Carbohydrate Polymers最新文献

In this study, carbon nanodot (CD)-corn starch (CS) nanocomposite films are fabricated for active food packaging applications. First, ginkgo biloba leaves (GBL) were used as a biomass-derived carbon precursor, and a facile hydrothermal method was employed to synthesise environmentally sustainable CDs. The GBL-derived carbon nanodots (gCDs) were then characterised and incorporated into a CS matrix via an extrusion process to fabricate the CS/gCD nanocomposite film. The effects of various gCD concentrations on the physicochemical and functional properties of CS/gCD composite films were systematically investigated. The gCD exhibited non-cytotoxic effect against human colorectal adenocarcinoma cell line (Caco-2) cells when exposed up to 1000 μg/mL. The incorporation of gCDs into the CS film improved its mechanical properties, with the toughness of the CS/gCD^2% nanocomposite film exhibiting 198 % superiority compared to the CS film. In addition, the oxygen barrier and UV-blocking properties were significantly improved. Furthermore, the CS/gCD nanocomposite film significantly extended the shelf life of ω-3 oils owing to the superior antioxidant activity of the gCDs, exhibiting only 9 meq/kg during the 15-day storage period. Our results suggest that the developed CS/gCD active composite film is a promising candidate for environmentally sustainable solutions to enhance food shelf life and reduce food waste.

The study focus is the valorization of banana agriculture by products by the extraction and derivatization of cellulose and its incorporation in formulations to produce superabsorbent materials endowed with high water absorption performances. The extracted cellulose (BP) was subjected to a controlled oxidation by sodium periodate to convert it to cellulose dialdehyde (DAC) with controlled aldehyde content. The cellulosic materials were incorporated into a suspension containing acrylic acid (AA) and itaconic acid (IA) to produce composite hybrid hydrogels (SA-BP/SA-DAC) by radical chain polymerization in water, using N,N-methylene-bis-acrylamide (MBA) as a cross-linking agent and potassium persulfate (KPS) as an initiator. The prepared materials were characterized using techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and rheological analysis. Additionally, the absorption and re-swelling capacities of the superabsorbent composites (SAPs) were assessed through kinetic studies in water and NaCl solution. Notably, dialdehyde cellulose (DAC), due to its low crystallinity index, hydrophilicity (attributed to aldehyde and hemiacetal functions), and high polarity, holds promise for enhancing the swelling and water retention capacity of the hydrogel. A water absorption capacity as high as 1240±60 g.g-1 was obtained for SA-DAC with a DAC content of 5 %wt. Additionally, the reusability of the SAPs was evidenced.

Thermoresponsive hydrogels can be used as smart flexible sensors. However, the design and facile preparation of multifunctional thermoresponsive hydrogel sensors still face great challenges. Herein, a tunable thermoresponsive, thermochromic and stretchable poly(2-hydroxypropyl acrylate-co-acrylamide) (P(HPA-co-AM))/hydroxypropyl cellulose (HPC)/lithium chloride (LiCl) hydrogel with the networks constructed from non-covalent interaction was fabricated by photopolymerization. PHPA exhibits excellent thermoresponsiveness. HPC endows the hydrogel with outstanding mechanical performance and enhanced temperature-sensitivity. LiCl not only provides good conductivity, but also regulates the lower critical solution temperature (LCST) of the hydrogel. The hydrogel shows tensile strength up to 300 kPa and maximum strain up to 790 %. The LCST value of the hydrogel can be adjusted from 38 to 75 °C. Therefore, the thermoresponsive conductive hydrogel can realize the information encryption, and be used as sensor through strain and temperature changes in the external environment to realize the motion and health detection, and visual signal transmission. This work is expected to provide ideas for the next generation of smart multifunctional electronic skin and information encryption device.

3D printing technology, especially coaxial 3D mode of multiple-component shaping, has great potential in the manufacture of personalized nutritional foods. However, integrating and stabilizing functional objectives of different natures remains a challenge for 3D customized foods. Here, we used starch nanoparticle (SNP) to assisted soy protein (SPI) emulsion to load hydrophilic and hydrophobic bioactives (anthocyanin, AC, and curcumin, Cur). The addition of SNP significantly improved the storage stability of the emulsion. Xanthan gum (XG) was also added to the SNP/SPI system to enhance its rheology and form an emulsion gel as inner core of coaxial 3D printing. Low field nuclear magnetic resonance and emulsification analyses showed that AC/Cur@SNP/SPI/XG functional inner core had a strong water binding state and good stability. After printing with outer layer, the SNP/SPI coaxial sample had the lowest deviation rate of 0.8 %. Also, SNP/SPI coaxial sample showed higher AC (90.2 %) and Cur (90.8 %) retention compared to pure starch (S), pure SNP, pure SPI, and S/SPI samples as well as SNP/SPI sample printed without outer layer. In summary, this study provides a new perspective for the manufacture of customized products as multifunctional foods, feeds and even potential delivery of drugs.

In recent years, active substances have been extensively applied in the fields of food, cosmetics, and pharmaceuticals. However, their preservation and transportation have posed challenges due to issues such as oxidation and photodegradation. This study proposes a method for synthesizing Zein-Hyaluronic Acid (Zein-HA) conjugate particles via the Schiff base reaction, utilizing these conjugate particles to encapsulate and protect active substances within a stable emulsion system. Compared to zein, the modified conjugate particles exhibit significantly improved dispersibility, amphiphilicity, interfacial affinity, and emulsifying properties. Consequently, these particles are capable of stabilizing high internal phase Pickering emulsions with an oil phase volume fraction of up to 80 (v/v)%, thereby enabling the carriage of a higher load of active components. Furthermore, the prepared emulsions demonstrate excellent storage stability, resistance to ionic strength (250–2000 mM NaCl), and outstanding antioxidative characteristics. Moreover, after 8 h of UV light exposure, the retention rates of the active substances (curcumin, astaxanthin, and resveratrol) exceed 60 %. Therefore, these emulsions hold substantial potential to be applied as a carrier system in the food, cosmetics, and pharmaceutical industries.

Effective wound care remains a significant challenge due to the need for infection prevention, inflammation reduction, and minimal tissue damage during dressing changes. To tackle these issues, we have developed a multifunctional hydrogel (CHI/CPBA/RU), composed of chitosan (CHI) modified with 4-carboxyphenylboronic acid (CPBA) and the natural flavonoid, rutin (RU). This design endows the hydrogel with body temperature-responsive adhesion and low temperature-triggered detachment, thus enabling painless removal during dressing changes. The CHI/CPBA/RU hydrogels exhibit excellent biocompatibility, maintaining over 97 % viability of L929 cells. They also demonstrate potent intracellular free radical scavenging activity, with scavenging ratios ranging from 53 % to 70 %. Additionally, these hydrogels show anti-inflammatory effects by inhibiting pro-inflammatory cytokines (TNF-α, IL-6, and iNOS) and increasing anti-inflammatory markers (Arg1 and CD206) in RAW 264.7 macrophages. Notably, they possess robust antimicrobial properties, inhibiting over 99.9 % of the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus growth. In vivo testing on a murine full-thickness skin defect model shows that the hydrogel significantly accelerates wound healing by reducing inflammation, increasing collagen deposition, and promoting angiogenesis, achieving 98 % healing by day 10 compared to 78 % in the control group. These attributes make the polysaccharide-based hydrogel a promising material for advanced wound care.

In this work, phosphorylated cellulosic fibers were functionalized with an aminosilane ((3-aminopropyl)triethoxysilane, APTES) using a simple and economical method. Several characterization were performed to determine the types of bonds between phosphorylated fibers and grafted APTES. The thermal behavior, hydrophobicity and surface charge variation as a function of pH of the multifunctional cellulose fibers were determined.

Results demonstrate that APTES should proceed through Si-O-C, and possibly Si-O-P, covalent bonds with cellulose although the dimerization of silane through Si-O-Si bonds has also been observed. The terminal amino groups are expected to be partially involved in hydrogen bonds with phosphate hydroxyl groups found at phosphorylated cellulose fiber surface, causing a pulling in the configuration of the grafted APTES. The two chemical modifications proposed in this work do not significantly modify the morphology of cellulose fibers. XRD analysis also shows that the crystal structure of the phosphorylated fibers did not change after functionalization with APTES. The silylated phosphorylated fibers show potential flame-retardant properties with improved hydrophobicity. Furthermore, the functionalization of phosphorylated fibers with APTES changes the pH of zero charge point from 3.2 to 9.4 and providing a zwitterionic structure suitable for the simultaneous adsorption of both cationic and anionic species.

Ophthalmic diseases can be presented as acute diseases like allergies, ocular infections, etc., or chronic ones that can be manifested as a result of systemic disorders, like diabetes mellitus, thyroid, rheumatic disorders, and others. Chitosan (CS) and its derivatives have been widely investigated as nanocarriers in the delivery of drugs, genes, and many biological products. The biocompatibility and biodegradability of CS made it a good candidate for ocular delivery of many ingredients, including immunomodulating agents, antibiotics, ocular hypertension medications, etc. CS-based nanosystems have been successfully reported to modulate ocular diseases by penetrating biological ocular barriers and targeting and controlling drug release. This review provides guidance to drug delivery formulators on the most recently published strategies that can enhance drug permeation to the ocular tissues in CS-based nanosystems, thus improving therapeutic effects through enhancing drug bioavailability. This review will highlight the main ocular barriers to drug delivery observed in the nano-delivery system. In addition, the CS physicochemical properties that contribute to formulation aspects are discussed. It also categorized the permeation enhancement strategies that can be optimized in CS-based nanosystems into four aspects: CS-related physicochemical properties, formulation components, fabrication conditions, and adopting a novel delivery system like implants, inserts, etc. as described in the published literature within the last ten years. Finally, challenges encountered in CS-based nanosystems and future perspectives are mentioned.

Selenium nanoparticles (SeNPs) possess unique features with excellent bioavailability and bioactivity, but the poor stability limits its application. A combination of polysaccharides and SeNPs is an effective strategy to overcome the limitation. Herein, a heteropolysaccharide (SVL-3) with an average molecular weight of 2.428 × 10⁴ Da was purified from the fruiting body residue of Sanghuangporus vaninii after soaking in sorghum wine, which was composed of fucose, galactose, glucose, fructose and 3-O-methyl-galactose. The main chain of SVL-3 was composed of →6)-α-3-MeO-Galp-(1→, →4)-α-D-Galp-(1→, →2,6)-β-D-Glcp-(1 → and →3)-α-D-Glcp-(1→, and the branched chain was composed of →4)-α-D-Xylp-(1 → and α-L-Fucp-(1→. For enhancing bioactivity of SVL-3 and stability of SeNPs, SVL-3-functionalized SeNPs (SVL-3-SeNPs) was prepared, which contained 45.31 % polysaccharide and 48.49 % selenium. SVL-3-SeNPs maintained an emphatic stability over 28 days at 4 °C and pH 6–8, and exhibited a higher cytotoxic effect on MCF-7 cells than SVL-3 and SeNPs. The inhibitory effect of SVL-3-SeNPs on the cancer cells may be associated with the mechanisms by inducing S-phase arrest, triggering apoptosis and elevating the protein levels of Cytochrome c, Caspases and cleaved caspases 3 and 9. These results indicated that SeNPs modified by S. vaninii polysaccharides can be utilized as a potential material for targeted antitumor drugs.

Cellulose is a major renewable resource for a wide variety of sustainable industrial products. However, for its utilization, finding new efficient enzymes for plant cell wall depolymerization is crucial. In addition to microbial sources, cellulases also exist in plants, however, are less studied. Fleshy fruit ripening includes enzymatic cell wall hydrolysis, leading to tissue softening. Therefore, bilberry (Vaccinium myrtillus L.), which produces small fruits that undergo extensive and rapid softening, was selected to explore cellulases of plant origin. We identified 20 glycoside hydrolase family 9 (GH9) cellulases from a recently sequenced bilberry genome, including four of which showed fruit ripening-specific expression and could be associated with fruit softening based on phylogenetic, transcriptomic and gene expression analyses. These four cellulases were secreted enzymes: two B-types and two C-types with a carbohydrate binding module 49. For functional characterization, these four cellulases were expressed in Pichia pastoris. All recombinant enzymes demonstrated glucanase activity toward cellulose and hemicellulose substrates. Particularly, VmGH9C1 demonstrated high activity and ability to degrade cellulose, xyloglucan, and glucomannan. In addition, all the enzymes retained activity under wide pH (6–10) and temperature ranges (optimum 70 °C), revealing the potential applications of plant GH9 cellulases in the industrial bioprocessing of lignocellulose.