Carbohydrate Polymer Technologies and Applications最新文献

Microencapsulation protects lactic acid bacteria against adverse conditions of environment and gastrointestinal tract and increases their survival. This study was conducted with three treatments, namely control, alginate-L. brevis (AL-LAB), and alginate-chitosan-L. brevis (AL-CHI-LAB). The results showed that the zeta-potential for microcapsules fixed by AL-CHI–LAB and AL–LAB were -16.5 and -17.2 mV, respectively. The SEM images showed cubic and non-aggregated structures for three types of microcapsules. The significantly highest survival rate for the AL-CHI-LAB observed in the GIT simulated conditions (59/50 %), and the significantly highest survival rate for the AL-LAB at the in vivo conditions of the GIT (50 %). To investigate SOD and GPX gene expression levels in roosters' testicular tissues, L. brevis was fed (10⁶ CFU/g) to thirty-two roosters aged about 60 weeks for two months. The GPX gene expression level in the testicular tissue was higher in the AL-CHI-LAB (6.57) than other treatments and it was not significantly different from the AL-LAB (4.09). The SOD gene expression was not significantly different among treatments. The results indicated that AL-CHI-LAB could improve the antioxidant capacity of testicular tissues by increasing the GPX gene expression, thereby improving aging-related reproductive performance.

Bletilla striata polysaccharide (BSP) is an extract derived from the rare and valuable Chinese herb Bletilla striata [Thunb.] Reichb. f. Although BSP research has progressed considerably, producing portable BSP dressings with hemostatic efficacy remains challenging. This study describes a novel dressing with a reticulate structure. To create this structure, BSP sponges were cross-linked with chitosan and lyophilized. The resulting BSP sponges had excellent mechanical properties, a high density of pores, and an outstanding capacity for fluid absorption. Both in vitro and in vivo experiments demonstrated that the BSP sponges had excellent hemostatic, antibacterial, and anti-inflammatory properties; they also exhibited good stimulation of cell growth and wound healing properties. Furthermore, they were less likely to provoke complications than traditional materials. Cytocompatibility assays revealed that they also stimulated cell proliferation. Therefore, our study suggests that BSP sponges have promising clinical applications as wound dressings.

Cellulose fibres from rice straw (RS) were obtained by applying a combined and green process consisting of subcritical water extraction (SWE) (at 160 and 180 °C), followed by bleaching with hydrogen peroxide (H₂O₂). The bleaching variables were optimised for both extraction residues (R160 and R180), obtaining optimum conditions for 4 % H₂O₂ at pH 12 for 1 h of reaction. Under these conditions, four successive bleaching cycles were applied to promote cellulose purification in both R160 and R180 lignocellulosic samples, which were characterised as to their yield, whiteness index (WI), chemical composition, microstructural characteristics, degree of crystallinity, and thermal stability. The samples pre-extracted with SWE at 180 °C were more susceptible to bleaching than those pre-treated at 160 °C, being richer in cellulose (86.2 vs. 72.4 %), with higher WI (80.1 vs. 78) and yield (46.2 vs. 36.7 %) after the four bleaching cycles. Likewise, the R180 bleached fractions had higher crystallinity (67 vs. 63%) and were more thermostable than the R160 bleached fibres. Therefore, the SWE at 180 °C, followed by four bleaching cycles with H₂O₂ (4 %, at pH 12, for 1 h), can be considered a green and more sustainable alternative for obtaining cellulose fibres from RS with high cellulose purity.

This study introduces a novel approach to oligosaccharide sensing utilizing hydrophobic interaction-driven fluorescent probes. The design involves three Boron dipyrromethene (BODIPY)-based Oligosaccharide sensing Fluorescent dyes (BOliFluor) with varying hydrophobic moieties synthesized to detect oligosaccharides precisely. The probes demonstrated sensitivity to linear maltooctaose and cyclic β-cyclodextrin, with a distinct response profile. The hydrophobic nature of the benzyl group in BOliFluor 2 enhanced interaction with β-cyclodextrin, resulting in a linear response with a low detection limit of 0.06 mM. In contrast, BOliFluor 1 and 3 exhibited a sigmoidal response according to Hill's equation, F = F_max·cⁿ/(K_d + cⁿ), suggesting a complex interaction mechanism influenced by the conformational flexibility of the recognition groups. The study also explored the impact of chaotropic salts on the binding mode of BOliFluor to β-cyclodextrin, revealing a salt-dependent response. Overall, this research presents a promising strategy for selective oligosaccharide detection through hydrophobic interactions, paving the way for enhanced sensitivity and specificity in this field. The findings contribute to developing a comprehensive analytical method for oligosaccharides, addressing existing challenges in their detection and quantification.

Antibiotics, widely used in human and animal medicine, pose a significant threat to water quality due to their persistent presence even after use. Their insolubility in water and resistance to conventional removal methods exacerbate their environmental impact. This study aimed to develop an antimicrobial composite, alginate-grafted-poly(3-aminophenol)/silver-decorated metal-organic framework (SA-g-P3AP@MOF(Fe)/Ag) via an in-situ copolymerization technique. This composite proved effective in removing neomycin from contaminated water. Characterization via FTIR, XRD, BET, and TGA analyses confirmed the composite's structure and properties. Under optimized conditions (pH = 7, 30-minute contact time, 5 mg adsorbent amount, 25 °C temperature, and 700 mg/L pollutant concentration), the composite removed 87 % of neomycin from water samples. The interaction between neomycin and the composite aligned with the Freundlich isotherm, exhibiting a maximum adsorption capacity (Q_max) of 625 mg/g, and adhered to the pseudo-second-order kinetic. Thermodynamic analysis indicated the exothermic and spontaneous nature of neomycin adsorption onto the synthesized composite. The proposed adsorption mechanism centered on intermolecular interactions between amine, alcohol, and imine functional groups of the SA-g-P3AP@MOF(Fe)/Ag and neomycin antibiotic. The incorporation of MOF(Fe)/Ag with its highly porous structure significantly bolstered neomycin adsorption, enhancing the antibacterial effectiveness of SA-g-P3AP@MOF(Fe)/Ag.

The aim of this work was to develop and characterise nanocomposite thin films containing silver nanoparticles (AgNPs), as wound dressings and antifungal materials, using a green process for the nanoparticles’ synthesis and a single step procedure for the preparation of the nanocomposite films. To this end, polyphenol-rich extracts obtained from kiwi peels, an agri-food industrial by-product, were used as a reducing agent of silver nitrate salt. The AgNPs were let form within the film-forming solution, which was composed by low acyl gellan gum and a plasticising agent (glycerol or PEG 400 g/mol) and the corresponding nanocomposite films were deposited by the solvent casting technique. The plasticising agent affected the AgNPs distribution within the films, as observed by SEM and EDS analyses, and consequently their tensile behaviour. In specific, AgNPs act as stress intensifiers in the presence of glycerol, whereas they act as film reinforcement with PEG₄₀₀. However, both glycerol-plasticised and PEG₄₀₀-plasticised films exhibited similar antifungal efficacy against 16 clinical isolates of 5 different Candida spp (C. albicans, C. lusitaniae, C. haemulonii, C. krusei and C. glabrata). Globally, the present study provides a green and single-step procedure to develop nanocomposite films embedding AgNPs obtained by in situ reduction of silver ions with polyphenol-rich extracts.

This research study focuses on a new magnetic nanobiocomposite designed and synthesized by the formation of cross-linked alginate (Alg) hydrogel using CaCl₂ cross-linker agent, its modification with flaxseed mucilage hydrogel and silk fibroin (SF) biopolymer extracted, and as well, the in-situ synthesis of Fe₃O₄ magnetic nanoparticles (Fe₃O₄ MNPs) in the presence of this biopolymeric substrate. FT-IR, EDX, FE-SEM, XRD, VSM, and TG technical analyses clarified the physical and chemical features of magnetic cross-linked Alg/flaxseed mucilage hydrogel/SF nanobiocomposite. Following the structural characterization of this magnetic natural-based composition, the in-vitro cytotoxicity and hemolysis assay studies with different concentrations resulted in prominent biological outcomes. The survival rates of normal HEK293T cells (95.74%, 94.18%) and breast cancer BT549 cells (79.23%, 77.76%) after 48 and 72 h verified the biocompatibility and anticancer properties of this new nanobiocomposite. Also, less than 5% of the hemolytic effect disclosed its hemocompatibility. Furthermore, a high specific absorption rate value (72.42 W/g) is generated by 1 mg/mL of this magnetic nanobiocomposite. Overall, it can be deduced that magnetic responsive cross-linked Alg/flaxseed mucilage hydrogel/SF nanobiocomposite could functionally perform in magnetic hyperthermia treatment.

In the current work, encapsulation of Lactobacillus reuteri (LR) by double-layer extrusion was investigated. The microencapsulated (bead) wall was prepared with sodium alginate and tomato seed mucilage (TSM) in different concentrations (0.2, 0.4, 0.6, and 0.8 %) as a first and second layer, respectively. The encapsulation efficiency (EE), survival at 72 °C, and cold storage were assessed in beads. The viscosity, acidity, pH, the survivability of LR in simulated gastrointestinal condition (GI), storage time were measured in ketchup sauce. The results showed that EE was 91.54 % for 0.8 % sample. In heat stress conditions, MLR showed a higher survival rate (52.8 %) than FLR (not detected after 4 min). Following the 28th day of cold storage, the survival of the MLR sample (54.08 %) remained higher than the FLR (42.37 %). In ketchup sauce, the survival rates were 57.37 and 51.61 % for MLR and FLR, respectively. In the GI simulating condition, the final survival rates of MLR and FLR samples were 54.93 % and 48.26 %, respectively. The MLR had the more significant value in viscosity (72,864 mPa s⁻¹), and acidity (4 g.100 g⁻¹) but pH was equal among the samples. Therefore, applying alginate and TSM can protect LR from harsh environmental conditions and in ketchup sauce.

Engineered transparent wood (ETW), derived from the modification of natural wood, presents a sustainable and aesthetically pleasing alternative to traditional glass. This review comprehensively explores the burgeoning field of ETW as a novel material for applications in the glass industry. A comprehensive overview of the various methodologies employed in the engineering of transparent wood, encompassing delignification, polymer infiltration, and other innovative techniques is provided. Additionally, the optical, mechanical, and thermal properties of ETW are systematically examined, highlighting its potential advantages over conventional glass materials. The review also discusses recent advancements, challenges, and future considerations of ETW. Furthermore, the review discusses key applications in the glass industry where ETW has demonstrated promising performance, including windows, facades, and decorative elements. Essentially, this review aims to enhance understanding of ETW's potential in glass applications by critically analyzing current research and advancements. It seeks to pave the way for future developments in this innovative and eco-friendly technology.

Polysaccharide derivatives with two types of functionalities were synthesized; reactive groups for click-chemistry approaches and groups that can tune the water solubility of the products. Xylan phenylcarbonates (XPCs) and cellulose phenylcarbonates (CPCs) with degrees of substitution (DS) ranging from 0.6 to 3.0 were prepared as starting materials. In a modular synthesis approach, these carbonate derivatives were converted with different amines to obtain functional xylan carbamates (XCs) and cellulose carbamates (CCs) with (i) reactive alkynyl- or furfuryl groups and / or (ii) hydrophilic hydroxyalkyl or tertiary amino groups. Both types of functionalities were introduced separately or simultaneously in a convenient one-pot-approach. Mixed polysaccharide carbamates with low, intermediate, and high DS values (0.6 to 2.5) were successfully prepared and characterized. The water solubility of the carbamates and mixed carbamates was tuned by variation of the type and DS of the two hydrophilic substituents. Surprisingly, some of the products showed lower or upper critical solution temperatures (LCSTs, UCSTs). Thus, the thermoreversible phase transition in aqueous solutions was studied. The products obtained in this work are very promising for the preparation of hydrogels through selective covalent crosslinking as well as for the fabrication of thermoresponsive biomaterials.