Cellulose is lack of UV-blocking and antibacterial properties, which have limited its application. In this work, the nanoscale lignin with high content of hydroxyl groups and small particle size in ...prehydrolysate was isolated and used as a green reinforcement ingredient for fabrication of cellulose nanofibril (CNF) films with excellent mechanical properties, as well as UV protection and antibacterial capabilities. Cryogenic transmission electron microscopy (Cryo-TEM) and nuclear magnetic resonance analyses showed that the resulting lignin was in the form of nanoparticles (6–12 nm) with high phenolic hydroxyl contents (4.9 mmol/g). The optimum lignin inclusion rate of 5% allowed it to reinforce CNF composite film, increasing its tensile strength from 108.5 to 143.3 MPa. In addition, the film exhibited excellent UV protection capabilities. It blocked 91.5% of UV-A and 99.9% of UV-B light. Finally, the resulting lignin-based CNF films exhibited antibacterial activities against both
Escherichia coli
and
Streptococcus hemolyticus
. This work demonstrates the utility of nanoscale lignin from prehydrolysate can be used to produce cellulose-based composite films with valuable properties.
Lignin–carbohydrate complexes (LCCs) have shown antioxidant ability to scavenge the individual free radicals in vitro, while little work has been carried out to show if the LCCs can efficiently ...scavenge the intracellular and endogenous reactive oxygen species (ROS), which are the multiple radicals derived from the reduction of molecular oxygen during the metabolism process. In this work, carbohydrate-rich LCCs from bamboo (LCCs–B-B) and poplar (LCCs–B-P) were isolated according to the classical method, and their antioxidant activities were evaluated by scavenging intracellular ROS in RAW 264.7 cells in vitro and endogenous ROS in zebrafish in vivo. Results from composition analysis show that both LCC preparations possess similar contents of carbohydrate (52.2% and 51.2%) and lignin (44.1% and 47.8%). However, NMR analysis revealed that the LCCs–B-B contain 16.1/100C9 LCCs linkages, higher than that in LCCs–B-P (12.3/100C9). Antioxidant assays indicated that LCCs–B-B exhibited better antioxidant activities for scavenging the individual free radicals. At the cellular and animal model levels, LCCs–B-B also outperformed the performance of LCCs–B-P in scavenging the endogenous ROS in H2O2-stimulated RAW 264.7 cells in vitro and zebrafish in vivo, which may be due to its better ability to prevent the reduction of antioxidant enzyme activity (superoxide dismutase and glutathione peroxidase) in oxidative stress.
As more and more countries have prohibited the manufacture and sale of plastic products with bisphenol A (BPA), a number of bisphenol analogues (BPs), including BPS, BPF and BPAF, have gradually been ...used as its primary substitutes. Ideally, substitutes used to replace chemicals with environmental risks should be inert, so it makes sense that the risk of the similar chemical substitutes (BPS, BPF, and BPAF) should be assessed before they used. Therefore, in the present study, the neurotoxicity of four BPs at environmentally relevant concentration (200 μg/L) were systematically compared using zebrafish as a model. Our results showed that the four BPs (BPA, BPS, BPF and BPAF) exhibited no obvious effect on the hatchability, survival rate and body length of zebrafish larvae, noteworthily a significant inhibitory effect on spontaneous movement at 24 hpf was observed in the BPA, BPF and BPAF treatment groups. Behavioral tests showed that BPAF, BPF and BPA exposure significantly reduced the locomotor activity of the larvae. Additionally, BPAF treatment adversely affected motor neuron axon length in transgenic lines hb9-GFP zebrafish and decreased central nervous system (CNS) neurogenesis in transgenic lines HuC-GFP zebrafish. Intriguingly, BPAF displayed the strongest effects on the levels and metabolism of neurotransmitters, followed by BPF and BPA, while BPS showed the weakest effects on neurotransmitters. In conclusion, our study deciphered that environmentally relevant concentrations of BPs exposure exhibited differential degrees of neurotoxicity, which ranked as below: BPAF > BPF ≈ BPA > BPS. The possible mechanisms can be partially ascribed to the dramatical changes of multiple neurotransmitters and the inhibitory effects on neuronal development. These results suggest that BPAF and BPF should be carefully considered as alternatives to BPA.
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•BPs reduced locomotion behavior.•BPs decreased central nervous system (CNS) neurogenesis.•BPs adversely affected motor neuron axon length.•BPs caused significant changes in several neurotransmitters.•BPs resulted in neurotoxicity, which ranked as below: BPAF > BPF ≈ BPA > BPS.
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•PVP and EC can be used to fabricate scaffolds by coaxial electrospinning.•The addition of gold nanoparticles improved the porosity and mechanical properties of PVP/EC scaffolds.•Gold ...nanoparticles-loadedPVP/EC coaxial electrospun nanofibers showed great osteogenic bioactivity both in vitro and in vivo.
Biomaterial-based scaffolds fabricated by electrospinning technique are promising platforms for bone tissue engineering. However, the current scaffolds have some limitations in terms of poor osteogenic bioactivities. In this study, citrate-stabilized gold-nanoparticles (GNPs) were encapsulated into polyvinylpyrrolidone/ethylcellulose scaffolds fabricated by coaxial electrospinning technique. Three types of GNPs-loaded electrospun scaffolds (P/E-0.5, P/E-1, and P/E-1.5) were prepared by changing the feeding GNPs. The morphological and physicochemical properties of these GNPs-incorporated electrospun scaffolds were comprehensively characterized. The results demonstrated that GNPs were successfully encapsulated into electrospun scaffolds, and their addition barely affected the morphology but improved the porosity and mechanical properties. In vitro studies revealed that GNPs-incorporated electrospun scaffolds showed excellent biocompatibility and osteogenic bioactivities, wherein the alkaline phosphatase activity, mineralized nodule formation, and the osteogenic-related genes expression were enhanced in GNPs-incorporated electrospun scaffolds compared to the neat P/E electrospun nanofibers. Then, the GNPs-incorporated electrospun scaffolds were surgically implanted into the defect area of the rat skull bone to test their in vivo bone repairing effect. It was observed that GNPs-incorporated scaffolds rapidly accelerated bone regeneration in vivo. Taken together, GNPs-incorporated coaxial electrospun nanofibers might be considered as promising scaffolds in the field of bone tissue regeneration.
•An integrated process for bio-ethanol and XOS productions from straw pulping residue.•Prewashing step greatly improved enzymatic glucose yield and XOS content.•Highly similar ethanol yields were ...obtained from SSF at varied substrate loadings.•Enzymatic post-hydrolysis significantly increased xylobiose and xylotriose.
A bio-refinery process of wheat straw pulping solid residue (waste wheat straw, WWS) was established by combining prewashing and liquid hot water pretreatment (LHWP). The results showed that employing a prewashing step prior to the LHWP remarkably improved enzymatic glucose yields from 39.7% to 76.6%. Moreover, after 96h simultaneous saccharification and fermentation (SSF), identical ethanol yields of 0.41g/g-cellulose were obtained despite varied solid loadings (5–30%). Beyond ethanol, enzymatic post-hydrolysis of the prehydrolyzate effectively increased xylobiose and xylotriose yields from 15mg/g-WWS and 14mg/g-WWS to 53mg/g-WWS and 20mg/g-WWS, respectively. For mass balance, about 10.9tons raw WWS will be consumed to produce 1ton ethanol, in addition to producing 614.8kg xylooligosaccharides (XOS) containing 334.3kg xylobiose and 124.8kg xylotriose. The results demonstrated that the integrated process for the WWS bio-refinery is promising, based on value-adding co-production in addition to robust ethanol yields.
Hemicellulose, one of the most abundant biopolymers next to cellulose, has been considered as a potential substitute to synthetic polymers. Film casting from water is the most basic route for ...material applications of xylan. However, depending on plant sources and separation methods, xylans do not always form films and the related mechanism is unclear, which significantly hinders their material applications. We extensively characterized various fractions of bagasse xylan to understand the molecular features promoting the film formation. The side groups of xylans or impurities contributed to the prevention of excessive aggregation or crystallization of xylan molecules, leading to the film-forming capacity. However, once the film is formed, the side groups do not seem to be necessarily contributing to the mechanical resistance.
Lignin–carbohydrate complexes (LCCs), a significant component of plant cell walls, have been found to bear biological functionality as antioxidants in food and as immunostimulants for living cell. In ...this work, a lignin-rich and a carbohydrate-rich LCCs preparations were isolated from bamboo residues (bamboo green and bamboo yellow). Each preparation was characterized by chemical composition and LCCs linkage types and quantities by high performance anion exchange chromatography (HPAEC) and NMR technologies (quantitative 13C NMR and 2D-HSQC NMR). Furthermore, evaluation of each LCCs preparation’s suitability as antioxidant and immunological substances were explored. Antioxidant assays indicated that all the LCCs preparations exhibited pronounced antioxidant activities for scavenging the 2,2-diphenyl-1-picryl-hydrazyl and hydroxyl radicals, while the lignin-rich LCCs outperformed the carbohydrate-rich LCCs. Immunological analysis showed that carbohydrate-rich LCCs could significantly inhibit the growth of breast tumor cells (MCF-7), while lignin-rich LCCs could stimulate the growth of macrophage cells (RAW 264.7). These results imply that LCCs extracted from bamboo may be used as novel and natural antioxidants or immunostimulants.
Lignosulfonate (LG), a water-soluble polymer from sulfite pulping process of lignocellulosic biomass, has been commercially applied as admixture for concrete. In this work, lignosulfonates were ...produced from alkaline lignin (AL) and enzymatic hydrolysis residue (EHR) by sulfomethylation and these lignosulfonates as water reducers for concrete were then evaluated. Results showed that 94.9% and 68.9% of lignins in AL and EHR could be sulfonated under optimum sulfomethylation conditions, respectively. The sulfonic groups in lignosulfonates from AL (AL-LG) and EHR (EHR-LG) were 1.6 mmol/g and 1.0 mmol/g, respectively. Surface tension and zeta potential analysis indicated that both AL-LG and EHR-LG can be potentially used to as dispersant for improving the fluidity of the cement paste, similarly to commercial lignosulfonate (CM-LG). Adding 0.2 wt % of AL-LG, EHR-LG, and CM-LG in the concrete, the compressive strength (28 days) of concretes increased from 38.4 Mpa to 41.6, 42.6, and 40.9 Mpa, respectively. These findings suggest that the lignosulfonate from biorefinery lignin by sulfomethylation can meet the industrial standards as water reducers for cement admixtures.
Xylo-oligosaccharides (XOS) enriched with high fractions of X2-X3 are regarded as an effective prebiotic for regulating the intestinal microflora. In this study, the original XOS solution was ...obtained from bamboo shoots through hydrothermal pretreatment under optimized conditions. Subsequently, enzymatic hydrolysis with endo-xylanase was performed on the original XOS solution to enhance the abundance of the X2-X3 fractions. The results demonstrated that hydrothermal pretreatment yielded 21.24% of XOS in the hydrolysate solution, and subsequent enzymatic hydrolysis significantly increased the proportion of the X2-X3 fractions from 38.87% to 68.21%. Moreover, the XOS solutions with higher amounts of X2-X3 fractions exhibited superior performance in promoting the growth of probiotics such as Bifidobacterium adolescentis and Lactobacillus acidophilus in vitro, leading to increased production of short-chain fatty acids. In the in vivo colitis mouse model, XOS solutions with higher contents of X2-X3 fractions demonstrated enhanced efficacy against intestinal inflammation. Compared with the colitis mice (model group), the XOS solution with higher X2-X3 fractions (S1 group) could significantly increase the number of Streptomyces in the intestinal microflora, while the original XOS solution (S2 group) could significantly increase the number of Bacteroides in the intestinal microflora of colitis mice. In addition, the abundances of Alcaligenes and Pasteurella in the intestinal microflora of the S1 and S2 groups were much lower than in the model group. This effect was attributed to the ability of these XOS solutions to enhance species diversity, reversing the imbalance and disorder within the intestinal microflora. Overall, this work highlights the outstanding potential of XOS enriched with high contents of X2-X3 fractions as a regulator of the intestinal microbiota and as an anti-colitis agent.
As one of the most abundant natural polymers in nature, polysaccharides have the potential to replace petroleum-based polymers that are difficult to degrade in paper coatings. Polysaccharide ...molecules have a large number of hydroxyl groups that can bind strongly with paper fibers through hydrogen bonds. Chemical modification can also effectively improve the mechanical, barrier, and hydrophobic properties of polysaccharide-based coating layers and thus can further improve the related properties of coated paper. Polysaccharides can also give paper additional functional properties by dispersing and adhering functional fillers, e.g., conductive particles, catalytic particles or antimicrobial chemicals, onto paper surface. Based on these, this paper reviews the application of natural polysaccharides, such as cellulose, hemicellulose, starch, chitosan, and sodium alginate, and their derivatives in paper coatings. This paper analyzes the improvements and influences of chemical structures and properties of polysaccharides on the mechanical, barrier, and hydrophobic properties of coated paper. This paper also summarizes the researches where polysaccharides are used as the adhesives to adhere inorganic or functional fillers onto paper surface to endow paper with great surface properties or special functions such as conductivity, catalytic, antibiotic, and fluorescence.
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