide (NIPA) based uniform thermosensitive microgels were synthesized by dispersion polymerization by using relatively hydrophilic crosslinking agents with hydroxyl functionality. Glycerol dimethacrylate (GDMA), pentaerythritol triacrylate (PETA) and pentaerythritol propoxylate triacrylate (PEPTA) were used as crosslinking agents with different hydrophilicities. A protocol was first proposed to determine the crosslinking density distribution in the thermosensitive microgel particles by confocal laser scanning microscopy (CLSM). The microgels were fluorescently labeled by using hydroxyl group of the crosslinking agent. The CLSM observations performed with the microgels synthesized by three different crosslinking agents showed that the crosslinking density exhibited a quadratic decrease with the increasing radial distance in the spherical microgel particles. This structure led to the formation of more loose gel structure on the particle surface with respect to the center. Then the use of hydrophilic crosslinking agents in the dispersion polymerization of NIPA made possible the synthesis of thermosensitive microgels carrying long, flexible and chemically derivatizable (i.e., hydroxyl functionalized) fringes on the surface by a single-stage dispersion polymerization. The microgels with all crosslinking agents exhibited volume phase transition with the increasing temperature. The microgel obtained by the most hydrophilic crosslinking agent, GDMA exhibited higher hydrodynamic diameters in the fully swollen form at low temperatures than those obtained by PETA and PEPTA. Higher hydrodynamic size decrease from fully swollen form to the fully shrunken form was also observed with the same microgel.

Controllable porous polymer particles generated by electrospraying

In this paper, an electrospraying technique was applied to prepare polycaprolactone (PCL) polymer particles with a different microstructure. The PCL particles can be controlled to have a porous microstructure by tailoring the evaporation of solvents during the electrospraying process. The effect of various concentrations on the morphology and microstructure of PCL particles was investigated. The experiment has demonstrated the versatile capability of the electrohydrodynamic atomization process for preparing polymer PCL porous particles and fibers. The thermally induced and evaporation-induced phase separations are proposed as the main mechanisms for the porous microstructure formation. The results demonstrate that the electrospraying method is a simple, innovative and cost-effective method for preparing polymer particles with controllable microstructures.