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1.
J Environ Sci (China) ; 147: 474-486, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003063

RESUMO

Nano zero-valent iron (nZVI) is widely used in soil remediation due to its high reactivity. However, the easy agglomeration, poor antioxidant ability and passivation layer of Fe-Cr coprecipitates of nZVI have limited its application scale in Cr-contaminated soil remediation, especially in high concentration of Cr-contaminated soil. Herein, we found that the carboxymethyl cellulose on nZVI particles could increase the zeta potential value of soil and change the phase of nZVI. Along with the presence of biochar, 97.0% and 96.6% Cr immobilization efficiency through CMC-nZVI/BC were respectively achieved in high and low concentrations of Cr-contaminated soils after 90-days remediation. In addition, the immobilization efficiency of Cr(VI) only decreased by 5.1% through CMC-nZVI/BC treatment after 10 weeks aging in air, attributing to the strong antioxidation ability. As for the surrounding Cr-contaminated groundwater, the Cr(VI) removal capacity of CMC-nZVI/BC was evaluated under different reaction conditions through column experiments and COMSOL Multiphysics. CMC-nZVI/BC could efficiently remove 85% of Cr(VI) in about 400 hr when the initial Cr(VI) concentration was 40 mg/L and the flow rate was 0.5 mL/min. This study demonstrates that uniformly dispersed CMC-nZVI/BC has an excellent remediation effect on different concentrations of Cr-contaminated soils.


Assuntos
Carboximetilcelulose Sódica , Carvão Vegetal , Cromo , Recuperação e Remediação Ambiental , Ferro , Poluentes do Solo , Poluentes do Solo/química , Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Ferro/química , Cromo/química , Carboximetilcelulose Sódica/química , Solo/química , Nanopartículas Metálicas/química
2.
Mol Pharm ; 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39088435

RESUMO

Amorphous solid dispersion (ASD) in a polymer matrix is a powerful method for enhancing the solubility and bioavailability of otherwise crystalline, poorly water-soluble drugs. 6-Carboxycellulose acetate butyrate (CCAB) is a relatively new commercial cellulose derivative that was introduced for use in waterborne coating applications. As CCAB is an amphiphilic, carboxyl-containing, high glass transition temperature (Tg) polymer, characteristics essential to excellent ASD polymer performance, we chose to explore its ASD potential. Structurally diverse drugs quercetin, ibuprofen, ritonavir, loratadine, and clarithromycin were dispersed in CCAB matrices. We evaluated the ability of CCAB to create ASDs with these drugs and its ability to provide solubility enhancement and effective drug release. CCAB/drug dispersions prepared by spray drying were amorphous up to 25 wt % drug, with loratadine remaining amorphous up to 50% drug. CCAB formulations with 10% drug proved effective at providing in vitro solubility enhancement for the crystalline flavonoid drug quercetin as well as ritonavir, but not for the more soluble APIs ibuprofen and clarithromycin and the more hydrophobic loratadine. CCAB did provide slow and controlled release of ibuprofen, offering a simple and promising Long-duration ibuprofen formulation. Formulation with clarithromycin showed the ability of the polymer to protect against degradation of the drug at stomach pH. Furthermore, CCAB ASDs with both loratadine and ibuprofen could be improved by the addition of the water-soluble polymer poly(vinylpyrrolidone) (PVP), with which CCAB shows good miscibility. CCAB provided solubility enhancement in some cases, and the slower drug release exhibited by CCAB, especially in the stomach, could be especially beneficial, for example, in formulations containing known stomach irritants like ibuprofen.

3.
Biopolymers ; : e23619, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115118

RESUMO

This research explores the integration of corn husk nanocellulose (CHNc) and pineapple leaf nanocellulose (PLNc) as reinforcing agents in a carboxymethyl cellulose-based film derived from durian husk (CMCDH). Through a solvent-casting method, composite films were fabricated with varying nanocellulose contents (15, 30, and 45 wt%). Analysis using Fourier transform infrared spectroscopy and x-ray diffraction confirmed the effectiveness of alkaline and bleaching treatments in eliminating noncellulosic components. Transmission electron microscopy image revealed the rod-like morphology of CHNc and PLNc, with dimensions approximately 206.5 × 7.2 nm and 150.7 × 6.5 nm, respectively. The inclusion of nanocellulose decreased the transparency of CMCDH films while enhancing their tensile strength, thermal stability, and water vapor transmission rate. Notably, CMCDH/PLNc(30%) exhibited the highest tensile strength at 5.06 ± 0.83 MPa, representing a remarkable 220% increase compared to CMCDH biofilm. Thermogravimetric analysis and differential scanning calorimeter results indicated that nanocellulose incorporation delayed the film's decomposition temperature by approximately 10°C. Moreover, CMCDH/PLNc(30%) demonstrated the lowest water vapor transmission rate, marking a 20% improvement. However, the film's properties were compromised at the highest nanocellulose content (45 wt%) due to observed fiber aggregation, as revealed by scanning electron microscopy analysis.

4.
Small Methods ; : e2400447, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115353

RESUMO

Various fascinating optical characteristics in organisms encourage scientists to develop biomimetic synthesis strategies and mimic their unique microstructure. Inspired by the Chameleon's skin with tunable color and superior flexibility, this work designs the evaporated-induced self-assembly technique to synthesize the chiral photonic crystal film. Ultrasonic-intensified and additive-assisted techniques synergistically optimize the film properties, on the aspects of optic and mechanic. The film shows considerable rigidity and superior flexibility, which can undergo multiple mechanical deformations. Without destroying the chiral nematic structure, the ultimate strain approaches 50%, which exceeds most cellulose-derived film materials. It also integrates excellent optical performance. The film color can cover the total visible region by tuning the photonic bandgap and has angle-dependent properties. It can make the response to humidity and solvents, and chromaticity variation reflects the degree of stimulation. Importantly, this structural-dependent color change is reversible. Lastly, the photonic crystal materials with excellent mechanics and unique optics have been applied in the security. The anti-counterfeiting material design contains photonic crystal ink, repeatable writing paper, information-hiding film, and color-changing labels, with the features of environmentally friendly, economical, non-destructive, and convenient for authentication.

5.
Bioact Mater ; 41: 15-29, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39101028

RESUMO

Fungal corneal ulcer is one of the leading causes of corneal blindness in developing countries. Corneal scars such as leukoplakia are formed due to inflammation, oxidative stress and non-directed repair, which seriously affect the patients' subsequent visual and life quality. In this study, drawing inspiration from the oriented structure of collagen fibers within the corneal stroma, we first proposed the directional arrangement of CuTA-CMHT hydrogel system at micro and macro scales based on the 3D printing extrusion method combined with secondary patterning. It played an antifungal role and induced oriented repair in therapy of fungal corneal ulcer. The results showed that it effectively inhibited Candida albicans, Aspergillus Niger, Fusarium sapropelum, which mainly affects TNF, NF-kappa B, and HIF-1 signaling pathways, achieving effective antifungal functions. More importantly, the fibroblasts interacted with extracellular matrix (ECM) of corneal stroma through formation of focal adhesions, promoted the proliferation and directional migration of cells in vitro, induced the directional alignment of collagen fibers and corneal stromal orthogonally oriented repair in vivo. This process is mainly associated with MYLK, MYL9, and ITGA3 molecules. Furthermore, the downregulation the growth factors TGF-ß and PDGF-ß inhibits myofibroblast development and reduces scar-type ECM production, thereby reducing corneal leukoplakia. It also activates the PI3K-AKT signaling pathway, promoting corneal healing. In conclusion, the oriented CuTA-CMHT hydrogel system mimics the orthogonal arrangement of collagen fibers, inhibits inflammation, eliminates reactive oxygen species, and reduces corneal leukoplakia, which is of great significance in the treatment of fungal corneal ulcer and is expected to write a new chapter in corneal tissue engineering.

6.
Artigo em Inglês | MEDLINE | ID: mdl-39102587

RESUMO

The proliferation of misleading information and counterfeit products in conjunction with technical progress presents substantial worldwide issues. To address the issue of counterfeiting, many tactics, such as the use of luminous anticounterfeiting systems, have been investigated. Nevertheless, traditional fluorescent compounds have a restricted effectiveness. Cellulose nanocrystals (CNCs), known for their renewable nature and outstanding qualities, present an excellent opportunity to develop intelligent, optically active materials formed due to their self-assembly behavior and stimuli response. CNCs and their derivatives-based self-assemblies allow for the creation of adaptable luminous materials that may be used to prevent counterfeiting. These materials integrate the photophysical characteristics of optically active components due to their stimuli-responsive behavior, enabling their use in fibers, labels, films, hydrogels, and inks. Despite substantial attention, existing materials frequently fall short of practical criteria due to limited knowledge and poor performance comparisons. This review aims to provide information on the latest developments in anticounterfeit materials based on stimuli-responsive CNCs and derivatives. It also includes the scope of artificial intelligence (AI) in the near future. It will emphasize the potential uses of these materials and encourage future investigation in this rapidly growing area of study.

7.
ACS Infect Dis ; 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39105738

RESUMO

When coordinating and adhering to a surface, microorganisms produce a biofilm matrix consisting of extracellular DNA, lipids, proteins, and polysaccharides that are intrinsic to the survival of bacterial communities. Indeed, bacteria produce a variety of structurally diverse polysaccharides that play integral roles in the emergence and maintenance of biofilms by providing structural rigidity, adhesion, and protection from environmental stressors. While the roles that polysaccharides play in biofilm dynamics have been described for several bacterial species, the difficulty in isolating homogeneous material has resulted in few structures being elucidated. Recently, Cegelski and co-workers discovered that uropathogenic Escherichia coli (UPEC) secrete a chemically modified cellulose called phosphoethanolamine cellulose (pEtN cellulose) that plays a vital role in biofilm assembly. However, limited chemical tools exist to further examine the functional role of this polysaccharide across bacterial species. To address this critical need, we hypothesized that we could design and synthesize an unnatural glycopolymer to mimic the structure of pEtN cellulose. Herein, we describe the synthesis and evaluation of a pEtN cellulose glycomimetic which was generated using ring-opening metathesis polymerization. Surprisingly, the synthetic polymers behave counter to native pEtN cellulose in that the synthetic polymers repress biofilm formation in E. coli laboratory strain 11775T and UPEC strain 700415 with longer glycopolymers displaying greater repression. To evaluate the mechanism of action, changes in biofilm and cell morphology were visualized using high resolution field-emission gun scanning electron microscopy which further revealed changes in cell surface appendages. Our results suggest synthetic pEtN cellulose glycopolymers act as an antiadhesive and inhibit biofilm formation across E. coli strains, highlighting a potential new inroad to the development of bioinspired, biofilm-modulating materials.

8.
Nano Lett ; 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39105760

RESUMO

Assembling active materials into dense electrodes is a promising way to obtain high-volumetric-capacitance supercapacitors, but insufficient ion channels in the dense structure lead to a low rate capability. Herein, a dense and robust wood electrode with a large MXene volumetric mass loading (1.25 g cm-3) and abundant ion diffusion channels is designed via a facile capillary-force-driven self-densification strategy. Specifically, MXene is assembled onto a wood cell wall, endowing the wood electrode with good electrical conductivity (86 S cm-1) and high electrochemical activity (5.9 F cm-2 at 1 mA cm-2). Notably, the oriented channels along with spaces between adjacent microfibrils recast after densification ensure efficient ion transport for the wood electrode, achieving an excellent rate capability with a high capacitance retention of 77% from 1 to 20 mA cm-2. Meanwhile, the capillary force induces self-densification on the softened wood cell wall, resulting in a highly compact and robust structure for the wood electrode.

9.
Int J Biol Macromol ; 277(Pt 3): 134169, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39097057

RESUMO

The uncontrolled administration of the cisplatin drug (CPTN) resulted in numerous drawbacks. Therefore, effective, affordable, and biocompatible delivery systems were suggested to regulate the loading, release, and therapeutic effect of CPTN. Zinc phosphate/hydroxyapatite hybrid form (ZP/HP) and core-shell nano-rod morphology, as well as its functionalized derivative with cellulose (CF@ZP/HP), were synthesized by the facile dissolution precipitation method followed by mixing with cellulose fibers, respectively. The developed CF@ZP/HP displayed remarkable enhanced CPTN loading properties (418.2 mg/g) as compared to ZP/HP (259.8 mg/g). The CPTN loading behaviors into CF@ZP/HP follow the Langmuir isotherm properties (R2 > 0.98) in addition to the kinetic activities of the pseudo-first-order model (R2 > 0.96). The steric assessment validates the notable increase in the existing loading receptors after the functionalization of ZP/HP with CF from 57.7 mg/g (ZP/HP) to 90.5 mg/g. The functionalization also impacted the capacity of each existing receptor to be able to ensure 5 CPTN molecules. This, in addition to the loading energies (<40 kJ/mol), donates the loading of CPTN by physical multi-molecular processes and in vertical orientation. The CPTN releasing patterns of CF@ZP/HP exhibit slow and controlled properties (95.7 % after 200 h at pH 7.4 and 100 % after 120 h at pH 5.5), but faster than the properties of ZP/HP. The kinetic modeling of the release activities together with the diffusion exponent (>0.45) reflected the release of CPTN according to both erosion and diffusion mechanisms. The loading of CPTN into both ZP/HP and CF@ZP/HP also resulted in a marked enhancement in the anticancer activity of CPTN against human cervical epithelial malignancies (HeLa) (cell viability = 5.6 % (CPTN), 3.2 % (CPTN loaded ZP/HP), and 1.12 % (CPTN loaded CF@ZP/HP)).

10.
Int J Biol Macromol ; 277(Pt 3): 134401, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39097049

RESUMO

An imbalance between energy intake and energy expenditure predisposes obesity and its related metabolic diseases. Soluble dietary fiber has been shown to improve metabolic homeostasis mainly via microbiota reshaping. However, the application and metabolic effects of insoluble fiber are less understood. Herein, we employed nanotechnology to design citric acid-crosslinked carboxymethyl cellulose nanofibers (CL-CNF) with a robust capacity of expansion upon swelling. Supplementation with CL-CNF reduced food intake and delayed digestion rate in mice by occupying stomach. Besides, CL-CNF treatment mitigated diet-induced obesity and insulin resistance in mice with enhanced energy expenditure, as well as ameliorated inflammation in adipose tissue, intestine and liver and reduced hepatic steatosis, without any discernible signs of toxicity. Additionally, CL-CNF supplementation resulted in enrichment of probiotics such as Bifidobacterium and decreased in the relative abundances of deleterious microbiota expressing bile salt hydrolase, which led to increased levels of conjugated bile acids and inhibited intestinal FXR signaling to stimulate the release of GLP-1. Taken together, our findings demonstrate that CL-CNF administration protects mice from diet-induced obesity and metabolic dysfunction by reducing food intake, enhancing energy expenditure and remodeling gut microbiota, making it a potential therapeutic strategy against metabolic diseases.

11.
Int J Biol Macromol ; 277(Pt 3): 134294, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39102925

RESUMO

Despite the significant properties of fossil plastics, the current unsustainable methods employed in production, usage and disposal present a grave threat to both energy and environment. The development of degradable biomass materials as substitutes for fossil plastics can effectively address the energy-environment paradox at the source. Here, we prepared novel micro-nano multiscale composite films through assembling and crosslinking nanocellulose with coniferous wood pulp microfibers. The composite film combines the advantages of microfibers and nanocellulose, achieving a maximum transmittance of 91 %, foldability, excellent mechanical properties (tensile strength: 51.3 MPa, elongation at break: 4 %, young's modulus: 3.4 GPa), high thermal stability and complete degradation within 40 days. The composite film exhibits mechanochemical self-healing and retains properties even after fracture. Such exceptional performance fully meets the requirements for substituting petroleum plastics. By incorporating CaAlSiN3:Eu2+ into the composite film, it enables dual emission of red and blue light, thereby being able to promote plant growth and presenting potential as a novel sustainable alternative for agricultural films. By assembling microfiber and nanocellulose, such novel strategy is presented for the fabrication of high-quality biomass materials, thereby offering a promising avenue towards environment-friendly resource-sustainable new materials.

12.
Bioresour Technol ; 408: 131204, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39102965

RESUMO

The synthetic superabsorbent polymers (SAPs) market is experiencing significant growth, with applications spanning agriculture, healthcare, and civil engineering, projected to increase from $9.0 billion USD in 2019 to $12.9 billion USD by 2024. Despite this positive trend, challenges such as fluctuating raw material costs and lower biodegradability of fossil fuel-based SAPs could impede further expansion. In contrast, cellulose and its derivatives present a sustainable alternative due to their renewable, biodegradable, and abundant characteristics. Lignocellulosic biomass (LCB), rich in cellulose and lignin, shows promise as a source for eco-friendly superabsorbent polymer (SAP) production. This review discusses the applications, challenges, and future prospects of SAPs derived from lignocellulosic resources, focusing on the cellulose extraction process through fractionation and various modification and crosslinking techniques. The review underscores the potential of cellulose-based SAPs to meet environmental and market needs, offering a viable path forward in the quest for more sustainable materials.

13.
Int J Biol Macromol ; 277(Pt 4): 134337, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39111482

RESUMO

Hydrogels as skin wound dressings have been extensively studied owing to their good flexibility and biocompatibility. Nevertheless, the mechanical performance, adhesive capability, antifouling and antibacterial properties of conventional hydrogels are still unsatisfactory, which hinder the application of hydrogel for cutaneous healing. Here, we developed a novel biocompatible multifunctional hydrogel with super flexible, fatigue resistant, antifouling and self-adhesive capability for effective wound healing, where naturally rigid polymers including quaternized chitosan (QCS) and Tunicate cellulose nanocrystals (TCNCs) are used as bioactive cross-linkers and reinforcers to endow the hydrogel with excellent mechanical and antibacterial property, and the synergistic contributions from the poly(acrylic acid/methacrylate anhydride dopamine/sulfobetaine methacrylate) (poly(AA/DMA/SBMA)) chains and QCS endow the hydrogel with excellent adhesive property, antioxidant, antifouling and pH-responsive sustained drug release capabilities. The optimized hydrogel exhibited high tensile strength (77.69 KPa), large tensile strain (889.9 %), large toughness (307.51KJ.m-3), high adhesive strength (35.57 KPa) and ideal compressive property. The in vivo infected full-thickness skin model demonstrated that the hydrogel with vanvomycin sustained release ability efficiently improved the granulation tissue formation, facilitating collagen deposition and reducing inflammatory expression, thus effectively accelerating wound healing. This superiorly skin-adhesive antibacterial biocompatible hydrogel appears to be a promising candidate for wound therapy.

14.
Heliyon ; 10(14): e34180, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39114082

RESUMO

This study evaluates the mechanical properties and formulation of dental restoration material comprised of cellulose acetate (CA) from water hyacinth and chitosan (C) from white shrimp shells. The research phases included extraction, formulation, functional group testing, antibacterial, toxicity, water absorption and solubility, compressive, shear, tensile, hardness, microleakage, thermal expansion, and shrinkage. The experimental data were analyzed using probit regression, one-way ANOVA, and Kruskal-Wallis test. The data showed that CA and C had microxyl and amine groups, could inhibit S. mutans, and were non-toxic. Composite resins were divided into nine formulations with different concentrations: F1 (1 % CA + 3 % C), F2 (1 % CA + 5 % C), F3 (1 % CA + 7 % C), F4 (3 % CA + 3 % C), F5 (3 % CA + 5 % C), F6 (3 % CA + 7 % C), F7 (5 % CA + 3 % C), F8 (5 % CA + 5 % C), and F9 (5 % CA + 7 % C). The F9 has mechanical strength close to the control group, with 113.33 µg/mm3 absorption, 80 µg/mm3 solubility, 32.67 Mpa compressive strength, 17.18 Mpa tensile strength, and no shrinkage. It shows that F9 has potential as an eco-friendly dental filling material. The present study completed the development of a formulation for a restoration material by combining water hyacinth fiber and shrimp skin chitosan. The outcomes of a comparative analysis of the mechanical properties of synthetic composite resins and water hyacinth fiber composites containing shrimp skin chitosan revealed that the F9 formulation (CA 5 % + C 7 %) exhibited the following fiber: absorption, compressive strength, tensile strength, hardness, and thermal expansion.

15.
Infect Drug Resist ; 17: 3353-3365, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39131519

RESUMO

Introduction: Patients who need to be readmitted to the hospital because of complications from infections or require long-term care and rehabilitation face substantial financial hardships. To ensure the safety of patients undergoing surgery, it is crucial to implement measures that prevent wound infections before and after the procedure. Antibacterial wound dressings are essential to prevent infections during surgical procedures. There are various types of antibacterial wound dressings available on the market, such as silver-based dressings, hydrocolloid dressings, polyhexamethylene biguanide, alginate dressings, collagen-based dressings, and iodine-based dressings. Methods: We used each type (standard, knit, fibril, and non-woven) of a commercial brand of oxidized regenerated cellulose (ORC) called Regecel to test bacterial growth. The choice of antibacterial wound dressing depends on the type of wound being treated. Different bacterial strains require specific culture conditions to thrive and grow in laboratory settings. To obtain accurate and reliable results, it is vital to follow the precise culture conditions required for each bacterial strain. Results: The evaluation of ORC highlighted its potential to inhibit bacterial growth, showing promising results against various bacterial strains and Candida albicans. Different variants of ORC, such as Regecel, have demonstrated impressive capacity to hinder the growth of 32 distinct bacterial strains, with inhibition rates ranging from 40-100%. These bacteria include methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and penicillin-resistant Streptococcus pneumoniae. Conclusion: This study supports the usage and development of ORC (Regecel) as an innovative approach to treating bacterial infections.

16.
ACS Nano ; 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39137301

RESUMO

Chiral architectures, one of the key structural features of natural systems ranging from the nanoscale to macroscale, are an infinite source of inspiration for functional materials. Researchers have been, and still are, strongly pursuing the goal of constructing such structures with renewable and sustainable building blocks via simple and efficient strategies. With the merits of high sustainability, renewability, and the ability to self-assemble into chiral nematic structures in aqueous suspensions that can be preserved in the solid state, polysaccharide nanocrystals (PNs) including cellulose nanocrystals (CNCs) and chitin nanocrystals (ChNCs) offer opportunities to reach the target. We herein provide a comprehensive review that focuses on the development of CNCs and ChNCs for the use in advanced functional materials. First, the introduction of CNCs and ChNCs, and cellulose- and chitin-formed chiral nematic organizations in the natural world, are given. Then, the self-assembly process of such PNs and the factors influencing this process are comprehensively discussed. After that, we showcased the emerging applications of the self-assembled chiral nematic structures of CNCs and ChNCs. Finally, this review concludes with perspectives on the challenges and opportunities in this field.

17.
Artigo em Inglês | MEDLINE | ID: mdl-39137951

RESUMO

Anisotropic cellulose nanofiber (CNF) foams represent the state-of-the-art in renewable insulation. These foams consist of large (diameter >10 µm) uniaxially aligned macropores with mesoporous pore-walls and aligned CNF. The foams show anisotropic thermal conduction, where heat transports more efficiently in the axial direction (along the aligned CNF and macropores) than in the radial direction (perpendicular to the aligned CNF and macropores). Here we explore the impact on axial and radial thermal conductivity upon depositing a thin film of reduced graphene oxide (rGO) on the macropore walls in anisotropic CNF foams. To obtain rGO films on the foam walls we developed liquid-phase self-assembly to deposit rGO in a layer-by-layer fashion. Using electron and ion microscopy, we thoroughly characterized the resulting rGO-CNF foams and confirmed the successful deposition of rGO. These hierarchical rGO-CNF foams show lower radial thermal conductivity (λr) across a wide range of relative humidity compared to CNF control foams. Our work therefore demonstrates a potential method for improved thermal insulation in anisotropic CNF foams and introduces versatile self-assembly for postmodification of such foams.

18.
Sci Rep ; 14(1): 18784, 2024 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-39138250

RESUMO

Previously, we constructed engineered M. circinelloides strains that can not only utilize cellulose, but also increase the yield of γ-linolenic acid (GLA). In the present study, an in-depth analysis of lipid accumulation by engineered M. circinelloides strains using corn straw was to be explored. When a two-stage temperature control strategy was adopted with adding 1.5% cellulase and 15% inoculum, the engineered strains led to increases in the lipid yield (up to 1.56 g per 100 g dry medium) and GLA yield (up to 274 mg per 100 g dry medium) of 1.8- and 2.3-fold, respectively, compared with the control strain. This study proved the engineered M. circinelloides strains, especially for Mc-C2PD6, possess advantages in using corn straw to produce GLA. This work provided a reference for transformation from agricultural cellulosic waste to functional lipid in one step, which might play a positive role in promoting the sustainable development of biological industry.


Assuntos
Celulose 1,4-beta-Celobiosidase , Fermentação , Mucor , Zea mays , Zea mays/metabolismo , Mucor/genética , Mucor/metabolismo , Mucor/enzimologia , Celulose 1,4-beta-Celobiosidase/metabolismo , Celulose 1,4-beta-Celobiosidase/genética , Ácido gama-Linolênico/metabolismo , Lipídeos/biossíntese , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Dessaturases/genética , Celulose/metabolismo , Engenharia Metabólica/métodos , Metabolismo dos Lipídeos
19.
Int J Biol Macromol ; 278(Pt 1): 134602, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39127282

RESUMO

This study evaluates the feasibility of using enzymatic technology to produce novel nanostructures of cellulose nanomaterials, specifically cellulose nanospheres (CNS), through enzymatic hydrolysis with endoglucanase and xylanase of pre-treated cellulose fibers. A statistical experimental design facilitated a comprehensive understanding of the process parameters, which enabled high yields of up to 82.7 %, while maintaining a uniform diameter of 54 nm and slightly improved crystallinity and thermal stability. Atomic force microscopy analyses revealed a distinct CNS formation mechanism, where initial fragmentation of rod-like nanoparticles and subsequent self-assembly of shorter rod-shaped nanoparticles led to CNS formation. Additionally, adjustments in process parameters allowed precise control over the CNS diameter, ranging from 20 to 100 nm, highlighting the potential for customization in high-performance applications. Furthermore, this study demonstrates how the process framework, originally developed for cellulose nanocrystals (CNC) production, was successfully adapted and optimized for CNS production, ensuring scalability and efficiency. In conclusion, this study emphasizes the versatility and efficiency of the enzyme-based platform for producing high-quality CNS, providing valuable insights into energy consumption for large-scale economic and environmental assessments.

20.
Int J Biol Macromol ; : 134643, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39128733

RESUMO

Chronic wounds (CWs) treatment still represents a demanding medical challenge. Several intrinsic physiological signals (i.e., pH) help to stimulate and support wound healing. CWs, in fact, are characterized by a predominantly alkaline pH of the exudate, which acidifies as the wound heals. Therefore, pH-responsive wound dressings hold great potential owing to their capability of tuning their functions according to the wound conditions. Herein, porous chitosan (CS)-based scaffolds loaded with cellulose nanocrystals (CNCs) and graphene oxide (GO) were successfully fabricated using a freeze-drying method. CNCs were extracted from bagasse pulps fibers through acid hydrolysis. GO was synthesised by Hummer's method. The scaffolds were then ionically cross-linked using the amino acid L-Arginine (Arg), as a bioactive agent, and tested as potential pH-responsive wound dressing. Notably, the effect of CNCs and GO singly and simultaneously loaded within the CS-Arg scaffolds was investigated. The modulation of CNCs and GO content within CS-Arg scaffolds facilitated the development of scaffolds with an optimal pH-dependent swelling ratio capability and extended degradation time. Furthermore, CS/CNC/GO-Arg scaffolds exhibited tuned biological features, in terms of antimicrobial activity, cellular proliferation/migration ability, and the expression of extracellular matrix specific markers (i.e., elastin and collagen I) related to wound healing in human dermal fibroblasts.

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