RESUMEN
In this study, we present a novel core-shell antibacterial agent designed for water disinfection purposes. The nanocomposite is synthesized by combining quince seed mucilage (QSM) as the shell material and Fe3O4 as the core material. The integration of antibacterial silver nanoparticles (Ag NPs) onto the QSM shell effectively prevents agglomeration of the Ag NPs, resulting in a larger contact surface area with bacteria and consequently exhibiting enhanced antibacterial activity. The incorporation of magnetic Fe3O4 NPs with a saturation magnetization of 55.2 emu·g-1 as the core allows for easy retrieval of the nanocomposites from the medium using a strong magnetic field, enabling their reusability. The Fe3O4/QSM/Ag nanocomposite is extensively characterized using XRD, FT-IR, VSM, DLS, FE-SEM, and TEM techniques. The characterization results confirm the successful synthesis of the nanocomposites, with an average particle size of 73 nm and no contamination or impurities detected. The nanocomposites exhibit superparamagnetic properties, with a saturated magnetization of 22.69 emu·g-1, ensuring facile separation from water. The antibacterial activity of the synthesized nanocomposite is evaluated using the disk diffusion method against both Gram-positive and Gram-negative bacteria. The results reveal excellent antibacterial efficacy, with minimum inhibition concentrations (MIC) of 0.8 mg·mL-1 against E. coli and S. typhimurium. Furthermore, the measurement of released silver ions in water using ICP-OES indicates a low concentration of remaining silver ions in the medium, highlighting the controlled release of antimicrobial agents. Overall, this study provides valuable insights into the development of advanced antibacterial agents for water disinfection applications, offering potential solutions to combat microbial contamination effectively.
Asunto(s)
Nanopartículas del Metal , Nanocompuestos , Óxido Ferrosoférrico/farmacología , Antibacterianos/farmacología , Plata/farmacología , Escherichia coli , Espectroscopía Infrarroja por Transformada de Fourier , Bacterias Gramnegativas , Bacterias Grampositivas , Pruebas de Sensibilidad Microbiana , Polisacáridos/farmacología , Semillas , Iones/farmacología , Agua/farmacologíaRESUMEN
This study reports the synthesis, characterization, and antibacterial activity of a novel Fe3O4 nanocomposite coated with fenugreek seed gums and silver nanoparticles (AgNPs). To enhance the antibacterial properties of AgNPs and overcome the limitations of conventional methods for the production of three-component nanocomposites, a layer of natural polymer was used. Fenugreek seed gums (FSG) were used to coat Fe3O4 NPs to prevent their decomposition and to facilitate the release of silver nanoparticles in aqueous media. The Fe3O4/FSG/Ag nanocomposites were characterized and then the antibacterial activity of the nanocomposites was evaluated against two gram-negative and two gram-positive bacteria and compared with Fe3O4, Fe3O4/FSG, FSG, and AgNO3. The results showed that the Fe3O4/FSG/Ag nanocomposites had higher antibacterial activity than the other samples and could be easily removed from treated water by a powerful magnet without causing pollution in the environment. Overall, these findings suggest that the Fe3O4/FSG/Ag nanocomposites have potential applications in water treatment for their improved antibacterial properties and ease of removal.
RESUMEN
This study evaluated several secondary metabolites, essential oils (EOs) compositions, and antioxidant activity in four medicinal plants that originated in Isfahan rangelands. The species were Astragalus verus, Astragalus adscendens, Daphne mucronata, and Phlomis olivieri. Thirty-two genotypes of these species were evaluated for different biochemical traits. Based on the evaluation of EOs compounds, GC/MS analysis revealed the total number of identified compounds. These compounds were 25, 22, 12, and 22 for A. adscendens, A. verus, D. mucronata, and P. olivieri, respectively. The dominant compounds were phthalate (59.88 %) in A. adscendens, phytol (38.02 %) in A. verus, hexanoic acid (32.05 %) in D. mucronata and ß-cubebene (30.94 %) in P. olivieri. Phytochemical analysis showed that D. mucronata, A. adscendens, and P. olivieri had the highest total phenolics content (TPC) (18.24â mg gallic acid equivalent/g dry weight), total flavonoids content (5.57â mg QE/g DW), and total anthocyanins content (0.23â mg/g DW), respectively. The highest total chlorophyll (0.27â mg/g DW), total carotenoids (0.03â mg/g DW), and antioxidant activity (71.36 %) were observed in A. adscendens, A. adscendens and A. verus, respectively. Among all genotypes, the highest TPC (20.1â mg GAE/g DW) was observed in genotypeâ 5 of D. mucronata. This study provided new information on the chemical compounds within the distribution range of these ecologically dominant rangeland species in Isfahan province, Iran. The data revealed that superior genotypes from these species are rich in natural antioxidants and bioactive compounds. Thus, they can be used in ethno pharmacological fields, food, and industrial applications.
Asunto(s)
Daphne , Aceites Volátiles , Phlomis , Antioxidantes/química , Aceites Volátiles/farmacología , Antocianinas , Irán , Fitoquímicos/química , Flavonoides/química , Fenoles/química , Ecosistema , Extractos Vegetales/químicaRESUMEN
In this study, we aimed to fabricate an enhanced antibacterial agent to act against pathogenic bacteria in aqueous environments. To achieve this, silver nanoparticles (AgNPs) were inlaid on a kappa-carrageenan (KC) base and coated on Fe3O4 magnetic cores (Fe3O4@KC@Ag). Superparamagnetic Fe3O4 nanoparticles were designed at the center of the composite nanostructure, allowing magnetic recovery from aqueous media in the presence of a magnet. The synthesized nanoconjugate was characterized in each step using XRD, FT-IR, EDX, FE-SEM, TEM, DLS, VSM, and disk-diffusion antibacterial method. Results show that the nanocomposite system is formed, while the magnetic properties remain practically stable. The agglomeration of the AgNPs was decreased by the trap-like function of KC coating, which resulted in an improved antibacterial activity for the Fe3O4@KC@Ag formulation. These findings suggest that Fe3O4@KC@Ag nanocomposites could be promising agents for combating bacterial infections in aqueous environments.
Asunto(s)
Nanopartículas de Magnetita , Nanopartículas del Metal , Nanocompuestos , Óxido Ferrosoférrico/química , Nanopartículas del Metal/química , Carragenina/química , Plata/farmacología , Plata/química , Espectroscopía Infrarroja por Transformada de Fourier , Antibacterianos/farmacología , Antibacterianos/química , Nanocompuestos/química , Nanopartículas de Magnetita/químicaRESUMEN
In this study, we fabricated magnetic Fe3O4 nanoparticles conjugated with anionic hydroxypropyl starch-graft-acrylic acid (Fe3O4@AHSG) for the efficient removal of methylene blue (MB) dye from aqueous solutions. The synthesized nanoconjugates were characterized using various techniques. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis revealed that the particles exhibited homogeneously distributed nanosized spherical shapes with a mean diameter of 41.72 ± 6.81 nm. The EDX analysis confirmed the absence of impurities, with the Fe3O4 particles comprising 64.76 % iron and 35.24 % atomic oxygen. Dynamic light scattering (DLS) measurements showed a monodisperse particle system with a mean hydrodynamic size of 135.4 nm (polydispersity index, PI = 0.530) for the Fe3O4 nanoparticles and 163.6 nm (PI = 0.498) for the Fe3O4@AHSG adsorbent. Vibrating sample magnetometer (VSM) analysis indicated superparamagnetic behavior for both Fe3O4 and Fe3O4@AHSG, with higher saturation magnetization (Ms) observed for Fe3O4. The dye adsorption studies demonstrated that the adsorbed dye capacity increased with increasing initial MB concentration and adsorbent dose. The pH of the dye solution significantly influenced the adsorption, with the highest adsorption observed at basic pH values. The presence of NaCl reduced the adsorption capacity due to increased ionic strength. Thermodynamic analysis indicated the thermodynamically favorable and spontaneous nature of the adsorption process. Kinetic studies revealed that the pseudo-second-order model provided the best fit to the experimental data, suggesting chemisorption as the rate-limiting step. Overall, Fe3O4@AHSG nanoconjugates exhibited excellent adsorption capacity and could be a promising material for effective removal of MB dye from wastewater.
Asunto(s)
Brassicaceae , Contaminantes Químicos del Agua , Agua/análisis , Azul de Metileno/química , Cinética , Nanoconjugados , Óxido Ferrosoférrico , Adsorción , Fenómenos Magnéticos , Semillas/química , Contaminantes Químicos del Agua/químicaRESUMEN
In this investigation, we have synthesized magnetite nanoparticles (Fe3O4 NPs) coated with quince seed mucilage (QSM) as a natural, biocompatible, and biodegradable component and loaded them with ciprofloxacin (CIP) to act as an antibacterial agent. The structural, magnetic, physicochemical, colloidal, and antibacterial properties of the samples were tested using various characterization tools such as XRD, TEM, FE-SEM, VSM, FT-IR, UV-Vis, DLS, BET, and disk diffusion for testing the antibacterial properties. XRD and VSM results confirmed the fabrication of a highly pure cubic spinel phase for Fe3O4. The results of FE-SEM and TEM analyses indicate a spherical morphology of the magnetite NPs with a mean diameter of about 13 nm, and the results of DLS show a hydrodynamic diameter of 81.9 to 119.2 nm. The zeta potential value for the magnetic Fe3O4 NPs was as high as -55.2 mV, indicating suitable colloidal stability of the NPs for biological applications. The VSM results indicate a high saturation magnetization of the samples as well as a small coercivity and Remanence of the samples, which indicate the superparamagnetic property of the NPs. It was also indicated that the amount of drug adsorbed on the magnetic nanoparticles at different pH values (5.5 to 6.5) is about 85 %. It was likewise detected that the synthesized Fe3O4@QSM-CIP NPs possess antibacterial activity against standard strains of both Gram positive and Gram-negative bacteria (minimum inhibitory concentration = 100 ppm). The overall findings imply that the proposed magnetic NPs with antibacterial activity are promising for biomedical applications.
Asunto(s)
Nanopartículas de Magnetita , Nanopartículas , Antibacterianos/farmacología , Antibacterianos/química , Ciprofloxacina/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Nanopartículas/química , Semillas , Polisacáridos , Fenómenos Magnéticos , Nanopartículas de Magnetita/químicaRESUMEN
Biocompatible electrospun nanofiber scaffolds were fabricated in this study using Persian gum (PG) and poly (vinyl alcohol) (PVA) to build an artificial extracellular matrix for cell growth. The preparation procedure involves mixing various ratios of PG/PVA to be electrospun and seeded with L929 fibroblasts. Upon addition of PG up to 60% to the solutions, a 30% decrease to around 240 µs·cm-1 is found in electrical conductivity which is in the range of semi-conductive polymers, whereas the surface tension is increased to around 3%. The fabricated scaffolds were characterized by morphological, chemical, thermal and structural analyses including SEM, FTIR spectroscopy, DSC, XRD, and tensile stress. The results showed that incorporation of 50% PG to the polymer solutions causes the formation of nanofibers with the least bead-shaped segments. All ratios of nanofibers containing PG showed significant biocompatibility with the cultured cells, which is presumably due to the radical scavenging feature of PG. The MTT and SEM analyses demonstrated that the scaffolds containing 50% PG possess the optimal cell compatibility, adhesion and proliferation properties. The fabricated PG/PVA cell culture scaffolds are potentially appropriate for wound dressing and cell culture applications in biomedicine.
Asunto(s)
Nanofibras , Técnicas de Cultivo de Célula , Nanofibras/química , Polímeros , Alcohol Polivinílico/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/químicaRESUMEN
In this study, hybrid nanofibrous 3D scaffolds containingAloe vera(AV), polyvinyl alcohol (PVA) and tetracycline hydrochloride (TCH) are fabricated by electrospinning for cell culture applications. The role of polysaccharides present in AV gel is found to enhance the biocompatibility of the nanofibrous scaffolds. Different combinations of the polymers were selected to produce homogenous nanofibers with favorable mean fiber diameter and tensile strength. The surface morphology of the products was studied by SEM and it is found that the mean fiber diameter is decreased to about 188 nm upon addition of the AV component. The electrospun scaffolds were investigated by FT-IR spectroscopy to reveal the chemical structure of the samples and their crystallinity was studied by XRD. The hydrophilicity of the scaffolds was tested by optical contact angle measurements and their mechanical strength was examined by tensile strength tests. It is found that PVA is the main component contributing the mechanical stability of the scaffold structure. The fabricated scaffolds presented a more pronounced inhibitory effect against Gram-positive bacterial strains ofS. aureusandB. cereus. Cell culture experiments using fibroblast L929 murine cells reveals that the AV/PVA/TCH scaffolds are promising for cell growth and the cells are capable of achieving a proper cell adhesion and proliferation. The cell viability experiment by MTT assay exhibits the contributing role of AV gel to L929 cell viability on the AV/PVA/TCH scaffolds.
Asunto(s)
Nanofibras , Alcohol Polivinílico , Animales , Antibacterianos/química , Antibacterianos/farmacología , Técnicas de Cultivo de Célula , Proliferación Celular , Ratones , Nanofibras/química , Alcohol Polivinílico/química , Espectroscopía Infrarroja por Transformada de Fourier , Tetraciclina/farmacología , Ingeniería de Tejidos/métodos , Andamios del Tejido/químicaRESUMEN
This study investigates the potential of iron oxide nanoparticles (Fe3O4) and quince seed mucilage as combined genetic carriers to deliver plasmid DNA (pDNA) through the gastrointestinal system. The samples are characterized by x-ray diffraction (XRD), zeta potential, dynamic light scattering, FT-IR spectroscopy, field emission scanning electron microscopy and vibrating sample magnetometry. The stability of pDNA loading on the nanocarriers and their release pattern are evaluated in simulated gastrointestinal environments by electrophoresis. The XRD patterns reveal that the nanocarriers could preserve their structure during various synthesis levels. The saturation magnetization (Ms) of the Fe3O4cores are 56.48 emu g-1without any magnetic hysteresis. Not only does the loaded pDNA contents experience a remarkable stability in the simulated gastric environment, but also, they could be released up to 99% when exposed to an alkaline environment similar to the intestinal fluid of fish. The results indicate that the synthesized nanoparticles could be employed as efficient low-cost pDNA carriers.
Asunto(s)
Técnicas de Transferencia de Gen , Nanopartículas de Magnetita/química , Sistema de Administración de Fármacos con Nanopartículas/química , Mucílago de Planta/química , Plásmidos , ADN/química , ADN/farmacocinética , Tamaño de la Partícula , Plásmidos/química , Plásmidos/farmacocinética , Rosaceae/química , Semillas/químicaRESUMEN
Synthesis of Balangu (Lallemantia royleana) seed mucilage (BSM) solutions combined with polyvinyl alcohol (PVA) was studied for the purpose of producing 3D electrospun cell culture scaffolds. Production of pure BSM nanofibers proved to be difficult, yet integration of PVA contributed to a facile and successful formation of BSM/PVA nanofibers. Different BSM/PVA ratios were fabricated to achieve the desired nanofibrous structure for cell proliferation. It is found that the optimal bead-free ratio of 50/50 with a mean fiber diameter of ≈180 nm presents the most desirable scaffold structure for cell growth. The positive effect of PVA incorporation was approved by analyzing BSM/PVA solutions through physiochemical assays such as electrical conductivity, viscosity and surface tension tests. According to the thermal analysis (TGA/DSC), incorporation of PVA enhanced thermal stability of the samples. Successful fabrication of the nanofibers is verified by FT-IR spectra, where no major chemical interaction between BSM and PVA is detected. The crystallinity of the electrospun nanofibers is investigated by XRD, revealing the nearly amorphous structure of BSM/PVA scaffolds. The MTT assay is employed to verify the biocompatibility of the scaffolds. The cell culture experiment using epithelial Vero cells shows the affinity of the cells to adhere to their nanofibrous substrate and grow to form continuous cell layers after 72 h of incubation.
Asunto(s)
Técnicas Electroquímicas/métodos , Lamiaceae/química , Mucílago de Planta/química , Alcohol Polivinílico/química , Andamios del Tejido/química , Animales , Materiales Biocompatibles/toxicidad , Técnicas de Cultivo de Célula/métodos , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Ensayo de Materiales , Nanofibras/química , Nanofibras/toxicidad , Semillas/química , Células VeroRESUMEN
Chitosan-based hydrogels are a suitable and versatile system for the design of localized and controlled drug delivery systems. In the current study, a hydrogel based on chitosan (CS), Dopamine (DA), and Inulin aldehyde (IA) was fabricated without the further use of catalyst or initiators. The effect of the IA contents as a crosslinking agent on the properties of the prepared hydrogel was studied. The crosslinking reaction between CS and IA was verified by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Various characteristics of the CS/DA/IA hydrogels were further assessed utilizing swelling experiment, in vitro drug release, in vitro cytotoxicity assay. The drug-loaded hydrogels represented the sustained release of Indomethacin according to the in vitro drug release test in acidic (pH = 4), basic (pH = 10) medium as well as physiological condition (pH = 7). Finally, the CS/DA/IA hydrogels exhibited appropriate cytocompatibility against the L-929 fibroblast cell line according to the direct contact MTT assay.
Asunto(s)
Quitosano/química , Dopamina/química , Fibroblastos/citología , Indometacina/farmacología , Inulina/química , Animales , Rastreo Diferencial de Calorimetría , Sistemas de Liberación de Medicamentos , Fibroblastos/efectos de los fármacos , Hidrogeles , Concentración de Iones de Hidrógeno , Indometacina/química , Ratones , Microscopía Electrónica de Rastreo , Porosidad , Espectroscopía Infrarroja por Transformada de Fourier , TermogravimetríaRESUMEN
A prominent medical application of nanotechnology is represented in drug delivery. In this work, carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) were used for producing CMC/PVA aqueous-based nanofibers loaded with flufenamic acid (FFA) as a drug containing amine groups. The CMC/PVA solutions with 90/10, 80/20, 70/30, 60/40 and 50/50 ratios were considered for electrospinning. Two integration methods were studied for loading FFA on the nanofibers during the electrospinning process. The characterization techniques of SEM, AFM, fluorescence microscopy and FT-IR spectroscopy were used to study the produced nanofibers, indicating a uniform distribution of FFA throughout the samples. The resulting nanofibers were formed in a diameter range of 176-285 nm and exhibited a 5 h degradation time in the PBS buffer solution. A standard diagram of drug loading was obtained for the samples. The drug release pattern was examined using a dialysis tube method. UV-visible spectroscopy revealed a time-dependent drug release behavior in CMC/PVA/FFA nanofibers where a sharp release occurred over the first 20 min. However, a prolonged release time of 10 h was achieved using a cross-linker (EDC).
Asunto(s)
Carboximetilcelulosa de Sodio/química , Sistemas de Liberación de Medicamentos , Ácido Flufenámico/farmacología , Nanofibras/química , Carboximetilcelulosa de Sodio/farmacología , Ácido Flufenámico/química , Humanos , Microscopía de Fuerza Atómica , Microscopía Fluorescente , Nanofibras/uso terapéutico , Nanofibras/ultraestructura , Nanotecnología/tendencias , Alcohol Polivinílico/química , Alcohol Polivinílico/uso terapéutico , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
In the present study, a porous structure consisting of three-dimensional graphene (3DG) decorated with Cu-based nanoparticles (NPs) (Cu or Cu-Cu2O) was synthesized in order to develop an enzyme-free electrochemical glucose sensor. Moreover, the effects of Cu-based nanoparticle concentrations on electrochemical properties and glucose detection were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. Cu-based NPs@3DG showed markedly better electrochemical performance in glucose oxidation in alkaline solution compared to 3DG foam. Moreover, Cu-Cu2O NPs@3DG foam with the lowest concentration of Cu precursor showed excellent performance in glucose detection. A high sensitivity of 230.86⯵Aâ¯mM-1â¯cm-2 was obtained for this electrode in a linear range of 0.8-10â¯mMâ¯(R2â¯=â¯0.9951) and a detection limit of 16⯵M. This sensor also showed good repeatability (relative standard deviation of 1.02%) and high selectivity (no observation of significant interference by interfering species such as ascorbic acid, dopamine, urea, and acetaminophen). The results confirmed that this electrode could be applied as a feasible and inexpensive non-enzymatic electrochemical glucose sensor.
Asunto(s)
Glucemia , Cobre/química , Técnicas Electroquímicas , Grafito/química , Nanopartículas/química , Glucemia/análisis , Glucemia/metabolismo , HumanosRESUMEN
In the present study, the polymer obtained from Cydonia oblonga Miller seeds (quince seed mucilage (QSM)) in combination with polycaprolactone (PCL) was used for producing hybrid electrospun scaffolds as three-dimensional (3D) cell culture platforms. Various PCL/QSM ratios were tested to obtain a uniform product with an appropriate mean fiber diameter for cell growth. The chemical structures of the scaffolds were studied by FT-IR spectroscopy and their crystallinity was investigated by XRD. Fiber morphology studies by SEM revealed that the fiber mean diameters decrease upon increasing the QSM component of the electrospun compound. The PCL/QSM ratio of 60/40 exhibited desirable uniform bead-free nanofibers. The hydrophilicity of the scaffolds were explored by contact angle measurements, which indicated that more hydrophilic fibers are produced as the PCL/QSM ratio is decreased. Porosity and strength of the scaffolds were also studied, which showed the key role of PCL in mechanical strength of the nanofibers. The results of cell culture experiments using epithelial Vero cells on the scaffolds displayed their high capacity in cell growth and proliferation. It was revealed that the electrospun PCL/QSM based scaffolds with 3D structures and 75-150 nm mean fiber diameters are able to maximize adhesion and growth of Vero cells.
Asunto(s)
Nanofibras/química , Mucílago de Planta/química , Poliésteres/química , Rosaceae/química , Ingeniería de Tejidos , Andamios del Tejido/química , Animales , Técnicas de Cultivo de Célula , Proliferación Celular , Chlorocebus aethiops , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Porosidad , Semillas/química , Espectroscopía Infrarroja por Transformada de Fourier , Células VeroRESUMEN
Along with the extensive range of exotic nanoparticle (NPs) applications, investigation of magnetic NPs (MNPs) in vitro has ushered modern antibacterial studies into an increasingly attractive research area. A great number of microorganisms exist in the size scales from nanometre to micrometre regions. The enormous potential of engineered MNPs in therapeutic procedures against various drug-resistant bacteria has declined the menace of fatal bacterial infections. Many biocompatible MNPs have been introduced that possess remarkable impacts on various bacterial strains. Conventional synthesis methods such as co-precipitation or hydrothermal techniques have been widely adopted in the production of MNPs. The MNPs for antibacterial applications are mainly required to be superparamagnetic, recyclable and biocompatible. To implement novel strategies in developing new generation antimicrobial magnetic nanomaterials, it is essential to obtain a comprehensive preview of recent achievements in synthesis, proposed antibacterial mechanisms and characterisation techniques of these nanomaterials. This review highlights notable aspects of antibacterial activity in engineered MNPs and nanocomposites including their particle properties (size, shape and saturation magnetisation), antibacterial mechanisms, synthesis methods, testing methods, surface modifications and minimum inhibitory concentrations.
Asunto(s)
Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Nanopartículas de Magnetita/uso terapéutico , Animales , Antibacterianos/síntesis química , Antibacterianos/química , Humanos , Nanopartículas de Magnetita/química , Pruebas de Sensibilidad Microbiana , Nanocompuestos/química , Nanocompuestos/uso terapéuticoRESUMEN
An immunomagnetic optical probe based on a core/shell magnetic nanoparticle-quantum dot was fabricated for detection of Streptococcus agalactiae, the causative agent of pneumonia and meningitis in newborns. The silica-coated magnetic nanoparticles conjugated with anti-S. agalactiae monoclonal antibody provided high specificity for pre-enrichment of bacteria from biological samples with a complex matrix such as milk. Compared with conventional methods such as culture and molecular techniques, the combination of fluorescent quantum dot and magnetic nanoparticle enhanced the sensitivity and speed of bacterial identification. The bio-functionalized fluorescent-magnetic nanoparticles were characterized by TEM, SEM, VSM, XRD, DLS, and FTIR and applied to the detection of S. agalactiae with a limit of 10 and 102 CFU/mL in PBS and milk, respectively. This immunomagnetic optical probe can be used for rapid isolation, sensitive, and specific detection of targeted bacteria without any treatment in clinical and animal samples in the presence of other infectious agents.
Asunto(s)
Técnicas Biosensibles/métodos , Colorantes Fluorescentes/química , Nanopartículas de Magnetita/química , Leche/microbiología , Streptococcus agalactiae/aislamiento & purificación , Animales , Anticuerpos Inmovilizados/química , Análisis de los Alimentos/métodos , Separación Inmunomagnética/métodos , Nanopartículas de Magnetita/ultraestructura , Microscopía Fluorescente/métodos , Puntos Cuánticos/química , Puntos Cuánticos/ultraestructura , Dióxido de Silicio/química , Espectrometría de Fluorescencia/métodos , Infecciones Estreptocócicas/microbiologíaRESUMEN
Due to applications of silver nanoparticles (Ag NPs) especially in advanced science fields, it is important to produce Ag antibacterial nanocomposites with enhanced antibacterial activity and reusability. Over the past decade researches about natural polymers have emphasized the use of them as nanoparticles coating. In this work, a novel core-shell antibacterial agent was synthesized through a three-step procedure. Fe3O4 nanoparticles (Fe3O4 NPs) were synthesized and coated with a natural polymer called Alyssum homolocarpum seed gum (AHSG). Ag NPs were immobilized on the AHSG resulting in formation of the new nanocomposite with improved antimicrobial properties. The immobilization of Ag NPs prevents the release of toxic Ag+ ions. The Fe3O4@AHSG@Ag nanocomposite could easily be separated from medium using an external magnetic field due to presence of the Fe3O4 superparamagnetic nanoparticles. The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, vibrating sample magnetometer and dynamic light scattering. The results showed that the magnetic nanocomposite was synthesized and coated successfully. Finally, results of disk diffusion method demonstrated that the nanocomposite exhibits excellent antibacterial activity against gram-positive and gram-negative bacteria.
Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Nanopartículas de Magnetita/química , Magnoliopsida/química , Nanocompuestos/química , Gomas de Plantas/química , Plata/química , Antibacterianos/química , Técnicas de Química Sintética , Nanopartículas del Metal/química , Semillas/químicaRESUMEN
Various concentrations of ß-carotene (2.5-20% w/w dry mucilage weight) were loaded within Cydonia oblonga mucilage (COM) which further processed through electrohydrodynamic processing (EHP) to attain BC-Loaded nanostructures of high thermochemical stability. The BC loaded COM systems were characterized in terms of droplet size, rheological properties, surface tension, and electrical conductivity and their subsequent impacts on the morphology and physicochemical attributes of the produced nanostructures were studied. Increasing the ß-carotene content, increased the viscosity and droplet size of colloidal systems but diminished their conductivity and surface tension. A transition from monomodal to bimodal size distribution was also observed at higher levels of ß-carotene incorporation. In the case of EHP-produced nanostructures, scanning electron microscopy observations revealed a transition from nanoparticle to nanofiber by increasing the BC content from 2.5 to 20%. At lower concentrations of BC (2.5 and 5%) electrospraying was the dominant phenomenon that resulted in producing homogenous nanoparticles while the beaded fibers and nanofiber structures were obtained at 10 and 20% concentrations of BC, respectively. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and encapsulation efficiency of the produced nanostructures revealed successful encapsulation of BC into the COM polymer structure through EHP. The results of these assessments showed that the nano-particles comprising BC had more homogenous structure and higher encapsulated BC compared to the BC-loaded nano-fibers. The results of X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements revealed amorphous structure of the produced nanostructures. Thermogravimetric assessments corroborated the higher thermal stability of BC loaded nanostructures compared with the free BC. These results provided novel information on the ability of COM in encapsulating bioactive agents through electrohydrodynamic processing.
Asunto(s)
Electroquímica/métodos , Nanoestructuras/química , Xilanos/química , beta Caroteno/química , Rastreo Diferencial de Calorimetría , Conductividad Eléctrica , Emulsiones , Microscopía Electrónica de Rastreo , Nanofibras/química , Nanopartículas/química , Mucílago de Planta/química , Polímeros/química , Reología , Rosaceae/química , Dispersión de Radiación , Semillas/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Tensión Superficial , Termogravimetría , ViscosidadRESUMEN
A magnetic nanocomposite adsorbent based on cress seed mucilage (CSM) was synthesized for removing methylene blue (MB) cationic dye from aqueous solutions. These adsorbent nanoparticles were prepared by in situ formation of magnetic iron oxide nanoparticles (MIONs) coupled with CSM mucilage and benefited from the advantages of both CSM and MIONs. The CSM-MIONs adsorbent exhibited a great dye adsorption capacity along with a strong magnetic character. The effect of various experimental parameters were studied on the adsorption performance of CSM-MIONs including pH, ionic strength, initial dye concentration, contact time and temperature. The adsorbent nanoparticles were characterized by FTIR, FESEM, XRD, DLS, and VSM techniques. Thermodynamic analysis indicated that the studied dye adsorption process has a spontaneous and exothermic nature. The equilibrium adsorption data were in agreement with the Langmuir kinetic model (R2â¯>â¯0.99) and described by the pseudo-second-order Langmuir equation (R2â¯>â¯0.98). It was revealed that intraparticle diffusion is not the only rate controlling factor. The CSM-MIONs adsorbents could be well regenerated using an acid solution, and showed high adsorption capability even after five desorption-adsorption cycles. The obtained results showed that the CSM-MIONs can potentially be used as a high-performance low cost adsorbent in wastewater treatment.
Asunto(s)
Brassicaceae/química , Nanopartículas de Magnetita/química , Azul de Metileno/química , Azul de Metileno/aislamiento & purificación , Nanocompuestos/química , Mucílago de Planta/química , Agua/química , Adsorción , Colorantes/química , Colorantes/aislamiento & purificación , Concentración de Iones de Hidrógeno , Cinética , Concentración Osmolar , Semillas/química , Termodinámica , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del AguaRESUMEN
This study reports the fabrication of cellulose nanoparticles through electrospraying the solution of cellulose in N,N-dimethylacetamide/lithium chloride solvent as well as investigating the effect of electrospraying conditions and molecular weight on the average size of electrosprayed nanoparticles. Electrospraying of cellulose was carried out with the following range for each factor, namely concentration = 1-3â wt%, voltage = 15-23â kV, nozzle-collector distance = 10-25â cm, and feed rate = 0.03-0.0875â ml/h. The smallest nanoparticles had an average size of around 40â nm. Results showed that lowering the solution concentration and feed rate, as well as increasing the nozzle-collector distance and applied voltage led to a decrease in the average size of the electrosprayed cellulose nanoparticles. Fourier transform infrared analysis proved that no chemical change had occurred in the cellulose structure after the electrospraying process. According to X-ray diffraction (XRD) results, cellulose nanoparticles showed a lower degree of crystallinity in comparison with the raw cellulose powder. XRD results also proved the absence of LiCl salt in the electrosprayed nanoparticles.