RESUMO
Deep-eutectic solvents (DES) have emerged as promising candidates for preparing nanocomposites. In this study, a DES-based graphitic carbon nitride (g-C3N4)/ZnO/Chitosan (Ch) nanocomposite was synthesized to remove malachite green (MG) dye from water. The DES was prepared by mixing and heating citric acid as a hydrogen bond acceptor and lactic acid as a hydrogen bond donor. This is the first report of the removal of MG using DES-based nanocomposites. Experiments on kinetics and isothermal adsorption were conducted to systematically explore the adsorption performances of nanocomposite toward dye. At 25 °C, the highest adsorption performance was obtained with alkaline media (>90 % removal). The greatest adsorption capacity (qm) was 59.52 mg g-1 at conditions (30 mg L-1 MG solution, pH 9, 3 mg nanocomposite per 10 mL of MG solution, 25 °C, 150 rpm, and 150 min) based on the calculation from the best-fitting isotherm model (Langmuir). The adsorption process was most appropriately kinetically described by the PSO model. The Monte Carlo (MC) and molecular dynamic (MC) results are correlated with experimental findings to validate the theoretical predictions and enhance the overall understanding of the adsorption process. Electronic structure calculations reveal the nature of interactions, including hydrogen bonding and electrostatic forces, between the nanocomposite and MG molecules.
Assuntos
Quitosana , Grafite , Simulação de Dinâmica Molecular , Método de Monte Carlo , Nanocompostos , Corantes de Rosanilina , Óxido de Zinco , Quitosana/química , Nanocompostos/química , Corantes de Rosanilina/química , Corantes de Rosanilina/isolamento & purificação , Adsorção , Grafite/química , Óxido de Zinco/química , Cinética , Solventes Eutéticos Profundos/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Compostos de Nitrogênio/química , Concentração de Íons de HidrogênioRESUMO
BACKGROUND: In recent years, anthropogenic activities have released heavy metals and polluted the aquatic environment. This study investigated the ability of the silica-stabilized magnetite (Si-M) nanocomposite materials to dispose of lead nitrate (Pb(NO3)2) toxicity in Nile tilapia and African catfish. RESULTS: Preliminary toxicity tests were conducted and determined the median lethal concentration (LC50) of lead nitrate (Pb(NO3)2) to Nile tilapia and African catfish to be 5 mg/l. The sublethal concentration, equivalent to 1/20 of the 96-hour LC50 Pb(NO3)2, was selected for our experiment. Fish of each species were divided into four duplicated groups. The first group served as the control negative group, while the second group (Pb group) was exposed to 0.25 mg/l Pb(NO3)2 (1/20 of the 96-hour LC50). The third group (Si-MNPs) was exposed to silica-stabilized magnetite nanoparticles at a concentration of 1 mg/l, and the fourth group (Pb + Si-MNPs) was exposed simultaneously to Pb(NO3)2 and Si-MNPs at the same concentrations as the second and third groups. Throughout the experimental period, no mortalities or abnormal clinical observations were recorded in any of the treated groups, except for melanosis and abnormal nervous behavior observed in some fish in the Pb group. After three weeks of sublethal exposure, we analyzed hepatorenal indices, oxidative stress parameters, and genotoxicity. Values of alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), urea, and creatinine were significantly higher in the Pb-intoxicated groups compared to the control and Pb + Si-MNPs groups in both fish species. Oxidative stress parameters showed a significant decrease in reduced glutathione (GSH) concentration, along with a significant increase in malondialdehyde (MDA) and protein carbonyl content (PCC) concentrations, as well as DNA fragmentation percentage in the Pb group. However, these values were nearly restored to control levels in the Pb + Si-MNPs groups. High lead accumulation was observed in the liver and gills of the Pb group, with the least accumulation in the muscles of tilapia and catfish in the Pb + Si-MNPs group. Histopathological analysis of tissue samples from Pb-exposed groups of tilapia and catfish revealed brain vacuolation, gill fusion, hyperplasia, and marked hepatocellular and renal necrosis, contrasting with Pb + Si-MNP group, which appeared to have an apparently normal tissue structure. CONCLUSIONS: Our results demonstrate that Si-MNPs are safe and effective aqueous additives in reducing the toxic effects of Pb (NO3)2 on fish tissue through the lead-chelating ability of Si-MNPs in water before being absorbed by fish.
Assuntos
Peixes-Gato , Ciclídeos , Chumbo , Fígado , Nitratos , Estresse Oxidativo , Dióxido de Silício , Poluentes Químicos da Água , Animais , Chumbo/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Dióxido de Silício/química , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/metabolismo , Poluentes Químicos da Água/toxicidade , Nanocompostos/química , Nanocompostos/toxicidade , Quelantes/farmacologia , Rim/efeitos dos fármacos , Rim/patologia , Bioacumulação , Brânquias/efeitos dos fármacos , Brânquias/patologia , Dano ao DNA/efeitos dos fármacosRESUMO
Researchers are now focusing on using the circular economy model to manufacture nanocellulose composites due to growing environmental issues related to waste management. The circular economy model offers a sustainable solution to the problem by optimizing resource efficiency and waste management by reducing waste, maintaining value over time, minimizing the use of primary resources, and creating closed loops for goods, components, and materials. With the use of the circular economy model, waste, such as industrial, agricultural, and textile waste, is used again to produce new products, which can solve waste management issues and improve resource efficiency. In order to encourage the use of circular economy ideas with a specific focus on nanocellulose composites, this review examines the concept of using circular economy, and explores ways to make nanocellulose composites from different types of waste, such as industrial, agricultural, and textile waste. Furthermore, this review investigates the application of nanocellulose composites across multiple industries. In addition, this review provides researchers useful insights of how circular economics can be applied to the development of nanocellulose composites, which have the goal of creating a flexible and environmentally friendly material that can address waste management issues and optimize resource efficiency.
Assuntos
Celulose , Celulose/química , Gerenciamento de Resíduos/métodos , Gerenciamento de Resíduos/economia , Nanocompostos/química , Nanoestruturas/química , Agricultura/economia , Agricultura/métodosRESUMO
In the present work, we explored Lewis acid catalysis, via FeCl3, for the heterogeneous surface functionalization of cellulose nanofibrils (CNFs). This approach, characterized by its simplicity and efficiency, facilitates the amidation of nonactivated carboxylic acids in carboxymethylated cellulose nanofibrils (c-CNF). Following the optimization of reaction conditions, we successfully introduced amine-containing polymers, such as polyethylenimine and Jeffamine, onto nanofibers. This introduction significantly enhanced the physicochemical properties of the CNF-based materials, resulting in improved characteristics such as adhesiveness and thermal stability. Reaction mechanistic investigations suggested that endocyclic oxygen of cellulose finely stabilizes the transition state required for further functionalization. Notably, a nanocomposite, containing CNF and a branched low molecular weight polyethylenimine (CNF-PEI 800), was synthesized using the catalytic reaction. The composite CNF-PEI 800 was thoroughly characterized having in mind its potential application as coating biomaterial for medical implants. The resulting CNF-PEI 800 hydrogel exhibits adhesive properties, which complement the established antibacterial qualities of polyethylenimine. Furthermore, CNF-PEI 800 demonstrates its ability to support the proliferation and differentiation of primary human osteoblasts over a period of 7 days.
Assuntos
Celulose , Cloretos , Nanocompostos , Nanofibras , Celulose/química , Nanocompostos/química , Humanos , Catálise , Nanofibras/química , Cloretos/química , Compostos Férricos/química , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Polietilenoimina/química , Próteses e Implantes , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese químicaRESUMO
Carbon nanotube (CNT)-based nanocomposites have found applications in making sensors for various types of physiological sensing. However, the sensors' fabrication process is usually complex, multistep, and requires longtime mixing and hazardous solvents that can be harmful to the environment. Here, we report a flexible dry silver (Ag)/CNT/polydimethylsiloxane (PDMS) nanocomposite-based sensor made by a solvent-free, low-temperature, time-effective, and simple approach for electrophysiological recording. By mechanical compression and thermal treatment of Ag/CNT, a connected conductive network of the fillers was formed, after which the PDMS was added as a polymer matrix. The CNTs make a continuous network for electrons transport, endowing the nanocomposite with high electrical conductivity, mechanical strength, and durability. This process is solvent-free and does not require a high temperature or complex mixing procedure. The sensor shows high flexibility and good conductivity. High-quality electroencephalography (EEG) and electrooculography (EOG) were performed using fabricated dry sensors. Our results show that the Ag/CNT/PDMS sensor has comparable skin-sensor interface impedance with commercial Ag/AgCl-coated dry electrodes, better performance for noninvasive electrophysiological signal recording, and a higher signal-to-noise ratio (SNR) even after 8 months of storage. The SNR of electrophysiological signal recording was measured to be 26.83 dB for our developed sensors versus 25.23 dB for commercial Ag/AgCl-coated dry electrodes. Our process of compress-heating the functional fillers provides a universal approach to fabricate various types of nanocomposites with different nanofillers and desired electrical and mechanical properties.
Assuntos
Dimetilpolisiloxanos , Nanocompostos , Nanotubos de Carbono , Prata , Nanocompostos/química , Nanotubos de Carbono/química , Prata/química , Dimetilpolisiloxanos/química , Eletroencefalografia , Condutividade Elétrica , Técnicas Biossensoriais , Humanos , Eletroculografia , Eletrodos , Razão Sinal-RuídoRESUMO
An eco-friendly hydrothermal method synthesized VS2 nanosheets. Several spectroscopic and microscopic approaches (TEM) were used to characterize the produced VS2 nanosheet microstructure. VS2, Chitosan, and nanocomposite were used to immobilize watermelon (Citrullus lanatus) urease. Optimization using the Response Surface Methodology and the Box-Behnken design yielded immobilization efficiencies of 65.23 %, 72.52 %, and 87.68 % for chitosan, VS2, and nanocomposite, respectively. The analysis of variance confirmed the mathematical model's validity, enabling additional research. AFM, SEM, FTIR, Fluorescence microscopy, and Cary Eclipse Fluorescence Spectrometer showed urease conjugation to the matrix. During and after immobilization, FTIR spectra showed a dynamic connectivity of chemical processes and bonding. The nanocomposite outperformed VS2 and chitosan in pH and temperature. Chitosan and VS2-immobilized urease were more thermally stable than soluble urease, but the nanocomposite-urease system was even more resilient. The nanocomposite retained 60 % of its residual activity after three months of storage. It retains 91.8 % of its initial activity after 12 reuse cycles. Nanocomposite-immobilized urease measured milk urea at 23.62 mg/dl. This result was compared favorably to the gold standard p-dimethylaminobenzaldehyde spectrophotometric result of 20 mg/dl. The linear range is 5 to 70 mg/dl, with a LOD of 1.07 (±0.05) mg/dl and SD of less than 5 %. The nanocomposite's ksel coefficient for interferents was exceptionally low (ksel < 0.07), indicating urea detection sensitivity. Watermelon urease is suitable for dairy sector applications due to its availability, immobilization on nanocomposite, and reuse.
Assuntos
Quitosana , Citrullus , Enzimas Imobilizadas , Leite , Nanocompostos , Urease , Citrullus/química , Citrullus/enzimologia , Urease/química , Urease/metabolismo , Quitosana/química , Enzimas Imobilizadas/química , Nanocompostos/química , Leite/química , Animais , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Ureia/químicaRESUMO
BACKGROUND: Graphene oxide nanosheets (GONS) are recognized for their role in enhancing drug delivery and effectiveness in cancer treatment. With colon cancer being a prevalent global issue and the significant side effects associated with chemotherapy, the primary treatment for colon cancer alongside surgery, there is a critical need for novel therapeutic strategies to support patients in combating this disease. Hesperetin (HSP), a natural compound found in specific fruits, exhibits anti-cancer properties. The aim of this study is to investigate the effect of GONS on the LS174t colon cancer cell line. METHODS: In this study, an anti-cancer nano-drug was synthesized by creating a hesperetin-graphene oxide nanocomposite (Hsp-GO), which was subsequently evaluated for its efficacy through in vitro cell toxicity assays. Three systems were investigated: HSP, GONS, and HSP-loaded GONS, to determine their cytotoxic and pro-apoptotic impacts on the LS174t colon cancer cell line, along with assessing the expression of BAX and BCL2. The morphology and properties of both GO and Hsp-GO were examined using scanning electron microscopy (SEM), X-ray diffraction, and Fourier transform infrared spectroscopy (FTIR). RESULTS: The Hsp-GO nanocomposite displayed potent cytotoxic and pro-apoptotic effects on LS174t colon cancer cells, outperforming individual treatments with HSP or GONS. Cell viability assays showed a significant decrease in cell viability with Hsp-GO treatment. Analysis of BAX and BCL2 expression revealed elevated BAX and reduced BCL2 levels in Hsp-GO treated cells, indicating enhanced apoptotic activity. Morphological analysis confirmed successful Hsp-GO synthesis, while structural integrity was supported by X-ray diffraction and FTIR analyses. CONCLUSIONS: These study highlight the potential of Hsp-GO as a promising anti-cancer nano-drug for colon cancer therapy.
Assuntos
Neoplasias do Colo , Sistemas de Liberação de Medicamentos , Grafite , Hesperidina , Grafite/química , Grafite/farmacologia , Humanos , Hesperidina/farmacologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Neoplasias do Colo/metabolismo , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Nanocompostos/química , Proteína X Associada a bcl-2/metabolismo , Proteína X Associada a bcl-2/genéticaRESUMO
Chitosan (Ch) is a linear biodegradable natural carbohydrate polymer and the most appealing biopolymer, such as low-cost biodegradability, biocompatibility, hydrophilicity, and non-toxicity. In this case, Ch was utilized to synthesize AgCoFe2O4@Ch/Activated Carbon (AC) by the modified microwave-assisted co-precipitation method. The physical and chemical structure of magnetic nanocomposites was analyzed and characterized by Field Emission Scanning Electron Microscope (FESEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Diffuse Reflection Spectroscopy (DRS), Value stream mapping (VSM), Fourier transform spectroscopy (FTIR) and BET. The effects of various parameters on the removal of dye (Acid Red18), including catalyst dose, dye concentration, pH, and time were studied. Results showed that the highest removal efficiencies were 96.68 % and 84 % for the synthetic sample and actual wastewater, respectively, in optimal conditions (pH: 3, the initial dye concentration: 10 mgL-1, the catalyst dose: 0.14 gL-1, time: 50 min). Mineralization, according to the COD analysis, was 89.56 %. Photocatalytic degradation kinetics of Acid Red 18 followed pseudo-first order and Langmuir-Hinshelwood with constants of kc = 0.12 mg L-1 min-1 and KL-H = 0.115 Lmg-1. Synthesized photocatalytic AgCoFe2O4@Ch/AC showed high stability and after five recycling cycles was able to remove the pollutant with an efficiency of 85.6 %. So, the synthesized heterogenous magnetic nanocatalyst AgCoFe2O4@Ch/AC was easily recycled from aqueous solutions and it can be used in the removal of dyes from industries with high efficiency.
Assuntos
Poluentes Químicos da Água , Catálise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Nanocompostos/química , Quitosana/química , Purificação da Água/métodos , Compostos Azo/química , Compostos Azo/isolamento & purificação , Reciclagem/métodos , Concentração de Íons de Hidrogênio , Águas Residuárias/química , Fotólise , Nanopartículas de Magnetita/química , Cinética , Compostos Férricos/química , Carbono/químicaRESUMO
Conversion of carbon-rich waste biomass into valuable products is an environmentally sustainable method. This study accentuates the synthesis of novel SnO2 QDs@g-C3N4/biochar using low-cost sawdust by applying the pyrolysis method. Morphology, structure, and composition of the synthesized SnO2 QDs@g-C3N4/biochar nanocomposite were characterized using SEM (scanning electron microscope), TEM (transmission electron microscope), XRD (X-ray diffraction), XPS (X-ray photoelectron spectroscopy), FT-IR (infrared spectroscopy) and PL (photoluminescence) spectroscopy. The average diameter of the SnO2 QDs was measured from TEM and found to be 6.79 nm. Optical properties of the as-synthesized SnO2 QDs@g-C3N4/biochar were characterized using UV-visible spectroscopy. The direct band gap of synthesized SnO2 QDs@g-C3N4/biochar nanocomposite was calculated from Tauc's plot and found to be 2.0 eV. The fabricated SnO2 QDs@g-C3N4/biochar photocatalyst exhibited outstanding photocatalytic degradation efficiency for the removal of Rose Bengal (RB) and Methylene Blue (MB) dye through the Advanced Oxidation Process (AOP). The synthesized photocatalyst showed a degradation efficiency of 95.67% for the removal of RB under optimum conditions of 0.3 mL H2O2, photocatalyst dosage of only 0.06 gL-1, and 15 ppm initial RB concentration within 80 min, and 94.5% for the removal of MB dye with 0.5 mL of H2O2, 0.08 gL-1 of the fabricated photocatalyst and 6 ppm of initial MB concentration within 120 min. The photodegradation pathway followed the pseudo-first-order reaction kinetics with a rate constant of 0.00268 min-1 and 0.00163 min-1 for RB and MB respectively. The photocatalyst can be reused up to the 4th cycle with 80% efficiency.
Assuntos
Azul de Metileno , Nanocompostos , Azul de Metileno/química , Rosa Bengala , Espectroscopia de Infravermelho com Transformada de Fourier , Peróxido de Hidrogênio , Nanocompostos/química , CatáliseRESUMO
Photocatalytic degradation of pharmaceutical residues through natural solar radiation represents a green and economical treatment process. In this work, ultrasonically assisted hydrothermal synthesis of WO3-TiO2 nanocomposite was carried out at 140-150 °C for 5 h and calcinated at 600 °C. The structural and optical properties of the synthesized material were investigated using techniques like XRD, FESEM/EDX, HRTEM, BET surface area, UV-DRS optical analysis, and photocurrent response. The band gap of TiO2 was successfully reduced from 3.0 to 2.54 eV and thus making it effective under solar light. Complete degradation of paracetamol (50 ppm and natural pH of 6.5) was achieved in 3.5 h under natural sunlight at catalyst dose of 0.5 g/l. The extent of mineralization was evaluated by measuring the COD reduction. Based on the degradation products identified by GC-MS/LC-TOF-MS, the degradation process under natural solar-light could be interpreted to initiate through OH. radical species. The toxicity removal of the treated paracetamol solution under natural solar-light was evaluated by the seed germination test using Spinacia oleracea seeds and exhibited 66.70% seed germination, confirming the reduction in toxicity. The enhanced photocatalytic efficiency of the nanocomposite is attributed to the higher surface area, low rutile content, lower band gap, and incorporation of WO3, which led to an extended absorption range and a slower rate of electron-hole recombination. The technical insights presented in this research offer a feasible approach for utilizing natural solar light driven photocatalysis for wastewater treatment in an efficient and sustainable way. The proposed degradation pathway, and seed germination test (toxicity removal) of the treated paracetamol solution under natural sunlight, has not been previously evaluated.
Assuntos
Nanocompostos , Luz Solar , Óxidos/química , Acetaminofen , Tungstênio , Titânio/química , Catálise , Nanocompostos/química , LuzRESUMO
Foodborne pathogens can have devastating repercussions and significantly threaten public health. Therefore, it is indeed essential to guarantee the sustainability of our food production. Food preservation and storage using nanocomposites is a promising strategy. Accordingly, the present research's objectives were to identify and isolate a few foodborne pathogens from food products, (ii) synthesize and characterize silver nanoparticles (AgNPs) using wet chemical reduction into the lamellar space layer of montmorillonite (MMT), and (iii) investigate the antibacterial potential of the AgNPs/MMT nanocomposite versus isolated strains of bacteria. Six bacterial species, including Escherichia coli, Salmonella spp., Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus were isolated from some food products (meat, fish, cheese, and vegetables). The Ag/MMT nanocomposite was synthesized and characterized using UV-visible spectroscopy, transmission electron microscopy, particle size analyzer, zeta potential, X-ray diffraction (XRD), and scanning electron microscopy with dispersive energy X-ray (EDX). The antibacterial effectiveness of the AgNPs/MMT nanocomposite further investigated distinct bacterial species using a zone of inhibition assay and microtiter-based methods. Nanoparticles with a narrow dimension range of 12 to 30 nm were identified using TEM analysis. The SEM was employed to view the sizeable flakes of the AgNPs/MMT. At 416 nm, the most excellent UV absorption was measured. Four silver metallic diffraction peaks were found in the XRD pattern during the study, and the EDX spectrum revealed a strong signal attributed to Ag nanocrystals. AgNPs/MMT figured out the powerful antibacterial action. The AgNPs/MMT nanocomposite confirmed outstanding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against six isolates of foodborne pathogens, ranging from 15 to 75 µg/mL, respectively. The AgNPs/MMT's antibacterial potential against gram-negative bacteria was noticeably better than gram-positive bacteria. Therefore, the AgNPs/MMT nanocomposite has the potential to be used as a reliable deactivator in food processing and preservation to protect against foodborne pathogenic bacteria. This suggests that the nanocomposite may be effective at inhibiting the growth and proliferation of harmful bacteria in food, which could help to reduce the risk of foodborne illness.
Assuntos
Anti-Infecciosos Locais , Nanopartículas Metálicas , Nanocompostos , Animais , Prata/farmacologia , Prata/química , Bentonita/farmacologia , Bentonita/química , Anti-Infecciosos Locais/farmacologia , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Bactérias , Nanocompostos/química , Difração de Raios XRESUMO
Investigating the structural integrity of carriers in transit from ocular surface to ocular posterior segment is essential for an efficient topical drug delivery system. In this study, dual-carrier hydroxypropyl-ß-cyclodextrin complex@Liposome (HPCD@Lip) nanocomposites were developed for the efficient delivery of dexamethasone. Förster Resonance Energy Transfer with near-infrared I fluorescent dyes and in vivo imaging system were used to investigate the structural integrity of HPCD@Lip nanocomposites after crossing Human conjunctival epithelial cells (HConEpiC) monolayer and in ocular tissues. The structural integrity of inner HPCD complexes was monitored for the first time. The results suggested that 23.1 ± 6.4 % of nanocomposites and 41.2 ± 4.3 % of HPCD complexes could cross HConEpiC monolayer with an intact structure at 1 h. 15.3 ± 8.4 % of intact nanocomposites could reach at least sclera and 22.9 ± 1.2 % of intact HPCD complexes could reach choroid-retina after 60 min in vivo, which showed that the dual-carrier drug delivery system could successfully deliver intact cyclodextrin complexes to ocular posterior segment. In conclusion, in vivo assessment of structural integrity of nanocarriers is greatly significant for guiding the rational design, higher drug delivery efficiency and clinical transformation for topical drug delivery system to the posterior segment of the eye.
Assuntos
Lipossomos , Nanocompostos , Humanos , Sistemas de Liberação de Medicamentos/métodos , 2-Hidroxipropil-beta-Ciclodextrina , Retina , Excipientes , Nanocompostos/químicaRESUMO
Incorporating single or combined nanofillers in polymeric matrices is a promising approach for developing antimicrobial materials for applications in wound healing and packaging etc. This study reports a facile fabrication of antimicrobial nanocomposite films using biocompatible polymers sodium carboxymethyl cellulose (CMC) and sodium alginate (SA) reinforced with nanosilver (Ag) and graphene oxide (GO) using the solvent casting approach. Eco-friendly synthesis of Ag nanoparticles within a size range of 20-30 nm was carried out within the polymeric solution. GO was introduced into the CMC/SA/Ag solution in different weight percentages. The films were characterized by UV-Vis, FT-IR, Raman, XRD, FE-SEM, EDAX, and TEM. The results indicated the enhanced thermal and mechanical performance of CMC/SA/Ag-GO nanocomposites with increased GO weight %. The antibacterial efficacy of the fabricated films was evaluated on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The CMC/SA/Ag-GO2% nanocomposite exhibited the highest zone of inhibition of 21.30 ± 0.70 mm against E. coli and 18.00 ± 1.00 mm against S. aureus. The CMC/SA/Ag-GO nanocomposites exhibited excellent antibacterial activity as compared to CMC/SA and CMC/SA-Ag due to the synergetic bacterial growth inhibition activities of the GO and Ag. The cytotoxic activity of the prepared nanocomposite films was also assessed to investigate their biocompatibility.
Assuntos
Nanopartículas Metálicas , Nanocompostos , Staphylococcus aureus , Alginatos/farmacologia , Prata/química , Nanopartículas Metálicas/química , Carboximetilcelulose Sódica/química , Escherichia coli , Espectroscopia de Infravermelho com Transformada de Fourier , Antibacterianos/farmacologia , Antibacterianos/química , Nanocompostos/químicaRESUMO
The fabrication of multifunctional scaffolds has attracted much attention in biological fields. In this research, some novel composites of Cu(II) or Zn(II) metal-organic framework (M-MOF) and polycaprolactone (PCL), M-MOF@PCL, have been fabricated as multifunctional scaffolds for application in the tissue engineering (TE) field. The porous three-dimensional sponges were prepared by the salt leaching method. Then, the M-MOF@PCL composite sponges have been prepared by in situ synthesis of M-MOF in the presence of the as-obtained PCL sponge to gain a new compound with proper features for biological applications. Finally, curcumin was attached to the M-MOF@PCL as a bioactive compound that can act as a wound-healing agent, anti-oxidant, and anti-inflammatory. The presence of the M-MOF in final composites was investigated by different methods such as FTIR (Fourier-transform infrared), XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy-dispersive X-ray spectroscopy), and TEM (transmission electron microscope). SEM images confirmed the porous structure of the as-obtained composites. According to the EDS and TEM images, M-MOFs were uniformly incorporated throughout the PCL sponges. The water sorption capacities of the blank PCL, Cu-MOF@PCL, and Zn-MOF@PCL were determined as 56%, 155%, and 119%, respectively. In vivo investigation on a third-degree burn model in adult male Wistar rats exhibited an accelerated wound healing for Cu-MOF@PCL compared to with Zn-MOF@PCL and the control group.
Assuntos
Curcumina , Estruturas Metalorgânicas , Nanocompostos , Ratos , Animais , Masculino , Ratos Wistar , Poliésteres/química , Nanocompostos/química , Cicatrização , Zinco , Alicerces Teciduais/químicaRESUMO
Polymer matrix composites have garnered the interest of the dentistry sector. Nano-fillers are frequently used as reinforcements in these composites to enhance their characteristics. Poly (methyl methacrylate) was filled with date seed nanoparticles (DSNP) and titanium oxide nanoparticles (TiO2NP). In this work, two nanofillers (DSNP and TiO2NP) were analyzed using Fourier-transform infrared spectroscopy (FTIR). In addition, the features of the PMMA-nanofiller composite were experimentally evaluated via compression, micro-hardness, wear rate (WR), and coefficients of friction (µ) testing. Utilizing a scanning electron microscope (SEM), the microstructure of the PMMA-DSNP composite was examined. The results of the experiments on the nanocomposites demonstrated that the elastic modulus, microhardness, wear resistance, and friction resistance increased with an increase in DSNP content to 1.2 wt, in comparison to TiO2NP at the same concentration. Finally, according to the guidelines, the ideal weight was determined to be 1.2 wt%, filler in the form of DSNP, at a normal load of 10 N.
Assuntos
Nanocompostos , Polimetil Metacrilato , Resinas Compostas/química , Teste de Materiais , Metacrilatos/química , Nanocompostos/química , Polimetil Metacrilato/química , Propriedades de Superfície , TitânioRESUMO
The current paper exhibited a green method for the manufacture of Ag-doped ZnO/CaO nanocomposites (NCPs) by the usage of Caccinia macranthera seed extract, zinc, calcium, and silver salts solution, for the first time. The chemical structure of NCPs was studied by the FT-IR technique. The XRD pattern shows a crystallite structure with an Fm3m group space and particle size of about 23 nm. The FESEM/PSA images displayed that NCPs have uniform distribution with spherical morphology. Also, the cytotoxicity of synthesized NCPs was examined on Huh-7 cells by MTT test and the IC50 value was 250 ppm. Additionally, the photocatalytic activity of NCPs was investigated to the methylene blue MB dye degradation, which resulted in a removal of about 90% after 100 min. According to the results of the broth microdilution process, which was done to evaluate the antibacterial activity of NCPs towards gram-positive and gram-negative bacteria, the MIC values were in the range of 0.97-125 ppm.
Assuntos
Nanocompostos , Óxido de Zinco , Antibacterianos/química , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Espectroscopia de Infravermelho com Transformada de Fourier , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Nanocompostos/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , CatáliseRESUMO
In this research work, Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites have been synthesized via an eco-friendly green synthesis technique, solgel route and co-precipitation method respectively for the assessment of antibacterial activity as well as in vivo toxicity. The XRD patterns confirm the formation of Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites showing monoclinic structures. Crystallite size and lattice strain are calculated by Scherrer equation, Scherrer plot and Willimson Hall plot methods. Average crystallite size measured for Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites by Scherrer equation, Scherrer plot and WH-plot methods are (5.1, 13.9, 11.5)nm, (5.4, 14.2, 11.3)nm and (5.2, 13.5, 12.0)nm respectively. Optical properties such as absorption peaks and band-gap energies are studied by UV-vis spectroscopy. The FTIR peaks at 513 cm-1, 553 cm-1 and 855 cm-1 confirms the successful synthesis of Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites. The antibacterial activity of synthesized Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites is examined against two gram-negative (Escherichia coli and pseudomonas) as well as gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) at dose 25 mg/kg and 40 mg/kg by disk diffusion technique. Zone of inhibition for Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO at dose 40 mg/kg against E. coli (gram - ve) are 12 mm, 17 mm and 18 mm respectively and against Pseudomonas (gram - ve) are 28 mm, 19 mm and 21 mm respectively. While the zone of inhibition for Bi2O3/GO and Bi2O3/CuO/GO at dose 40 mg/kg against B. cereus (gram + ve) are 8 mm and 8.5 mm respectively and against S. aureus (gram + ve) are 5 mm and 10.5 mm respectively. These amazing results reveal that Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposite as a kind of antibacterial content, have enormous potential for biomedical applications. In addition, the in vivo toxicity of synthesized Bi2O3/CuO/GO nanocomposite is investigated on Swiss Albino mice at dose of 20 mg/kg by evaluating immune response, hematology and biochemistry at the time period of 2, 7, 14 and 30 days. No severe damage is observed in mice during whole treatment. The p value calculated by statistical analysis of hematological and biochemistry tests is nonsignificant which ensures that synthesized nanocomposites are safe and non-toxic as they do not affect mice significantly. This study proves that Bi2O3/CuO/GO nanocomposites are biocompatible and can be explored further for different biomedical applications.
Assuntos
Nanocompostos , Staphylococcus aureus , Animais , Antibacterianos/toxicidade , Cobre/química , Análise Custo-Benefício , Escherichia coli , Camundongos , Testes de Sensibilidade Microbiana , Nanocompostos/química , Nanocompostos/toxicidadeRESUMO
Graphene and its composites with semiconductor materials have been received highly attention in many research areas because of their unique properties. Efficient application of graphene is hindered by the lack of cost-effective synthesis methods. In this work, an economic and facile route for mass production of graphene-titanate nanocomposite has been discussed. Graphene was prepared by exfoliation of graphite powder in 40% ethanol aqueous solution. Titanate nanotubes were grown on graphene sheets by hydrothermal method, where the dispersed graphene sheets were mixed with titanate solution and then placed in autoclave and placed in oven for 16 h at 160 °C. The prepared composite was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), thermogravimetric analysis (TGA). All the obtained results confirmed the synthesis of graphene and its composite with titanate in highly uniform and pure form. The adsorption efficiency of the prepared composite was tested using methylene blue (MB) as a model dye. The adsorption isotherm was investigated using Freundlich and Langmuir models. The adsorption capacity of MB was 270.27 mg/g. The obtained correlation coefficients (R2) by Freundlich and Langmuir model were 0.996 and 0.973, respectively. The adsorption kinetics was investigated and discussed using different models. The thermal stability of the developed composite is improved after MB adsorption.
Assuntos
Grafite , Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Adsorção , Etanol , Grafite/química , Cinética , Azul de Metileno/química , Nanocompostos/química , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Poluentes Químicos da Água/química , Purificação da Água/métodosRESUMO
Sustainable wastewater treatment is crucial to remediate the water pollutants through the development of highly efficient, low-cost and separation free photocatalyst. The aim of this study is to construct a novel CoNiO2-BiFeO3-NiS ternary nanocomposite (NCs) for the efficient degradation of organic pollutants by utilising visible light. The NCs was characterized by various physiochemical techniques, including HR-TEM, SEM, XPS, FT-IR, ESR, EIS, PL, UV-visible DRS, and N2 adsorption and desorption analysis. The photocatalyst exhibits extraordinary degradation efficiency towards MO (99.8%) and RhB (97.8%). The intermediates were determined using GC-MS analysis and the degradation pathway was elucidated. The complete mineralization was further confirmed by TOC analysis. The CoNiO2-BiFeO3-NiS ternary NCs have shown excellent photostability, structural stability and reusability even after six cycles and it is confirmed by XRD and XPS analysis. The kinetic study reveals that the photodegradation of the dyes follows first order reaction. The influence of different pH, dye concentrations and NCs dosages were investigated. The intermediate toxicity was predicted by computational stimulation using ECOSAR software. The NCs shows promising potential for ecological safety which demonstrates its practical application in the treatment of waste water pollutants in large scale.
Assuntos
Nanocompostos , Poluentes Químicos da Água , Compostos Azo , Catálise , Corantes/química , Cinética , Luz , Nanocompostos/química , Rodaminas , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/químicaRESUMO
Scaffolds based on biopolymers and nanomaterials with appropriate mechanical properties and high biocompatibility are desirable in tissue engineering. Therefore, polylactic acid (PLA) nanocomposites were prepared with ceramic nanobioglass (PLA/n-BGs) at 5 and 10 wt.%. Bioglass nanoparticles (n-BGs) were prepared using a sol-gel methodology with a size of ca. 24.87 ± 6.26 nm. In addition, they showed the ability to inhibit bacteria such as Escherichia coli (ATCC 11775), Vibrio parahaemolyticus (ATCC 17802), Staphylococcus aureus subsp. aureus (ATCC 55804), and Bacillus cereus (ATCC 13061) at concentrations of 20 w/v%. The analysis of the nanocomposite microstructures exhibited a heterogeneous sponge-like morphology. The mechanical properties showed that the addition of 5 wt.% n-BG increased the elastic modulus of PLA by ca. 91.3% (from 1.49 ± 0.44 to 2.85 ± 0.99 MPa) and influenced the resorption capacity, as shown by histological analyses in biomodels. The incorporation of n-BGs decreased the PLA crystallinity (from 7.1% to 4.98%) and increased the glass transition temperature (Tg) from 53 °C to 63 °C. In addition, the n-BGs increased the thermal stability due to the nanoparticle's intercalation between the polymeric chains and the reduction in their movement. The histological implantation of the nanocomposites and the cell viability with HeLa cells higher than 80% demonstrated their biocompatibility character with a greater resorption capacity than PLA. These results show the potential of PLA/n-BGs nanocomposites for biomedical applications, especially for long healing processes such as bone tissue repair and avoiding microbial contamination.