Cellulose最新文献

Biomaterials engineering approaches for treating bone defects involve utilizing a combination of potent bioactive molecules to stimulate cell proliferation, fostering a conducive environment and scaffold for the regeneration process. Due to the aging global population, there is an urgent need for research in bone regeneration and wound healing. Hydroxyapatite (HAP) is a major mineral component of bone tissue with high biocompatibility and bioactivity. Agar and carboxymethyl cellulose (CMC) both exhibit the essential characteristics of biomaterials, either separately or in combination. Hence, this present study aimed to prepare HAP nanoparticles loaded Agar/CMC composite film for enhanced bone regenerative applications. The crystal structure, morphology, phase composition, thermal stability, and chemical state of the film composites were characterized using XRD, SEM, TGA, and FTIR. Cytotoxicity evaluation on rat fibroblasts cells indicated over 90% biocompatibility for the film composites. Moreover, in wound healing assays, the nanocomposite film-treated group (98.14 ± 0.15%) exhibited a 35% higher wound closure rate compared to the negative control group (62.08 ± 1.87%). Alizarin Red Staining assay revealed a 20.89 ± 6.9% increase in calcium deposition in treated MC3T3-E1 cells compared to the negative control, affirming their osteogenic potential. These results demonstrate that the developed nanocomposite film is a promising therapeutic platform for effectively addressing complex bone-related ailments.

This study harnesses the potential of green and rooibos tea (GT and RT) aqueous extracts for obtaining colored bioactive cotton and cotton/flax fabrics with intended applications in medical textiles. The chemical characterization of the tea aqueous extracts was conducted using LC–HRMS/MS analysis, resulting in the detection of 129 bioactive compounds. GT demonstrates 2.2 times higher total phenolic content, a 14.7% lower total flavonoid content, and 3 times higher reducing power than RT. Both extracts exhibit excellent antioxidant activity (> 99.8%) and antibacterial activity (99.99%) against both tested bacteria, E. coli and S. aureus. Cotton and cotton/flax fabrics functionalized with GT or RT display outstanding antioxidant (99.63–100%) and antibacterial activity against S. aureus (90.95–99.33%), and high color strength values (5.48–11.08). The cytotoxicity assay confirmed the non-cytotoxic nature of 100% cotton fabric functionalized with GT. This sample additionally demonstrated an antibacterial reduction against E. coli and S. aureus higher than 99% and the highest release of bioactive compounds rendering it highly suitable for disposable medical textiles-wound dressings. To address the shortcomings of functionalized fabrics observed after washing, including decreased antioxidant activity (55.8–81.0%), diminished bacterial reduction, and reduced color strength values (0.80–1.36), copper-based nanoparticles (CuNPs) were biosynthesized in situ on their surfaces utilizing GT and RT aqueous extracts as reducing agents. The successful fabric decoration with CuNPs was proven by quantifying Cu²⁺ uptake, and characterization of the surface chemical composition and morphology of CuNPs. Colored CuNPs-decorated cotton and cotton/flax fabrics exhibited excellent antioxidant (> 98.28%) and antibacterial (99.99%) activity that remained almost unchanged after washing (94.44–98.90% and 99.99%, respectively). These fabrics are non-cytotoxic and characterized by small quantities of released bioactive compounds and Cu²⁺ ions into the physiological saline solution and hold promise as protective, reusable medical textiles suitable for producing gowns and drapes.

The envelope structure with high light transmittance accounts for an increasing proportion of building energy consumption, which is one of the shortcomings of energy conservation and emission reduction. Cellulose-based aerogel has become a research topic of interest because of its low thermal conductivity and good mechanical properties. However, most cellulose-based aerogels are opaque and flammable limiting their applications. Herein, cellulose/silica composite aerogels (CAS) with "organic–inorganic" structures were fabricated by two-step sol–gel method, spin-coating technique and supercritical CO₂ drying, using the ionic liquid 1-allyl 3-methylimidazolium chloride salt to dissolve the Cotton pulp, followed by the addition of tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) co-precursors into the cellulose gels. The synthesis mechanism, microstructure, mechanical and thermal properties of as-prepared aerogels samples were investigated. The obtained CAS have low density (0.093–0.170 g/cm³), high specific surface area (660.87–1089.70 m²/g), and high mechanical property (compressive strength of 18.74 MPa, tensile strength as high as 1.54 MPa, and bending tests above 500 times). In particular, the CAS4 shows the lowest thermal conductivity (0.0188 W·m⁻¹·K⁻¹), good thermal stability (> 331 °C), high transparency (91.7%) and excellent flame retardancy. In addition, the self-designed aerogels glasses model was placed in a real outdoor environment for 5 h. The results showed that the temperature difference between the inside and outside of the aerogels glasses model was as high as 12 ℃ under the thermal equilibrium state. Thus, the as-prepared high-performance cellulose/silica composite aerogels may increase the role of aerogels glasses in the building envelope and have promising applications in transparent energy-efficient construction and thermal insulation.

Natural dyes extracted from plants have gained increased importance in textile dyeing over the last few years for the development of sustainable chemical processes in the textile industry. In the above research, a novel natural dye was extracted from broccoli vegetables by ultrasonic extraction and subsequently applied to cotton material. The extracted natural dye and dyed cotton samples were characterized via FTIR, thermal, LC–MS, UV resistance and other functional tests, such as analysis of their color characteristics (K/S), fastness and antimicrobial properties. The results showed vibrant shades of green color with K/S values ranging from 0.55 to 2.71. The color fastness of the treated cotton samples ranged from moderately good to excellent. Additionally, the, dyed cotton samples showed greater reductions in the abundance of bacteria against S. aureus and E. coli. Hence, the overall results prove that the natural dye extracted from the vegetable broccoli has excellent dyeing potential for use with cellulosic material, increasing the greenness and sustainability of the process.

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Cellulose derived biochar can be used for adsorbent and photocatalyst mainly because of its good compatibility, high hydrophilicity, and the large amount of electron-rich hydroxy groups. Nevertheless, the impact of the crystal structure of cellulose on the absorption and photocatalytic efficiency of biochar-based composites derived from cellulose remains uncertain. Herein, four different types of biochar derived from cotton (cellulose I_β, II, III, and IV) were individually impregnated with a TiO₂ catalyst through hydrothermal and pyrolysis processes, and were analyzed using various characterization methods. Their adsorption behavior and photocatalytic activities were compared using Congo red and methylene blue dye as the model. The analysis and test outcomes suggested that the crystal structure of cotton cellulose impacted the pore structure and TiO₂ content of biochar-TiO₂ composites to different degrees, resulting in variations in the adsorption and photocatalytic capabilities of biochar-TiO₂ composites. In comparison with cellulose II, III and IV, cellulose I derived biochar-TiO₂ composite had a large specific surface area, a more stable structure, a high aromatic carbon content, and a high TiO₂ loading, resulting in the strong adsorption ability and superior photoactivity to organic dyes. The adsorption and photocatalysis mechanisms were also clarified.

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Research on functional cotton fabrics has been focused on flame retardancy and antibacterial propertie to address the hazard of fire and harmful microorganisms. However, flame retardant and antibacterial treatments face the problems of cumbersome processes and unsatisfactory performance due to compatibility issues between additives and the nondurability of functional cotton fabrics. Herein, we prepared multifunctional cotton fabrics (DAM-CF-Cl) based on surface graft copolymerization of three vinyl monomers, namely diethyl methacryloyl phosphoramidate, 3-allyl-5, 5-dimethylhydantoin (ADMH, N-halamine precursor monomer) and N, N'-methylenebisacrylamide, which exhibited notably enhanced flame retardant, smoke suppression and antibacterial properties compared to the widely adopted complex methods. Compared to control cotton fabrics, the limiting oxygen index of DAM-CF-Cl containing fabrics improved from 18 to 27.6%, and the heat and smoke production of DAM-CF-Cl equipped samples exhibited a conspicuously decreasing tendency in cone calorimetry tests. In addition, due to the introduction of the N-halamine structure of ADMH, the efficient and rapid antibacterial properties of DAM-CF-Cl were confirmed. This work provides a new insight into a convenient method for comprehensive multifunctional treatment of textiles.

Phytic acid as an efficient, green and renewable bio-based flame retardant. However, in view of the large number of toxic fumes generated during combustion and the easy loss of flame retardants, to tackle these issues, the current study employed a straightforward two-step process to generate phytate metal salt wood composites (PAN-M, M = Mg, Cu, Fe, Ai and Ni) in cell walls. Compared with natural wood (Control), PAN-M has good leaching resistance of 15~50%, lower hygroscopicity of 15~30% and improved mechanical strength. The total heat release and smoke emission of PAN-Cu are reduced by 34.54% and 83.05% respectively, the LOI of PAN-Cu is increased by 117%, the smoke density SDR is only 8.38 and the weight gain is 16.9%. This is mainly due to the apparent surface coke protection of metal phytates and catalytic graphitisation of solid residues by metal ions. The improved carbon layer plays an effective insulating role, limiting flue gas emissions, flame retardant loss and water contact. In addition, results show that PAN-Cu can significantly enhance the dehydration effect of carbon compared to other metal ions. Therefore, PAN-M is an efficient, green and sustainable flame retardant for wood.

A casein-methyl cellulose nanocomplex, loaded with curcumin and coated with dextran (DX-CasCur-MC), is designed to enhance curcumin’s oral delivery and inhibit cancer growth. Its physicochemical properties reveal chemical bonding between protein and polysaccharides, transforming curcumin from crystalline into amorphous state to improve water solubility. The encapsulation efficiency of curcumin reaches 92%, and its release profile in physiological and tumor microenvironments exhibits controlled and sustained release. In vitro studies confirm the significant therapeutic efficacy of DX-CasCur-MC in inducing cancer cell death and DNA damage compared to free curcumin. The effectiveness of DX-CasCur-MC for oral drug delivery is validated in simulated gastrointestinal fluids, with 23 and 69% release in gastric and intestinal fluids, respectively. In vivo studies demonstrate a significant reduction in tumor volume in mice treated with DX-CasCur-MC compared to those treated with free curcumin or untreated, confirming DX-CasCur-MC’s ability to improve curcumin’s pharmacological properties and inhibit tumor growth via repeated oral administration. The conjugation of the two polysaccharides with the hydrocolloidal casein nanomicelles improves the nanocomplexes stability, making DX-CasCur-MC a promising natural candidate for oral curcumin delivery with a significant cancer therapeutic efficacy.