Carbohydrate Polymers最新文献

Alginate films were prepared from the brown seaweed Dictyota mertensii using glycerol as a plasticizer. The effects of extraction conditions-time, temperature, and Na₂CO₃ concentration-on the optical, barrier, and mechanical properties of the films were investigated using a central composite design (CCD). ANOVA and F tests confirmed the models' statistical significance at p ≤ 0.05, 95 % CI. Na2CO3 concentration significantly influenced moisture absorption, water vapor permeability, solubility, opacity, L*, b*, and elongation at break. Temperature mainly affected the color parameter a* and tensile strength, while time was more relevant for the modulus of elasticity. The properties of alginate from Dictyota mertensii were correlated to the film properties. Optimization through numerical desirability function yielded a global desirability index of 0.767, with optimal conditions at 1.390 h, 54.927 °C, and 0.361 mol.L^-1 Na₂CO₃. Under these conditions, the films showed low moisture content (0.277 %), moderate WVP (31.278 g.mm/kPa.m².h), low solubility (18.825 %), appropriate color parameters (Opacity: 12.411 AU.nm/mm, L*: 49.655, a*: 17.680, b*: 44.657), and balanced mechanical properties (TS: 13.270 MPa, EB: 20.638 %, and E: 64.592 MPa). These findings emphasize the potential of alginate films from Dictyota mertensii and promote sustainable use of marine resources.

Superhydrophilic hydrogel was typically used as the membrane coating on various substrates for oil/water separation. Nevertheless, these coatings may suffer from such limitations as poor adhesion strength and abrasion-resistance. Thus, the facile construction of hydrogel sponge with 3D connecting channels would be an ideal choice. Herein, we reported a free-standing polyvinyl alcohol (PVA)/cellulose nanocrystal (CNC) hydrogel sponge for controllable oil/water separation. In the design, the salt/CNC hybrid crystals instead of conventional salt particles were employed as the sacrificial template, thus CNC was creatively integrated into the long and tortuous 3D interconnected channels via the solvent displacement combined template-leaching strategy. The resultant microstructure woven by CNC bundles in sponge channels could alleviate severe pore collapse in leaching process and oil intrusion. Moreover, it could serve as the superhydrophilic "sieve", promoting the separation efficiency significantly. The gravity-based separation efficiencies for PC₅-HL hydrogel sponge in processing of diverse oil/water mixture and oil-in-water emulsions could achieve up to 99.7 and 99.4 %, respectively. In addition, this hydrogel sponge can be used for continuous oil/water separation without obvious decline upon several cycles. This work provides a different way to fabricate the eco-friendly, low-cost and energy-saving filtration hydrogel sponge, showing high potential in oily wastewater treatment.

Cellulose nanocrystals (CNCs) are powerful biosourced nanomaterials for the construction of chiral photonic films. While various techniques have been used to enrich the optical properties of such systems, surface roughness engineering has yet to be exploited to significantly modify their optical properties. In this work, by using vacuum filtration-assisted self-assembly, CNCs are densely packed into films with high optical transparency. Filtration membrane texture-imprinted chiral photonic CNC-based films with engineered surface roughness are demonstrated. Simultaneously optimized optical haze of 99 % and transmittance of 62 % are achieved in the chiral photonic CNC-based films with broadband transmission and tunable structural colors across the visible spectrum. We show experimentally a control over their haze values and the potential of these films to be used as optical diffusers with added advantages in tuning the correlated color temperature in lighting. This simple and yet powerful technique presents possibilities in constructing hazy transparent CNC-based films, paving the way for the development of chiral photonic films from biosourced nanomaterials for optical diffusion applications.

Environmental pH is an important parameter that impacts the growth, reproduction, and carbohydrate metabolism of Aureobasidium spp.. This study identifies the ApGph1 gene (encoded with Glycogen Phosphatase) reflecting significant carbohydrate metabolism difference through transcriptome analysis of Aureobasidium Pullulans YQ65 cultured under different pH. It is subsequently analyzed using the Conserved Domains and Expasy tools. It has been found that compared with its wild type, the △ApGph1 strain exhibits no significant differences in its growth pattern and morphology but a production volume of pullulan inversely proportional to its glycogen content. In addition, through fed-batch fermentation, an over-expressed ApGph1 strain can produce 42.7 g/L of pullulan within 144 h, which is related to the increased expression of key genes involved in pullulan synthesis. The results can provide a guide for the industrial production of pullulan.

The combination of chemotherapy and gene therapy holds promise in treating cancer. A key strategy is to use small interfering RNAs (siRNAs) to silence programmed death-ligand 1 (PD-L1) expression in cancer cells, disrupting tumor immune evasion and enhancing anticancer treatments, particularly when used in conjunction with chemotherapy drugs such as doxorubicin (Dox). However, effective codelivery of drugs and genes requires carefully designed carriers and complex synthesis procedures. To address this challenge, we propose a convenient modular self-assembly system for creating multifunctional micellar carriers that can efficiently codeliver both Dox and siRNA, where micelles are formed by cationic amphiphilic supramolecular architectures that are constructed through host-guest interactions between β-cyclodextrin (β-CD) and adamantane (Ad) to incorporate various functional polymer segments, such as low-molecular-weight polyethylenimine (oligoethylenimine, OEI), poly(ethylene glycol) (PEG), and polycaprolactone (PCL), at adjustable ratios. The supramolecular micellar carrier systems can be easily optimized to achieve excellent structural stability, drug and gene loading, and delivery efficiency, resulting in significant anticancer effects from Dox delivery and simultaneous inhibition of PD-L1 due to the siRNA delivery. Therefore, this modular supramolecular strategy offers a sophisticated, adaptable, and straightforward approach to creating multifunctional micellar carriers, with potential for drug- and gene-based immune-assisted cancer therapy.

Cellulose nanocrystals (CNCs) have emerged as promising, sustainable materials, with applications in sensors, coatings, pharmaceuticals, and composites. Their modification with block copolymers such as PEO-PPO-PEO triblock copolymers of the Pluronic family has been attempted many times in the literature, with claims that such modification would happen by an anchor(PEO)-buoy(PPO)-anchor(PEO) mechanism. However, there is much disagreement in the literature on this. We herein physically adsorbed Pluronic F127, a nontoxic triblock copolymer poloxamer, comprising hydrophilic polyethylene oxide (PEO) and hydrophobic polypropylene oxide (PPO) blocks, onto the surface of TEMPO oxidised CNCs by simple mixing in an aqueous medium. The adsorption of F127 onto the surface of these CNCs was successful and persistent even after solubilisation. The thermal stability of modified TOCNCs increased (by ∼19 °C) compared to their neat and oxidised counterparts. F127-TOCNC suspensions exhibited comparable viscosity to their neat and oxidised counterparts without premature gelation of F127. NOESY NMR observations showed that PPO blocks are more proximal to the TOCNC than the PEO blocks. AFM and QCM-D analyses supported the formation of a rigid, thin layer of block copolymer surrounding the TOCNC. A degree of modification (7 %) was achieved, even after washing, proving that adsorption is persistent and mainly irreversible.

Biomass foam with porous structure has broad application prospects in thermal energy management. However, traditional foams can only passively insulate heat, unable to effectively store thermal energy and prolong the insulation time. In this work, microcapsules rich in paraffin were prepared using the Pickering emulsion template method with phosphorylated cellulose nanocrystals (CNC) as an emulsifier. Phase change microcapsules were combined with konjac glucomannan (KGM) foam to prepare thermal energy management materials with excellent thermal insulation and storage properties. The synergistic interaction between CNC and KGM molecules could form the hydrogen bond cross-linking network to further improve the water resistance and mechanical properties of foams. The encapsulation of CNC microcapsules and the capillary action of KGM foam could effectively inhibit paraffin leakage in the KGM/CNC/paraffin (KCP) foams. Moreover, the enthalpy of melting and crystallization of KCP-8 foam was 144.9 J/g and 141.3 J/g, respectively. The thermal conductivity and infrared thermal imaging results showed that KCP-8 foams exhibited excellent thermal insulation and heat storage properties. This study provides ideas for the design and preparation of porous foams with thermal regulation properties, which has great potential in the field of intelligent textile and building energy conservation.

Cellulose nanofiber/polyacrylic acid (CNF/PAA) hydrogel-based colorimetric sensor was fabricated for non-invasive screening of prostate cancer (PCa) via selective detection of sarcosine. The hydrogel was synthesized by photo-crosslinking of acrylic acid in the presence of CNF which acted as mechanical reinforcement and as color enhancer. The hydrogel exhibited a high aqueous absorption and high mechanical strength. A homogeneous distribution of CNF in the hydrogel was confirmed by TEM. A significant improvement in the compressive modulus and stress in the hydrogel were obtained after the incorporation of 0.25%wt CNF. The hydrogel sensor was integrated within a 3D printing strip on a diaper, and it offered a vivid color change from light yellow to blue for detecting sarcosine for PCa indication with a detection limit starting from 10 μM. The colorimetric results were semi-quantitatively evaluated by a spectrophotometer offering a linear range of 0-100 μM with R² of 0.9901. Furthermore, the increase in CNF content significantly enhanced the sensor's sensitivity toward sarcosine. This sensor could open new avenues for non-invasive screening of prostate cancer in the future.

Human milk oligosaccharides (HMOs) are crucial for promoting neonatal health, with sialylated oligosaccharides, a significant subclass, offering a variety of health benefits such as prebiotic effects, anti-inflammatory and antimicrobial properties, antiviral defense, and cognitive development support. Among these, 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL) have received "GRAS" status from the U.S. Food and Drug Administration and approval from the European Food Safety Authority for use as novel food additives in infant formula and supplements. This review focuses on the synthesis methods of sialylated human milk oligosaccharides (SHMOs), their functional properties, downstreaming developments and application technologies. Given the challenges associated with achieving sufficient availability for food and medical applications, the review emphasizes the viability and efficiency of various production strategies. The review also highlights recent research advancements and offers insights for optimizing large-scale production to support future applications in the food and pharmaceutical industries.

The conventional hydrothermal synthesis and inherent hysteresis behavior limited the application of MOFs owing to the low kinetic efficiency in dynamic molecular adsorption. Herein, we developed an in-situ nucleation strategy for the preparation of MIL-100-Fe and immobilized it with hierarchy porous scaffold of TEMPO oxidized cellulose nanofiber (TCNF) sponge in the absence of additional organic solvent during fabrication under ambient conditions. The newly recognized mechanisms of gradient molecular transfer were proposed to illustrate the comprehensive DCF adsorption process from solution to micropores of MIL-100-Fe at molecule level triggered by the stray capacitance, varied Laplace pressure, size exclusion and cellulosic labyrinth. Additionally, the superior biocompatibility and natural degradability (in 24 h) of MIL@TCNF sponge were demonstrated. The used material could be converted rapidly to zero-valent iron (ZVI) sponge via simple reduction process, achieving both dehalogenation of Diclofenac (DCF) and material regeneration. These findings uncover the propagable mechanisms of molecular-diffusion driven adsorption cascade and provide a novel fabrication strategy of 3-D environmental functional sponge with reusability and biodegradability for water pollution control.