Carbohydrate Polymers最新文献

Chemically crosslinked foams possess good wet mechanical stability, and they are promising systems for applications in oil recovery, water treatment, energy storage, etc. However, reports on the effect of crosslinker length on the physical properties of the foam are scarce. Various cellulose nanofiber (CNF) foams (denoted as CPM) were prepared using different molecular weights dicarboxylated-PEG crosslinkers via the esterification reaction. The effect of PEG chain length on the crosslinking efficiency, mechanical strength, porosity, wettability, and oil recovery performance of the produced foams was elucidated. Additionally, the application potential of CPM 600 foam was explored as a nutrient promoter and water retention platform in the field of sustainable agriculture. This fundamental research could provide guidance for the preparation of high-performance porous materials.

Ulcerative colitis (UC) remains a major challenge in clinical treatment due to its multivariate pathology. Developing an oral formulation that encapsulates and delivers multiple active ingredients to target colon tissues by suppressing intestinal inflammation and restoring the intestinal barrier is crucial for effectively treating UC. Here, we developed rhubarb-derived nanovesicles (RNs) and a supramolecular hydrogel platform formed by furfural-functionalized chitosan-mannose polymer and synthesized 3-maleimide HP-β-CD, with kaempferol (Kae) integrated into the hydrophobic cavity. The hydrogel's cross-linking network effectively encapsulates RNs, forming the Kae/CMCHD@RNs system. Rheology, SEM, TGA, degradation behavior, in vitro drug release, and a macrophage-targeted permeability test were performed. The results indicate that the hydrogel utilizes pH/enzyme sensitivity to ensure sustained release in the colon, while also facilitating targeted delivery to macrophages. In vivo imaging further reveals a prolonged local drug retention time in the colon. Moreover, both in vitro and in vivo studies demonstrate RNs and Kae exhibit synergistic therapeutic effects for UC, including inflammation reduction, oxidative stress alleviation, M1-to-M2 macrophage repolarization, and restoration of the intestinal barrier. Consequently, this study underscores the potential of Kae/CMCHD@RNs as a promising therapeutic approach for managing UC.

Due to the increasing pollution of electromagnetic waves and the vigorous development of intelligent electronic devices, there is great interest in finding high-quality electromagnetic wave absorbing materials for integrated control boxes (ICBs) that integrate various electronic components. Polyaniline (PANI) is a new type of absorbing material with great potential due to its designable structure, simple preparation process, low density and adjustable conductivity. Herein, we prepared BCNF/PANI nanoscale conductive fibers with core-shell structure by in-situ growth of PANI on the surface of bacterial cellulose nanofibers (BCNF) by oxidative polymerization and further prepared cellulose/polyaniline/polyvinyl alcohol (BCNF/PANI/PVA) composite aerogel absorbing material by a freeze-drying process. The results show that the prepared BCNF/PANI/PVA aerogel has excellent absorption performance: the minimum reflection loss is -53.19 dB at 4.16 GHz with 6.11 mm thickness, and the effective absorption bandwidth is 2.20 GHz. The influence of the macrostructure of the BCNF/PANI/PVA absorbing unit on the absorption performance was further explored through numerical simulation, and the efficient electromagnetic protection of the small ICB was finally realized with the help of the macro-optimization strategy. This achievement provides an important reference and guidance for further developing and applying high-performance electromagnetic wave absorbing materials.

Current conventional wound dressings used for wound healing are often characterized by restricted bioactivity and devoid of multifunctionality resulting in suboptimal treatment and prolonged healing. Despite recent advances, the simultaneous incorporation of excellent flexibility, good mechanical performance, self-healing, bioactivity, and adhesion properties into the dressings without complicating their efficacy while maintaining simple synthesis remains a grand challenge. Herein, we effectively synthesized hybrid hydrogels of cellulose nanofiber (CNF), polyvinyl alcohol (PVA), and curcumin-modified silver nanoparticles (cAg) through a one-step synthesis method based on hydrogen bonds, dynamic boronic ester bonds, and coordinate covalent bonds. A flexible high mechanical strength (tensile stress (231 kPa) and compressive stress (1.23 MPa), self-healing, adhesive, yet highly antioxidant and antimicrobial hydrogel (with improved activity against C. albicans, S. aureus, and E. coli) is successfully obtained. Concentric structure of the micropores endows the hydrogels, good biodegradability, and sustained drug release of silver and curcumin. More remarkably, the designed hydrogel dressings not only significantly enhance cell viability (over 98 %) and cell proliferation but also promote angiogenesis, re-epithelialization, and deposition of collagen, all of which signal wound closure and substantiate the therapeutic effect of CNF/PB/cAg hydrogels in chronic wounds. These findings open up new perspectives for the design of wound healing hydrogels and beyond.

This study investigates the application of levan- produced from Paenibacillus polymyxa SG09-12 as an antiviral agent against cucumber mosaic virus (CMV). A high-purity microbial levan was produced and purified using diafiltration. The chemical composition, structure, and functional groups of the levan were characterised using high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Antiviral effects of the levan were evaluated in Nicotiana tabacum plants infected with CMV. Treatment with the purified levan significantly attenuated viral symptoms and reduced viral titres, demonstrating a remarkable, long-lasting antiviral effect and highlighting its potential as an antiviral agent. This antiviral effect may have been mediated by transcriptional activation of disease resistance genes encoding RPP13. These findings enhance the understanding of levan produced by Paenibacillus species and their application as an antiviral defense mechanism, which may contribute towards sustainable and environmentally friendly crop protection strategies.

Consumer demand for nutritional supplements has fueled the rapid growth of the functional food market. However, ensuring the stability of functional factors in harsh environments remains a major challenge. The development of encapsulation systems is regarded as an effective method for enhancing the stability of functional factors, encapsulation carriers can offer protection for these functional factors. However, the selection of materials remains a significant constraint in the construction of delivery systems. Therefore, developing new encapsulation materials is crucial for advancing delivery systems, preserving the stability of functional factors, and ensuring public health. Fucoidan, a sulfated marine polysaccharide, has garnered significant attention in the field of encapsulation due to its notable advantages, including its remarkable bioactivity, biocompatibility, and targeted binding properties. Fucoidan-improved delivery systems provide new strategies for encapsulation of functional factors. This review first describes the structure of fucoidan, its modification and lists the applications of modified fucoidan, and assesses its feasibility for enhancing delivery systems. Second, it summarizes several common encapsulation technologies and methods, and outlines various carrier types based on fucoidan. Finally, it elucidates recent advances in the biomedical applications of fucoidan-improved delivery systems. Notably, it also presents the challenges and future prospects of this promising field.

Xylan-derived packaging materials have gained considerable popularity owing to their renewability, non-toxicity, and biodegradability. However, thermoforming is challenging owing to its rigid structure and hydrogen-bonding network of the xylan molecular chain, which limits its large-scale production. Herein, a heat-processable xylan derivative, xylan cinnamate (XC), was synthesized via an esterification reaction in ionic liquids. The glass transition temperature of XC can be adjusted by the degree of substitution, ranging from 65 to 150 °C. XC plastics can be obtained by hot pressing and exhibit competitive mechanical properties, excellent water resistance, high transparency, and re-processability. Furthermore, the tensile strength of the XC plastics increased from 25 to 50 MPa after 365 nm ultraviolet (UV) irradiation because the double bonds of the cinnamon substituents were photodimerized under UV irradiation. Compared with commercial polyethylene packaging materials, XC plastics have suitable water vapour and oxygen transmittance, effectively protecting seeds under storage conditions. This study developed a novel strategy for preparing recycled xylan thermoplastics.

κ-Carrageenan hydrogels have been prepared at very high concentrations beyond the previous limit of conventional κ-carrageenan hydrogels. By dissolving κ-carrageenan using subcritical water at 150 °C, homogeneous translucent hydrogels have been obtained from 15 wt% to 40 wt%. The high-concentration hydrogels have exceptionally high Young's modulus (E₀) ranging 10⁶-10⁷ Pa and exhibit an unknown concentration (c)-dependence of E₀ ∝ c^1.0-1.1. The distinctive mechanical properties of the high-concentration hydrogels are also demonstrated by modifying the stress (σ)-strain (ε) curves. Curves of σ / E₀ versus ε for the high-concentration hydrogels seem to fall on a single curve that is remarkably different from that for the conventional 3 wt% hydrogel. The gel-to-sol transition temperature (T_m) proves high thermal resistance of the high-concentration hydrogels; T_m increases with c and exceeds 100 °C at 30 wt% and 40 wt%. It has been confirmed that separated pieces of high-concentration hydrogels are unified into a single disk above T_m. The endothermic enthalpy of the gel-to-sol transition per unit weight of κ-carrageenan is almost constant regardless of c among the high-concentration hydrogels, which is consistent with the claim that the high-concentration hydrogels have similar distinctive network structure.

Intestinal injury and microbiota disorder take part in the development of UC. In this research, we obtained an arabinogalactan (LBP-m) from Lycium barbarum and firstly characterized its physicochemical properties. LBP-m was a homogeneous polysaccharide (172 kDa) consisted of Ara, Gal, Glc, GalA, and GlcA with a mole ratio of 1.00: 0.73: 0.18: 0.20: 0.07, and constructed a →6)-β-Galp(1→ backbone with different Araf branches at O-3 position, which exerted as random coil in PBS with single helical structure. Furthermore, oral administration of LBP-m ameliorated the DSS induced UC from different aspects, including regulating barrier dysfunction by promoting the expression of TJs, elevating the anti-oxidative stress capacity through activating the Nrf2/HO-1 pathway, relieving the mucosal inflammation via inhibiting NF-κB pathway. In addition, LBP-m regulated the gut microbiota disorder by reshaping the microbial composition and enhancing the generation of SCFAs. Our research revealed the physicochemical properties of LBP-m and systematically indicated its mitigative effect against DSS induced UC, which could benefit its application in food and pharmacy fields.

The study involves the modification of a non-conventional starch isolated from the under-utilized variety of Chinese water chestnut (CWC (Eleocharis tuberosa) and integrating it to fabricate stabilized and curcumin-enriched Pickering emulsions with enhanced bioavailability, thermal stability, and retention of encapsulated curcumin. A time-efficient, semi-dried esterification method was used to prepare modified amphiphilic starches using 3, 6, or 9 % (w/v) octenyl succinic anhydride (OSA) and characterized through degree of substitution (DS), contact angle, particle size, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and in-vitro digestibility. Moreover, Pickering emulsions were formulated using CWCS-OSA at 3 %, 6 %, or 9 % concentrations to serve as a carrier for curcumin to improve its water solubility and storage stability. The research investigated Pickering emulsions' encapsulation efficiency, curcumin retention, emulsifying properties, micromorphology, temperature stability, and bioaccessibility. Results showed that CWCS-OSA, with an OSA concentration between 3 % and 9 %, exhibited a degree of substitution (DS) ranging from 0.017 to 0.031 and an expansion in contact angle from 68.36^o to 85.45^o. CWCS-9%OSA showed the highest encapsulation efficiency at 89.4 % and maintained an emulsification index above 80 % during a 10-day storage period. A significantly higher bio-accessibility (41.26 ± 1.34 %) of curcumin in Pickering emulsions stabilized with CWCS-9%OSA than in the bulk oil system (19.53 ± 1.62 %). This study highlights the potential of chemically modified amphiphilic starch from an underutilized variety of CWCS (Eleocharis tuberosa) to produce the stabilized Pickering emulsion gels as a stable and effective carrier for unstable hydrophobic polyphenolic compounds by enhancing their bioavailability in the foods and pharmaceutics.