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Three-dimensional polymeric networks called hydrogels have drawn a lot of interest in a variety of biomedical applications because of their distinctive qualities, like high water content and biocompatibility. Hydrogels can be strengthened mechanically and become more stable via cross-linking. In this study, we described the synthesis and characterization of a cross-linked hydrogel made of polyethylene glycol (PEG) capable of absorbing drug. The hydrogel was created by using a polymerization procedure to cross-link PEG chains. In order to allay this worry, we added particular functional groups to the hydrogel matrix that had a strong affinity for glutaraldehyde. These functional groups made it easier for excess glutaraldehyde to be absorbed and sequestered inside the hydrogel, lowering its cytotoxic potential. After incubation with the hydrogel, the residual glutaraldehyde concentration in solution was measured in order to assess the glutaraldehyde absorption potential. [ABSTRACT FROM AUTHOR]

Aim. This work was aimed at developing a new design of an enzyme biosensor for highly sensitive determination of creatinine. Methods. The electrochemical transducers consist of two identical pairs of gold interdigitated electrodes obtained by gold sputtering onto ceramic plate. The sensitive surface of each electrode pair was approximately 1.0×1.5 mm. The transducers were connected to the measuring device “MХP-3”. The immobilization procedure was performed as follows. The enzyme solution was prepared by dissolving 20% creatinine deiminase (microbial, EC 3.5.4.21, with activity of 36 U/mg, from SigmaAldrich, Japan) in 20 mM phosphate buffer solution (PBS), pH 6.5, containing 10% bovine serum albumin (BSA) and 10% glycerol. The mixture for reference membrane was prepared by the same procedure using BSA instead of enzymes. The solutions were mixed with 1% aqueous solution of glutaraldehyde (GA) in 1:1 ratio and were deposited on the electrodes. Then the membranes were dried in open air at room temperature. Before starting the experiments, the electrodes with membranes were washed out excess of unbound components used PBS. Measurements were carried out at room temperature in an open cell filled with 5 mM PBS, pH 7.35, with constant stirring. The required substrate concentration in the cell was obtained by adding the aliquots of substrates stock solutions in the cell with PBS. Non-specific changes in the output signal associated with fluctuations of temperature, medium pH, and electrical noise, were compensated by using differential mode of measurement. At least three series of experiments were performed. Results and Discussion. Various immobilization procedures of the bioselective element were tested. Immobilization method with 1% GA solution was chosen. The optimal conditions for biosensors operation were found. The biosensors were characterized by high signal reproducibility at determination of substrate (RSD = 6%). The linear range of determination of creatinine was 0.01–1 mM. Conclusions. The new construction of enzyme biosensor based on creatinine deiminase was developed for the creatinine determination. The production and measurement conditions of proposed biosensor were optimized. The biosensor was characterized by high reproducibility of responses and showed high storage stability. In future the developed biosensor can be used for express evaluation of the creatinine in biological samples. [ABSTRACT FROM AUTHOR]

Glutaraldehyde is a widely used biocide on the market for about 50 years. Despite its broad application, several reports on the emergence of bacterial resistance, and occasional outbreaks caused by poorly disinfection, there is a gap of knowledge on the bacterial adaptation, tolerance, and resistance mechanisms to glutaraldehyde. Here, we analyze the effects of the independent selection of mutations in the transcriptional regulator yqhC for biological replicates of Escherichia coli cells subjected to adaptive laboratory evolution (ALE) in the presence of glutaraldehyde. The evolved strains showed improved survival in the biocide (11-26% increase in fitness) as a result of mutations in the activator yqhC, which led to the overexpression of the yqhD aldehyde reductase gene by 8 to over 30-fold (3.1-5.2 log2FC range). The protective effect was exclusive to yqhD as other aldehyde reductase genes of E. coli, such as yahK, ybbO, yghA, and ahr did not offer protection against the biocide. We describe a novel mechanism of tolerance to glutaraldehyde based on the activation of the aldehyde reductase YqhD by YqhC and bring attention to the potential for the selection of such tolerance mechanism outside the laboratory, given the existence of YqhD homologs in various pathogenic and opportunistic bacterial species.

Glutaraldehyde is a widely used biocide on the market for about 50 years. Despite its broad application, several reports on the emergence of bacterial resistance, and occasional outbreaks caused by poorly disinfection, there is a gap of knowledge on the bacterial adaptation, tolerance, and resistance mechanisms to glutaraldehyde. Here, we analyze the effects of the independent selection of mutations in the transcriptional regulator yqhC for biological replicates of Escherichia coli cells subjected to adaptive laboratory evolution (ALE) in the presence of glutaraldehyde. The evolved strains showed improved survival in the biocide (11-26% increase in fitness) as a result of mutations in the activator yqhC, which led to the overexpression of the yqhD aldehyde reductase gene by 8 to over 30-fold (3.1-5.2 log2FC range). The protective effect was exclusive to yqhD as other aldehyde reductase genes of E. coli, such as yahK, ybbO, yghA, and ahr did not offer protection against the biocide. We describe a novel mechanism of tolerance to glutaraldehyde based on the activation of the aldehyde reductase YqhD by YqhC and bring attention to the potential for the selection of such tolerance mechanism outside the laboratory, given the existence of YqhD homologs in various pathogenic and opportunistic bacterial species.

BACKGROUND: Bovine pericardium (BP) is a scaffold widely used in soft tissues regeneration; however, its calcification in contact with glutaraldehyde, represent an opportunity for its application in hard tissues, such as bone in the oral cavity. OBJECTIVE: To develop and to characterize decellularized and glutaraldehyde-crosslinked bovine pericardium (GC-BP) as a potential scaffold for guided bone regeneration GBR. METHODS: BP samples from healthy animals of the bovine zebu breed were decellularized and crosslinked by digestion with detergents and glutaraldehyde respectively. The resulting cell-free scaffold was physical, chemical, mechanical, and biologically characterized thought hematoxylin and eosin staining, DNA quantification, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), uniaxial tensile test, cell viability and live and dead assay in cultures of dental pulp stem cells (DPSCs). RESULTS: The decellularization and crosslinking of BP appeared to induce conformational changes of the CLG molecules, which led to lower mechanical properties at the GC-BP scaffold, at the same time that promoted cell adhesion and viability of DPSCs. CONCLUSION: This study suggests that the decellularized and GC-BP is a scaffold with the potential to be used promoting DPSCs recruitment, which has a great impact on the dental area. [ABSTRACT FROM AUTHOR]

Phytoplankton play a key role in marine ecosystems, making the accurate quantification of functional groups/species, using standardized microscopy techniques, essential in many research efforts. In this study we aimed to evaluate the effects of (a) storage time on the abundance of microphytoplankton in samples fixed with acid Lugol's solution; (b) storage time on the abundance of pico- and nanophytoplankton in frozen microscopy slides; (c) storage time on the abundance of pico- and nanophytoplankton in fixed refrigerated samples and (d) storage protocol (refrigerated versus frozen) on the abundance of pico- and nanophytoplankton. Microphytoplankton were analyzed using inverted microscopy, and pico- and nanophytoplankton using epifluorescence microscopy. Results indicate storage time negatively impacted the abundances of all phytoplankton size classes; however, effects were group-specific. For accurate abundance estimates, we suggest that samples fixed with acid Lugol's should be analyzed within 30 and 180 days, for dinoflagellates/total microphytoplankton and diatoms, respectively. For picoeukaryotes, glutaraldehyde fixed samples should be kept refrigerated for up to 4 days, and slides should be prepared immediately before observation. It is recommended that authors specify the exact lag times between sample collection, fixation and analysis, to allow the comparability of phytoplankton datasets across different studies and/or monitoring programs. [ABSTRACT FROM AUTHOR]

Chitosan is a linear biopolymer composed of D-glucosamine and N-acetylglucosamine units. The percentage of D-glucosamine in the polymeric chain can vary from one sample to another and is expressed as the degree of deacetylation (DDA). Since this parameter has an impact on many properties, its determination is often critical, and potentiometric titration is a common analytical technique to measure the DDA. Cross-linking with glutaraldehyde is one of the most explored modifications of chitosan; however, the determination of the DDA for the resulting reticulated chitosan resins can be challenging. In this paper, we report a new, rapid, and efficient method to determine the DDA of glutaraldehyde-cross-linked chitosan resins via HPLC. This method relies on the use of 2,4-dinitrophenylhydrazine (DNPH) as a derivatizing agent to measure the level of reticulation of the polymer (LR) after the reticulation step. In this study, we prepare three calibration curves (with an R2 value over 0.92) for three series of reticulated polymers covering a large range of reticulation levels to demonstrate that a correlation can be established between the LR established via HPLC and the DDA obtained via titration. The polymers are derived from three different chitosan starting materials. These standard calibration curves are now used on a routine basis in our lab, and the HPLC method has allowed us to change our DDA analysis time from 20 h to 5 min. [ABSTRACT FROM AUTHOR]

Hybrid crosslinked hydrogel-based drug delivery systems can deliver therapeutically beneficial drug release effects through controlled release on a temporal and spatial scale. Due to their tuneable physicochemical properties and the ability to prevent drug degradation, these systems facilitate different physicochemical interactions that control drug release. This research aims to synthesize a potent pH-sensitive crosslinked chitosan/polyvinylpyrrolidone hydrogel using different ratios of both the polymers and varying the glutaraldehyde crosslinking agent amount by the solution casting technique for controlled amoxicillin-release properties to mitigate gastrointestinal tract bacterial infection. The effect of polymer ratios and glutaraldehyde amount is investigated by the developing porosity, gel fraction, and extent of swelling in simulated physiological fluids of pH 1.2, 6.8, and 7.4 and in vitro biodegradation at pH 7.4. Interaction between the polymers with the formation of crosslinked structures, good stability, amorphous phase nature, and honeycomb-like structures of the hydrogels is revealed by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. Based on these properties, a chitosan/polyvinylpyrrolidone hydrogel (ratio of 60:40) crosslinked with 600 μL glutaraldehyde in 8 g of the polymers displaying adequate swelling in acidic to basic pH and in vitro biodegradation at pH 7.4 is chosen for the in situ loading of 200 mg of the drug amoxicillin. The cumulative drug release in simulated physiological fluids and the drug release kinetics using different models show that the best-fit Korsmeyer-Peppas model suggests amoxicillin release from the matrix follows diffusion and swelling-controlled time-dependent non-Fickian transport related to hydrogel erosion. This composition displays excellent antimicrobial activity against Streptococcus pyogenes and Escherichia coli. Graphical Abstract [ABSTRACT FROM AUTHOR]

This work has been performed to synthesize a new dithiooxamide/glutaraldehyde resin (R-DTGA) polymer, and to determine the adsorption behavior as well as the adsorption kinetics of the reaction of the synthesized polymer towards the removal of mercury (II) ions from contaminated aqueous and industrial waste media. The synthesized resin polymer has been characterized by using the X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier-Transform Infrared spectroscopy (FT-IR), the DTA, and the TGA measurements and techniques. The adsorption behavior of mercury ions and species was studied using the batch technique. The batch adsorption experiments were performed by using the synthesized polymer, and the effect of various parameters affecting the mercury (II) ions removal has been carefully investigated. The studied parameters are the solution pH, mercury ions concentration, and adsorption time. The obtained experimental results and data indicated the adsorption of mercury was maximum at the pH value (4.6). Also, it was found the adsorption of mercury ions onto the synthesized resin is best fitted by the Langmuir adsorption model, and the adsorption kinetics is best fitted by pseudo-second order kinetics model. The studied adsorbent polymer gave a superior maximum uptake (adsorption) capacity of 11 mmol/g. Based on the obtained results, the synthesized polymer provided extraordinary maximum capacity, selectivity, reusability, sensitivity, and fast adsorption kinetics to remove, extract, and recover mercury (II) ions from industrial, aqueous, and wastewater solutions. [ABSTRACT FROM AUTHOR]

The combined treatment method integrated photothermal therapy (PTT) with chemotherapy is extremely promising owing to the synergistic therapeutic effect as compared to single PTT or chemotherapy. To facilitate more novel and facile photothermal-chemotherapy drugs as well as promote controllable combination therapy, we have developed a mild and facile method to fabricate polymer polypyrrole (PPy)-doxorubicin (DOX) nanoparticles (NPs) as pH-responsive drug nanocarriers for synergistic photothermal-chemotherapy. In the nanoplatform, poly-L-lysine (PLL)-modified PPy serves as the photothermal material, and (DOX) molecules are adopted as the chemotherapy agent. Based on the cross-linking reaction of glutaraldehyde, DOX molecules are flexibly and efficiently assembled on the surface of PLL-modified PPy NPs. The obtained PPy-DOX NPs possess high photothermal effect, superior loading capacity of DOX, and controlled drug release behavior. The combination photothermal-chemotherapy based on PPy-DOX NPs has significantly enhanced the antitumor therapy effect. In general, the designed PPy-DOX NPs may be a potential drug delivery nanoplatform for cancer combination therapy. [ABSTRACT FROM AUTHOR]

A novel adsorbent–contaminant system was investigated for its ability to remove a contaminant of emerging concern, diclofenac potassium, from contaminated water. Bio-based crosslinked chitosan beads functionalized with poly(itaconic acid) side chains were examined for their potential to remove the emerging contaminant. To evaluate the impact of the polymeric microstructure on its adsorptive capacity, several adsorbent samples were prepared using different combinations of initiator and monomeric concentrations. Fourier Transform Infrared (FTIR) analysis confirmed the crosslinking of the chitosan chains and the incorporation of the carboxylic groups on the surface of the final chitosan beads. After the grafting copolymerization process, an additional peak at 1726 cm−1 corresponding to the carboxylic C=O groups of the grafted chains appeared, indicating the successful preparation of poly(IA)-g-chitosan. Thermal stability studies showed that the grafting copolymerization improved the thermal stability of the beads. X-ray and Scanning Electron Microscopy confirmed the successful grafting of the itaconic acid on the surface of the beads. The study revealed that the higher the initiator concentration, the greater the number of side chains, whereas the higher the monomeric concentration, the longer the length of these side chains. The adsorption mechanism involved hydrogen bonding to the carboxylic groups of the grafted chains along with n-π* stacking interaction between the amino group of the chitosan and the aromatic rings of diclofenac potassium. The adsorption efficiencies of diclofenac potassium onto the grafted beads were significantly improved compared to the unfunctionalized chitosan beads, reaching values above 90%. The removal efficiency of grafted chitosan increased with an increase in the concentration in the range of 10–30 ppm and then flattened out in the range of 30–50 ppm. The removal efficiencies of 1–50 ppm of DCF ranged between about 75% and 92% for the grafted chitosan and 30–45% for the crosslinked chitosan. Rapid adsorption occurred within 20 min for all grafted sample combinations, and the adsorption kinetics followed a pseudo-second-order model with qe values ranging from 28 to 44.25 g/mg and R2 values greater than 0.9915. The results highlight the potential of grafted chitosan beads in removing emerging contaminants from contaminated water without harming the environment. [ABSTRACT FROM AUTHOR]

Currently, glutaraldehyde (GA)-crosslinked bioprosthetic heart valves (BHVs) still do not guarantee good biocompatibility and long-term effective durability for clinical application due to their subacute thrombus, inflammation, calcification, tearing and limited durability. In this study, double-modified xanthan gum (oxidized/vinylated xanthan gum (O 2 CXG)) was acquired from xanthan gum for subsequent double crosslinking and modification platform construction. Sulfonic acid groups with anticoagulant properties were also introduced through the free radical polymerization of vinyl sulfonate (VS) and vinyl on O 2 CXG. Taking advantage of the drug-loading function of xanthan gum, the treated pericardium was further loaded with inflammation-triggered dual drug-loaded nanogel (heparin (Hep) and atorvastatin (Ator)). Mechanical properties of O 2 CXG-crosslinked porcine pericardium (O 2 CXG-PP) were significantly improved via the first network formed by Schiff base bonds and the second C-C bonds network. Due to the presence of sulfonic acid groups as well as the dual drug release from nanogels under the stimulation of H 2 O 2 , the hemocompatibility, anti-inflammatory, pro-endothelialization and anti-calcification properties of the crosslinked pericardium modified with nanogels loaded with Hep and Ator (O 2 CXG+VS+(Hep+Ator) nanogel-PP) was significantly better than that of GA-crosslinked PP (GA-PP). The collaborative strategy of double crosslinking and sequential release of anticoagulant/endothelium-promoting drugs triggered by inflammation could effectively meet the requirement of enhanced multiple performance and long-term durability of bioprosthetic heart valves and provide a valuable pattern for multi-functionalization of blood contacting materials. Currently, glutaraldehyde-crosslinked bioprosthetic heart valves (BHVs) are subject to subacute thrombus, inflammation, calcification and tearing, which would not guarantee good biocompatibility and long-term effective durability. We developed a cooperative strategy of double crosslinking and surface modification in which double-modified xanthan gum plays a cornerstone. The mechanical properties of this BHV were significantly improved via the first network formed by Schiff base bonds and the second C-C bonds network. Inflammation-triggered combination delivery of heparin and atorvastatin has been demonstrated to enhance anticoagulation, anti-inflammatory and pro-endothelialization of BHVs by utilizing local inflammatory response. The collaborative strategy could effectively meet the requirement of enhanced multiple performance and long-term durability of BHVs and provide a valuable pattern for the multi-functionalization of blood-contacting materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Immobilized lipase is a green and sustainable catalyst for hydrolysis of acidified oil. Glutaraldehyde is widely used for lipase immobilization while the appropriate strategy optimizes the catalytic performance of lipase. In this research, lipase from Candida rugosa (CRL) was immobilized on spherical silica (SiO2) by glutaraldehyde multipoint covalent treatments, including covalent binding method and adsorption-crosslinking method. The enzymatic stability properties and performance in hydrolysis of refined oil and acidified oil were studied. We confirmed that the residual activity decreased while the stability increased because of the influence on secondary structure of lipase after multipoint covalent treatments. In the comparison of different immobilization strategies in multipoint covalent treatment, SiO2-CRL (covalent binding method) showed lower loading capacity than SiO2-CRL (adsorption-crosslinking method), resulting in low activity. However, SiO2-CRL (covalent binding method) showed better reusability and stability. Immobilized lipase via covalent binding method was more potential in the application of catalytic hydrolysis of acidified oils. [ABSTRACT FROM AUTHOR]

The hydrothermal production of chitosan from the carapaces of gray shrimp was carried out, and the obtained material was characterized via X-ray diffraction analysis, infrared spectroscopy, and pH zero-charge point, giving the expected results. Orange G dye adsorption onto synthetized chitosan was investigated in a batch system, the kinetic study was well-described by a nonlinearized pseudo-second-order model, and the equilibrium data indicated that the nonlinear Langmuir form was appropriate to describe the adsorption system with a maximum adsorption capacity of 34.63 mg/g compared with that found experimentally of 31.9 mg/g. The influences of most of the operating parameters, such as pH, adsorbent concentration, temperature, initial dye concentration, and contact time, were studied. These five independent variables acting on the adsorption performance of Orange G were selected for optimization and modeling processes through a central rotating composite design using response surface methodology (RSM). The percentage of removal of Orange G by chitosan prepared from shrimp shells was predicted with a second-degree polynomial equation, and the postulated model was valid and represented well the phenomenon studied in the experimental domain, with an R2 = 0.98 and an RAdj = 0.95. An initial Orange G concentration of 10 mg/L, a pH of 6.5, a chitosan amount of 0.3 g/L, a temperature of 25 °C, and an adsorption time of 450 min were found to be the optimum conditions in batch mode for the maximum uptake of Orange G (removal of 97.43%). [ABSTRACT FROM AUTHOR]

Valved conduits are often required to replace pulmonary arteries (PA). A widely used Contegra device is made of bovine jugular vein (BJV), preserved with glutaraldehyde (GA) and iso-propanol. However, it has several drawbacks that may be attributed to its chemical treatment. We hypothesized that the use of an alternative preservation compound may significantly improve BJV conduit performance. This study aimed to compare the macroscopic and microscopic properties of the BJV treated with diepoxide (DE) and GA in a porcine model. Twelve DE-BJVs and four Contegra conduits were used for PA replacement in minipigs. To assess the isolated influence of GA, we included an additional control group—BJV treated with 0.625% GA (n = 4). The animals were withdrawn after 6 months of follow-up and the conduits were examined. Explanted DE-BJV had a soft elastic wall with no signs of thrombosis or calcification and good conduit integration, including myofibroblast germination, an ingrowth of soft connective tissue formations and remarkable neoangiogenesis. The inner surface of DE-BJVs was covered by a thin neointimal layer with a solid endothelium. Contegra grafts had a stiffer wall with thrombosis on the leaflets. Calcified foci, chondroid metaplasia, and hyalinosis were observed within the wall. The distal anastomotic sites had hyperplastic neointima, partially covered with the endothelium. The wall of GA-BJV was stiff and rigid with degenerative changes, a substantial amount of calcium deposits and dense fibrotic formations in adventitia. An irregular neointimal layer was presented in the anastomotic sites without endothelial cover in the GA BJV wall. These results demonstrate that DE treatment improves conduit integration and the endothelialization of the inner surface while preventing the mineralization of the BJV, which may reduce the risk of early conduit dysfunction. [ABSTRACT FROM AUTHOR]

The immobilized enzymes' properties can be affected by cross-linkers on the surface of supports. To study how cross-linkers alter enzymes function, chitosan-coated magnetic nanoparticles (CMNPs) with immobilized papain were prepared using glutaraldehyde and or genipin, and then, the properties of the nanoparticles and the immobilized enzymes were assessed. The Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), and X-Ray Diffraction (XRD) results showed that the CMNPs were prepared and papain molecules were immobilized on CMNPs by glutaraldehyde (CMNP-Glu-Papain) or by genipin (CMNP-Gen-Papain). Also, the results associated with enzymes activity indicated that the immobilization by glutaraldehyde and genipin increased the pH optimum of papain from 7 to 7.5 and 9, respectively. The kinetic results indicated that the immobilization by genipin slightly affects the enzyme affinity to the substrate. The stability results showed that CMNP-Gen-Papain has more thermal stability than CMNP-Glu-Papain and papain immobilization on CMNPs by genipin leads to stabilization of the enzyme in the presence of polar solvents, probably due to the more hydroxyl groups on CMNPs activated by genipin. In conclusion, this study suggests that there is a relationship between the types of cross-linker on the surface of supports, and the mechanism of action, kinetic parameters, and the stability of immobilized papain. [ABSTRACT FROM AUTHOR]

Microbial biofilm is one of the most serious problems facing poultry farms all over the world and especially in Egypt. Salmonella, E. coli and S. aureus were the highest implicated bacteria in biofilm formation in poultry farms. Consequently, 440 samples were collected from 8- broiler and 8-layer farms at El- Sharkia Province, Egypt, during the period from (July 2021 till August 2022). The objective of the study was to evaluate biofilm development capacity of the tested bacterial species by the microtiter plate (MTP) assay. Also, the efficacy of five disinfectants commonly used in poultry farms (Sodium hypochlorite, hydrogen peroxide, Virkon S, glutaraldehyde and copper sulphate) with different concentrations (1, 2 and 5%) and different contact times (10, 60 and 120 m) on reducing the biofilms produced by S. Enteritidis, E. coli O78 and S. aureus was estimated. Results showed that out of 440 collected samples, 17 (3.8%), 200(45.5%) and 66 (15%) strains were identified as Salmonella, E. coli and S. aureus, respectively. 88.2%, 92% and 87.8% of the isolates of Salmonella, E. coli and S. aureus were biofilm producers. The most effective disinfectant was sodium hypochlorite which eliminated the biofilms of S. Enteritidis and E. coli O78 when used at concentration 5% for 120 m while 5% for 60 m against S. aureus biofilm. Additionally, hydrogen peroxide showed great efficiency and complete removal of biofilm of S. Enteritidis when used at concentration 2% for 120m and 5%f or 120 m against S. aureus biofilm, meanwhile removed 91% of E. coli O78 biofilm when used at concentration of 5% for 120 m. However, Copper Sulphate was insufficient disinfectant to be used against the biofilms. It can be concluded that the anti-biofilm efficiency of the disinfectants increases with the increase concentration and contact time with biofilms especially when using oxidizing disinfectants (hypochlorite and peroxides). [ABSTRACT FROM AUTHOR]

This study investigated the impact of a support matrix and active group on the support to the nutritional properties of orange juice after juice clarification. Pectinase was immobilized on chitosan and aminated silica supports, activated with genipin or glutaraldehyde, and applied for juice clarification. The effects on various juice properties, including reducing sugars, total soluble solids, vitamin C, and phenolic compounds, juice color, and pH, were evaluated. The results revealed that the immobilization on chitosan activated using genipin resulted in the highest biocatalyst activity (1211.21 U·g−1). The juice treatments using the biocatalysts led to turbidity reduction in the juice (up to 90%), with the highest reductions observed in treatments involving immobilized enzyme on chitosan. Importantly, the enzymatic treatments preserved the natural sugar content, total soluble solids, and pH of the juice. Color differences between treated and raw juice samples were especially relevant for those treated using enzymes, with significant differences in L* and b*, showing loss of yellow vivid color. Analysis of phenolic compounds and vitamin C showed no significant alterations after the enzymatic treatment of the raw juice. According to our results, the clarification of orange juice using immobilized enzymes can be a compromise in turbidity reduction and color reduction to maintain juice quality. [ABSTRACT FROM AUTHOR]

Chitosan coatings could effectively increase the biostability and biocompatibility of biomaterials while maintaining their structural integrity. In this study, electrospun fibrous polyhydroxybutyrate (PHB) membranes were pre-treated with potassium hydroxide (KOH) or hydrogen peroxide (H2O2) and then modified with dopamine (DA) and glutaraldehyde (GA) to improve their adhesion with chitosan (CS). Scanning electron microscopy (SEM), water contact angles (WCA), and Fourier transform infrared spectroscopy (FTIR) were used to demonstrate the successful generation of DA and GA-modified PHB fibers. KOH pre-treated PHB membranes exhibited superior binding efficiency with CS at low concentrations compared to their H2O2 pre-treated counterparts. The thermal analysis demonstrated a considerable decrease in the degradation temperature and crystallinity of KOH pre-treated membranes, with temperatures dropping from 309 °C to 265.5 °C and crystallinity reducing from 100% to 25.59% as CS concentration increased from 0 to 2 w/v%. In comparison, H2O2 pre-treated membranes experienced a mild reduction in degradation temperature, from 309 °C to 284.4 °C, and a large decrease in crystallinity from 100% to 43%. UV-vis analysis using Cibacron Brilliant Red 3B-A dye (CBR) indicated similar binding efficiencies at low CS concentrations for both pre-treatments, but decreased stability at higher concentrations for KOH pre-treated membranes. Mechanical testing revealed a considerable increase in Young's modulus (2 to 14%), toughness (31 to 60%), and ultimate tensile stress (UTS) (14 to 63%) for KOH-treated membranes compared with H2O2 pre-treated membranes as CS concentration increased from 0 to 2 w/v%. [ABSTRACT FROM AUTHOR]

As significant transition metal sulfides, nickel sulfides integrated with carbon were successfully synthesized in the presence of polyethylenimine and glutaraldehyde with a solvothermal route at 180 °C followed by carbonization. Glutaraldehyde prevented complete sulfur loss and allowed the formation of a mixed phase of nickel sulfide. The electrochemical performances of pure NiS2, NiS@C0, NiS2/NiS@C1, and NiS2/NiS@C2 electrodes were tested by a series of measurements. The specific capacitances obtained from GCD analysis were 698, 1160, 1484, and 908 F g−1 at 1 A g−1 for NiS2, NiS@C0, NiS2/NiS@C1, and NiS2/NiS@C2 electrodes, respectively. The results implied that the NiS2/NiS@C1 electrode possessed the highest specific capacitances and this study can be a good reference for the preparation of other hybrid metal sulfides as pseudocapacitive electrode materials. [ABSTRACT FROM AUTHOR]

Lipases are widely used in industry. Free lipases are difficult to recover and have poor stability under operational conditions. Herein, lipases are immobilized onto the methyltrimethoxysilane (MTMS)-modified ceramic membranes (~ 5 nm) with reverse filtration method, and further cross-linking by glutaraldehyde (GA) is used to improve the lipase stability. FTIR and XPS analyses demonstrate the successful immobilization of lipase. The immobilized lipases are used to hydrolyze glycerol triacetate (GT) to fatty acids and glycerol. Under the optimal immobilization conditions (MTMS concentration 0.1 M, lipase immobilization time 80 min, lipase concentration 3 mg/mL, and GA concentration 2%), the loading of lipases reaches 0.24 mg/g. Under the optimal operational conditions (temperature 45 °C, pH 7, pressure 0.2 MPa, GT concentration 0.05 M), the immobilized lipases have the highest catalytic activity of 25 U/mg. Moreover, the thermal and pH stabilities of immobilized lipases are found to be higher than those of the free lipases. In the long-term runs, the immobilized lipases still have 64% of the initial activity after 7 cycles, indicating good reusability. This paper provides a simple process for immobilizing lipase on ceramic membranes. The immobilized lipases have better stability at high temperature and basic environments (pH 7–9), which would have broad applications in lipase-catalyzed reactions. [ABSTRACT FROM AUTHOR]

In this study, a copper (II) oxide‐glutardialdehyde modified boron doped diamond electrode was used as a sensor for the electroanalysis of pyridoxine hydrochloride (vitamin B6) for the first time. A copper oxide‐glutardialdehyde modified boron doped diamond electrode (CuO‐GA2/BDDE) was prepared by a simple drop casting method on boron diamond electrode (BDDE) by suspending CuO with glutardialdehyde (CuO‐GA2). The electrochemical behavior of vitamin B6 was examined using cyclic voltammetry (CV) and its electrochemical determination was found by differential pulse voltammetry (DPV). Under optimum experimental conditions, the linear working range of vitamin B6 on CuO‐GA2/BDDE via the DPV method was calculated as 5.96×10−6–3.75×10−4 mol.L−1. The limit of detection (LOD) was calculated as 1.99×10−7 mol.L−1. In order to demonstrate the selectivity of the method improved for the quantitative determination of vitamin B6 on the CuO‐GA2/BDDE, the interference effect of some cations (Zn2+, Cu2+, Pb2+) and anions (NO3−, Cl−) was investigated via the DPV method. The improved electrode was successfully used for the electroanalysis of vitamin B6 in a tablet sample of the commercial Tribeksol® (deva) (250/250/1 mg B1+B6+B12). [ABSTRACT FROM AUTHOR]

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Background: Neonatal truncal valve plasty remains a significant challenge. Several surgical techniques have been reported, but there is no standard procedure. We herein report a novel operative technique for the quadricuspid truncal valve with axisymmetric morphology. Case presentation: A 17-day-old neonate with severe truncal valve insufficiency developed persistent congestive heart failure and underwent urgent truncal valve plasty. The truncal valve was quadricuspid with four equal sinuses, and all four cusps were hypoplastic, resulting in a complete lack of coaptation. We performed bicuspidization valvuloplasty with leaflet reconstruction using autologous pericardium for this valve. The patient had an uneventful recovery and was free from recurrent truncal valve insufficiency for 10 months. Conclusions: Bicuspidization with leaflet reconstruction is a suitable surgical option for overcoming neonatal truncal valve insufficiency in cases with quadricuspid truncal valves with axisymmetric morphologies. Although the durability of a bicuspid neo-leaflet using glutaraldehyde-treated autologous pericardium is unknown, this technique is expected to postpone subsequent truncal valve replacement in such neonates. [ABSTRACT FROM AUTHOR]

Two non-canonical amino acids (ncAAs) with bio-orthogonal reactive groups, namely, p-azido-L-phenylalanine (p-AzF) and p-propargyloxy-L-phenylalanine (p-PaF), were genetically inserted into an aldo-keto reductase (AKR) and an alcohol dehydrogenase (ADH), respectively, at two preselected sites for each enzyme. The variants were expressed in the genome recoded bacterium Escherichia coli C321.ΔA. Supernatants of the individual cell lysates were subsequently mixed to produce orderly combi-crosslinked enzymes (O-CLEs) of AKR and ADH by co-polymerization of the two variants through their reactive bioorthogonal groups. The site-specific cross-linked enzymes (S-CLEs) and cross-linked enzyme aggregates (CLEAs) were produced using dibenzocycloocta-4a,6a-diene-5,11-diyne (DBA) and glutaraldehyde as the crosslinking agent, respectively. The catalytic efficiencies of the O-CLEs, S-CLEs and combi-CLEAs were determined using the water soluble dihydro-4, 4-dimethyl-2, 3-furandione as a surrogate substrate in aqueous solution at 37 °C. The O-CLEs exhibited the highest catalytic efficiency (Kcat/KM = 11.36 S-1 mM-1) that was 4.24 and 22.27 times that of S-CLEs and combi-CLEAs, respectively. In the asymmetric cascade synthesis of (R)-1-(2-chlorophenyl) ethanol the product yield after 14 h using the O-CLEs, S-CLEs and the combi-CLEAs was 93%, 55% and 16%, respectively. Moreover, high activities and selectivity (ee > 99.99%) were maintained at high substrate concentrations in prolonged operation. [ABSTRACT FROM AUTHOR]

Bacterial infection seriously endangers patients' health. Thus, it is imperative to develop highly efficient antibacterial materials. In this study, antibacterial and antioxidant hydrogel with photothermal effect and nitric oxide (NO) gasreleasing property was designed and synthesized. The hydrogel was formed by crosslinking ε-polylysine and tannic acid using Fe3+ and glutaraldehyde and loading NO donor S-nitroso-N-acetyl-DL penicillamine (SNAP). The Fe9-TA20 hydrogel shows high photothermal effect and the temperature of the hydrogel can reach 43.8 ℃ within 10 min under 1 W/cm2 near-infrared irradiation. Additionally, the NO-Fe9-TA20 hydrogel shows effective NO-release activities. Under visible light and at 37 ℃, the amount of NO released from the hydrogel reach 36.48 μmol/L within 3 h. Benefitting from the synergetic effect of cations of ε-poly-L-lysine (EPL) and the released NO, NO-Fe9-TA20 hydrogel exhibits antibacterial activity (> 99.9%) towards Staphylococcus aureus, and can effectively scavenge 1,1-dipheny-2-picrylhydrazyl (DPPH) free radicals (> 84.3%), which may protect cells from oxidative stress damage. This study may provide a new approach for bacterial infections treatment. [ABSTRACT FROM AUTHOR]

This research article first time reports the concept of thin film composite (TFC) membranes preparation using novel functional copolymer based on poly(vinyl alcohol-co-styrenesulfonic acid) (PVA-co-SSA). Polysulfone ultrafiltration membrane was coated by applying PVA-co-SSA solution via eco-friendly method. The selective coating layer was crosslinked by glutaraldehyde (GA) aqueous solution. The effects of PVA-co-SSA and GA solution concentrations used for TFC membranes preparation were evaluated to study the membranes' characteristics. Infrared and Raman spectroscopy was used to confirm the structural characteristics of composite membranes. The resultant TFC membranes were found hydrophilic (exhibited water contact angle in the span of 41° to 60°) and possessed a smooth surface having surface roughness ranging from 20.9 to 26.3 nm with the selective layer thickness in the range of 123 to 276 nm. Membrane exhibited maximum water flux of 32.78 l m−2 h−1 at when operated in cross-flow cell at 0.69 MPa; at same pressure the membrane gave 74.8% rejection of MgSO4 when fed with 1000 ppm solution of MgSO4; while NaCl rejection of membranes was in the range of 33.75 to 54% when tested using 2000 ppm NaCl feed solution supplied at operating pressure of 1.7 MPa. The trade-off relationship between membrane solute rejection and flux was observed, and composite membranes showed higher rejection of bivalent salt i.e. MgSO4 compared to monovalent salt i.e. NaCl. [ABSTRACT FROM AUTHOR]

Surface-crosslinked hydrogel particles encapsulating E. coli cells harboring nitrilase were constructed and used as a durable biocatalyst in the synthesis of gabapentin intermediate. E. coli cells (50 g/L) expressing nitrilase were encapsulated in 2% (w/v) alginate hydrogel, 0.5%(w/v) glutaraldehyde and 1%(w/v) polyethyleneimine were sequentially used as crosslinker. The constructed alginate particles with GA&PEI composite crosslinking had a similar catalytic capacity compared to equivalent free cells, which could completely hydrolyze 1.0 M substrate 1-cyanocyclohexaneacetonitrile within 4 h at pH 7.5 and 35 °C, and have a specific activity of 134.6 U/g, an optimum temperature at 55 °C and a corresponding half-life up to 19.1 ± 1.9 h. The particles showed excellent storage stability, reusability and mechanical strength, which retained 90.3% activity after 2-month storage at 4 °C, and 83.2% activity after 14-day storage at 35 °C. In batch reactions, 50 g/L particles could be reused for maximum 32 cycles, maintained 63.5% residual activity and 50.7% particle integrity, providing an average product yield of 94.6% in the first 30 batches and a productivity of 1467.03 g/L/day. Besides, the stability and catalytic activity of the particles were almost unaffected in several organic co-solvents and in purified water, showing their good industrial potential. [Display omitted] • Surface-crosslinked hydrogel particles encapsulating E. coli cells were prepared as biocatalysts. • The particles have similar catalytic capacity compared to equivalent free cells. • High activity and strength enable it to completely hydrolyze 1 M substrate within 4 h. • The particles retained 90.3% activity after 2 months of storage and could be reused up to 32 times. [ABSTRACT FROM AUTHOR]

Background: Capecitabine (CAP), a BCS class-I drug which is used for the treatment of Colorectal Cancer (CRC). Site specific and enzyme activated drug delivery was achieved by albumin coated nanoparticles. Co-administration of Proton Pump Inhibitors (PPI) with the tablet dosage form of CAP lowers the dissolution of the CAP due to elevated gastric pH, resulting in decreased CAP absorption. To overcome this absorption, issue the albumin coated CAP NPs were administered through rectal route as suppositories dosage form. Materials and Methods: The capecitabine nanoparticles were prepared using different concentrations of Poly Lactic-co-Glycolic Acid (PLGA) polymer by salting-out technique and were characterized. Further, the optimized polymeric nanoparticles were coated with Egg Albumin (EA) using a glutaraldehyde cross-linker and characterized for their particle size, zeta potential, polydispersity index, drug content, SEM, and in vitro drug release. The suppositories were prepared by fusion moulding method using different grades of PEG as a base and evaluated for various parameters and in vitro drug release. Results and Discussion: The particle size of the optimized CAP NPs and the EA coated CAP NPs were determined to be 171.7 nm and 239.6 nm respectively. The in vitro release of CAP from the EA coated NPs and the suppository formulation shows 88.3% and 81.0% respectively. Conclusion: Capecitabine suppositories were formulated and the quality control parameters were assessed for the site specific and enzyme activated drug delivery in the management of colorectal cancer with help of literature references. [ABSTRACT FROM AUTHOR]

Four types of classical tannin-based foam samples were prepared via different methods in the current study with an attempt to find out the impact of each one on the physico-mechanical properties. The results of performed tests showed similarity to the general trend of related research, with typical negative relation between the foam density and mechanical strength. A critical point was found for each type of foam samples, for example, for tannin-formaldehyde foams (TFF), they were in the range of 85–95 kg/m3, while for tannin-glutaraldehyde foams (TGF), mechanically-generated tannin foams (MTF) and steam-driven tannin furanic foams (STDF), they were about 52–62 kg/m3, 53–63 kg/m3, and 73–83 kg/m3, respectively. This implies a significant change for density and mechanical strength, has been dig out by intensive experimental results and analysis. In addition, a non-liner relationship between density and pulverization ratio was obtained by fitting the curves obtained by the experiment results. Finally, visualization using scanning electron microscopy (SEM) together with evaluation of the compression strength presented a deeper insight to illustrate the different factors affecting foam density and pulverization ratio. [ABSTRACT FROM AUTHOR]

A sensitive electrochemiluminescence (ECL) biosensor for the specific DNA sequence of hepatitis C virus (HCV) was developed based on the efficient quenching effect of the ferrocene cluster functionalized gold nanoparticles (Fc@AuNPs) on the ECL of electrodeposited silica@Ru(bpy)32+‐chitosan‐graphene oxide nanocomposite (SiO2@Ru−CS−GO). Graphene oxide (GO) can accelerate electron transfer rate, thus improving the ECL of Ru(bpy)32+ on electrode surface. The molecular beacons (MB) was fixed to SiO2@Ru−CS−GO by glutaraldehyde (GA) using the Schiff reaction between amino groups of chitosan (CS) and MB. The ECL of SiO2@Ru−CS−GO was depressed greatly by the Fc@AuNPs labelled at the end of MB, then, a stronger ECL was observed when the distance between Fc@AuNPs and SiO2@Ru−CS−GO increased after the hybridization of target DNA with MB. Under optimum conditions, the restored ECL intensity increased linearly with the target DNA concentration in the range of 1.0×10−16∼1.0×10−10 mol ⋅ L−1, and the limit of detection (LOD) is 1.4×10−17 mol ⋅ L−1. The proposed method exhibits acceptable stability and reproducibility. In general, the constructed HCV biosensor can be used for the sensitive detection of HCV in human serum, suggesting potential application prospects in bioanalysis. [ABSTRACT FROM AUTHOR]

A reverse duality between the asymmetric simple exclusion process (ASEP) with open boundary conditions and a biased random walk of a single particle is proved for a special manifold of boundary parameters of the ASEP. The duality function is given by the configuration probabilities of a family of Bernoulli shock measures with a microscopic shock at site x of the lattice. The boundary conditions of the dual random walk, which can be reflecting or absorbing, depend on the choice of the duality function. As a consequence of this duality, the full time-dependent distribution of the open ASEP starting from a fixed shock measure at x is given for any time t > 0 by a convex combination of shock measures with shock at position y. The coefficients are the transition probabilities P(x, t|y, 0) at time t of the random walk starting at site y. It is also shown that this family of shock measures arises from a similarity transformation of the two-dimensional representation of the matrix algebra for the stationary matrix product measure of the open ASEP. This implies a further duality between random walks with different boundary conditions. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) is a frequent and serious complication of sepsis with limited therapeutic options. Gaining insights into the inflammatory dysregulation that causes sepsis‐associated ALI can help develop new therapeutic strategies. Herein, the crucial role of cell‐free mitochondrial DNA (cf‐mtDNA) in the regulation of alveolar macrophage activation during sepsis‐associated ALI is identified. Most importantly, a biocompatible hybrid protein nanomotor (NM) composed of recombinant deoxyribonuclease I (DNase‐I) and human serum albumin (HSA) via glutaraldehyde‐mediated crosslinking is prepared to obtain an inhalable nanotherapeutic platform targeting pulmonary cf‐mtDNA clearance. The synthesized DNase‐I/HSA NMs are endowed with self‐propulsive capability and demonstrate superior performances in stability, DNA hydrolysis, and biosafety. Pulmonary delivery of DNase‐I/HSA NMs effectively eliminates cf‐mtDNAs in the lungs, and also improves sepsis survival by attenuating pulmonary inflammation and lung injury. Therefore, pulmonary cf‐mtDNA clearance strategy using DNase‐I/HSA NMs is considered to be an attractive approach for sepsis‐associated ALI. [ABSTRACT FROM AUTHOR]

Background The usefulness of autologous pericardium treated with glutaraldehyde (GA) for tracheal defect closure is unknown. This study preliminarily evaluated whether a GA-treated autologous pericardial graft can effectively close tracheal defects in a beagle model. Methods Defects of 10 mm × 10 mm were created on the trachea of 10 beagles and divided into a GA-treated group (n = 5), with tracheal reconstruction using GA-treated pericardium, and control group (n = 5), using fresh pericardium. Repair sites were evaluated through bronchoscopy and histology. Blood flows on graft were measured using laser Doppler technique on postoperative days (PODs) 0, 4, 7, 14, 28, and 56. Repair sites were histologically evaluated on POD 56. In addition, GA-treated pericardia of three other beagles were histologically evaluated 12 months postoperatively, for long-term follow-up. Results All animals survived; none developed anastomotic insufficiency. The mean suturing time and frequency of additional suture were significantly shorter and lower in the GA-treated group than in the control group (p = 0.002, 0.004). All animals in the control group exhibited graft contraction, whereas the GA-treated group healed with most graft residual and reepithelialization in the bronchoscopic and histological findings (p = 0.01, 0.004). Further, all long-term GA-treated pericardia of three beagles were confirmed as residual grafts with reepithelialization, without contraction, at 12 months postoperatively. Blood flows on graft using laser Doppler technique in the GA-treated group were detected at POD 14 or thereafter. Conclusion GA-treated pericardium was easier to handle and provided favorable scaffolding, without graft contraction, compared with the nontreated pericardium at short- and long-term follow-up. [ABSTRACT FROM AUTHOR]

An easy and versatile method was designed and applied successfully to obtain access to lipase-based cross-linked-enzyme aggregate-like copolymers (CLEA-LCs) using one-pot, consecutive cross-linking steps using two types of homobifunctional cross-linkers (glutaraldehyde and putrescine), mediated with amine activation through pH alteration (pH jump) as a key step in the process. Six lipases were utilised in order to assess the effectiveness of the technique, in terms of immobilization yields, hydrolytic activities, thermal stability and application in kinetic resolution. A good retention of catalytic properties was found for all cases, together with an important thermal and storage stability improvement. Particularly, the CLEA-LCs derived from Candida rugosa lipase showed an outstanding behaviour in terms of thermostability and capability for catalysing the enantioselective hydrolysis of racemic ibuprofen ethyl ester, furnishing the eutomer (S)-ibuprofen with very high conversion and enantioselectivity. [ABSTRACT FROM AUTHOR]

In the present study, the immobilization of Trametes versicolor laccase (Tv Lac) was optimized on the synthesized NaY-zeolite by experimental of design. For this purpose, the central composite design was employed to study the effects of the immobilization parameters on the activity of the immobilized Tv Lac on the NaY-zeolite. The optimum conditions were occurred at 2.5 mg/mL of NaY-zeolite concentration, 1 U/mg of enzyme concentration, 1 mM of glutaraldehyde concentration for 4 h immobilization time at 4 °C. In these conditions, the laccase activity developed to 15.68 ± 0.56 U/mg, which was very close to the predicted amount (16.09 ± 1.6 U/mg). Generally, the immobilized Tv Lac showed stability higher than that of the free Tv Lac at the different temperatures and pHs. The activity of the immobilized Tv Lac on the NaY-zeolite was 88.2% and 98.3% after incubation for 120 min at 60 °C and pH 5, respectively. Moreover, the free Tv Lac and immobilized Tv Lac on NaY-zeolite retained about 54.2% and 78.3% of its initial activity after 15 days of storage. The immobilized Tv Lac lost near 20% of its initial activity after 5 cycles of uses. The immobilized Tv Lac exhibited higher efficiency (93.0 ± 1.7% and 80.3 ± 1.8%, respectively) in removal of bromothymol blue (BTB) and trypan blue compared with the free Tv Lac (23.7 ± 1.8% and 15.1 ± 1.5%, respectively). Meanwhile, the kinetic parameters (K m and V max) for immobilized Tv Lac were 0.07 µM and 1.38 µmol/min, respectively, for removal of BTB. Therefore, the immobilized Tv Lac as a good candidate could be suggested for the elimination of dye-containing pollutants due to its high efficiency (more than 80%), which requires further investigations. [Display omitted] • The NaY-zeolite was used for immobilization of Trametes versicolor laccase (Tv Lac). • Central composite design was employed to optimize the immobilization conditions. • Tv Lac was successfully immobilized on NaY-zeolite by IY of 97.22% and IE of 101.04%. • Stabilities and reusability of the immobilized laccase were significantly improved. • The immobilized Tv Lac exhibited high efficiency in removal of BTB. [ABSTRACT FROM AUTHOR]

Summary: Pickering emulsions stabilised by nanoparticles are recognised as enzyme carriers, enabling advanced catalysis efficiency. Herein, we immobilised lipase on acetylated arachin nanoparticles/chitosan composites (AAPs/CS) through cross linking with glutaraldehyde (GDA) resulting in the formation of AAPs/CS‐Lipase to stabilise water in oil (W/O) Pickering emulsion catalytic systems (PEC). The specific activity of AAPs/CS‐Lipase was increased to 160% compared with free lipase (1.48 ± 0.02 U mg−1). Increasing the mass of CS led to an increase in the droplet size of W/O PEC from 2.53 ± 0.82 μm to 7.94 ± 1.24 μm. AAPs/CS‐Lipase decreased the interfacial tension and enhanced the interfacial viscosity of W/O PEC. The catalytic efficiency of W/O PEC is 2.75 times of biphasic catalytic system (BCS). The content of DAG exceeded 50% of the total oil. The specific activity of AAPs/CS‐Lipase remained above 70% even after 10 cycles. W/O PEC provided an efficient catalytic platform to prepare DAG‐rich soybean oil. [ABSTRACT FROM AUTHOR]

Infection control is essential to protect both the doctor and the patient by preventing the spread of infectious diseases. There is no exception in the field of dentistry, particularly in orthodontics, where numerous appliances are used for a variety of functions and also because the mouth cavity has the highest concentration of bacteria of any body part. Through this systematic review, we aimed to assess the various methods of sterilization employed in an orthodontic setting. Using relevant keywords, reference searches, and citation searches, the databases such as PubMed, MEDLINE, Web of Science, Cochrane, and Scopus were all searched; a total of 206 documents were found, of which 113 were initially selected. The remaining 23 distinct papers were initially made available after 90 publications that were identical to or similar to one another were eliminated. The final selection was made from eight documents that met all inclusion and exclusion requirements. The existing methods of sterilization were found to be competent in dealing with the microorganisms found in a typical orthodontic setting. The chemical method of sterilization was the norm in most of the studies that we assessed, with glutaraldehyde and peracetic acid (PAA) being the most commonly employed compounds for disinfection. [ABSTRACT FROM AUTHOR]

The zoonotic illness brucellosis may spread between humans and animals in a variety of ways. The prevention and management of brucellosis depend heavily on the cleanliness of the areas around animals and the effective eradication of infection from animal housing. In our investigation, we tested a variety of disinfectants against Brucella melitensis to see how well they worked and whether they would work in various environmental settings. In addition to three different types of nano-disinfectants (Dettol with Silver-NPs, Glutaraldehyde with Silver-NPs, and Calcium oxide-NPs), our study included various conventional forms of disinfectants and antiseptics (Virkon Ⓡ S, Cidex, Sodium hypochlorite, Betadine, and Dettol). For estimating the effectiveness of various types of applied disinfectants, reduction rate was employed. The findings indicated that the concentration and length of exposure time of the disinfectants employed, particularly Vircon S, had an impact on their ability to kill bacteria. However, the presence of filthy circumstances and low temperatures considerably reduced the effectiveness of disinfectants, particularly Dettol. On the other hand, nano-disinfectants, particularly glutaraldehyde containing silver nanoparticles, showed better effects than conventional ones. Our research indicated that disinfectants used in everyday life had an impact on Brucella melitensis. However, the presence of filthy environments and low temperatures reduced the bactericidal effectiveness. The impact of nano-disinfectants on Brucella was better. [ABSTRACT FROM AUTHOR]

Despite being rich in starch, over half of acorn production is undervalued. High hydrostatic pressure was used to modify the properties of Q. pyrenaica (0.1 and 460 MPa for 20 min) and Q. robur (0.1 and 333 MPa for 17.4 min) acorn starches to obtain high-valued ingredients. Pressure significantly altered the span distribution and heterogeneity of the acorn starch granules depending on the species, but their morphology was unaffected. Pressurization increased the amylose/amylopectin ratio and damaged starch contents, but the effect was more prominent in Q. pyrenaica than in Q. robur. However, the polymorphism, relative crystallinity, gelatinization temperatures, and enthalpies were preserved. The pressure effect on the starch properties depended on the property and species. The solubility, swelling power, and acorn gels' resistance towards deformation for both species decreased after pressurization. For Q. pyrenaica starch, the in vitro digestibility increased, but the pseudoplastic behavior decreased after pressurization. No differences were seen for Q. robur. Regarding the commercial starch, acorn starches had lower gelatinization temperatures and enthalpies, lower in vitro digestibility, lower resistance towards deformation, superior pseudoplastic behavior, and overall higher solubility and swelling power until 80 °C. This encourages the usage of acorn starches as a new food ingredient. [ABSTRACT FROM AUTHOR]

To date, few publications describe CEC's properties and possible applications—thus, further evaluation of these properties is a point of interest. The present in vitro model study aimed to evaluate a carboxyethylchitosan (CEC) gel with a degree of substitution of 1, cross-linked with glutaraldehyde at a polymer:aldehyde molar ratio of 10:1, as a potential carrier for delivering bacteriophages to various pH-fixed media (acidic, alkaline), and including gastrointestinal tract (GIT) variable medium. A quantitative analysis of bacteriophages released from the gel was performed using photon correlation spectrophotometry, and phage activity after emission into medium was evaluated using the spot test. The results showed that the CEC gel's maximum swelling ratios were at a nearly neutral alkaline pH. Increasing temperature enhances the swelling ratio of the gel independent from pH, up to 1127% at 37 °C and alkaline pH. The UV and photon correlation spectrophotometry showed equal gel release kinetics in both fixed media with acidic (pH = 2.2) and alkaline (pH = 7.4) pH environments at 37 °C, with the maximum release within two hours. However, phage lytic activity in the spot test during this simulation was absent. At the same time, we obtained an opaque phage lytic activity in the alkaline pH-fixed medium for at least three hours. Phages released from the tested CEC gel in different pHs suggest that this gel could be used for applications that require fast release at the treatment site both in acidic and alkaline pH. Such treatment sites could be a wound or even soil with mild acidic or alkaline pH. However, such CEC gel is not suitable as a delivery system to the GIT because of possible transported acid-sensitive agent (such as phages) release and destruction already in the stomach. [ABSTRACT FROM AUTHOR]

Water pollution is an issue of global concern that demands effective and sustainable solutions through water purification. Adsorption is a popular method for water treatment because it is inexpensive and has a high performance rate. Although commercial activated carbon is the generally preferred adsorbent for adsorption, its widespread use is affected by the high cost and challenges encountered during column adsorption. Biopolymers like cellulose and its derivatives have the potential to replace expensive adsorbents due to their unique characteristics. In recent years, cellulose-bead nanocomposites have gained significant attention as promising adsorbents due to their ability to circumvent the challenges encountered when using powdered adsorbents. To fabricate cellulose beads, cellulose fiber is separated from its source, dissolved in appropriate solvents, shaped into spherical particles and subsequently modified (via esterification, oxidation, crosslinking agents, etc.) to improve its adsorption capacity. This comprehensive review paper presents a detailed analysis of the recent development in the formation and surface modification of 3-D structured cellulose nanocomposites. The outcome of this review on modified cellulose-bead demonstrates their successful fabrication and high adsorption capacities for different contaminants. It is anticipated that cellulose beads, as a bio-adsorbent in industrial settings, will be a low-cost alternative to the more expensive adsorbents shortly. [ABSTRACT FROM AUTHOR]

From the environmental point of view, azo dye industrial effluent is a major public health concern due to its toxic, carcinogenic, and teratogenic characteristics. On the other hand, using enzyme-based technologies offers a promising systematic and controllable method for removing synthetic dyes from wastewater. In the present study, yttrium (Y3+) phosphate was applied for the synthesis of hybrid nanoparticles (HNPs) consisting of laccase as the green catalyst. When the association of HNPs was fixed by glutaraldehyde (GA), three-dimensional cubic structures with the regular arrangement were provided. GA increased the reusability of the fabricated hybrid nanostructures (HNSs) up to 32 successive cycles. About 85% of Direct Blue-15 was removed after a 4 h-treatment using laccase@YPO4•HNPs and laccase@GA@YPO4•HNSs. The azo dye removal data were well-fitted with a pseudo-second-order model for both types of the prepared HNSs. For the model freshwater green alga Raphidocelis subcapitata, the half maximal effective concentration (EC50) of the dye decreased 10- and 100-fold after the removal with laccase@YPO4•HNPs and laccase@GA@YPO4•HNSs, respectively. GA-treated HNSs (250 U L−1) inhibited the biofilm formation by approximately 78%, 82%, and 79% for Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, respectively. Thus, the fabricated laccase@GA@YPO4•HNSs could be presented as a novel, efficient, and recyclable heterogeneous biocatalyst for wastewater treatment and clean-up. [ABSTRACT FROM AUTHOR]

Viscose fabric is susceptible to mold erosion and nourish bacteria, which limit its application. In this study, the efficient and green silver-loaded viscose fabric was prepared by simple liquid phase spray deposition method. The microstructure, physical properties, antibacterial durability of silver-loaded viscose fabric were further evaluated. The result showed that the silver-loaded viscose fabric not only kept their superior comfortability but also had an air permeability that was more than three times higher than the bare viscose fabric. In addition, the silver-loaded viscose fabric showed good antibacterial activity and the antibacterial rate reach to 99.9%. Meanwhile, the silver-loaded viscose fabric still maintained good antibacterial activity after friction treatment. The washing and chemical resistance of the silver-loaded viscose fabric could be further improved through chemical crosslinking with glutaraldehyde. This work provided a feasible way to manufacture green and durable antibacterial viscose fabric, which also improves the application potential of viscose fabric during current respiratory disease pandemic. [ABSTRACT FROM AUTHOR]

Wenli Hui, Wenhua Mu, Cong Zhao, Dan Xue, Zihua Zhong, Yani Fang, Ming Gao, Xiao Li, Shihao Gao, Kaiyue Liu, Kunping Yan College of Life Science, Northwest University, Xi’an City, Shaanxi Province, 710069, People’s Republic of ChinaCorrespondence: Kunping Yan, Email kpyan@nwu.edu.cnIntroduction: A limitation of hemoglobin-based oxygen carriers (HBOCs) as oxygen therapeutics is unpolymerized hemoglobin, which induces vasoconstriction leading to hypertension. The removal of unpolymerized hemoglobin from polymerized hemoglobin (PolyHb) is complex, expensive, and time-consuming.Methods: Herein, we developed a method to completely polymerize hemoglobin almost without unpolymerized hemoglobin. Hemoglobin was adsorbed on the anion-exchange resin Q Sepharose Fast Flow or DEAE Sepharose Fast Flow, and acetal, a crosslinker prepared from glutaraldehyde and ethylene glycol, was employed to polymerize the hemoglobin. The polymerization conditions, including reaction time, pH, resin type, and molar ratios of glutaraldehyde to ethylene glycol and hemoglobin to acetal, were optimized. The blood pressure and blood gas of mice injected with PolyHb were monitored as well.Results: The optimal polymerization condition of PolyHb was when the molar ratio of glutaraldehyde to ethylene glycol was 1:20, and the molar ratio of 10 mg/mL hemoglobin adsorbed on anion-exchange resin to glutaraldehyde was 1:300 for 60 min. Under optimized reactive conditions, hemoglobin was almost completely polymerized, with < 1% hemoglobin remaining unpolymerized, and the molecular weight of PolyHb was more centrally distributed. Furthermore, hypertension was not induced in mice by PolyHb, and there were also no pathological changes observed in arterial oxygen, blood gas, electrolytes, and some metabolic indicators.Conclusion: The findings of this study indicate that the use of solid-phase polymerization and acetal is a highly effective and innovative approach to HBOCs, resulting in the almost completely polymerized hemoglobin. These results offer promising implications for the development of new methods for preparing HBOCs.Graphical Abstract: Keywords: polymerized hemoglobin, glutaraldehyde, acetal, solid-phase adsorption, hemoglobin-based oxygen carriers, HBOCs

The objectives of this study were to synthesize zeolite/NPK coated with Cu-alginate-PVA-glutaraldehyde as a material for slow-release fertilizers and to study the effect of various Cu concentrations in the coating material on the resistance of the zeolite/NPK fertilizer and to study the release rate reaction in citric acid. The study began with the synthesis of the zeolite/NPK fertilizer and the Cu-alginate-PVA-glutaraldehyde coating materials with variations of Cu concentration of 0.0; 0.2; 0.4; 0.6; 0.8; and 1.0 M. The Zeolite/NPK fertilizer and the coated NPK fertilizer were characterized by XRD and FTIR. The determination of the released N and P was conducted using a UV-Visible spectrophotometer, while released K and Cu was analyzed using AAS. XRD showed that the composite had a crystalline structure. The FTIR spectra showed characteristic cross-linking interactions between PVA-glutaraldehyde and Cu-alginate. A study of the release kinetics of zeolite/NPK coated with Cu-alginate-PVA-glutaraldehyde showed that increasing Cu concentration to 0.4 M decreased the amount of nutrition released, and the release process followed the pseudo-second-order kinetics. The release rate constants of N,P,K and Cu in the citric acid medium on zeolite/NPK coated with Cu 0.4 M were 8.49 × 10−3, 17.48 × 10−3, 21.73 × 10−3, and 8.57 × 10−3 mg g−1 h−1, respectively.