Cryogel Membranes Research Articles

Naringenin-loaded pHEMA cryogel membrane: preparation, characterization, antibacterial activity and in silico studies

Naringenin-loaded pHEMA cryogel membrane: preparation, characterization, antibacterial activity and in silico studies

Hemoglobin Purification Using His-Tag Affinity Chromatography With the Assistance of Ni Ions

In this study, an affinity adsorbent of poly(2-hydroxyethyl methacrylate) [(p(HEMA)] was developed to purify hemoglobin (Hb). Initially, cryogel membranes of p(HEMA) were prepared and their surfaces were modified with the dopamine monomer to create polydopamine (pda) modified p(HEMA) cryogel [pda(HEMA)] membranes. After the modification, the nickel (Ni) ions were immobilized on pda(HEMA ) for Hb purification in the aqueous solution. At pH 5, 23.5 mg/g Hb was adsorbed by the adsorbent and the Langmuir adsorption isotherm model was suitable for this adsorption process thanks to the R2 and q max values; moreover, the prepared adsorbent without notable decreases in its adsorption capacity

Controlled Release Simvastatine from Molecularly Imprinted Cryogel Membranes

AbstractIn this study, poly(2‐hydroxyethyl methacrylate‐N‐methacryloyl‐L‐tryptophan methyl ester) cryogel membranes were synthesized in different concentrations by using molecular imprinting technique, for controlled release of simvastatin. The cryogel membranes were prepared in various compositions and thus the releases of cryogels containing 0.5, 0.75 and 1 mg hydrophilic simvstatin were compared. The chemical and morphological properties of the poly(HEMA‐MATrp) cryogel membranes were evaluated through a series of characterization techniques. The membranes were subjected to swelling tests to assess their ability to absorb water and their degree of crosslinking. Fourier‐transform infrared spectroscopy was applied to determine the functional groups present in the cryogel matrix and to evaluate the degree of chemical modification that occurred during synthesis. Additionally, scanning electron microscopy was employed to visualize the cryogel at high resolution, providing insights into the pore structure and overall architecture of the matrix. Then, cryogel membranes were evaluated for cell proliferation abilities by 3‐(4,5‐dimethyl/thiazol‐2‐yl) 2,5‐diphenyltetra zolium bromide thiazolyl blue (MTT) assay for cell viability. The prepared cryogel membranes have a diameter and thickness of about 10 mm and 1.0 mm, respectively. The increasing attention towards the use of cryogel membranes in tissue‐engineering has resulted in demonstrating the dependency of release profiles of simvastatin cryogel membranes on their composition.

Specific DNA aptamer-immobilized cryogel membranes as novel bioaffinity supports and their potential for the purification of activated protein C.

Activated protein C (APC), a serine protease produced from zymogen protein C (PC), is the key enzyme of the protein C pathway. APC has anticoagulant, anti-inflammatory, and cytoprotective features. APC has recently been shown to significantly reduce coagulation as well as mortality in patients with severe sepsis. Herein, we aimed to develop an affinity support material that allows the purification of plasma APC for the first time. In this research, a novel APC-specific DNA aptamer-based poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) (poly(HEMA-GMA/DNA-Apt)) macroporous cryogel membrane at different molar ratios was prepared using affinity binding method and their potential for purification and identification of APC was investigated. The DNA aptamer-immobilized cryogels were characterized to examine their structural and morphological properties. The effect of pH, initial concentration, temperature, ionic strength difference, and flow rate changes was examined. Selectivity studies were performed in the presence of APC and competitive proteins, and cryogel support materials were shown to have a very high affinity for APC. Adsorption capacity was found to be 89.02 mg/g. Finally, NaCl revealed efficiency for APC desorption and the reuse of cryogels was successfully tested for ten cycles.

Advancing drug delivery and antimicrobial activity: Development and molecular docking analysis of quercetin-loaded pHEMA cryogel membranes

Quercetin (QT), found in Hypericum perforatum, Allium cepa, and citrus fruits, exhibits several pharmacological effects, including anti-cancer, anti-inflammatory, anti-bacterial, and anti-viral activities. Despite these significant benefits, the application of QT in pharmaceutical formulations is constrained by various challenges, such as its sensitivity to temperature, stability issues, low water solubility, and poor bioavailability. Cryogels, known for their remarkable physical properties such as swelling ratio, pore size, and pore interconnectivity, also offer tunable mechanical properties through the variation of monomer types, monomer-to-solvent ratios, and polymerization temperatures. In this study, we evaluated molecular docking analysis of QT against Staphylococcus aureus and developed QT-loaded pHEMA cryogel membranes (QT-pHEMA-GelCryoMem) to combat bacterial infections. The loading of QT within these membranes was characterized using Scanning Electron Microscopy and Fourier-transform infrared spectroscopy. The highest binding affinity of QT compound against different Staphylococcus aureus proteins (PDB ID:3U2D, PDB ID:2W9S, PDB ID:4H8E, PDB ID:3VSL, PDB ID:6U3Y and PDB ID:1JIJ) was found to be 8.429 kcal/mol for 2W9S while the lowest binding affinity was found to be -4.992 kcal/mol for 3VSL. The QT-pHEMA-GelCryoMem demonstrated good biocompatibility with HDFa cells and effective antimicrobial activity against Staphylococcus aureus. The obtained datas suggest that QT-pHEMA-GelCryoMem could be used in various applications, such as wound dressings, scaffolds, or food packaging.

Preparation and application of naringenin imprinted cryogel membranes for selectively separation of naringenin from natural environment

Naringenin imprinted cryogel membranes (Nar-ICMs) were constructed for the selective separation of naringenin from the natural media. Acrylamide was used as functional monomer, while 2-hydroxyethyl methacrylate was used as co-monomer. Nar-ICMs were subjected to some characterization analyses, e.g., contact angle measurement, swelling tests, FTIR and SEM. Selectivity studies of Nar-ICMs were carried out both in aqueous media and natural orange juice. In selectivity studies, gallic and caffeic acid molecules were used as competitor agents due to their structural similarity to naringenin. Some results obtained as follows: Contact angle values for Nar-ICMs and non-imprinted cryogel membranes (non-ICMs) were found to be 58.5° and 71.8°, respectively. The maximum adsorption capacities of Nar-ICMs and non-ICMs for naringenin were found to be 66.5 and 14 mg/g, respectively at an initial concentration of 2 mg/mL. The qmax and Kd values of the high-affinity binding sites of the obtained Scatchard plot were found to be 0.126 mmol/g (34.4 mg/g) and 0.16 mM (1.6.10–4 M), respectively. The selectivity of Nar-ICMs for naringenin was found as 1.99 and 2.26 times high when compared to gallic and caffeic acids, respectively. The adsorption of naringenin from natural orange juice with Nar-ICMs was found to be 843 µg/g.

Lysozyme Imprinted poly(hydroxyethyl methacrylate) Cryogel Membrane with the Assistance of polydopamine

The surface imprinted technique was utilized in creating the synthetic lysozyme receptors on the poly(hydroxyethyl methacrylate) [p(HEMA)] cryogel membrane with the assistance of polydopamine under alkaline conditions. Following the design of the artificial receptors, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and the swelling test were used for the characterization studies and the lysozyme adsorption capability of the adsorbent was evaluated in the aqueous solution. The maximum adsorption capacity (Qmax) of lysozyme was found as 108.9 mg/g and the adsorption of the target protein on the adsorbent was monolayer and showed a good fit to the Langmuir isotherm model. The IF factor was 3.26 and the adsorbent was highly selective against creatinine and bovine serum albumin (BSA). Furthermore, the adsorbent maintained its stability after 5 adsorption, desorption, and regeneration cycles.

Pterostilbene loaded poly(vinyl alcohol)-gelatin cryogels as potential bioactive wound dressing material.

Cryogels are support materials which are good at mimicking extracellular matrix due to their excellent hydrophilicity, biocompatibility, and macroporous structure, thus they are useful in facilitating cell activities during healing process. In this study, polyvinyl alcohol-gelatin (PVA-Gel) based cryogel membranes loaded with pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene; PTS) (PVA-Gel/PTS) was synthesized as wound dressing materials. PVA-Gel and PVA-Gel/PTS were synthesized with the polymerization yields of 96% ± 0.23% and 98% ± 0.18%, respectively, and characterized by swelling tests, Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) analysis. The swelling ratios were calculated as 98.6% ± 4.93% and 102% ± 5.1%, macroporosities were determined as 85% ± 2.13% and 88% ± 2.2%, for PVA-Gel and PVA-Gel/PTS, respectively. It was determined that PVA-Gel and PVA-Gel/PTS have 17 m2 /g ± 0.76 m2 /g and 20 m2 /g ± 0.92 m2 /g surface areas, respectively. SEM studies were demonstrated that they have ~100 μm pore sizes. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), trypan blue exclusion and live-dead assay results, it was observed that cell proliferation, cell number and cell viability were higher in PVA-Gel/PTS cryogel at 24, 48, and 72 h compared to PVA-Gel. A strong and transparent fluorescent light intensity was observed indicating higher cell population in PVA-Gel/PTS in comparison with PVA-Gel, according to 4',6-diamidino-2-phenylindole (DAPI) staining. SEM, F-Actin, Giemsa staining and inverted-phase microscope image of fibroblasts in PVA-Gel/PTS cryogels revealed that dense fibroblast proliferation and spindle-shaped morphology of cells were preserved. Moreover, DNA agarose gel data demonstrated that PVA-Gel/PTS cryogels had no effect on DNA integrity. Consequently, produced PVA-Gel/PTS cryogel can be used as wound dressing material to promote wound therapies, inducing cell viability and proliferation.

Preparation and Characterization of Protein Molecularly Imprinted Poly (Ionic Liquid)/Calcium Alginate Composite Cryogel Membrane with High Mechanical Strength for the Separation of Bovine Serum Albumin.

In order to improve the mechanical strength and imprinting efficiency, a novel bovine serum albumin (BSA) molecularly imprinted poly(ionic liquid)/calcium alginate composite cryogel membrane (MICM) was prepared. The results of the tensile test indicated that the MICM had excellent mechanical strength which could reach up to 90.00 KPa, 30.30 times higher than the poly (ionic liquid) membrane without calcium alginate; the elongation of it could reach up to 93.70%, 8.28 times higher than the poly (ionic liquid) membrane without calcium alginate. The MICM had a very high welling ratio of 1026.56% and macropore porosity of 62.29%, which can provide effective mass transport of proteins. More remarkably, it had a very high adsorption capacity of 485.87 mg g-1 at 20 °C and 0.66 mg mL-1 of the initial concentration of BSA. Moreover, MICM also had good selective and competitive recognition toward BSA, exhibiting potential utility in protein separation. This work can provide a potential method to prepare the protein-imprinted cryogel membrane with both high mechanical strength and imprinting efficiency.

Poly(Vinyl Alcohol) Cryogel Membranes Loaded with Resveratrol as Potential Active Wound Dressings

Hydrogel wound dressings are highly effective in the therapy of wounds. Yet, most of them do not contain any active ingredient that could accelerate healing. The aim of this study was to prepare hydrophilic active dressings loaded with an anti-inflammatory compound - trans-resveratrol (RSV) of hydrophobic properties. A special attention was paid to select such a technological strategy that could both reduce the risk of irritation at the application site and ensure the homogeneity of the final hydrogel. RSV dissolved in Labrasol was combined with an aqueous sol of poly(vinyl) alcohol (PVA), containing propylene glycol (PG) as a plasticizer. This sol was transformed into a gel under six consecutive cycles of freezing (-80 °C) and thawing (RT). White, uniform and elastic membranes were successfully produced. Their critical features, namely microstructure, mechanical properties, water uptake and RSV release were studied using SEM, DSC, MRI, texture analyser and Franz-diffusion cells. The cryogels made of 8 % of PVA showed optimal tensile strength (0.22 MPa) and elasticity (0.082 MPa). The application of MRI enabled to elucidate mass transport related phenomena in this complex system at the molecular (detection of PG, confinement effects related to pore size) as well as at the macro level (swelling). The controlled release of RSV from membranes was observed for 48 h with mean dissolution time of 18 h and dissolution efficiency of 35 %. All in all, these cryogels could be considered as a promising new active wound dressings.

Antibacterial effect against both Gram-positive and Gram-negative bacteria via lysozyme imprinted cryogel membranes

The development of novel biocompatible and cost effective cryogel membrane which shows enhanced antimicrobial properties in order to use for several approaches such as wound dressing, scaffold or food packaging was aimed in this study. A super macro porous lysozyme imprinted cryogel membranes showing antibacterial effect against both Gram-positive and Gram-negative bacteria were prepared by using molecular imprinting technique. N-methacryloyl-(L)-histidine methyl ester (MAH) was used as the pseudo specific ligand and complexed with Cu++ in order to provide metal ion coordination between MAH and template molecule (lysozyme). Comparing the antibacterial activity of different lysozyme concentrations, cryogel membranes were prepared in three different concentrations. To synthesize Poly (hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methylester) P(HEMA-MAH) cryogel membrane, free radical polymerization initiated by N, N, N′, N′-tetramethylene diamine (TEMED) and ammonium persulfate (APS) was carried out at −12 °C. The characterization of the lysozyme imprinted cryogel membrane was accomplished by using scanning electron microscopy (SEM), swelling degree measurements and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) spectroscopy. The cytotoxicity test of produced membrane was performed by using mouse fibroblast cell line L929. The antibacterial activity of P(HEMA-MAH) lysozyme molecular imprinted [P(HEMA-MAH) Lyz-MIP] cryogel membranes against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were determined by Kirby-Bauer membranes diffusion and viable cell counting methods. When the antibacterial effect of P(HEMA-MAH) Lyz-MIP cryogel membranes were evaluated, it was found that P(HEMA-MAH) Lyz-MIP cryogel membranes had stronger antibacterial effects against Gram-negative E. coli bacteria even in low lysozyme concentrations. In addition, 100% bacterial inhibition was detected for both of two bacteria at increasing lysozyme concentrations.

Spongy membranes for peroxidase purification from Brassica oleracea roots

In this work, it was aimed to purify peroxidase from Brassica oleracea roots using newly synthesized cryogel membranes. 2-4-vinylphenylboronic acid (VPBA) containing 2-hydroxyethyl methacrylate (HEMA) [PHEMABA] cryogel membranes were prepared successfully and swelling tests, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, contact angle measurements, and Brauner-Emmet-Teller (BET) surface area analysis were done for characterization. Effect of experimental conditions on peroxidase binding capacity of PHEMABA cryogel membranes was determined by examining parameters such as pH, temperature and time with binding studies. Maximum peroxidase binding capacity of PHEMABA cryogel membranes was determined as 22.01 mg/g for 2 mg/mL equilibrium peroxidase concentration at pH 8.0. Finally, peroxidase was purified from Brassica oleracea roots with 85.38% yield and 18.38 purification fold. According to obtained results, spongy PHEMABA cryogel membranes show high peroxidase binding capacity and could be suggested as a boronate affinity model system for enzyme purification.

Synthesis of 2-Methacryloyloxyethyl Phosphorylcholine (MPC) Based P(2-hydroxyethyl methacrylate) P(HEMA) Cryogel Membranes

Synthesis of artificial/natural polymeric biomaterials having resistance to nonspecific protein adsorption, blood coagulation and bacterial adhesion has attracted great attention, so nonspecific adsorption of proteins and biomolecules causes unfavorable biological responses inluding blood clotting, inflammation, cell adhesion, cell differentiation, and biofilm formation. A zwitterionic phosphorylcholine (PC) group of 2-methacryloyloxyethyl phosphorylcholine (MPC) is employed for biologically inert functions, especially in resistance to protein adsorption. So, it is aimed to develop bio-inspired, efficient and environmentally friendly MPC containing cryogel membranes for polymeric scaffolds for promoting cell-biomaterial. Cryogel membranes were synthesized in semi-frozen medium by free radical polymerization in an ice bath and characterized by SEM/EDX, micro-CT, and swelling ratio measurements. In vitro biocompatibility was assessed from cell viability studies performed using cultured fibroblast cells.

A dye-affinity cryogel membrane for malate dehydrogenase purification from Saccharomyces cerevisiae

Cibacron blue F3GA functionalized poly(hydroxyethyl methacrylate) cryogel membranes were prepared and applied for a simple purification of malate dehydrogenase (MDH) from crude extract of Saccharomyces cerevisiae. Swelling tests, scanning electron microscopy, surface area measurements and Fourier transform infrared (FTIR) spectroscopy techniques were used for the characterization of dye-affinity cryogel membranes. Following cell homogenization and extraction, MDH was purified using the dye-affinity cryogel membranes at a high yield of 80.5% with 54-fold purification. Maximum MDH adsorption amount was determined to be 267.7 mg/g of membranes at pH 7.4, 25 °C and a flow rate of 1.0 mL/min. Interestingly, the cryogel membranes were used for several purification runs without any significant decrease in MDH adsorption capacity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis was carried out to assess the purity of the eluted MDH. The obtained results highlight the dye-affinity cryogel membranes as powerful dye affinity adsorbents for MDH purification from S. cerevisiae.

Nanocellulose and Nanochitin Cryogels Improve the Efficiency of Dye Solar Cells

Biobased cryogel membranes were applied as electrolyte holders in dye solar cells (DSC) while facilitating carrier transport during operation. They also improved device performance and stability. F...

Preparation of a novel supermacroporous molecularly imprinted cryogel membrane with a specific ionic liquid for protein recognition and permselectivity

ABSTRACTA novel supermacroporous molecularly imprinted cryogel membrane (MICM) was prepared via cryopolymerization using a functionalized ionic liquid {(1‐vinyl‐3–(2‐amino‐2‐oxoethyl) imidazolium chloride, [VAMIM]Cl]} as functional monomer. Bovine serum albumin (BSA) was selected as the model protein. The novel membrane has the advantages of several concepts, such as, the easy mass transport of cryogel, the multiple weak interactions of ionic liquid with protein, high selectivity of molecularly imprinted polymer, and continuous separation of membrane separation. The membrane was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT‐IR), thermal gravimetric analysis (TGA), and X‐ray photoelectron spectroscopy (XPS). Ovalbumin (Ova), lysozyme (Lys), and bovine hemoglobin (BHb) were selected as reference proteins to examine the selective recognition of BSA on MICM. The results of SEM images and the swelling ratios showed that MICM had a larger amount of interconnected supermacropores compared with NMICM, which was beneficial for BSA to be adsorbed onto and pass through MICM. The adsorption and permeation results indicated that MICM had better recognition selectivity and permselectivity to the objective protein BSA than NMICM. Overall, the results showed that the functionalized ionic liquid was a good choice to prepare supermacroporous MICM via cryopolymerization for selective recognition of BSA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46740.

Controlled release of mitomycin C from PHEMAH–Cu(II) cryogel membranes

Molecular imprinting technique was used for the preparation of antibiotic and anti-neoplastic chemotherapy drug (mitomycin C) imprinted cryogel membranes (MMC-ICM). The membranes were synthezied by using metal ion coordination interactions with N-methacryloyl-(l)-histidine methyl ester (MAH) functional monomer and template molecules (i.e. MMC). The 2-hydroxyethyl methacrylate (HEMA) monomer and methylene bisacrylamide (MBAAm) crosslinker were used for the preparation of mitomycin C imprinted cryogel membranes by radical suspension polymerization technique. The imprinted cryogel membranes were characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) and swelling degree measurements. Cytotoxicity of MMC-ICMs was investigated using mouse fibroblast cell line L929. Time-dependent release of MMC was demonstrated within 150 h from cryogel membranes. Cryogels demonstrated very high MMC loading efficiency (70–80%) and sustained MMC release over hours.

Molecularly imprinted cryogel membranes for mitomycin C delivery

In this study, cryogel-based implantable molecularly imprinted drug delivery systems were designed for the delivery of antineoplastic agent. Mitomycin C imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-glutamic acid) cryogel membranes were produced by free-radical bulk polymerization under partially frozen conditions. The membranes were characterized by swelling tests, Fourier transform infrared spectroscopy, scanning electron microscopy, surface area measurements and in vitro hemocompatibility tests. In vitro delivery studies were carried out to examine the effects of cross-linker ratio and template content. Mitomycin C imprinted cryogel membranes have megaporous structure (10–100 μm in diameter). The cumulative release of mitomycin C was decreased with increasing cross-linking agent ratio and increased with the amount of template in the cryogel structure. The nature of transport mechanism of the mitomycin C from the membranes was non-Fickian.

Removal of Cu(II) ions from water by ion-imprinted magnetic and non-magnetic cryogels: A comparison of their selective Cu(II) removal performances

2-Hydroxyethylmethacrylate (HEMA) based ion-imprinted cryogel membranes (IIP) were synthesized using histidine containing functional monomer, N-methacryloyl-l-histidine (MAH) as complexing/chelating agent, Cu(II) ions as template, methylene bisacrylamide as cross-linker, TEMED and APS as redox pair in both magnetic and non-magnetic forms through free radical polymerization method for selective Cu(II) ion removal. A control non-imprinted cryogel (NIP) was also prepared for comparison. The matrices were characterized by swelling tests, scanning electron microscopy (SEM), BET, and FTIR. Effect of several parameters (pH, temperature, contact time, etc.) on adsorption capacities was examined in batch mode.The maximum adsorption capacities of cryogel membranes under optimized conditions were 77.2mg/g and 182.7mg/g for non-magnetic and magnetic IIP cryogels, respectively. The adsorption process best fitted to Langmuir isotherm while pseudo-second-order kinetic model was well suited to explain controlling step in adsorption kinetics. The reusability of matrices was tested for three successive cycles. Competitive adsorption studies were finally performed to prove the selectivity of resulting matrices for Cu(II) ions in binary and multi-ion containing synthetic water samples.

Affinity purification lipase from wheat germ: comparison of hydrophobic and metal chelation effect

Cryogels are used quite a lot nowadays for adsorption studies as synthetic adsorbents. In this study, lipase enzyme (obtained from Candida cylindracea) adsorption capacity of poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan), poly(HEMA-MATrp), and Cu(II) ions immobilized poly(HEMA-MATrp), poly(HEMA-MATrp)-Cu(II), cryogel membranes were synthesized to determine and compare the adsorption behavior of lipase enzyme. In this regard, the effect of pH, interaction time, lipase initial concentration, temperature and ionic strength on the adsorption capacity of these membranes was investigated. Maximum lipase enzyme adsorption capacities of poly(HEMA-MATrp) and poly(HEMA-MATrp)-Cu(II) cryogel membranes were determined as 166.4 mg/g and 196.4 mg/g, respectively.