RESUMO
BACKGROUND: This study aims to elucidate the therapeutic effects and underlying mechanisms of montmorillonite powder on wound healing in mice with Stage II pressure ulcers, thereby providing a robust foundation for its clinical application in the treatment of such ulcers. MATERIALS AND METHODS: Sixty 8-week-old specific pathogen-free male BALB/c mice were randomly allocated into three groups: a model group (where Stage II pressure ulcers were induced using the magnet pressure method and the wounds were dressed with gauze soaked in 0.9% sodium chloride solution), a treatment group (where, following the induction of Stage II pressure ulcer models, wounds were uniformly treated with montmorillonite powder), and a control group (where magnets were placed in the same location without exerting magnetic pressure). Skin histopathology was assessed via light microscopy. Wound healing progress over various intervals was quantified utilizing Image-Pro Plus software. Histopathological alterations in the wounds were examined through hematoxylin and eosin (H&E) staining. The expression of growth factor proteins within the wound tissue was analyzed using the streptavidin-peroxidase method. Furthermore, the levels of vascular endothelial growth factor (VEGF), collagen types I and III (COL-I, COL-III) proteins were quantified via Western blotting, serum concentrations of inflammatory mediators in mice were determined by enzyme-linked immunosorbent assay, and the levels of oxidative stress markers in wound tissues were measured using UV-visible spectrophotometry. RESULTS: The treatment group exhibited significantly reduced serum levels of interleukin-1ß, interleukin-6, and tumor necrosis factor-alpha, and elevated levels of interleukin-4 compared to the model group (p < 0.05). Additionally, the expression of transforming growth factor-beta1, basic fibroblast growth factor, epidermal growth factor, VEGF, COL-I, and COL-III proteins in wound tissues was significantly higher in the treatment group than in the model group (p < 0.05). Levels of superoxide dismutase and glutathione peroxidase in wound tissues were higher, and levels of malondialdehyde were lower in the treatment group compared to the model group (p < 0.05). CONCLUSION: Montmorillonite powder facilitates wound healing and augments the healing rate of Stage II pressure ulcers in model mice. Its mechanism of action is likely associated with mitigating wound inflammation, reducing oxidative stress damage, promoting angiogenesis, and enhancing the synthesis of growth factors and collagen.
Assuntos
Bentonita , Modelos Animais de Doenças , Camundongos Endogâmicos BALB C , Pós , Úlcera por Pressão , Cicatrização , Animais , Bentonita/farmacologia , Masculino , Úlcera por Pressão/tratamento farmacológico , Úlcera por Pressão/patologia , Camundongos , Cicatrização/efeitos dos fármacos , Pele/patologia , Pele/efeitos dos fármacos , Pele/lesões , Pele/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Citocinas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Leachate emanating from landfills contains ammonia which may cause serious health effects on living things. An effectively designed clay barrier should not allow the contaminant to infiltrate the soil and groundwater systems. The utilization of certain industrial by-products in engineered landfill barriers, not only reduces the need for conventional liner materials but also helps in sustainable waste management. This study investigated the hydraulic conductivity, unconfined compressive strength, compaction, and adsorption characteristics of lithomargic clay blended with an optimum percentage of bentonite (10%) and granulated blast furnace slag (15%) permeated with ammonia. The results revealed that increasing the content of granulated blast furnace slag decreased the maximum dry density while increasing the optimum moisture content. In comparison to lithomargic clay, the hydraulic conductivity of the amended soil liner permeated with ammonia decreased from a value of 3 × 10-8 m/s to 5 × 10-10 m/s. The unconfined compressive strength of the amended soil specimens showed an increasing trend with curing times (i.e., 0, 14, 28, and 56 days). The batch adsorption results revealed that Freundlich and Langmuir's isotherm fits the equilibrium adsorption data and the adsorption of ammonia on clay liner follows non-linear behaviour. Overall, the experimental results implied that lithomargic clay blended with 10% bentonite and 15% granulated blast furnace slag can be used as an impermeable soil reactive barrier in engineered landfills.
Assuntos
Amônia , Bentonita , Resíduos Sólidos , Instalações de Eliminação de Resíduos , Bentonita/química , Amônia/química , Adsorção , Eliminação de Resíduos/métodos , Solo/química , Gerenciamento de Resíduos/métodos , Poluentes Químicos da Água/química , Argila/químicaRESUMO
Carvacrol and thymol are broad-spectrum natural antimicrobial agents. To reduce their volatility and improve their antimicrobial performance, synergistic systems were prepared loading the active molecules in zinc-modified clays. Montmorillonite (MMT) and zeolite (ZEO) were modified with zinc ions (ZnMMT and ZnZEO), with well-known antimicrobial properties, and then with carvacrol or thymol, reaching the 26 ± 3% and 33 ± 2% w/w of loading, respectively. The resulting hybrid materials were characterized by FT-IR, XPS, XRD, TGA, and GC-MS to evaluate carvacrol/thymol release in simulating food matrices. Antimicrobial assays carried out using spoiler and pathogenic bacterial strains showed that the antimicrobial activity of both thymol and carvacrol was largely preserved once they were loaded into Zn-modified clays. However, MMT hybrids showed an antibacterial activity significantly higher than ZEO hybrids at 50 mg/mL of thymol and carvacrol. For this reason, deeper antimicrobial evaluations were carried out only for ZnMMT composites. ZnMMT loaded with thymol or carvacrol produced inhibition zones against most of the target strains, also at 3.12 mg/mL, while the positive controls represented by the single molecule thymol or carvacrol were not active. The hybrid materials can be useful for applications in which the antimicrobial activity of natural molecules need to be displayed over time as requested for the control of microbial pathogens and spoilage bacteria in different applications, such as active packaging, biomaterials, and medical devices.
Assuntos
Anti-Infecciosos , Argila , Cimenos , Testes de Sensibilidade Microbiana , Timol , Zinco , Cimenos/química , Cimenos/farmacologia , Timol/química , Timol/farmacologia , Zinco/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Argila/química , Espectroscopia de Infravermelho com Transformada de Fourier , Bactérias/efeitos dos fármacos , Bentonita/químicaRESUMO
Soil-bentonite (S-B) barriers have been widely used for heavy metal pollution containment. This study conducted batch adsorption tests and diffusion-through tests to evaluate how ionic strength and bentonite ratio influence the migration of Cr(VI) in natural clay-bentonite mixtures. The test results indicated that the adsorption of Cr(VI) exhibited an obvious anion adsorption effect, the pH of the soil mixture increased with the addition of bentonite, resulting in a decrease in the positive surface charge. This change led to a decrease in Cr(VI) adsorption capacity, from 775.19 mg/kg for pure clay to 378 mg/kg for mixture samples with excessive bentonite. Furthermore, as the ionic strength increases from 0 to 0.1 M, the Cr(VI) adsorption capacity increases slightly due to the weakening of electrostatic repulsion on the clay particle surface, but the effective diffusion coefficient (De) increases by 21.97%. The compression of the diffusion double layer (DDL) under high ionic strength conditions enlarges the diffusion path and enhances the migration of Cr(VI) through the pore flow paths. Moreover, hydrated bentonite effectively fills the interaggregate pores of natural clay, thus creating narrower and more tortuous flow paths. However, excessive bentonite increases the pH value and pore volume, resulting in changes to the soil microstructure and disrupting the continuous skeleton of natural clay, which is unfavorable for Cr(VI) containment. Based on the study of the Cr(VI) contaminated site, a bentonite ratio of 2:10 is recommended for optimal natural performance of the natural clay-bentonite barrier.
Assuntos
Bentonita , Cromo , Argila , Poluentes do Solo , Solo , Bentonita/química , Concentração Osmolar , Adsorção , Cromo/química , Solo/química , Argila/química , Poluentes do Solo/química , Concentração de Íons de HidrogênioRESUMO
Pimelea poisoning of cattle causes distinct symptoms and frequently death, attributable to the toxin simplexin. Pimelea poisoning was induced via addition of ground Pimelea trichostachya plant to the daily feed in a three-month trial with Droughtmaster steers. The trial tested four potential mitigation treatments, namely, biochar, activated biochar, bentonite, and a bacterial inoculum, and incorporated negative and positive control groups. All treatments tested were unable to prevent the development of simplexin poisoning effects. However, steers consuming a bentonite adsorbent together with Pimelea showed lesser rates-of-decline for body weight (P < 0.05) and four hematological parameters (P < 0.02), compared to the positive control group fed Pimelea only. Microbiome analysis revealed that despite displaying poisoning symptoms, the rumen microbial populations of animals receiving Pimelea were very resilient, with dominant bacterial populations maintained over time. Unexpectedly, clinical edema developed in some animals up to 2 weeks after Pimelea dosing was ceased.
Assuntos
Ração Animal , Doenças dos Bovinos , Animais , Bovinos , Ração Animal/análise , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/microbiologia , Masculino , Carvão Vegetal/administração & dosagem , Austrália , Intoxicação por Plantas/veterinária , Intoxicação por Plantas/prevenção & controle , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bentonita/química , Rúmen/microbiologia , Rúmen/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacosRESUMO
Montmorillonite (MM) crystal nanoplates acquire anticancer properties when coated with the mitochondrial protein cytochrome c (cytC) due to the cancer cells' capability to phagocytize cytC-MM colloid particles. The introduced exogenous cytC initiates apoptosis: an irreversible cascade of biochemical reactions leading to cell death. In the present research, we investigate the organization of the cytC layer on the MM surface by employing physicochemical and computer methods-microelectrophoresis, static, and electric light scattering-to study cytC adsorption on the MM surface, and protein electrostatics and docking to calculate the local electric potential and Gibbs free energy of interacting protein globules. The found protein concentration dependence of the adsorbed cytC quantity is nonlinear, manifesting a positive cooperative effect that emerges when the adsorbed cytC globules occupy more than one-third of the MM surface. Computer analysis reveals that the cooperative effect is caused by the formation of protein associates in which the cytC globules are oriented with oppositely charged surfaces. The formation of dimers and trimers is accompanied by a strong reduction in the electrostatic component of the Gibbs free energy of protein association, while the van der Waals component plays a secondary role.
Assuntos
Bentonita , Citocromos c , Eletricidade Estática , Citocromos c/química , Citocromos c/metabolismo , Bentonita/química , Adsorção , Animais , Propriedades de Superfície , Simulação de Acoplamento Molecular , Termodinâmica , Silicatos de AlumínioRESUMO
Soil minerals influence the biogeochemical cycles of fluoride (F) and phosphorus (P), impacting soil quality and bioavailability to plants. However, the cooperative mechanisms of soil minerals in governing F and P in the soil environment remain a grand challenge. Here, we reveal the essential role of a typical soil mineral, montmorillonite (Mt), in the cycling and fate of F and P. The results show that the enrichment of metal sites on the Mt surface promotes the mineralization of F to the fluorapatite (FAP) phase, thereby remaining stable in the environment, simultaneously promoting P release. This differential behavior leads to a reduction in the level of F pollution and an enhancement of P availability. Moreover, solid-state NMR and HRTEM observations confirm the existence of metastable F-Ca-F intermediates, emphasizing the pivotal role of Mt surface sites in regulating crystallization pathways and crystal growth of FAP. Furthermore, the in situ atomic force microscopy and theoretical calculations reveal molecular fractionation mechanisms and adsorption processes. It is observed that a competitive relationship exists between F and P at the Mt interface, highlighting the thermodynamically advantageous pathway of forming metastable intermediates, thereby governing the activity of F and P in the soil environment at a molecular level. This work paves the way to reveal the important role of clay minerals as a mineralization matrix for soil quality management and offers new strategies for modulating F and P dynamics in soil ecosystems.
Assuntos
Fluoretos , Fósforo , Fluoretos/química , Fósforo/química , Solo/química , Argila/química , Apatitas/química , Bentonita/química , Adsorção , Minerais/química , Silicatos de Alumínio/químicaRESUMO
Developing multifunctional materials for water treatment remains a significant challenge. Bacterial cellulose (BC) holds immense potential as an adsorbent with high pollutant-binding capacity, hydrophilicity, and biosafety. In this study, N-acetylglucosamine was used as a carbon source to ferment BC, incorporating amide bonds in situ. Bentonite, renowned for its adsorption properties, was added to the culture medium, resulting in BC-bentonite composite membranes via a one-step fermentation process. Polyethyleneimine (PEI) was crosslinked with amide bonds on the membrane via glutaraldehyde through Schiff base reactions to enhance the performance of the composite membrane. The obtained membrane exhibited increased hydrophilicity, enhanced active adsorption sites, and enlarged specific surface area. It not only physically adsorbed contaminants through its unique structure but also effectively captured dye molecules (Congo red, Methylene blue, Malachite green) via electrostatic interactions. Additionally, it formed stable complexes with metal ions (Cd²âº, Pb²âº, Cu²âº) through coordination and effectively adsorbed their mixtures. Moreover, the composite membrane demonstrated the broad-spectrum antibacterial activity, effectively inhibiting the growth of tested bacteria. This study introduces an innovative method for fabricating composite membranes as adsorbents for complex water pollutants, showing significant potential for long-term wastewater treatment of organic dyes, heavy metal ions, and pathogens.
Assuntos
Antibacterianos , Bentonita , Celulose , Corantes , Membranas Artificiais , Polietilenoimina , Poluentes Químicos da Água , Purificação da Água , Adsorção , Celulose/química , Bentonita/química , Corantes/química , Polietilenoimina/química , Purificação da Água/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Poluentes Químicos da Água/química , Metais Pesados/químicaRESUMO
Clay-algae flocculation is a promising method to remove harmful algal blooms (HABs) in aquatic ecosystems. Many HAB-generating species, such as Microcystis aeruginosa (M. aeruginosa), a common species in lakes, produce toxins and harm the environment, human health, and the economy. Natural clays, such as bentonite and kaolinite, and modification of these clays have been applied to mitigate HABs by forming large aggregates and settling down. In this study, we aim to examine the impact of laponite, a commercially available smectite clay that is synthetic, transparent, compatible with human tissues, and degradable, on removing HABs. We compare the cell removal efficiencies (RE) of laponite, two natural clays, and their polyaluminum chloride (PAC)-modified versions through clay-algae flocculation experiments. Our results show that the optimum concentrations of laponite, bentonite, kaolinite, PAC-modified bentonite, and PAC-modified kaolinite to remove 80 % of the M. aeruginosa cells from the water column are 0.05 g/L, 2 g/L, 4 g/L, 2 g/L and 0.3 g/L respectively. Therefore, to achieve the same cell removal efficiency, the amount of laponite needed is 40 to 80 times less than bentonite and kaolinite, and 6 times less than PAC-modified kaolinite. We demonstrate that the superior performance of laponite clay is because of its smaller particle size, which increases the encounter rate between cells and clay particles. Furthermore, experiments using water samples from Powderhorn Lake confirmed laponite's effectiveness in mitigating HABs. Our price analysis also suggests that this commercially-available clay, laponite, can be used in the field at a relatively low cost.
Assuntos
Argila , Floculação , Microcystis , Argila/química , Proliferação Nociva de Algas , Silicatos/química , Silicatos de Alumínio/química , Caulim/química , Bentonita/química , Hidróxido de Alumínio/químicaRESUMO
Desiccation-induced cracks in a compacted clay liner significantly deteriorate the hydraulic barrier performance of landfill covers. The present study explores the effects of polypropylene (PP) fiber reinforcement on the hydrological response and crack resistance of compacted steel slag (SS; 90 wt%) - bentonite (10 wt%) mixtures under drying and wetting cycles. Comprehensive tests were conducted to explore the impact of different fiber lengths (6-12 mm) and contents (0-0.4 % wt.%), including hydraulic conductivity tests for measuring the saturated hydraulic conductivity (ks), unconfined-penetration tests for measuring the tensile strength, small-sized plate tests for quantifying crack development, and large-sized bucket tests for studying the hydrological response and crack characteristics. Higher fiber contents and longer fiber lengths increased the ks-value of the specimens. For a 0.3 % fiber content, the tensile strength peaked for the 9-mm fiber. Consistently, the specimen reinforced with the 9-mm fibers exhibited significantly fewer cracks than those reinforced with the 6-mm and 12-mm fibers. It was because the 6-mm fibers had a shorter anchorage length, while the 12-mm fibers tended to agglomerate. The large-sized bucket tests showed that fiber reinforcement limited crack development significantly under wetting and drying cycles, reducing the rainfall infiltration by 40 % and enhancing the soil water retention capacity. Finally, a 0.3 wt% of 9-mm PP was recommended to reinforce the compacted SS-bentonite mixtures.
Assuntos
Bentonita , Polipropilenos , Aço , Polipropilenos/química , Bentonita/química , Aço/química , Resistência à Tração , Hidrologia , Dessecação/métodos , Eliminação de Resíduos/métodosRESUMO
Bentonite is an integral part of the engineered barrier system (EBS) in deep geological repositories (DGR) for nuclear waste, but its indigenous microorganisms may jeopardize long-term EBS integrity. To predict microbial activity in DGRs, it is essential to understand microbial reactions to the early hot phase of DGR evolution. Two bentonites (BCV and MX-80) with varied bentonite/water ratios and saturation levels (compacted to 1600 kg.m- 3 dry density/powder/suspension), were subjected to heat (90-150 °C) and irradiation (0.4 Gy.h- 1) in the long-term experiments (up to 18 months). Molecular-genetic, microscopic, and cultivation-based techniques assessed microbial survivability. Exposure to 90 °C and 150 °C notably diminished microbial viability, irrespective of bentonite form, with negligible impacts from irradiation or sample type compared to temperature. Bentonite powder samples exhibited microbial recovery after 90 °C heating for up to 6 months but not 12 months in most cases; exposure to 150 °C had an even stronger effect. Further long-term experiments at additional temperatures combined with the mathematical prediction of temperature evolution in DGR are recommended to validate the possible evolution and spatial distribution of microbially depleted zones in bentonite buffer around the waste canisters and refine predictions of microbial effects over time in the DGR.
Assuntos
Bactérias , Bentonita , Raios gama , Temperatura Alta , Viabilidade Microbiana , Bentonita/química , Viabilidade Microbiana/efeitos da radiação , Bactérias/classificação , Bactérias/efeitos da radiação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Resíduos Radioativos/análise , Microbiologia do SoloRESUMO
The complexity in structure and function of the nervous system, as well as its slow rate of regeneration, makes it more difficult to treat it compared to other tissues. Neural tissue engineering aims to create an appropriate environment for nerve cell proliferation and differentiation. Fibrous scaffolds with suitable morphology and topography and better mimicry of the extracellular matrix have been promising for the alignment and migration of neural cells. On this premise, to improve the properties of the scaffold, we combined montmorillonite (MMT) with chitosan (CS) polymer and created microfibers with variable diameters and varied concentrations of MMT using microfluidic technology and tested its suitability for the rat pheochromocytoma cell line (PC12). According to the findings, CS/MMT 0.1 % compared to CS/MMT 0 % microfibers showed a 201 MPa increase in Young's modulus, a 68 mS/m increase in conductivity, and a 1.4-fold increase in output voltage. Analysis of cell mitochondrial activity verified the non-toxicity, resulting in good cell morphology with orientation along the microfiber. Overall, the results of this project showed that with a low concentration of MMT, the properties of microfibers can be significantly improved and a suitable scaffold can be designed for neural tissue engineering.
Assuntos
Bentonita , Quitosana , Neurônios , Engenharia Tecidual , Alicerces Teciduais , Quitosana/química , Animais , Células PC12 , Engenharia Tecidual/métodos , Ratos , Bentonita/química , Alicerces Teciduais/química , Neurônios/efeitos dos fármacos , Neurônios/citologia , Proliferação de Células/efeitos dos fármacos , Microfluídica/métodos , Diferenciação Celular/efeitos dos fármacos , Módulo de Elasticidade , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacosRESUMO
The widespread utilization of plastic products ineluctably leads to the ubiquity of nanoplastics (NPs), causing potential risks for aquatic environments. Interactions of NPs with mineral surfaces may affect NPs transport, fate and ecotoxicity. This study aims to investigate systematically the deposition and aggregation behaviors of carboxylated polystyrene nanoplastics (COOH-PSNPs) by four types of clay minerals (illite, kaolinite, Na-montmorillonite, and Ca-montmorillonite) under various solution chemistry conditions (pH, temperature, ionic strength and type). Results demonstrate that the deposition process was dominated by electrostatic interactions. Divalent cations (i.e., Ca2+, Mg2+, Cd2+, or Pb2+) were more efficient for screening surface negative charges and compressing the electrical double layer (EDL). Hence, there were significant increases in deposition rates of COOH-PSNPs with clay minerals in suspension containing divalent cations, whereas only slight increases in deposition rates of COOH-PSNPs were observed in monovalent cations (Na+, K+). Negligible deposition occurred in the presence of anions (F-, Cl-, NO3-, CO32-, SO42-, or PO43-). Divalent Ca2+ could incrementally facilitate the deposition of COOH-PSNPs through Ca2+-assisted bridging with increasing CaCl2 concentrations (0-100â¯mM). The weakened deposition of COOH-PSNPs with increasing pH (2.0-10.0) was primarily attributed to the reduce in positive charge density at the edges of clay minerals. In suspensions containing 2â¯mM CaCl2, increased Na+ ionic strength (0-100â¯mM) and temperature (15-55 â¦C) also favored the deposition of COOH-PSNPs. The ability of COOH-PSNPs deposited by four types of clay minerals followed the sequence of kaolinite > Na-montmorillonite > Ca-montmorillonite > illite, which was related to their structural and surface charge properties. This study revealed the deposition behaviors and mechanisms between NPs and clay minerals under environmentally representative conditions, which provided novel insights into the transport and fate of NPs in natural aquatic environments.
Assuntos
Cálcio , Argila , Poluentes Químicos da Água , Argila/química , Cálcio/química , Cálcio/análise , Poluentes Químicos da Água/química , Concentração Osmolar , Concentração de Íons de Hidrogênio , Silicatos de Alumínio/química , Poliestirenos/química , Temperatura , Minerais/química , Bentonita/química , Nanopartículas/química , Caulim/química , Eletricidade EstáticaRESUMO
Glucosamine-chitosan synthesized by the Maillard reaction was combined with montmorillonite to obtain a nanohybrid composite to immobilize horseradish peroxidase. The material combines the advantageous properties of clay with those of the chitosan derivative; has improved water solubility and reduced molecular weight and viscosity; involves an eco-friendly synthesis; and exhibits ion exchange capacity, good adhesiveness, and a large specific surface area for enzyme adsorption. The physicochemical characteristics of the composite were analyzed by infrared spectroscopy and X-ray diffraction to determine clay-polycation interactions. The electrochemical response of the different polyphenols to glassy carbon electrodes modified with the composite was evaluated by cyclic voltammetry. The sensitivity and detection limit values obtained with the biosensor toward hydroquinone, chlorogenic acid, catechol, and resorcinol are (1.6 ± 0.2) × 102 µA mM-1 and (74 ± 8) nM; (1.2 ± 0.1) × 102 µA mM-1 and (26 ± 3) nM; (16 ± 2) µA mM-1 and (0.74 ± 0.09) µM; and (3.7± 0.3) µA mM-1 and (3.3 ± 0.2) µM, respectively. The biosensor was applied to quantify polyphenols in pennyroyal and lemon verbena extracts.
Assuntos
Bentonita , Técnicas Biossensoriais , Quitosana , Técnicas Eletroquímicas , Enzimas Imobilizadas , Glucosamina , Peroxidase do Rábano Silvestre , Polifenóis , Bentonita/química , Polifenóis/análise , Quitosana/química , Peroxidase do Rábano Silvestre/química , Enzimas Imobilizadas/química , Glucosamina/análise , EletrodosRESUMO
Dye wastewater poses a serious threat to the environment and human health, necessitating sustainable degradation methods. In this study, Na-based Montmorillonite (MMT) was exfoliated using different ionic liquids ([C16MIM][Cl], [C16MIM][BF4], [C16MIM][PF6]), and silver nanoparticles (Ag NPs) were green-synthesized using hydroxypropyl cellulose (HPC). The HPC significantly enhanced the dispersion of MMT in the hydrogel. By introducing lauryl methacrylate (LMA), a hydrophobic associative network was constructed in PAM/LMA/HPC/MMT@ILs&Ag NPs hydrogel. This hydrogel demonstrated outstanding mechanical properties, with a stress of 833.21 kPa, strain of 3300 %, and toughness of 14.36 MJ/m3. It also exhibited excellent catalytic activity, with a rate constant of 0.83 min-1 for 4-nitrophenol degradation at 28 °C. The effects of temperature and catalyst concentration on the catalytic reaction were systematically investigated. This study presents a simple green synthesis approach for Ag NPs using HPC, achieving superior mechanical performance and stable MMT dispersion in aqueous solutions.
Assuntos
Bentonita , Celulose , Hidrogéis , Líquidos Iônicos , Nanopartículas Metálicas , Prata , Poluentes Químicos da Água , Celulose/química , Celulose/análogos & derivados , Líquidos Iônicos/química , Catálise , Bentonita/química , Hidrogéis/química , Poluentes Químicos da Água/química , Prata/química , Nanopartículas Metálicas/química , Ânions/química , Nitrofenóis/química , Química Verde , Purificação da Água/métodosRESUMO
Bacterial infections and the emergence of super-resistant bacteria pose a significant risk to human health. Effective sterilization to prevent the development of bacterial drug resistance remains a challenge. Herein, curcumin/silver/montmorillonite (Cur/Ag/Mt) was prepared through a green chemical reduction method with montmorillonite as the carrier, curcumin as the reducing agent and the capping agent, and citric acid as the structure guide agent. Then, a novel dual light-responsive and thermosensitive Pluronic F127-based hydrogel (CAM-F) was prepared by encapsulating Cur/Ag/Mt within the F127 hydrogel. The Cur/Ag/Mt showed strong absorption in the near-infrared region that efficiently converts light into heat for photothermal therapy when the molar ratio of curcumin to silver nitrate was 2 : 1. Specifically, triangular silver nanoparticles reduced by curcumin were immobilized on the Mt layers, which could enhance photodynamic therapy by the metal-enhanced singlet oxygen and metal-enhanced fluorescence mechanisms. Upon combining 405 nm and 808 nm laser irradiation, the CAM-F hydrogel could simultaneously generate reactive oxygen species, increase the local temperature, and sustain the release of Ag+, thus displaying excellent bactericidal performance against Gram-negative and Gram-positive bacteria. The antibacterial rates of CAM-F hydrogels were 99.26 ± 0.95% and 99.95 ± 0.98% for Escherichia coli and Staphylococcus aureus, respectively. The findings suggest the potential of the CAM-F hydrogel as a stable, biologically safe, and broad-spectrum antimicrobial material. The thermosensitive CAM-F hydrogels for synergetic phototherapy may provide a promising strategy for solving clinical problems caused by pathogenic infections.
Assuntos
Antibacterianos , Bentonita , Curcumina , Escherichia coli , Hidrogéis , Testes de Sensibilidade Microbiana , Fotoquimioterapia , Prata , Staphylococcus aureus , Curcumina/farmacologia , Curcumina/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Prata/química , Prata/farmacologia , Bentonita/química , Bentonita/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Tamanho da Partícula , Temperatura , Poloxâmero/química , Poloxâmero/farmacologia , Humanos , Íons/química , Nanopartículas Metálicas/químicaRESUMO
The purpose of this research was to examine the potential effects of bentonite (BN) supplemented diets on growth, feed utilization, blood biochemistry, and histomorphology of Dicentrarchus labrax. Six treatments in triplicate were tested: B0, B0.5, B1.0, B1.5, B3.0, and B4.5, which represented fish groups fed diets supplemented with 0, 0.5, 1, 1.5, 3, and 4.5% BN, respectively. For 84 days, juveniles' seabass (initial weight = 32.73 g) were fed diets containing 46% protein, three times daily at 3% of body weight. With a 5% daily water exchange, underground seawater (32 ppt) was used. Findings revealed significant improvements in water quality (TAN and NH3), growth (FW, WG and SGR) and feed utilization (FCR, PER and PPV) in fish fed BN-supplemented diets, with the best values in favor of the B1.5 group. Additional enhancements in kidney function indicators (urea and uric acid) and liver enzymes were observed in fish of the BN-treated groups along with a decrease in cholesterol level in the B1.5 group. Further improvements in fish innate immunity (hemoglobin, red blood cells, glucose, total protein, globulin, and immunoglobulin IgM), antioxidant activity (total antioxidative capacity and catalase), and decreased cortisol levels in fish of the BN-treated groups. Histological examinations of the anterior and posterior intestines and liver in groups B1.5 and B3 revealed the healthiest organs. This study recommends BN at a concentration of 1.5% as a feed additive in the Dicentrarchus labrax diet.
Assuntos
Amônia , Ração Animal , Antioxidantes , Bass , Bentonita , Suplementos Nutricionais , Animais , Bass/imunologia , Bass/crescimento & desenvolvimento , Bass/metabolismo , Antioxidantes/metabolismo , Bentonita/farmacologia , Bentonita/administração & dosagem , Amônia/metabolismo , Ração Animal/análise , Dieta/veterináriaRESUMO
This study is to examine zinc exchanged montmorillonite (Zn-MMT) as a potential slow release nanofertilizer for rice crop. The effective intercalation of zinc within the montmorillonite inter layers was firmly established via analytical techniques including Zeta potential, FE-SEM (Field Emission Scanning Electron Microscopy) with Energy Dispersive X-ray Analysis (EDAX), Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The efficacy of Zn-MMT was examined by evaluating its ability to facilitate controlled zinc release, as confirmed through an incubation study. Subsequently, the kinetics of zinc release was analyzed by different mathematical models such as Zero-order kinetics, First-order kinetics, the Higuchi model, and the Korsmeyer-Peppas model. From the pot culture study spanning 90 days the results indicated that Zn-MMT had significantly high plant height, Leaf Area Index (LAI), Dry Matter Production (DMP), number of tillers per hill, panicles length, increased grain and straw yield, in comparison with conventional zinc sulphate (ZnSO4). Total phenol, total protein and total chlorophyll content were significantly at higher levels with Zn-MMT treated rice crops as compared to conventional fertilizers and control. A similar trend was seen with phytochemicals such as Indole Acetic Acid (IAA), Superoxide Dismutase (SOD) and Carbonic Anhydrase (CA). Notably, rice grains harvested from Zn-MMTtreated crops exhibited significantly higher zinc content than those using other treatments. This Zn-MMT can be confirmed as a better alternative to conventional zinc sulphate fertilizers owing to its slow-release of nutrient into the soil and thus increased zinc use efficiency.
Assuntos
Bentonita , Fertilizantes , Oryza , Zinco , Oryza/metabolismo , Bentonita/metabolismo , Zinco/metabolismo , Argila/química , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The efficient degradation of antibiotics holds significant implications for mitigating environmental pollution. This study synthesized a montmorillonite chitosan composite material (MMT-CS) using the gel template method. Subsequently, a bio-enhanced reactor was constructed to facilitate the degradation of chlorotetracycline (CTC). The addition of MMT-CS composite material enables the degradation of different concentrations of CTC. MMT-CS, a conductive carrier, effectively promotes microbial adhesion and boosts the metabolic activity of functional microorganisms. Additionally, it facilitates the maintenance of microbial activity under CTC pressure by promoting the secretion of extracellular polymeric substances, increasing critical enzyme activity, and enhancing the electron transfer capacity within the system. In this MMT-CS bio-enhanced process, Paracoccus (11.4%) and Bacillus (3.9%) are utilized as essential bacteria genes. The results of metabolic pathways prediction indicated significant enhancements in membrane-transport, nucleotide-metabolism, replication-repair, and lipid-metabolism. Thus, the developed self-supporting MMT-CS bio-enhanced process ensured the stability of the system during the removal of antibiotics.
Assuntos
Bentonita , Biodegradação Ambiental , Quitosana , Clortetraciclina , Bentonita/química , Clortetraciclina/metabolismo , Transporte de Elétrons , Quitosana/química , Antibacterianos/farmacologia , Reatores BiológicosRESUMO
A rising quantity of drugs has been discharged into the aquatic environment, posing a substantial hazard to public health. In the current work, a novel hydrogel (i.Carr@Bent@PTC), comprised of iota-carrageenan, bentonite, and 4-phenyl-3-thiosemicarbazide, was successfully prepared. The introduction of 4-phenyl-3-thiosemicarbazide and bentonite in iota-carrageenan significantly increased the mechanical strength of iota-carrageenan hydrogel and improved its degree of swelling, which can be attributed to the hydrophilic properties of PTC and Bent. The recorded contact angle was 70.8°, 59.1°, 53.9°, and 34.6° for pristine i.Carr, i.Carr@Bent, and i.Carr@Bent@PTC, respectively. The low contact angle measurement of the Bent and PTC loaded-i.Carr hydrogel was attributed to the hydrophilic Bent and PTC. The ternary i.Carr@Bent@PTC hydrogel demonstrated broad pH adaptability and excellent adsorption capacities for sulfamethoxazole (SMX) and losartan potassium (LP), i.e., 467.61 mg. g-1 and 274.43 mg. g-1 at 298.15 K, respectively. The pseudo-first-order (PSO) model provided a better fit for the adsorption kinetics. The adsorption of SMX and LP can be better explained by employing the Sips and Langmuir isotherm models. As revealed by XPS and FTIR investigations, π-π stacking, complexation, electrostatic interaction, and hydrogen bonding were primarily involved in the adsorption mechanisms.