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We prepared guggul gum-based hydrogel (GgG-cl-poly(AA)) through a free radical graft copolymerization mechanism in this work. The preparation was carried out using ammonium persulfate as an initiator, acrylic acid as the monomer, and N, N′-methylenebisacrylamide as the crosslinker. The synthesized hydrogel's swelling capacity and equilibrium swelling ratio were thoroughly investigated by optimizing various reaction parameters: reaction time, solvent volume, microwave power, crosslinker amount, initiator concentration, and monomer concentration. The swelling results demonstrated that the synthesized hydrogel can attain a maximum percentage swelling of 980% within 3 h in an aqueous solution. The prepared hydrogel sample was characterized using Fourier transform infrared, X-ray diffraction, scanning electron microscopy, nuclear magnetic resonance, and thermogravimetric analysis. The prepared hydrogel was studied for water retention behavior in the soil, water absorbance in the open air at room temperature, reswelling studies, and resistive swelling studies in various salt solutions at different temperatures and pH values. Notably, the crosslinked hydrogel exhibited a reduced swelling capacity across various salt solutions compared to the aqueous solutions. The biodegradation studies were examined in both soil burial and vermicomposting methods for two months, revealing a maximum biodegradation of 95.65% through the vermicomposting method and 87.7% through the soil burial method. The results indicate that the crosslinked hydrogel based on guggul gum is a potential candidate for various agricultural applications. [ABSTRACT FROM AUTHOR]

Alginate microcapsules are the most frequently used materials for cell transplantation. Different crosslinkers affect crosslinking affinity, which has a significant influence on microcapsule properties. The objective was to prepare in vitro microcapsules using calcium, barium, iron, manganese, nickel, and strontium as divalent cations to observe their potential for use in cell transplantation. Sodium alginate was added dropwise to the individually prepared crosslinkers to observe diffusion-based gelling. Alginate microcapsules were investigated regarding capsule stability, physiological properties, and cell viability. After 30 days of incubation, cell viability was greater than 90% for the cell-encapsulated microcapsules when crosslinked with CaCl2 and NiCl2. Viability decreased in the following order: CaCl2>NiCl2>BaCl2>SrCl2>MnCl2>FeCl2. A compression test was performed to investigate the required force to deform 30% of microcapsules, and only MnCl2, FeCl2 (180mM), and NiCl2 (50mM) demonstrated higher resistance to the applied force than CaCl2. Except for the FeCl2 group, all cell-encapsulated microcapsules remained intact for 45 days. Potential sensitivities to CaCl2 during cell transplantation may compel alternative crosslinker usage, and our study revealed that NiCl2 and BaCl2 can be used as alternative crosslinkers to CaCl2 due to their high cell viability and consistent stability. [ABSTRACT FROM AUTHOR]

Abstract Cadmium is a highly toxic metal, and its presence can have adverse effects on both human health and aquatic ecosystems. The efficient removal of cadmium from wastewater is therefore of crucial importance, but traditional methods have proved to be inadequate. Thus, technologies for the treatment of wastewater containing cadmium, including adsorption, have been developed. The aim of this study was the preparation of a polymeric material by the grafting reaction of κ-carrageenan and its use as an adsorbent for cadmium removal. This was performed to study the removal capacity of cadmium ions in synthetic solutions, as well as the effects of pH and ions on adsorption capacity, adsorption kinetics, isotherms, and reusability. Additionally, the disinfectant potential of the solution was evaluated for the inactivation of total coliforms and E. coli in river water. The best adsorption capacity was 75.52 ± 1.325 mg g−1, with the kinetics described by the pseudo-second order model. Maximum adsorption capacity (127.6 ± 1.833 mg g−1) and RL (0.0113) were determined using the Langmuir model, the Freundlich model was the one that best fits the experimental data and indicated cooperative adsorption, and the Dubinin-Radushkevich isotherm was used to obtain the adsorption energy and identify that it is physical. The presence of ions K+, Na+, Mg2+, and Ca2+ in a concentration of 0.5% decreased the adsorption capacity, and that at pH 2.0, the adsorption capacity was drastically reduced. The study indicates that the polymer has potential as an adsorbent for removing cadmium from aqueous solutions and exhibits self-disinfecting properties.

Cadmium is a highly toxic metal, and its presence can have adverse effects on both human health and aquatic ecosystems. The efficient removal of cadmium from wastewater is therefore of crucial importance, but traditional methods have proved to be inadequate. Thus, technologies for the treatment of wastewater containing cadmium, including adsorption, have been developed. The aim of this study was the preparation of a polymeric material by the grafting reaction of κ-carrageenan and its use as an adsorbent for cadmium removal. This was performed to study the removal capacity of cadmium ions in synthetic solutions, as well as the effects of pH and ions on adsorption capacity, adsorption kinetics, isotherms, and reusability. Additionally, the disinfectant potential of the solution was evaluated for the inactivation of total coliforms and E. coli in river water. The best adsorption capacity was 75.52 ± 1.325 mg g−1, with the kinetics described by the pseudo-second order model. Maximum adsorption capacity (127.6 ± 1.833 mg g−1) and RL (0.0113) were determined using the Langmuir model, the Freundlich model was the one that best fits the experimental data and indicated cooperative adsorption, and the Dubinin-Radushkevich isotherm was used to obtain the adsorption energy and identify that it is physical. The presence of ions K+, Na+, Mg2+, and Ca2+ in a concentration of 0.5% decreased the adsorption capacity, and that at pH 2.0, the adsorption capacity was drastically reduced. The study indicates that the polymer has potential as an adsorbent for removing cadmium from aqueous solutions and exhibits self-disinfecting properties. [ABSTRACT FROM AUTHOR]

5-Fluorouracil (5-FU) is a chemotherapeutic agent used in therapies for both systematically and topical treatment of different types of cancers. Depending on the period of application, its administration may lead to different side effects such as nausea, headache, pain or even photosensitivity. To avoid them, the drug may be encapsulated into polymeric particles. In the present study, bio polymeric spheres based on chitosan, a linear polysaccharide, are presented. The spheres are formulated by an emulsion technique with solvent evaporation. Three types of particles are synthesized: without crosslinker, with sodium tripolyphosphate and glutaraldehyde crosslinker. The resultant structures are evaluated regarding their size, morphology, and encapsulation efficiency. The crosslinking process and the drug presence in the particles is confirmed by FT-IR. A drug release study is conducted to examine the release kinetics and understand the release behaviour depending on the presence and the type of the crosslinker. [ABSTRACT FROM AUTHOR]

Collagen with its bioactive ligand motives would be predestined as coating on bone implant surfaces like titanium hip stems to facilitate receptor‐mediated cell adhesion and thereby improve early osseointegration. Unfortunately, collagen as coating exhibits very low proteolytic resistance in vivo. To overcome this limitation, different crosslinking methods of collagen (transglutaminase, GTA, EDC/NHS, riboflavin, and lysyl oxidase) with silanized titanium alloy (Ti6Al4V) were investigated in terms of degradation resistance, hydrolysis stability, tensile strength, and metabolic cell activity. The in vitro osteogenic differentiation ability of human mesenchymal stem cells (hMSCs) induced by the surface modification was evaluated by immunofluorescence of early osteogenic markers, Alizarin red staining, and energy dispersive X‐ray spectroscopy. The expression of the adhesion‐related protein vinculin was analyzed on the different functionalized surfaces. The results revealed that the enzymatic crosslinker transglutaminase offered high degradation resistance, tensile strength, and hydrolysis stability compared to the other crosslinking reagents tested. Remarkably, the adhesion sequences within the collagen were accessible to the hMSCs despite the transglutaminase crosslinking procedure. In conclusion, the organochemical functionalization of Ti6Al4V surfaces with collagen using transglutaminase holds great potential to facilitate an enhanced interaction with attached bone cells and thereby could potentially improve and accelerate osseointegration of a titanium‐based bone implant in vivo. [ABSTRACT FROM AUTHOR]

As people became more conscious of the risks associated with pollution in the early 21st century, eco‐friendly adhesives made from plant oil began to be used. Bio‐based adhesives are widely used due to their low price, easy accessibility, and high biodegradability; however, their low adhesive strength is an issue. This work incorporates three natural crosslinkers: tannic acid (TA), sorbitol (SR), and cellulose (CL) to address the drawbacks of bio‐based adhesives, such as low adhesive strength, inferior output in humidity and longer curing time that result from excess water. Methylene diphenyl diisocyanate (MDI) was used to react with soybean oil‐based polyol (SOP) plus the crosslinkers to make bio‐based polyurethane adhesives. The maximum bonding strength of the soybean‐based adhesive containing 10 wt.% of SR (SR‐10%) was measured at 6.19 MPa which is about 44% higher than the sample without SR. The higher strength is due to the crosslinking ability of SR. The effect of crosslinking is also observed in the study of polar protic and polar aprotic solvents used to dissolve the adhesive. As compared with the polar aprotic solvent tetrahydrofuran, TA‐containing adhesive samples showed a maximum tensile strength of 3.69 MPa in methanol; a polar protic solvent that can participate in further hydrogen bonding to form a higher crosslinked complex. The glass transition temperature (Tg) increases with the increase in crosslinker amount. The observed increase in Tg may be attributable to an increase in crosslinking density, which reduces polymer chain flexibility and causes a stronger material. Highlights: Bio‐adhesives based on soybean oil and diisocyanate were synthesized.Natural crosslinking agents such as tannic acid, sorbitol, and cellulose were used.The effect of crosslinking using polar protic and aprotic solvents was studied.The glass transition temperature increases with the increase in crosslinker amount. [ABSTRACT FROM AUTHOR]

In this study, a series of crosslinked waterborne polyurethane/acrylate copolymer latexes with different compositions were fabricated via emulsion polymerization using oil-soluble initiator (AIBN) based on a solvent-/emulsifiers-free method. Using the blend of styrene (St), butyl acrylate (BA) and crosslinkers (pentaerythritol triacrylate (PET3A) and pentaerythritol tetraacrylate (PET4A)) instead of acetone as a diluent and modifier, polyurethane prepolymers terminated with hydroxyethyl acrylate composite emulsions were prepared using polypropylene glycol (PPG), toluene diisocyanate (TDI), 2,2-dihydroxymethylpropionic acid (DMPA) and diethylene glycol (DEG) without other solvents. It was found that for all the emulsion polymerization of waterborne polyurethane and acrylates initiated by AIBN, the monomer conversions exceeded 96% when the concentration of AIBN was in the range of 0.5% to 0.9% (w/w) and the optimal reaction temperature was 75 °C. The introduction of St, BA and crosslinkers would form the polymer network, improving the tensile strength, water absorption of the copolymer latex films. Dynamic light scattering analyses showed that the copolymer latexes exhibited a unimodal distribution and showed no precipitates and unstable aggregates. The average particle size distribution was in the range of 131–154 nm. Transmission electron microscopy studies have confirmed the similar results and the latex particles possessed the core–shell morphology structure. [ABSTRACT FROM AUTHOR]

Collagen is widely used in the development of new functional materials due to its high structural stability, good biocompatibility, and excellent hydrophilicity, but the collagen protein denatures easily, which makes its thermal stability and mechanical strength difficult to reach some of the parameters required in the application. To solve this, protein crosslinking is an effective way to better use collagen. In this paper, we compared the thermal stability and morphological stability of three kinds of sulfonated calixarenes crosslinked collagen before and after the treatment. The results showed that sulfonated calixarenes could significantly improve the thermal stability and morphological stability of dermal collagen. The reinforcing and toughening mechanism of the sulfonated calixarenes was revealed by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), ultraviolet--visible--near-infrared (UV--vis--NIR) spectrometer, X-ray diffraction detection (XRD), atomic force microscopy (AFM), and circular dichroism (CD) detection. The results showed that sulfonated calixarenes were evenly distributed in collagen fibers and formed hydrogen bonds or electrovalent bonds with amino groups, peptide groups, or amide groups in collagen to improve the thermal stability of the collagen. Three kinds of sulfonated calixarenes enter collagen fiber to support the collagen, increase the three-dimensional weave angle of collagen, and improve the physical and mechanical properties of collagen, thereby toughening and enhancing the collagen. Based on the above studies, the reinforcing and toughening mechanism of the sulfonated calixarenes crosslinked collagen was established. Confirmed the existence of hydrogen bonds between the three sulfonated calixarenes and collagen, and the nonchemical bond energy of the system was proportional to the molecular size of sulfonated calixarenes. [ABSTRACT FROM AUTHOR]

The crystallinity of polyethylene has been extensively studied, but in situ experiments designed to investigate the crystallization of PE and XLPE have hardly been discussed. In this work, the crystallization behavior of PE and XLPE was investigated by designing in situ crystallization observation experiments. We have compared the crystallinity, crosslinking, viscosity properties, and gas byproducts of different XLPE insulating materials. COMSOL simulations demonstrate that the DTAP and DTBP crosslinker initiated crosslinks have better insulating properties and cable stability than the DTBC and DTBTMC crosslinkers. The formation of an insulation layer initiated by the DTAP crosslinker is beneficial for improving the breakdown strength, processing performance, and stable operation of cables. Our work is of great significance for understanding the crystallinity of XLPE and determining the correct crosslinker. Highlights: In situ crystallization observation of PE and XLPE.Simulation of ultra‐high voltage cables.Finite element analysis.Investigation of gas byproducts in XLPE. [ABSTRACT FROM AUTHOR]

Lyocell fiber is a green synthetic fiber widely used in the twenty-first century. However, its flammability and fibrillation limit its further use. In this paper, we used online-treatment of coagulated fibers during spinning to obtain flame-retardant and anti-fibrillation Lyocell fibers with crosslinkers and flame retardants that penetrate the fiber surface easily and react more quickly with the cellulose molecular chains. The results of infrared spectroscopy, X-ray diffraction and birefringence showed that the coagulated filaments had more micropores, lower crystallinity and orientation compared to heat setting fibers. At lower concentrations of flame retardant (200 g/L) and cross-linking agent (60–80 g/L), the limit oxygen index (LOI) of Lyocell fibers treated on-line was about 30.2%, the char residue was increased from 7.1 to 23.0%, and the peak of heat release rate (PHRR) and total heat release were reduced by 86.4% and 49.6%, respectively. This is attributed to the better adsorption ability and accessibility of coagulated filaments and the rapid reaction between cellulose and the crosslinker to capture more flame retardant during the online-treatment. After washing 20 times, the LOI was still maintained at 28.7%, and the degree of fibrillation of the fiber was obviously reduced. Compared with conventional Lyocell fibers post-treatment technology, this work provides an industrially feasible and efficient method to continuous prepare Lyocell fibers with both favorable flame retardant and anti-fibrillation properties. [ABSTRACT FROM AUTHOR]

Achieving the desired properties of paper such as strength, durability, and printability remains challenging. Paper mills employ calcium carbonate (CaCO3) as a filler to boost paper's brightness, opacity, and printability. However, weak interaction between cellulose fibers and CaCO3 particles creates different issues in the papermaking industry. Therefore, this study explores the influence of various inorganic additives as crosslinkers such as mesoporous SiO2 nanospheres, TiO2 nanoparticles, h-BN nanoflakes, and hydroxylated h-BN nanoflakes (h-BN-OH) on inorganic fillers content in the paper. They were introduced to the paper pulp in the form of a polyethylene glycol (PEG) suspension to enable bonding between the inorganic particles and the paper pulp. Our findings have been revealed based on detailed microscopic and structural analyses, e.g., transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and N2 adsorption/desorption isotherms. Finally, the inorganic fillers (CaCO3 and respective inorganic additives) content was evaluated following ISO 1762:2001 guidelines. Conducted evaluations allowed us to identify the most efficient crosslinker (SiO2 nanoparticles) in terms of inorganic filler retention. Paper sheets modified with SiO2 enhance the retention of the fillers by ~12.1%. Therefore, we believe these findings offer valuable insights for enhancing the papermaking process toward boosting the quality of the resulting paper. [ABSTRACT FROM AUTHOR]

This work demonstrates the use of a modified mica to concentrate proteins, which is required for proteomic profiling of blood plasma by mass spectrometry (MS). The surface of mica substrates, which are routinely used in atomic force microscopy (AFM), was modified with a photocrosslinker to allow "irreversible" binding of proteins via covalent bond formation. This modified substrate was called the AFM chip. This study aimed to determine the role of the surface and crosslinker in the efficient concentration of various types of proteins in plasma over a wide concentration range. The substrate surface was modified with a 4-benzoylbenzoic acid N-succinimidyl ester (SuccBB) photocrosslinker, activated by UV irradiation. AFM chips were incubated with plasma samples from a healthy volunteer at various dilution ratios (102X, 104X, and 106X). Control experiments were performed without UV irradiation to evaluate the contribution of physical protein adsorption to the concentration efficiency. AFM imaging confirmed the presence of protein layers on the chip surface after incubation with the samples. MS analysis of different samples indicated that the proteomic profile of the AFM-visualized layers contained common and unique proteins. In the working series of experiments, 228 proteins were identified on the chip surface for all samples, and 21 proteins were not identified in the control series. In the control series, a total of 220 proteins were identified on the chip surface, seven of which were not found in the working series. In plasma samples at various dilution ratios, a total of 146 proteins were identified without the concentration step, while 17 proteins were not detected in the series using AFM chips. The introduction of a concentration step using AFM chips allowed us to identify more proteins than in plasma samples without this step. We found that AFM chips with a modified surface facilitate the efficient concentration of proteins owing to the adsorption factor and the formation of covalent bonds between the proteins and the chip surface. The results of our study can be applied in the development of highly sensitive analytical systems for determining the complete composition of the plasma proteome. [ABSTRACT FROM AUTHOR]

Cyclodextrin nanosponges are solid nanoparticles, designed by cross-linking of cyclodextrin polymer; it has been used widely as a good delivery system for water insoluble drugs. The aim of this study is to enhance the solubility of Piroxicam (PXM) using β-Cyclodextrin based nanosponges formulations. PXM nanosponge (PXM-NS) formulations were prepared using β-cyclodextrin and carbonyldiimidazole as a cross linker, three ratios of β-cyclodextrin to crosslinker in addition to three drug to nanosponges ratios were tested. Piroxicam nanosponge formulations were characterized for its particle size, zeta potential, physical compatibility and in vitro release. Stability studies at three temperatures (4 °C, 25 °C and 40 °C) were done for optimal formula. Finally, the in vivo analgesic activity and pharmacokinetic parameters of the optimal formula were conducted. The optimized PXM-NS formula (PXM-NS10) showed particle size (362 ± 14.06 nm), polydispersity index (0.0518), zeta potential (17 ± 1.05 mV), and %EE (79.13 ± 4.33). The dissolution study showed a significant increase in the amount of PXM dissolved compared with the unformulated drug. Stability studies confirmed that nanosponge showed accepted stability for 90 days at 4 °C and 25 °C. In vivo analgesic studies verified that there was a significant enhancement in the analgesic response to PXM in mice, and 1.42 fold enhancement in the relative bioavailability of PXM-NS10 as compared to commercial tablets. Nanosponge prepared under optimal conditions is an encouraging formula for increasing the solubility and therefore the bioavailability of Piroxicam. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The modification of vinyl groups on polyrotaxane derivatives, obtained with polyethylene glycol as the axial molecule and α-cyclodextrin as the cyclic molecule, allows the production of crosslinkers that react with various monomers, facilitating the formation of polymer networks. In contrast to conventional polymer crosslinked networks using typical crosslinking agents, polymer networks employing polyrotaxane crosslinking agents allow for mobile crosslinking points. Consequently, the resulting polymeric crosslinked network may exhibit increased toughness, as external stress is uniformly distributed throughout the polymeric network. This distribution helps to avoid excessive stress concentration in specific areas. To optimize the mechanical properties of polymer networks formed using polyrotaxane crosslinkers, we investigated the impact of the molecular weight of the axial molecules and the number of crosslinking points of the cyclic molecules in the polyrotaxane crosslinkers on the mechanical properties of the resulting polymer networks. Our results show that the fracture strain, fracture stress, and fracture energy of the resultant polymer networks increase with increasing molecular weight of polyethylene glycol. We also observed that the fracture stress and toughness of the polymer networks increased when there was less than one modified vinyl group on α-cyclodextrin, compared to the case with multiple vinyl groups.

AbstractCyclodextrin nanosponges are solid nanoparticles, designed by cross-linking of cyclodextrin polymer; it has been used widely as a good delivery system for water insoluble drugs. The aim of this study is to enhance the solubility of Piroxicam (PXM) using β-Cyclodextrin based nanosponges formulations. PXM nanosponge (PXM-NS) formulations were prepared using β-cyclodextrin and carbonyldiimidazole as a cross linker, three ratios of β-cyclodextrin to crosslinker in addition to three drug to nanosponges ratios were tested. Piroxicam nanosponge formulations were characterized for its particle size, zeta potential, physical compatibility and in vitro release. Stability studies at three temperatures (4 °C, 25 °C and 40 °C) were done for optimal formula. Finally, the in vivo analgesic activity and pharmacokinetic parameters of the optimal formula were conducted. The optimized PXM-NS formula (PXM-NS10) showed particle size (362 ± 14.06 nm), polydispersity index (0.0518), zeta potential (17 ± 1.05 mV), and %EE (79.13 ± 4.33). The dissolution study showed a significant increase in the amount of PXM dissolved compared with the unformulated drug. Stability studies confirmed that nanosponge showed accepted stability for 90 days at 4 °C and 25 °C. In vivo analgesic studies verified that there was a significant enhancement in the analgesic response to PXM in mice, and 1.42 fold enhancement in the relative bioavailability of PXM-NS10 as compared to commercial tablets. Nanosponge prepared under optimal conditions is an encouraging formula for increasing the solubility and therefore the bioavailability of Piroxicam.

Purpose: The goal of this study was to make pH-sensitive HPMC/Neocel C19-based interpenetrating polymeric networks (IPNs) that could be used to treat different diseases. An assembled novel carrier system was demonstrated in this study to achieve multiple functions such as drug protection and self-regulated release. Methods: Misoprostol (MPT) was incorporated as a model drug in hydroxyl-propyl-methylcellulose (HPMC)- and Neocel C19-based IPNs for controlled release. HPMC- and Neocel C19-based IPNs were fabricated through an aqueous polymerization method by utilizing the polymers HPMC and Neocel C19, the initiator ammonium peroxodisulfate (APS), the crosslinker methylenebisacrylamide (MBA), and the monomer methacrylic acid (MAA). An IPN based on these materials was created using an aqueous polymerization technique. Samples of IPN were analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), thermal analysis (TGA), and powder X-ray diffraction (PXRD). The effects of the pH levels 1.2 and 7.4 on these polymeric networks were also studied in vitro and through swelling experiments. We also performed in vivo studies on rabbits using commercial tablets and hydrogels. Results: The thermal stability measured using TGA and DSC for the revised formulation was higher than that of the individual components. Crystallinity was low and amorphousness was high in the polymeric networks, as revealed using powder X-ray diffraction (PXRD). The results from the SEM analysis demonstrated that the surface of the polymeric networks is uneven and porous. Better swelling and in vitro results were achieved at a high pH (7.4), which endorses the pH-responsive characteristics of IPN. Drug release was also increased in 7.4 pH (80% in hours). The pharmacokinetic properties of the drugs showed improvement in our work with hydrogel. The tablet MRT was 13.17 h, which was decreased in the hydrogels, and its AUC was increased from 314.41 ng h/mL to 400.50 ng h/mL in hydrogels. The blood compatibility of the IPN hydrogel was measured using different weights (100 mg, 200 mg, 400 mg, and 600 mg; 5.34%, 12.51%, 20.23%, and 29.37%, respectively). Conclusions: As a result, IPN composed of HPMC and Neocel C19 was successfully synthesized, and it is now possible to use it for the controlled release of MPT. [ABSTRACT FROM AUTHOR]

Stabilization and reusability of enzyme transglutaminase (TGM) are important goals for the enzymatic process since immobilizing TGM plays an important role in different technologies and industries. TGM can be used in many applications. In the food industry, it plays a role as a protein-modifying enzyme, while, in biotechnology and pharmaceutical applications, it is used in mediated bioconjugation due to its extraordinary crosslinking ability. TGMs (EC 2.3.2.13) are enzymes that catalyze the formation of a covalent bond between a free amino group of protein-bound or peptide-bound lysine, which acts as an acyl acceptor, and the γ-carboxamide group of protein-bound or peptide-bound glutamine, which acts as an acyl donor. This results in the modification of proteins through either intramolecular or intermolecular crosslinking, which improves the use of the respective proteins significantly. [ABSTRACT FROM AUTHOR]

In this paper, acrylic super absorbent polymer (SAP) was synthesizes by the free radical water copolymerization method at room temperature with acrylic acid (AA), acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) as the monomer, N, N’-methylene bisacrylamide (NMBA) as the cross-linking agent, ammonium persulfate ( (NH4) 2S2O8) and sodium thionosulfate (Na2S2O3) as the redox initiator, sodium hydroxide (NaOH) as the neutralizing agent.The as-prepared products were analyzed and characterized by FI-IR, GPC, TG and SEM, and the effect of the crosslinker on properties for SAP was also investigated.The result shows that the undecomposed SAP has good thermal stability under 240 ℃.When the content of crosslinker is 0.01%, the water absorption rate could reach the maximum value (625.21 g/g). After drying at 60 ℃ for 24 hours, the water holding rate reachs 19.06%, which is higher than that of free evaporation of water.After five cycles of water absorption, the water absorption rate could still reach more than 600 g/g stably. [ABSTRACT FROM AUTHOR]

Mohammed F Aldawsari,1 Ahmad H Alhowail,2 Md Khalid Anwer,1 Mohammed Muqtader Ahmed1 1Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj, 11942, Saudi Arabia; 2Department of Pharmacology and Toxicology, College of Pharmacy, Qassim University, Buraydah, Al-Qassim, 51452, Saudi ArabiaCorrespondence: Mohammed F Aldawsari, Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj, 11942, Saudi Arabia, Tel +966-555101369, Email moh.aldawsari@psau.edu.saBackground: The aim of the present investigation is to prepare baricitinib (BAR)-loaded diphenyl carbonate (DPC) β-cyclodextrin (βCD) based nanosponges (NSs) to improve the oral bioavailability.Methods: BAR-loaded DPC-crosslinked βCD NSs (B-DCNs) were prepared prepared by varying the molar ratio of βCD: DPC (1:1.5 to 1:6). The developed B-DCNs loaded with BAR were characterized for particle size, polydispersity index (PDI), zeta potential (ZP), % yield and percent entrapment efficiency (%EE).Results: Based on the above evaluations, BAR-loaded DPC βCD NSs (B-CDN3) was optimized with mean size (345.8± 4.7 nm), PDI (0.335± 0.005), Yield (91.46± 7.4%) and EE (79.1± 1.6%). The optimized NSs (B-CDN3) was further confirmed by SEM, spectral analysis, BET analysis, in vitro release and pharmacokinetic studies. The optimized NSs (B-CDN3) showed 2.13 times enhancement in bioavailability in comparison to pure BAR suspension.Conclusion: It could be anticipated that NSs loaded with BAR as a promising tool for release and bioavailability for the treatment of rheumatic arthritis and Covid-19.Keywords: baricitinib, cyclodextrin, diphenyl carbonate, crosslinker, bioavailability, BAR, DPC

The investigation of the mechanical, thermal, and adsorption properties of hydroxyethyl methacrylate (HEMA) cryogels as a function of a reactant ratio is herein reported to better address materials for specific applications. To this aim, cryogels have been synthesized using different monomer/crosslinker (N,N′-methylene-bisacrylamide–MBAA) ratios. The study of SEM images made it possible to identify the trend in the material’s macroporosity. As would be expected, the average measured pore width decreased as the amount of MBAA increased while the number of pores grew. Swelling capacity ranges from 8.7 gW/ggel (grams of water per gram of gel) to 9.3 gW/ggel. These values are strictly connected with the pore’s size and distribution, revealing that the water uptake for the most crosslinked sample is inferior to other samples. The equilibrium-adsorption capacity (Qe) towards the methylene violet (MV) was also assessed, revealing no remarkable differences after 24 h of a batch test. As expected, thermogravimetric analysis (TGA) also showed no significant changes in stability that ranged from a maximum weight loss temperature (T Max) of 420 °C to 425 °C, which increased as a function of crosslinker content. Conversely, compression strength measurements showed a notable difference of about 50% in modulus (Ec), moving from the higher to the lower HEMA/MBAA ratio. These new comparative results indicate how slight variations in the reactant’s ratio can steadily improve the mechanical properties of the HEMA cryogel without affecting its adsorption efficiency. This can be helpful in the design of materials for water and energy purposes. Since swelling properties are needed in the case of biomedical applications, the HEMA/MBAA ratio should be tuned versus high values.

The efficiency obtained by using TiO2 semiconductors is still low due to interfacial charge recombination. In this research, two coating methods were carried out, namely doping and bilayer using ZnO as a semiconductor to reduce recombination to collect charge and increase the efficiency of Dye-Sensitized Solar Cells. The use of UV-DRS in this study to see the band gap shows a decrease in the band gap after doping and bilayer processes. The XRD used in the study to look at the phase and molecular structure showed that the intensity of TiO2 was lower due to doping and bilayer. The dye used is Quercetin which is polymerized to increase conjugated bonds. To see the polymerized Quercetin tested using FTIR. In the quercetin crosslinker polymerization process varied to 1.5 ml; 2.5 ml; and 3.5 ml to see how many conjugate bonds are formed so that the efficiency obtained is also high. Efficiency measurement using a multimeter. Based on the results of this study, it was found that the efficiency of solar cells increased. In the doping process, the highest efficiency was 11.3%, while the highest efficiency in the coating process was 9.1%. [ABSTRACT FROM AUTHOR]

This study was determine methamphetamine by the addition to the glycidyl methacrylate (GMA) monomer resulting from bulk polymerization formation. To acquire the highest adsorption capacity, molar ratios of the template, monomer, and cross-linking agent, as well as solvents and multiple monomers were investigated. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyze the Methamphetamine polymer. The elution of Methamphetamine had a small effect on the surfaces of the three-dimensional network structure. Methamphetamine was successfully eluted using a mixture of methanol and acetic acid. The Methamphetamine adsorption capacities were 3.8145 and 9.01773 mol/g (Qmax), respectively. A Langmuir isotherm model follows Methamphetamine adsorption. Solid-phase extraction (SPE) syringes packed with molecular imprinted polymers (MIPs) were used to selectively separate and preconcentration the Methamphetamine from different patients. [ABSTRACT FROM AUTHOR]

In this study, nonwoven gelatin (Gel) fabrics crosslinked using N-acetyl-D-glucosamine (GlcNAc) were characterized and compared with those crosslinked using methylglyoxal (MG) and by thermal dehydration. We prepared Gel with 25% concentration along with Gel/GlcNAc and Gel/MG with a GlcNAc-to-Gel ratio of 5% and MG-to-Gel ratio of 0.6%. A high voltage of 23 kV, solution temperature of 45 °C, and distance of 10 cm between the tip and the collector were applied during electrospinning. The electrospun Gel fabrics were crosslinked by heat treatment at 140 and 150 °C for 1 d. The electrospun Gel/GlcNAc fabrics were treated at 100 and 150 °C for 2 d, while the Gel/MG fabrics were heat-treated for 1 d. The Gel/MG fabrics exhibited higher tensile strength and lower elongation than the Gel/GlcNAc fabrics. Overall, Gel/MG crosslinked at 150 °C for 1 d showed a significant enhancement in tensile strength, high hydrolytic degradation, and excellent biocompatibility, with cell viability percentages of 105 and 130% at 1 and 3 d, respectively. Therefore, MG is a promising Gel crosslinker. [ABSTRACT FROM AUTHOR]

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Mass spectrometry (MS) is one of the main techniques for protein identification. Herein, MS has been employed for the identification of bovine serum albumin (BSA), which was covalently immobilized on the surface of a mica chip intended for investigation by atomic force microscopy (AFM). For the immobilization, two different types of crosslinkers have been used: 4-benzoylbenzoic acid N-succinimidyl ester (SuccBB) and dithiobis(succinimidyl propionate) (DSP). According to the data obtained by using an AFM-based molecular detector, the SuccBB crosslinker was more efficient in BSA immobilization than the DSP. The type of crosslinker used for protein capturing has been found to affect the results of MS identification. The results obtained herein can be applied in the development of novel systems intended for the highly sensitive analysis of proteins with molecular detectors. [ABSTRACT FROM AUTHOR]

4:1 two-component silicone sealant was prepared with α,ω-dihydroxy-poly dimethylsiloxane as the base material, nano-calcium carbonate as the reinforcing filler, and dimethylsilicone oil as the plasticizer, crosslinking agent, tackifiers and catalyst. The effects of the amount of nano calcium carbonate, mass ratio of crosslinking agent, type and amount of catalyst on the properties of sealant were studied. The results indicated that the optimal preparation conditions were when the mass ratio of a, ardihydroxy-polydimethylsiloxane to nano-calcium carbonate in the component A reached 1 : 1.1, and the crosslinking agent was mixed with methyl orthosilicate and methyl trimethoxy-silane oligomers at a mass ratio of 1 : 1 with a catalyst of 0.4 phr of sulfur-containing organotin. Under this condition, the tensile break time of the two-component silicone sealant was 25 min, with a debonding time of 75 min, a Shore A hardness of 48A, a tensile strength of 2.07 MPa, an elongation at break at 344%, and a shear strength of 2.06 MPa. After heat treatment at 90 °C for 7 days, the rubber has maintained comparatively stable mechanical properties, with slightly decreased vulcanization rate. [ABSTRACT FROM AUTHOR]

Small-molecule crosslinkers are invaluable for probing biomolecular interactions and for crosslinking mass spectrometry. Existing chemical crosslinkers target only a small selection of amino acids, while conventional photo-crosslinkers target almost all residues non-specifically, complicating data analysis. Herein, we report photocaged quinone methide (PQM)-based crosslinkers that target nine nucleophilic residues through Michael addition, including Gln, Arg, and Asn, which are inaccessible to existing chemical crosslinkers. PQM crosslinkers were used in vitro, in Escherichia coli, and in mammalian cells to crosslink dimeric proteins and endogenous membrane receptors. The heterobifunctional crosslinker NHQM could crosslink proteins to DNA, for which few crosslinkers exist. The photoactivatable reactivity of these crosslinkers and their ability to target multiple amino acids will enhance the use of chemical crosslinking for studies of protein-protein and protein-DNA networks and for structural biology.

Plastic waste has become a pervasive and global threat to every ecosystem, and the continuous surge in plastic production has triggered the need for sustainable alternatives. This study focuses on harnessing a hundred percent biodegradable composite sheets with a natural crosslinker, which can be used in several end applications like seedling trays, gardening pots, sampling trays, one-time plates, ear and nasal swabs, etc. The proposed composite is manufactured with all-natural ingredients and zero harmful chemicals. The waste Kibisu silk or filature silk fibre (Bombyx mori) is used here as the fibre reinforcement, and wheat gluten (WG) is used as the matrix material. For plasticising and crosslinking the WG, castor oil and fresh lemon extract (Citrus limon) are used. In addition, pellets of sodium hydroxide are also added as a dispersion agent for WG. All the significant constituents used here are industrial waste or abundantly available in nature. The properties obtained from the characterisation processes indicate that natural crosslinker adds better physio-chemical properties in the developed samples. [ABSTRACT FROM AUTHOR]

Purpose: This work investigated carboxymethyl hydroxypropyl guar (CMHPG) as a potential base polymer for a fracturing fluid used in deep tight gas wells, synonym to high-temperature reservoirs. Fracturing is a common method to improve oil production by creating fractures in potentially productive reservoirs using fracturing fluids. Fracturing fluids are typically composed of water, sand, proppant, and many different additives to alter the capabilities of the fluid. Design/methodology/approach: A stable high-density fracturing fluid (HDFF) was developed to cope with scorching good temperatures up to 350°F (177°C)as well as to reduce the surface treating pressure. The HDFF consists of NaBr heavy brine, CMHPG, clay stabilizers, and zirconium and borate crosslinkers. A linear gel fluid was prepared by combining NaBr brine with CMHPG before adding the additives. The resulting fluid was then tested using a high-pressure, high-temperature (HPHT) rheometer. Findings: The results showed that the performance of the HDFF was optimum in an alkaline environment between pH 10 to 12. The efficiency of zirconium and borate crosslinkers were optimum at 0.7 ppm and 1.5 ppt, respectively. Concentrations higher than these values are not only uneconomical but will cause the fluid to be overly crosslinked, consequently reducing efficiency. In actual field operation, this is disastrous when the fluid does not flow to the fracturing column but instead swirls around the drill string as the drill string rotates. On the other hand, a reduction of concentration below the optimum values can cause fluid instability at high temperature reservoirs. Research limitations/implications: The study was limited to using two different kinds of crosslinkers and various concentrations. Future studies can be conducted using other kinds of crosslinkers, as well as an investigation into the effects of varying temperatures, pressures, and pH on the HDFF using CMHPG. Practical implications: It can be concluded that HDFF using CMHPG as the base polymer can be a potential use in formulating fracturing fluids. [ABSTRACT FROM AUTHOR]

Efficient polymeric room-temperature phosphorescence (PRTP) with excellent processability and flexibility is highly desirable but still faces formidable challenge. Herein, a general strategy is developed for efficient PRTP through photo-polymerization of phosphor monomers and N-isopropylacrylamide (NIPAM) spontaneously without a crosslinker. Remarkably ultralong lifetime of 3.54 s with afterglow duration time of 25 s and decent phosphorescent quantum efficiency of 13% are achieved. This efficient PRTP has been demonstrated to be derived from the synergistic effect of the covalent and hydrogen bonds networks formed through photo-polymerization of NIPAM. The electron paramagnetic resonance (EPR) spectra confirmed that methyl radicals are generated under the irradiation of ultraviolet light and promote the formation of covalent cross-linking networks. This strategy has also been proved to be generalizable to several other phosphor monomers. Interestingly, the polymer films display ultrahigh temperature resistance with long afterglows even at 140 °C and unexampled ultralong lifetime of 2.45 s in aqueous solutions. This work provides a simple and feasible avenue to obtain efficient PRTP. [ABSTRACT FROM AUTHOR]

It has become crucial to develop new adsorbents to remove toxic dye wastes from wastewater to protect our existing aquatic ecosystem. Here, to remove methyl orange azo dye from aqueous solutions, a new p(HEMA-co-AETAC)/VMt nanocomposite hydrogel was prepared by using 2-hydroxyethyl methacrylate and [2-(acryloyloxy)ethyl]trimethylammonium chloride monomers using vinyl-based montmorillonite crosslinker. Obtained new types of crosslinker and nanocomposite hydrogels have been characterized by various analysis methods. In addition, the effects of crosslinker amount, monomer amount and pH on the swelling behavior of nanocomposite hydrogel were investigated. The effects of essential parameters such as contact time, initial dye concentration, pH effect of the solution, adsorbent amount, and temperature on adsorption were evaluated. It was determined that there was no significant change in the adsorption ability of the nanocomposite hydrogel in the pH range of 3–10. Experimental results showed that the Langmuir isotherm model fit better, and the calculated maximum adsorption capacity was 961.54 mg/g. In addition, it was determined that vinyl-based montmorillonite used as a crosslinker supported MO adsorption. p(HEMA-co-AETAC)/VMt nanocomposite hydrogel may be a new type of adsorbent to remove toxic synthetic dye residues from aqueous media. A new adsorbent for the removal of toxic synthetic dye residues from aqueous media in a wide range of pH. Hydrogels containing AETAC and HEMA are easily obtained with modified montmorillonite. The adsorption properties of the nanocomposite hydrogel were evaluated with methyl orange dye molecules. According to Langmuir isotherm, the maximum adsorption capacity was determined to be 961.54 mg/g. [ABSTRACT FROM AUTHOR]

Poly(N-isopropylacrylamide) (P(NIPAAm)) hydrogels were prepared by free-radical polymerization with biodegradable poly (β-amino ester) (PBAE) crosslinkers at 1 wt% and 3 wt% ratio, and compared with conventional N,N′-methylene bisacrylamide (MBA)-crosslinked hydrogel. The influence of the type, molecular weight, and diacrylate/amine ratio of the crosslinker on the crosslink density, compressive strength, and swelling and biodegradation behavior of the hydrogels was investigated. The hydrogels synthesized with lower molecular weight PBAE crosslinkers showed higher crosslinking degrees and compressive strength and lower swelling ratios. To reveal the controlled release behavior of the fertilizer, KNO3 was used as the model, and its loading and release behavior from these hydrogels was also examined. The N/T5/1 sample with 1.5/1.0 diacrylate/amine molar ratio and 1 wt% PBAE ratio demonstrated the most controlled release of KNO3 with 66.9% after 18 days in soil. In addition, the hydrogel with the porosity of 71.65% and crosslinking degree of 2.85 × 10−5 mol cm−3 showed a swelling ratio of 69.44 g/g, biodegradation rate of 23.9%, and compressive strength of 1.074 MPa. Thus, it can be concluded that the new designed biodegradable P(NIPAAm) hydrogels can be promising materials as nitrate fertilizer reservoirs and also for controlled fertilizer release in soil media for agricultural applications. [ABSTRACT FROM AUTHOR]

This work demonstrates the use of a modified mica to concentrate proteins, which is required for proteomic profiling of blood plasma by mass spectrometry (MS). The surface of mica substrates, which are routinely used in atomic force microscopy (AFM), was modified with a photocrosslinker to allow “irreversible” binding of proteins via covalent bond formation. This modified substrate was called the AFM chip. This study aimed to determine the role of the surface and crosslinker in the efficient concentration of various types of proteins in plasma over a wide concentration range. The substrate surface was modified with a 4-benzoylbenzoic acid N-succinimidyl ester (SuccBB) photocrosslinker, activated by UV irradiation. AFM chips were incubated with plasma samples from a healthy volunteer at various dilution ratios (102X, 104X, and 106X). Control experiments were performed without UV irradiation to evaluate the contribution of physical protein adsorption to the concentration efficiency. AFM imaging confirmed the presence of protein layers on the chip surface after incubation with the samples. MS analysis of different samples indicated that the proteomic profile of the AFM-visualized layers contained common and unique proteins. In the working series of experiments, 228 proteins were identified on the chip surface for all samples, and 21 proteins were not identified in the control series. In the control series, a total of 220 proteins were identified on the chip surface, seven of which were not found in the working series. In plasma samples at various dilution ratios, a total of 146 proteins were identified without the concentration step, while 17 proteins were not detected in the series using AFM chips. The introduction of a concentration step using AFM chips allowed us to identify more proteins than in plasma samples without this step. We found that AFM chips with a modified surface facilitate the efficient concentration of proteins owing to the adsorption factor and the formation of covalent bonds between the proteins and the chip surface. The results of our study can be applied in the development of highly sensitive analytical systems for determining the complete composition of the plasma proteome.

Achieving the desired properties of paper such as strength, durability, and printability remains challenging. Paper mills employ calcium carbonate (CaCO3) as a filler to boost paper’s brightness, opacity, and printability. However, weak interaction between cellulose fibers and CaCO3 particles creates different issues in the papermaking industry. Therefore, this study explores the influence of various inorganic additives as crosslinkers such as mesoporous SiO2 nanospheres, TiO2 nanoparticles, h-BN nanoflakes, and hydroxylated h-BN nanoflakes (h-BN-OH) on inorganic fillers content in the paper. They were introduced to the paper pulp in the form of a polyethylene glycol (PEG) suspension to enable bonding between the inorganic particles and the paper pulp. Our findings have been revealed based on detailed microscopic and structural analyses, e.g., transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and N2 adsorption/desorption isotherms. Finally, the inorganic fillers (CaCO3 and respective inorganic additives) content was evaluated following ISO 1762:2001 guidelines. Conducted evaluations allowed us to identify the most efficient crosslinker (SiO2 nanoparticles) in terms of inorganic filler retention. Paper sheets modified with SiO2 enhance the retention of the fillers by ~12.1%. Therefore, we believe these findings offer valuable insights for enhancing the papermaking process toward boosting the quality of the resulting paper.

This review summarized the research progress on the preparation methods of nano-delivery systems, the types of proteins used to construct plant polyphenol nano-delivery carriers, and the modification of nano-delivery carriers by cross-linking agents domestically and internationally. The development of protein-based plant polyphenol nano-delivery carriers in the food field was also prospected.

Core-shell thermally expandable microspheres (TEMs) were prepared via Pickering suspension polymerization. Acrylonitrile (AN), methacrylic acid (MAA) and N,N-dimethylacrylamide (DMAA) were used as the comonomers, the 2,2′-azobisisobutyronitrile (AIBN) was used as the initiator and the ethyleneglycol dimethacrylate (EGDMA) was used as the crosslinker. The effects of initiator concentration, cross-linking agent concentration and modified monomer type on the morphology, thermal properties and encapsulation content of TEMs were investigated. The results show that the small change in initiator concentration had a significant effect on the properties of TEMs. When the initiator concentration was 0.55%, the microspheres showed core-shell structure and the maximum expansion ratio was 3.06 times. According to the scanning electron microscope (SEM) image, the heat resistance of the microspheres increased with the increase of the content of crosslinking agent. The lower the water solubility of the modified monomer, the more stable the foaming of the TEMs. When methyl acrylate (MA) was used as a modified monomer, the initial expansion temperature of the microspheres was 163.2°C, the maximum expansion temperature was 223.5 °C, and the encapsulation content of the blowing agent was 14.70%.

Cashmere fiber is pretreated with oxygen low temperature plasma to increase the content of polar groups (-OH, -COOH) on the surface. Then by using aziridine crosslinker and polycarbodiimide crosslinker, the sericin with health-care function is grafted onto the surface of the pretreated cashmere fiber. Plasma treatment is optimized after the assessing of methylene blue staining and fiber tensile strength. The grafting rate of sericin indicates that both aziridine and polycarbodiimide crosslinker could play a bridging role. Compared with untreated fiber, oxygen plasma treatment can improve the grafting rate significantly. The chemical changes and morphological structures of the fiber surface are analyzed by infrared spectroscopy and scanning electron microscope. After modification, cashmere exhibited good antibacterial and antioxidant properties. In addition, the fiber still has excellent dyeability while its crimp property and whiteness are slightly reduced.

Abstract Most commonly used dielectric elastomers (DEs) such as acrylic dielectric elastomers VHBTM 4910 need a high actuation voltage and pre‐stretching to obtain a large actuation strain, and present high mechanical loss caused by viscoelasticity. In this work, we fabricated a new acrylic elastomer by UV curing based on CN9021 and lauryl acrylate. By manipulating crosslinker content, crosslink density changed and physical entanglements of the new material can be affected. Therefore, mechanical properties such as Young's Modulus and mechanical loss of the new material can be controlled, and little change of its glass transition temperature was induced. Results of the actuation test show that the new DE is capable of 9.0% actuation area strain under 11 kV/mm and a good performance under oscillating voltage with different waveforms and frequencies.

The actin cytoskeleton represents a highly dynamic filament system providing cell structure and mechanical forces to drive a variety of cellular processes. The dynamics of the actin cytoskeleton are controlled by a number of conserved proteins that maintain the pool of actin monomers, promote actin nucleation, restrict the length of actin filaments and cross-link filaments into networks or bundles. Previous work has been established that cytoplasmic calcium is an important signal to rapidly relay information to the actin cytoskeleton, but the underlying mechanisms remain poorly understood. Here, we summarize new recent perspectives on how calcium fluxes are transduced to the actin cytoskeleton in a physiological context. In this mini-review we will focus on three calcium-binding EF-hand-containing actin cross-linking proteins, α-actinin, plastin and EFHD2/Swiprosin-1, and how these conserved proteins affect the cell’s actin reorganization in the context of cell migration and wound closure in response to calcium.

In this study, it is aimed to develop glucose/fructose sensitive poly(ethylene glycol) methyl ether methacrylate (PEGMA) particles which can be employed in controlled drug delivery applications. For this purpose, a boric acid based crosslinker was synthesized using 4-vinylphenylboronic acid and its formation was confirmed by 1H-NMR and FT-IR analyses. Sugar-sensitive polymeric particles were then achieved using this crosslinker and PEGMA monomer in single step and surfactant free emulsion polymerization technique. Polymeric particles were characterized by DLS, SEM, and TEM in terms of size and morphology. In order to determine the sensitivity of the particles to sugar molecules, first Rhodamine B dye (as a model drug) loading experiments were performed. Then, the particles were subjected to glucose/fructose rich media and dye release was monitored as a function of time using UV-Vis spectrophotometry. The results of the current study revealed that the PEGMA particles were more sensitive to fructose (~39% release) compared to glucose (~25% release) at pH 7.4 and 310 K.

Hypothesis: Chitosan is a biodegradable biopolymer used today as an effective and practical material in various industries. To produce chitosan hydrogels, different crosslinkers are utilized, most of which are toxic and, dangerous. Due to the many applications of chitosan in medicine, pharmaceuticals, tissue engineering and food industries, it is better to use safe and non-toxic crosslinkers to produce biopolymers and hydrogels. Vanillin is a natural and non-toxic aldehyde that can be used as a crosslinker to produce chitosan hydrogels. The cross-links that vanillin make with chitosan are, on the one hand, the Schiff base type bond, and on the other hand, the hydrogen bond, which makes the chitosan-vanillin (CV) hydrogel more mechanically weaker than other chitosan-dialdehyde hydrogels. Chitosan-vanillin hydrogels have been studied in micro- and nanoscale and biofilm shape. In this study, montmorillonite (MMT) fillers have been used to fabricate chitosan-vanillin-montmorillonite (CMV) macrohydrogels, and their effect on improving mechanical properties has been investigated.Methods: In this study, chitosan hydrogels were fabricated with vanillin crosslinker and montmorillonite as fillers. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were performed to identify the bonds formed and to examine the morphology of the hydrogels, respectively. Then, the gel content, swelling, porosity, and mechanical properties of hydrogels were investigated.Finding: The results showed that the presence of vanillin increased the porosity and caused regular porosity in the chitosan hydrogel. Chitosan and vanillin macrohydrogels have good mechanical properties with a porosity greater than 90%, gel content > 86%, swelling, and mechanical strength. The addition of filler to chitosan-vanillin hydrogels also reduces the porosity and swelling and increases the mechanical properties of this system

• Biobased fertilizers offer 120-day nitrogen release at a 4 wt% coating ratio. • Biowaste-derived bionanocomposite can coat urea for well-tunable nitrogen release. • A mathematic model is built to design tailored slow-release porous materials. • This BCRF offers extended N-release, cost-efficiency, and tunability. Controlled-release fertilizers (CRFs) present a promising solution for alleviating food and nutrient scarcity. However, their development has been mainly hindered by both rapid and unsynchronized nutrient release and unsustainable coating materials. In this study, we address this issue by developing a new coating layer for CRFs using a programmable biopolyurethane nanocomposite. This nanocomposite is prepared from diphenylmethane diisocyanate (MDI)-functionalized bentonite nanoclay (BNT-MDI) and a biopolyol from biomass waste. The results show that the BNT-MDI-doped CRFs (BCRFs) exhibit an impressive nitrogen (N)-release longevity of approximately 120 days at a 4 wt% coating ratio, surpassing previous CRF formulations. In a 30-day snap bean cultivation study, BCRF significantly improved root length (1000 %), leaf length (257 %), leaf width (400 %), and plant height (1400 %) compared to the control. The superior performance of BCRF is attributed to the PU-nanoclay biocomposite film, with full nano-exfoliation, controllable porosity, and high crosslinking density. Furthermore, we introduce a new dynamic release mechanism and establish a quantitative relationship between the nanostructure, property, and release performance of BCRF by combining the multiplicative and diffusion models for porous materials. This study provides a theoretical framework and a straightforward methodology for designing programmable nanocomposite structures for future biobased CRFs. [ABSTRACT FROM AUTHOR]

• GCSF achieved the efficient, fast, safe, and low-carbon removal of MPs. • MPs removal mechanism was verified via DFT and XDLVO calculation. • The environmental benefits and risks of GCSF were fully evaluated. • Interactions among the solid, liquid, and gas phases in GCSF were clarified. • –FeO 6 has a stronger adsorption energy for O 2 than that of –AlO 6. To address the problems of unstable efficiency, long treatment period, and high energy consumption during microplastics (MPs) removal by traditional coagulation–flotation technology, a gel coagulation–spontaneous flotation (GCSF) process is proposed that employs laminarin (LA) as the crosslinker and polyaluminum chloride (PAC)/polyaluminum ferric chloride (PAFC) as the coagulant to remove MPs. Herein, the effects of GCSF chemical conditions on microplastic-humic acid composite pollutants (MP-HAs) removal were investigated, and the removal mechanisms were analyzed through theoretical calculations and floc structure characterization. Results showed that an LA to PAC/PAFC ratio of 2.5:1 achieved the highest removal of HA (86 %) and MPs (93 %–99 %) in short coagulation (< 1 min) and spontaneous flotation (< 9 min) period. PAC-LA exhibited strong removal ability for MP-HAs while PAFC-LA induced fast flotation speed. The peak intensity and peak shift in Fourier-transformed infrared and X-ray photo-electron spectra indicated that the removal mechanisms of MPs include hydrogen bond adsorption and the sweeping effect, mainly relying on –OH/–C = O on the MPs surface and entrapment of gel flocs with a high degree of aggregation, respectively. The extended Derjaguin-Landau-Verwey-Overbeek calculation also revealed that interactions between PAC/PAFC-LA and MP-HAs were mainly polar interaction (hydrogen bonding) and intermolecular attraction interaction (Lifshitz-van der Waals force), and the sweep effect was reflected by intermolecular interaction. In addition, density function theory calculations indicated that –OH in LA mainly adsorbs DO through a double hydrogen bond configuration, and the crosslinking ligand FeO 6 /AlO 6 assists in DO absorption by –OH. [Display omitted] [ABSTRACT FROM AUTHOR]

Crosslinked enzyme aggregates of L-asparaginase (A-CLEAs) were prepared using genipin, a non-toxic crosslinker. The process parameters for the preparation of A-CLEAs were optimized using a 3-level factorial design, which predicted the optimized conditions to be 60 mg/mL BSA, 2 mg/mL genipin and a crosslinking time of 4 h. The model which was validated experimentally, resulted in a recovery of 90% activity of L-asparaginase. While the optimum pH shifted to a slightly acidic range, the optimum temperature remained unchanged. A-CLEAs displayed the best pH stability at pH 9 (48%) after 24 h of incubation. At 50 °C, the deactivation rate constant (K d) of A-CLEA decreased by 24%. A-CLEAs showed excellent reusability, retaining 79% of their initial activity after 10 cycles of use. The formation of a dark-blue coloured pigmented A-CLEA and the presence of the carboxymethyl group of genipin in FTIR spectrum confirmed the crosslinking reaction. The increase in the β-sheet content of A-CLEA, correlated with its improved stability. The improved thermostability with regards to structural integrity was well established by TGA-DSC analyses. Morphologically, A-CLEAs showed a highly clustered ball-like appearance. As a model example, the ability of genipin crosslinked A-CLEAs to reduce acrylamide in sweet potato chips was checked. The asparagine content of sweet potato was found to be 2906 ± 15.02 mg/kg as quantified by HPTLC. Analysis of acrylamide by GC-FID showed a 94% reduction in sweet potato chips on contact of sweet potato slices with A-CLEAs for 40 min. [Display omitted] • The non-toxic genipin was used as a crosslinker to form L-asparaginase CLEAs. • First report on preparation of L-asparaginase CLEAs. • CLEAs retained 79% of its initial activity after 10 cycles of use. • CLEAs were used to reduce acrylamide formation in sweet potato chips. [ABSTRACT FROM AUTHOR]