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Showing papers on "Glutaraldehyde published in 2020"


Journal ArticleDOI
TL;DR: Pectin lyase (from Rohapect 10 L) was immobilized on glutaraldehyde supports at low ionic strength at pH 5, 6.5 or 8 and later incubated at pH 8 for 48 h maintaining more than 90% of the initial activity.

58 citations


Journal ArticleDOI
TL;DR: It has been shown that due to better mechanical, thermal and surface properties as well as lower toxicity, dialdehyde chitosan is a very promising crosslinking agent.
Abstract: Materials based on natural high molecular compounds are particularly interesting for biomedical applications. It is known that the cross-linking agent used for preparation of biomacromolecule-based materials is as important as used biopolymer. Therefore, natural cross-linkers containing reactive carbonyl groups are of great interest especially for modifying properties of natural polysaccharides. One of the most popular cross-linking agents is glutaraldehyde. Nevertheless, the unreacted particles can be released from the cross-linked material and cause cytotoxic effects. This can be eliminated when using a cross-linker based e.g., on polysaccharides. This article describes quick and efficient synthesis of dialdehyde chitosan (DACS) and its application for the preparation of chitosan films. Materials obtained with different amount of DACS were fully characterized in terms of structure and surface morphology. Thermal and mechanical properties as well as hydrophilic character were also examined. The results obtained were compared with the materials obtained by cross-linking chitosan with low molecular weight glutaraldehyde and high molecular weight cross-linking agent based on polysaccharide–dialdehyde starch. Toxicity of all obtained materials was tested using the Microtox® test. It has been shown that due to better mechanical, thermal and surface properties as well as lower toxicity, dialdehyde chitosan is a very promising crosslinking agent.

47 citations


Journal ArticleDOI
TL;DR: The synergy between amino hydroxyapatite and chitosan crosslinked by glutaraldehyde was demonstrated and the formation of CN moieties was highlighted as the main interaction mechanism between the aldehyde and amino groups.

43 citations


Journal ArticleDOI
TL;DR: The results obtained in this study suggest that the immobilized-enzyme preparation may be effectively exploited for FOS production and easily recovered from the reaction mixture by action of a magnetic field.

41 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the biocompatibility and swelling tendency of nanofibers increased by adding alginates to a polymer solution, and the results showed that the presence of chitosan 1% (w/v) in the shell side of nanometrics helped better control the drug release.

41 citations


Journal ArticleDOI
TL;DR: The results showed that the GA-crosslinked CS/PVA/ASC-MWCNTs NC 3 wt% has good hydroxyapatite-forming ability in SBF solution.

39 citations


Journal ArticleDOI
TL;DR: In this work, porous biochar derived from sugarcane bagasse was prepared and then coated with different amounts of chitosan (C@CS) for cellulase immobilization, showing good activity and reusability and the properties of immobilized enzyme were evaluated by activity recovery, optimum pH value and temperature, and recyclability.

37 citations


Journal ArticleDOI
Chen Chi1, Fei Liu1, Zhe Yu1, Yun Ma1, H. Douglas Goff2, Fang Zhong1 
TL;DR: The physicochemical properties of collagen casings were successfully improved by glutaraldehyde (GA) cross-linking, where the properties could be further regulated by drying temperature, and the mechanical properties of films under wet and boiled state were significantly improved.

33 citations


Journal ArticleDOI
TL;DR: In this article, a novel biomass-based amphoteric retanning agent, which can reduce free formaldehyde significantly, was prepared using hydrolyzed collagen and oxidized valonia extract as the raw materials.

30 citations


Journal ArticleDOI
30 Mar 2020-Polymers
TL;DR: The TGA results showed that the tannin-based NIPU foams prepared had similar thermal stability, although one of them (T-Fs-7) presented the highest char production and residual matter, approaching 18.7% at 790 °C.
Abstract: Ambient temperature self-blowing mimosa tannin-based non-isocyanate polyurethane (NIPU) rigid foam was produced, based on a formulation of tannin-based non-isocyanate polyurethane (NIPU) resin. A citric acid and glutaraldehyde mixture served as a blowing agent used to provide foaming energy and cross-link the tannin-derived products to synthesize the NIPU foams. Series of tannin-based NIPU foams containing a different amount of citric acid and glutaraldehyde were prepared. The reaction mechanism of tannin-based NIPU foams were investigated by Fourier Trasform InfraRed (FT-IR), Matrix Assisted Laser Desorption Ionization (MALDI-TOF) mass spectrometry, and 13C Nuclear Magnetic Resonance (13C NMR). The results indicated that urethane linkages were formed. The Tannin-based NIPU foams morphology including physical and mechanical properties were characterized by mechanical compression, by scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). All the foams prepared showed a similar open-cell morphology. Nevertheless, the number of cell-wall pores decreased with increasing additions of glutaraldehyde, while bigger foam cells were obtained with increasing additions of citric acid. The compressive mechanical properties improved with the higher level of crosslinking at the higher amount of glutaraldehyde. Moreover, the TGA results showed that the tannin-based NIPU foams prepared had similar thermal stability, although one of them (T-Fs-7) presented the highest char production and residual matter, approaching 18.7% at 790 °C.

29 citations


Journal ArticleDOI
TL;DR: Immobilized trypsin on the polyvinyl alcohol coated magnetic nanoparticles could be promising biocatalyst for large-scale proteomics studies and practical applications.

Journal ArticleDOI
TL;DR: The obtained results indicated that the immobilized BaL exhibited better stability at extreme temperature and pH than the free BaL and was introduced as an effective biocatalyst to synthesize green apple flavour ester.

Journal ArticleDOI
12 Nov 2020-Polymers
TL;DR: The chitosan/magnetic porous biochar has great potential applications as a support for enzyme immobilization and in the reusability assay, the immobilized cellulase showed initial glucose productivity of 330.9 mg glucose/g CMC and remained at 86.0% after 10 uses.
Abstract: In this work, porous biochar was obtained from sugarcane bagasse by alkali activation and pyrolysis and then magnetized with γ-Fe2O3 by calcination. After functionalization with chitosan and activation with glutaraldehyde, the as-prepared chitosan/magnetic porous biochar served as a support to immobilize cellulase by covalent bonds. The immobilization amount of cellulase was 80.5 mg cellulase/g support at pH 5 and 25 °C for 12 h of immobilization. To determine the enzymatic properties, 1% carboxymethyl cellulose sodium (CMC) (dissolved in 0.1 M buffer) was considered as a substrate for hydrolysis at different pH values (3-7) and temperatures (30-70 °C) for 30 min. The results showed that the optimum pH and temperature of the free and immobilized cellulase did not change, which were pH 4 and 60 °C, respectively. The immobilized cellulase had a relatively high activity recovery of 73.0%. However, it also exhibited a higher Michaelis-Menten constant (Km) value and a slower maximum reaction velocity (Vmax) value compared to the free enzyme. In the reusability assay, the immobilized cellulase showed initial glucose productivity of 330.9 mg glucose/g CMC and remained at 86.0% after 10 uses. In conclusion, the chitosan/magnetic porous biochar has great potential applications as a support for enzyme immobilization.

Journal ArticleDOI
TL;DR: The results from this bench-scale work show that employing bacteria-embedded PVA/GA hydrogel for the treatment of municipal wastewater yield promising results which should be further explored in pilot/field-scale studies.
Abstract: A new approach for easy synthesis of Bacillus pseudomycoides immobilized polyvinyl alcohol (PVA)/glutaraldehyde (GA) hydrogel for application in a wastewater treatment system is reported. Optimization studies revealed that GA/PVA mass ratio of 0.03 and acidic pH of 2 were required for hydrogel synthesis and eventually for bacterial cell immobilization. The synthesized crosslinked matrix possessed a pore size suitable for microbial cell entrapment while maintaining cell accessibility to external environment for bioremediation. Possible crosslinking and bacterial cell immobilization in the hydrogel were evidenced by FTIR, XRD, and SEM studies, respectively. Further, the extent of crosslinking of GA with PVA was investigated and confirmed by transmittance and permeability experiments. The viability and proliferation of hydrogel embedded cells (after 25 days) was confirmed by confocal fluorescence microscopy which also indicated that acidic pH of polymer solution did not affect the immobilized live cells. B. pseudomycoides immobilized hydrogel were demonstrated to be effective for treatment of municipal wastewater and reduced biochemical oxygen demand (BOD), chemical oxygen demand (COD), and protein content below the recommended levels. Overall, the results from this bench-scale work show that employing bacteria-embedded PVA/GA hydrogel for the treatment of municipal wastewater yield promising results which should be further explored in pilot/field-scale studies.

Journal ArticleDOI
TL;DR: This work implemented a controlled method of gas exchange and reagent addition that results in a more homogenous PolyhHb product and assessed how the hemoglobin scavenging protein haptoglobin (Hp) would interact with polymerized human hemoglobins molecules of varying size and quarternary state.

Journal ArticleDOI
TL;DR: In this study, films produced with starch, CTLW gelatin, commercial gelatin (as a comparative), and their blends were cross-linked with glutaraldehyde, which reduced the crystallinity of the films, impairing the reorganization of gelatin chains into a triple helix structure, which balanced the effect of the higher molecular chain.
Abstract: Gelatin extracted from chromium-tanned leather wastes (CTLW) has a lower molar mass because of the more aggressive extraction process needed to disrupt chromium-collagen bonds when compared to gelatin extracted from the bones, skin, and connective tissues of animals. As a consequence, CTLW gelatin is more hydrophilic, thus it is harder to apply in the production of polymers. To overcome this issue, in this study, films produced with starch, CTLW gelatin, commercial gelatin (as a comparative), and their blends were cross-linked with glutaraldehyde. The cross-linking reduced the crystallinity of the films, impairing the reorganization of gelatin chains into a triple helix structure, which balanced the effect of the higher molecular chain, while not altering the films’ tensile strength. It increased the elongation at break and reduced the solubility and the swelling degree by up to 53% and 69%, respectively. These results stand as a great advance for the practical use of starch-CTLW gelatin films.

Journal ArticleDOI
TL;DR: In this paper, the effects of crosslinker content and operating conditions (including feed concentration and temperature) on the pervaporative dehydration performance for isopropanol dehydration were also investigated.

Journal ArticleDOI
TL;DR: In this article, a series of hybrid polyvinyl alcohol (PVA) membranes filled with chitosan particles and its four derivatives were prepared and tested in the pervaporative separation process of a water/ethanol mixture.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated different cross-linkers, such as tannic acid, ascorbic acid and glucose crosslinker, to optimize albumin nanoparticles.
Abstract: Albumin nanoparticles are considerable in nanotechnology due to their high solubility in aqueous media, their ability to interact with various compounds, and their ease of nanoparticle tailoring from them. Due to the undesirable effects of glutaraldehyde (GT) as a cross-linker, the aim of this study was to investigate different cross-linking agents such as tannic acid, ascorbic acid, citric acid, sorbitol, and glucose (GLU) and to optimize particle production. For this purpose, final particle size, polydispersity index, and zeta potential were measured. Nanoparticles of different cross-linkers were compared to those prepared with GT using UV–Vis and FTIR spectra. Optimal conditions were defined as 20 mg/mL bovine serum albumin (BSA) solution (2 mL), pH 9, temperature of 4 °C, ethanol as desolvation agent, and GLU as cross-linker. BSA nanoparticles were obtained 125.1 nm in size, with a polydispersity index of 0.132 at the optimum point of the desolvation process. Studying FTIR and UV–Vis results showed that cross-linking occurred in the presence of all cross-linkers.

Journal ArticleDOI
TL;DR: The β-glucosidase was extracted from fruiting bodies of Agrocybe aegirit and was purified by anion exchange and immobilized by SiO2 nanoparticles (nano-SiO2) crosslink with glutaraldehyde (GA).

Journal ArticleDOI
TL;DR: A series of κ-carrageenan (κ-CG) hydrogels were prepared by using glutaraldehyde (GA) as crosslinker for controlled releasing of copper and manganese micronutrients as mentioned in this paper.
Abstract: A series of κ-carrageenan (κ-CG) hydrogels were prepared by using glutaraldehyde (GA) as crosslinker for controlled releasing of copper and manganese micronutrients. The hydrogels were characterized by gel content, swelling and degradation tests, Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Scanning Electron Microscope (SEM) observations. The variations of swelling percentages (S%) with time, temperature and pH were determined for all hydrogels. As the amounts of crosslinker increased, S% decreased regularly in contrast to gel content results. The higher swelling values were obtained in basic medium than acidic and neutral mediums for all κ-CG hydrogels. Releasing of copper and manganese micronutrients from κ-CG hydrogels was investigated in water and soil. A simulated releasing model was also applied to estimate the releasing behaviors in agricultural irrigations. In all release studies, the cumulative release values increased with decreasing GA amounts. The release kinetic parameters were also calculated. It was detected that the releasing of micronutrients in soil was slower than that in water.

Journal ArticleDOI
TL;DR: The comparison shows that the catalase immobilized by the adsorption method has strong activity and high operational stability, and the cross-linking agent glutaraldehyde and the initial enzyme concentration have a significant effect on the immobilization.
Abstract: Based on the excellent biocompatibility of collagen, collagen was extracted from pig skin by acid-enzymatic method. The films were prepared by the self-aggregation behavior of collagen, and the catalase was immobilized by adsorption, cross-linking and embedding. The experiment investigated the effects of glutaraldehyde on the mechanical properties, external sensory properties, and denaturation temperature of the films. The results showed that self-aggregating material could maintain the triple helix structure of pig skin collagen. The self-aggregation treatment and cross-linking treatment can improve the mechanical properties to 53 MPa, while the glutaraldehyde cross-linking agent can increase the denaturation temperature of the pig skin collagen self-aggregating membrane by 20.35% to 84.48 °C. This means that its application to immobilized catalase has better stability. The comparison shows that the catalase immobilized by the adsorption method has strong activity and high operational stability, and the cross-linking agent glutaraldehyde and the initial enzyme concentration have a significant effect on the immobilization, and the activity can reach 175 U g−1. After 16 uses of the film, the catalase was completely inactivated. This study provides a reference for the preparation of a catalase sensor that can be used to detect hydrogen peroxide in food by a catalase sensor.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the synthesis, characterization and drug release behaviors of organo-hydrogels containing pH-sensitive Agar (A), Glycerol (G), Thyme Oil (TO), N, N, methylenebisacrylamide (MBA) or glutaraldehyde (GA) reagent.

Journal ArticleDOI
TL;DR: It is demonstrated how glutaraldehyde crosslinking can be used to modify and improve biopolymer membrane properties for broader applications, such as in an acidic environment or when Pluronic passivation is needed.
Abstract: Flow-assembled chitosan membranes are robust and semipermeable hydrogel structures formed in microfluidic devices that have been used for important applications such as gradient generation and studying cell-cell signaling. One challenge, however, remains unresolved. When a polydimethylsiloxane (PDMS) microchannel with a flow-assembled, deprotonated chitosan membrane (DCM) is treated with anti-adhesion agents such as Pluronic F-127 to prevent biomolecular and cellular adsorption on PDMS, the interaction between DCM and PDMS is compromised and the DCM easily delaminates. To address this challenge, DCMs in microfluidics are crosslinked with glutaraldehyde to modulate their properties, and the altered properties of the glutaraldehyde treated chitosan membrane (GTCM) are investigated. First, the GTCM's acidic resistance was confirmed, its mechanical robustness against hydrostatic pressure was significantly improved, and it remained intact on PDMS after Pluronic treatment. Second, crystallization in DCM and GTCM was investigated with quantitative polarized light microscopy (qPLM), which revealed that GTCM's optical retardance and anisotropy were lower, implying less molecular alignment than in DCM. Finally, membrane permeability was tested with FITC-labeled dextran transport experiments, which showed that the transport across GTCM was slightly higher than that across DCM. Overall, glutaraldehyde-crosslinked chitosan membrane has better acidic resistance, higher strength under Pluronic treatment, and less molecular microalignment, while its semi-permeability is retained. This study demonstrates how glutaraldehyde crosslinking can be used to modify and improve biopolymer membrane properties for broader applications, such as in an acidic environment or when Pluronic passivation is needed.

Journal ArticleDOI
Yadi Hu1, Jie Liu1, Lan Luo1, Xiumin Li1, Fang Wang1, Keyong Tang1 
TL;DR: In this paper, the thermal degradation of hides before and after tanning with formaldehyde and glutaraldehyde were studied using thermogravimetric analyzer and TGA coupled with Fourier transform infrared spectrometry (TGA-FTIR), which indicated that the pyrolysis products of both untanned hides and tanned leathers are mainly CO2, NH3, and C O contained organic components with some HNCO, CH4 and H2O.

Journal ArticleDOI
TL;DR: A new nanobiosorbent based on cross-linked chitosan magnetic beads modified with methionine-glutaraldehyde schiff's base (MG-Chi/Fe3O4) was synthesized for removing Cu(II), Pb(II) and Cd(II).
Abstract: A new nanobiosorbent based on cross-linked chitosan magnetic beads modified with methionine-glutaraldehyde schiff’s base (MG-Chi/Fe3O4) was synthesised for removing Cu(II), Pb(II) and Cd(II) from w...

Journal ArticleDOI
TL;DR: In this paper, a kind of glutaraldehyde crosslinked PVA membrane with gradient structure has been successfully designed and prepared by the casting membrane of pure PVA aqueous solution and the following surface post-crosslinking processes.
Abstract: Poly(vinyl alcohol) (PVA) is an attractive polymer for various applications based on membranes. To increase water resistance, PVA material has to be adequately crosslinked. However, crosslinking behavior on the whole PVA membrane generally leads to obviously increased brittleness and deteriorated transparency. In the present research, a kind of glutaraldehyde crosslinked PVA membrane with gradient structure has been successfully designed and prepared by the casting membrane of pure PVA aqueous solution and the following surface post-crosslinking processes. The method can endow the PVA membrane with the gradiently decreased crosslinking degree from the surface to inside. Such gradient cross-linked PVA membrane not only keeps good flexibility and transparency, but also possesses satisfactory water-proof property. The structure and properties of the prepared the gradient acetalized PVA (GAPVA) membranes were analyzed and characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), tensile measurement, water resistance test and transparency observation, etc. Compared with pure PVA membrane and uniform acetalized PVA (UAPVA) one, such GAPVA membrane displays excellent performance including good water resistance, transparency and mechanical properties, much higher than those of UAPVA membrane.


Journal ArticleDOI
TL;DR: In this paper, the effects of different amounts of glutaraldehyde on drug release profiles were studied, and it was concluded that the drugloaded HAp-GEL composites have the potential to be used in drug delivery applications.
Abstract: In this study, 5-fluorouracil- (5-FU-) loaded hydroxyapatite-gelatin (HAp-GEL) polymer composites were produced in the presence of a simulated body fluid (SBF) to investigate the effects of temperature and cross-linking agents on drug release. The composites were produced by wet precipitation at pH 7.4 and temperature 37°C using glutaraldehyde (GA) as the cross-linker. The effects of different amounts of glutaraldehyde on drug release profiles were studied. Encapsulation (drug loading) was performed with 5-FU using a spray drier, and the drug release of 5-FU from the HAp-GEL composites was determined at temperatures of 32°C, 37°C, and 42°C. Different mathematical models were used to obtain the release mechanism of the drug. The morphologies and structures of the composites were analyzed by X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results demonstrated that for the HAp-GEL composites, the initial burst decreased with increasing GA content at all three studied temperatures. Further, three kinetic models were investigated, and it was determined that all the composites best fit the Higuchi model. It was concluded that the drug-loaded HAp-GEL composites have the potential to be used in drug delivery applications.

Journal ArticleDOI
TL;DR: In the present study, the impact of the biocides 2,2-dibromo-2-cyanoacetamide (DBNPA) and glutaraldehyde on the biodegradation process by CW microorganisms was quantified in batch experiments in which benzoic acid was incubated with realistic CTW biocide concentrations.