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1.
Int J Mol Sci ; 22(5)2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33806682

RESUMEN

Dentistry, as a branch of medicine, has undergone continuous evolution over time. The scientific world has focused its attention on the development of new methods and materials with improved properties that meet the needs of patients. For this purpose, the replacement of so-called "passive" dental materials that do not interact with the oral environment with "smart/intelligent" materials that have the capability to change their shape, color, or size in response to an externally stimulus, such as the temperature, pH, light, moisture, stress, electric or magnetic fields, and chemical compounds, has received much attention in recent years. A strong trend in dental applications is to apply nanotechnology and smart nanomaterials such as nanoclays, nanofibers, nanocomposites, nanobubbles, nanocapsules, solid-lipid nanoparticles, nanospheres, metallic nanoparticles, nanotubes, and nanocrystals. Among the nanomaterials, the smart nanoparticles present several advantages compared to other materials, creating the possibility to use them in various dental applications, including preventive dentistry, endodontics, restoration, and periodontal diseases. This review is focused on the recent developments and dental applications (drug delivery systems and restoration materials) of smart nanoparticles.


Asunto(s)
Nanopartículas del Metal/química , Tecnología Odontológica/métodos , Animales , Odontología , Humanos , Lípidos/química , Nanocápsulas/química , Nanocompuestos/química , Nanotecnología/métodos , Temperatura
2.
Int J Mol Sci ; 22(5)2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33802469

RESUMEN

In this study, nanocomposite hydrogels composed of sodium carboxymethylated starch (CMS)-containing CuO nanoparticles (CMS@CuO) were synthesized and used as experimental wound healing materials. The hydrogels were fabricated by a solution-casting technique using citric acid as a crosslinking agent. They were characterized by Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) to evaluate their physicochemical properties. In addition, swelling, antibacterial activities, antioxidant activities, cytotoxicity, and in vivo wound healing were investigated to evaluate the wound healing potential of the CMS@CuO nanocomposite hydrogels. Growth inhibition of the Gram-positive and Gram-negative pathogens, antioxidant activity, and swelling were observed in the CMS@CuO nanocomposite hydrogels containing 2 wt.% and 4 wt.% CuO nanoparticles. The hydrogel containing 2 wt.% CuO nanoparticles displayed low toxicity to human fibroblasts and exhibited good biocompatibility. Wounds created in rats and treated with the CMS@2%CuO nanocomposite hydrogel healed within 13 days, whereas wounds were still present when treated for the same time-period with CMS only. The impact of antibacterial and antioxidant activities on accelerating wound healing could be ascribed to the antibacterial and antioxidant activities of the nanocomposite hydrogel. Incorporation of CuO nanoparticles in the hydrogel improved its antibacterial properties, antioxidant activity, and degree of swelling. The present nanocomposite hydrogel has the potential to be used clinically as a novel wound healing material.


Asunto(s)
Antibacterianos/química , Antioxidantes/química , Cobre/química , Hidrogeles/química , Nanopartículas/química , Almidón/análogos & derivados , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/farmacología , Antioxidantes/farmacología , Células Cultivadas , Quitosano/química , Fibroblastos/efectos de los fármacos , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Nanocompuestos/química , Ratas , Ratas Wistar , Almidón/química , Difracción de Rayos X
3.
Sci Rep ; 11(1): 8692, 2021 04 22.
Artículo en Inglés | MEDLINE | ID: mdl-33888738

RESUMEN

A metal nanoparticle composite, namely TPNT1, which contains Au-NP (1 ppm), Ag-NP (5 ppm), ZnO-NP (60 ppm) and ClO2 (42.5 ppm) in aqueous solution was prepared and characterized by spectroscopy, transmission electron microscopy, dynamic light scattering analysis and potentiometric titration. Based on the in vitro cell-based assay, TPNT1 inhibited six major clades of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with effective concentration within the range to be used as food additives. TPNT1 was shown to block viral entry by inhibiting the binding of SARS-CoV-2 spike proteins to the angiotensin-converting enzyme 2 (ACE2) receptor and to interfere with the syncytium formation. In addition, TPNT1 also effectively reduced the cytopathic effects induced by human (H1N1) and avian (H5N1) influenza viruses, including the wild-type and oseltamivir-resistant virus isolates. Together with previously demonstrated efficacy as antimicrobials, TPNT1 can block viral entry and inhibit or prevent viral infection to provide prophylactic effects against both SARS-CoV-2 and opportunistic infections.


Asunto(s)
Oro/farmacología , Subtipo H1N1 del Virus de la Influenza A/fisiología , Subtipo H5N1 del Virus de la Influenza A/fisiología , Plata/farmacología , Óxido de Zinc/farmacología , /metabolismo , Antivirales/química , Antivirales/farmacología , Farmacorresistencia Viral/efectos de los fármacos , Aditivos Alimentarios/farmacología , Oro/química , Células HEK293 , Humanos , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H5N1 del Virus de la Influenza A/efectos de los fármacos , Nanopartículas del Metal/química , Nanocompuestos/química , Oseltamivir/farmacología , Tamaño de la Partícula , Unión Proteica/efectos de los fármacos , Plata/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , Internalización del Virus/efectos de los fármacos , Óxido de Zinc/química
4.
Int J Nanomedicine ; 16: 1601-1616, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33688181

RESUMEN

Introduction: Cancer is the second leading cause of death globally and is responsible, where about 1 in 6 deaths in the world. Therefore, there is a need to develop effective antitumor agents that are targeted only to the specific site of the tumor to improve the efficiency of cancer diagnosis and treatment and, consequently, limit the unwanted systemic side effects currently obtained by the use of chemotherapeutic agents. In this context, due to its unique physical and chemical properties of graphene oxide (GO), it has attracted interest in biomedicine for cancer therapy. Methods: In this study, we report the in vivo application of nanocomposites based on Graphene Oxide (nc-GO) with surface modified with PEG-folic acid, Rhodamine B and Indocyanine Green. In addition to displaying red fluorescence spectra Rhodamine B as the fluorescent label), in vivo experiments were performed using nc-GO to apply Photodynamic Therapy (PDT) and Photothermal Therapy (PTT) in the treatment of Ehrlich tumors in mice using NIR light (808 nm 1.8 W/cm2). Results: This study based on fluorescence images was performed in the tumor in order to obtain the highest concentration of nc-GO in the tumor as a function of time (time after intraperitoneal injection). The time obtained was used for the efficient treatment of the tumor by PDT/PTT. Discussion: The current study shows an example of successful using nc-GO nanocomposites as a theranostic nanomedicine to perform simultaneously in vivo fluorescence diagnostic as well as combined PDT-PTT effects for cancer treatments.


Asunto(s)
Grafito/química , Fotoquimioterapia , Nanomedicina Teranóstica , Adsorción , Animales , Benzofuranos/química , Carcinoma de Ehrlich/patología , Carcinoma de Ehrlich/terapia , Humanos , Verde de Indocianina/farmacología , Masculino , Ratones , Nanocompuestos/química , Tamaño de la Partícula , Rodaminas/farmacología , Espectrometría de Fluorescencia , Espectrometría Raman , Electricidad Estática , Carga Tumoral
5.
Carbohydr Polym ; 259: 117739, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33673999

RESUMEN

To fabricate antibacterial activity and simultaneous strengthened and toughened carboxylated nitrile butadiene rubber (XNBR) composites, starch was oxidized by H2O2 to achieve oxidized starch (OST) with different carboxyl content, meanwhile, ZnO were utilized to promote the in-situ interfacial reaction for improving compatibility of starch and XNBR. The formation of ionic cross-link networks and "Zinc-carboxylate polymers" in the XNBR/OST/ZnO composites were confirmed by FT-IR, XRD, XPS, SEM-EDS and TEM. Interestingly, because of the carboxyl groups of OSTs which provided a low pH surroundings to inhibit the growth of bacteria, XNBR/OST/ZnO composites achieved a significant antibacterial activity. Noteworthy, the sulfur-free XNBR composites achieved 3.04 and 1.99 times increase for tensile strength and elongation at break compared with neat XNBR. The mechanism of simultaneous strengthened and toughened for composites had been proposed. These new sustainable, green and facile fabricated XNBR/OST/ZnO could be utilized as the medical protective appliance to against the bacteria.


Asunto(s)
Butadienos/química , Nitrilos/química , Goma/química , Almidón/química , Antibacterianos/química , Antibacterianos/farmacología , Nanocompuestos/química , Oxidación-Reducción , Pseudomonas fluorescens/efectos de los fármacos , Goma/farmacología , Staphylococcus aureus/efectos de los fármacos , Temperatura , Resistencia a la Tracción , Zea mays/metabolismo , Óxido de Zinc/química
6.
Int J Mol Sci ; 22(4)2021 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-33668676

RESUMEN

Biopolymer composites based on silk fibroin have shown widespread potential due to their brilliant applications in tissue engineering, medicine and bioelectronics. In our present work, biocomposite nanofilms with different special topologies were obtained through blending silk fibroin with crystallizable poly(L-lactic acid) (PLLA) at various mixture rates using a stirring-reflux condensation blending method. The microstructure, phase components, and miscibility of the blended films were studied through thermal analysis in combination with Fourier-transform infrared spectroscopy and Raman analysis. X-ray diffraction and scanning electron microscope were also used for advanced structural analysis. Furthermore, their conformation transition, interaction mechanism, and thermal stability were also discussed. The results showed that the hydrogen bonds and hydrophobic interactions existed between silk fibroin (SF) and PLLA polymer chains in the blended films. The secondary structures of silk fibroin and phase components of PLLA in composites vary at different ratios of silk to PLLA. The ß-sheet content increased with the increase of the silk fibroin content, while the glass transition temperature was raised mainly due to the rigid amorphous phase presence in the blended system. This results in an increase in thermal stability in blended films compared to the pure silk fibroin films. This study provided detailed insights into the influence of synthetic polymer phases (crystalline, rigid amorphous, and mobile amorphous) on protein secondary structures through blending, which has direct applications on the design and fabrication of novel protein-synthetic polymer composites for the biomedical and green chemistry fields.


Asunto(s)
Materiales Biocompatibles/química , Fibroínas/química , Membranas Artificiales , Nanocompuestos/química , Poliésteres/química
7.
Carbohydr Polym ; 260: 117760, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712122

RESUMEN

A transparent versatile cellulose platform film was prepared from Eucalyptus pulp in this work. Based on such cellulose platform, multifunctional cellulose films with ultraviolet-shielding, photochromism, and strong mechanical strength were fabricated via nucleophilic postmodification strategy by introducing a versatile spiropyran moiety into cellulose molecules. The fabricated cellulose films exhibited super-high transmittance up to 96% and performed notable ultraviolet-shielding capacity at 200-400 nm. Moreover, the photochromic performance of cellulose films with color changes could be clearly observed by the naked eyes, and the fluorescent blue could be excited. Besides, the tensile stress of multi-functional cellulose film was about 80 MPa, which was almost 8 times stronger than that of the commercial polyethylene film at the same thickness. It is noteworthy that these superior performances promote such a cellulose platform to be a versatile precursor for fabricating various multi-functional cellulose used in the fields of out-door coating, transparent packaging, optical screen,etc.


Asunto(s)
Celulosa/química , Benzopiranos/química , Eucalyptus/metabolismo , Indoles/química , Nanocompuestos/química , Nitrocompuestos/química , Espectroscopía Infrarroja por Transformada de Fourier , Protectores Solares/química , Propiedades de Superficie , Resistencia a la Tracción , Rayos Ultravioleta
8.
Carbohydr Polym ; 260: 117772, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712130

RESUMEN

Nanoparticle-polymer composites are important functional materials but structural control of their assembly is challenging. Owing to its crystalline internal structure and tunable nanoscale morphology, cellulose is promising polymer scaffold for templating such composite materials. Here, we show bottom-up synthesis of reducing end thiol-modified cellulose chains by iterative bi-enzymatic ß-1,4-glycosylation of 1-thio-ß-d-glucose (10 mM), to a degree of polymerization of ∼8 and in a yield of ∼41% on the donor substrate (α-d-glucose 1-phosphate, 100 mM). Synthetic cellulose oligomers self-assemble into highly ordered crystalline (cellulose allomorph II) material showing long (micrometers) and thin nanosheet-like morphologies, with thickness of 5-7 nm. Silver nanoparticles were attached selectively and well dispersed on the surface of the thiol-modified cellulose, in excellent yield (≥ 95%) and high loading efficiency (∼2.2 g silver/g thiol-cellulose). Examined against Escherichia coli and Staphylococcus aureus, surface-patterned nanoparticles show excellent biocidal activity. Bottom-up approach by chemical design to a functional cellulose nanocomposite is presented. Synthetic thiol-containing nanocellulose can expand the scope of top-down produced cellulose materials.


Asunto(s)
Antibacterianos/química , Celulosa/química , Nanopartículas del Metal/química , Nanocompuestos/química , Compuestos de Sulfhidrilo/química , Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Escherichia coli/efectos de los fármacos , Nanocompuestos/toxicidad , Plata/química , Staphylococcus aureus/efectos de los fármacos
9.
Carbohydr Polym ; 260: 117800, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712148

RESUMEN

Topical drug delivery system to the posterior segment of the eye is facing many challenges, such as rapid drug elimination, low permeability, and low concentration at the targeted sites. To overcome these challenges, Multifunctional nanocomposite eye drops of dexamethasone-carboxymethyl-ß-cyclodextrin@layered double hydroxides-glycylsarcosine (DEX-CM-ß-CD@LDH-GS) were developed for relay drug delivery. Herein, our studies demonstrated that DEX-CM-ß-CD@LDH-GS could penetrate through human conjunctival epithelial cells with an intact structure and exhibited integrity in the sclera of rabbits' eyes with in vivo fluorescence resonance energy transfer imaging. Consequently, tissue distribution indicated that DEX-CM-ß-CD@LDH-GS nanocomposite eye drops could maintain the effective therapeutic concentration of DEX in choroid-retina within 3 h. As a relay drug delivery system, drug-CD@LDH nanocomposites offer an efficient strategy for drug delivery from ocular surface to the posterior segment.


Asunto(s)
Dexametasona/química , Portadores de Fármacos/química , Hidróxidos/química , Nanocompuestos/química , Soluciones Oftálmicas/química , beta-Ciclodextrinas/química , Animales , Córnea/efectos de los fármacos , Dexametasona/metabolismo , Dexametasona/farmacología , Dipéptidos/química , Liberación de Fármacos , Imagen Óptica/métodos , Conejos
10.
Carbohydr Polym ; 260: 117802, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712150

RESUMEN

Due to the significance growth in application of polymer-based nanocomposites, different methods of synthesis and different reinforces have been studied in recent years for specific purposes. In this study, using the direct blending process, polyvinyl alcohol-arabic gum-magnesium oxide nanocomposites were synthesized. These synthesized nanocomposites were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray energy diffraction (EDS) spectroscopy, X-ray surface elemental mapping (X-Ray Map), transmission electron microscopy (TEM), ultraviolet -visible (UV-vis) spectrophotometry and thermal gravimetery analysis (TGA). The results revealed that size distributions of magnesium oxide nanoparticles and synthesized nanocomposites were between 25-40 nm and 20-90 nm, respectively. Elemental map results show the magnesium oxide nanoparticles were well distributed on polymer matrix walls.


Asunto(s)
Goma Arábiga/química , Óxido de Magnesio/química , Nanocompuestos/química , Alcohol Polivinílico/química , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos X
11.
Carbohydr Polym ; 260: 117835, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712172

RESUMEN

Bacterial breeding is the main cause of food perishability, which is harmful to human health. Silver nanoparticles (AgNPs) are one of the most widely used antimicrobial agents, but they are easy to release and cause cumulative toxicity. In this work, with corn stalk as green reductant and GO as template, a simple electrostatic self-assembled sandwich-like chitosan (CS) wrapped rGO@AgNPs nanocomposite film (CS/rGO@AgNPs) was synthesized to achieve stabilizing and controlled-release of AgNPs. The results showed that the the CS/rGO@AgNPs film continued releasing AgNPs for up to 14 days, and the final release amount of silver nanoparticles was only about 1.9 %. More importantly, the nanocomposite film showed durable antibacterial effect and good antibacterial activity against E. coli and S. aureus, and they showed no toxicity to cells. Hence, the nanocomposite film has potential application as an effective and safe packaging material to prolong the shelf life of food products.


Asunto(s)
Antibacterianos/química , Quitosano/química , Grafito/química , Nanopartículas del Metal/química , Nanocompuestos/química , Antibacterianos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Escherichia coli/efectos de los fármacos , Humanos , Nanocompuestos/toxicidad , Plata/química , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Tracción
12.
Carbohydr Polym ; 261: 117883, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33766370

RESUMEN

A new biosorbent Ca-crosslinked pectin/lignocellulose nanofibers/chitin nanofibers (PLCN) was synthesized for cholesterol and bile salts adsorption from simulated intestinal fluid during gastric-intestinal passage. The physico-chemical properties of PLCN were studied using SEM, FTIR, XRD, DSC and BET. Before gastrointestinal passage, PLCN had an amorphous single-phase, compact structure formed via hydrogen and van der Waals bonds that revealed an irregular shape with the shriveled surface but watery condition and enzymatic digestion led to create a porous structure without destruction because of the water-insoluble nanofibers, therefore increasing the adsorption capacity. The maximum adsorption capacity reached 37.9 and 5578.4 mg/g for cholesterol and bile salts, respectively. Freundlich isotherm model indicated the reversible heterogeneous adsorption of both cholesterol and bile salts on PLCN. Further, their adsorption followed pseudo-second order kinetic model. These results suggest that PLCN has potential as a gastrointestinal-resistant biosorbent for cholesterol and bile salts adsorption applicable in medicine and food industry.


Asunto(s)
Ácidos y Sales Biliares/farmacocinética , Quitina/química , Colesterol/farmacocinética , Lignina/química , Nanofibras/química , Pectinas/química , Absorción Fisicoquímica/efectos de los fármacos , Adsorción/efectos de los fármacos , Quitina/farmacocinética , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/metabolismo , Humanos , Técnicas In Vitro , Cinética , Lignina/farmacocinética , Nanocompuestos/análisis , Nanocompuestos/química , Pectinas/farmacocinética
13.
Carbohydr Polym ; 261: 117894, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33766379

RESUMEN

The advent of electric skins (E-skin) with tactile sensation, flexibility, and human affinity characteristics have attracted considerable attention in extensive research fields, including intelligent robots and health monitoring, etc. To improve the intrinsic brittleness of hydrogels, a multifunctional E-skin was fabricated involving a TEMPO-NFC and a covalently cross-linked polyacrylamide (PAM) network. In this work, silver nanoparticles (AgNPs) as long-term antibacterial agent and conductive fillers were coated onto NFC nanofibers. Subsequently, this nanocomposite hydrogel was synthesized by free radical copolymerization of AM monomers with PNAg fibers as interpenetrating fibers network. Importantly with NFC present, the nanocomposite hydrogel exhibited superior mechanical performance and excellent self-recovery ability. The obtained sensor with excellent mechanical stability and sensing performance could detect mechanotransduction signal of human movements. This work provides a practicable method to prepare high antibacterial efficiency, excellent mechanical performance, and dual-modal nanocellulose-based hydrogel sensor for the broad-range application in human-motion detection and intelligence skins.


Asunto(s)
Antibacterianos , Materiales Biomiméticos/síntesis química , Técnicas Biosensibles/instrumentación , Hidrogeles , Dispositivos Electrónicos Vestibles , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/uso terapéutico , Materiales Biomiméticos/química , Celulosa/química , Conductividad Eléctrica , Humanos , Hidrogeles/síntesis química , Hidrogeles/química , Hidrogeles/uso terapéutico , Ensayo de Materiales , Mecanotransducción Celular/fisiología , Nanocompuestos/química , Nanofibras/química , Plata/química , Piel/química , Fenómenos Fisiológicos de la Piel , Estrés Mecánico , Resistencia a la Tracción
14.
Carbohydr Polym ; 261: 117904, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33766382

RESUMEN

Chitosan, a low-cost and multipurpose polymer with numerous desired physicochemical and biological properties has been tested for various applications in agriculture, pharmacy, and biomedicine industries. The availability of functional groups along the backbone makes chitosan readily available for other polymers and metal ions to form bio-nanocomposites. Different types of chitosan-based nanocomposites have been designed and tested for the enhancement of chitosan efficiency and ultimately widening the application areas of chitosan in plants. These nanocomposites serve different purposes such as eliciting plant's defence systems against different threats (pathogen attack), antimicrobial agent against bacteria, fungi and viruses, enhancement of nutrient uptake by plants, control release of micro/macronutrients, fungicides and herbicides. In this review, an extensive outlook has been provided (mainly in the last five years) to recent trends and advances in the fabrication and application of chitosan-based composites. Finally, current challenges and future development opportunities of chitosan-based nanocomposites for plants are discussed.


Asunto(s)
Química Agrícola/tendencias , Quitosano/química , Fungicidas Industriales/síntesis química , Nanocompuestos , Enfermedades de las Plantas/prevención & control , Agricultura/métodos , Agricultura/tendencias , Química Agrícola/métodos , Fungicidas Industriales/química , Humanos , Nanocompuestos/química , Nanocompuestos/uso terapéutico
15.
Carbohydr Polym ; 261: 117905, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33766383

RESUMEN

Development of hybrid materials with molecular structure of organic-inorganic co-network is a promising method to enhance the stability and mechanical properties of biopolymers. Chitosan-silica hybrid nanocomposite scaffolds loaded with mangiferin, a plant-derived active compound possessing several bioactivities, were fabricated using the sol-gel synthesis and the freeze-drying processes. Investigation on the physicochemical and mechanical properties of the fabricated scaffolds showed that their properties can be improved and tailored by the formation of 3-dimensional crosslinked network and the addition of ZnO nanoparticles. The scaffolds possessed porosity, fluid uptake, morphology, thermal properties and mechanical strength suitable for bone tissue engineering application. Investigation on the biomineralization and cell viability indicated that the inclusion of bioactive mangiferin further promote potential use of the hybrid nanocomposite scaffolds in guided bone regeneration application.


Asunto(s)
Materiales Biocompatibles/síntesis química , Quitosano/química , Dióxido de Silicio/química , Andamios del Tejido/química , Xantonas/administración & dosificación , Animales , Materiales Biocompatibles/química , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Materiales Biocompatibles Revestidos/síntesis química , Materiales Biocompatibles Revestidos/química , Ensayo de Materiales , Ratones , Nanocompuestos/química , Porosidad , Xantonas/farmacocinética
16.
Food Chem ; 349: 129127, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33561794

RESUMEN

Metal-organic structures (MOFs) have been designed for a wide range of applications due to their high porosity, large surface area, and flexibility. For the first time in this work, the successful immobilization of α-amylase is confirmed by the use of ZIF-8 as easy and good support. The morphology, functional groups, and chemical composition of the support and immobilized α-amylase were tested using different methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA). The enzymatic activities of the immobilized olibanum-bovine serum albumin@zeolitic imidazolate frameworks nanocomposite (OLB/BSA@ZIF-8)-α-amylase were compared with the free one. The pH and thermal stability of the OLB/BSA@ZIF-8-α-amylase were significantly enhanced compared to the free enzyme. The OLB/BSA@ZIF-8-α-amylase displayed excellent long-term storage stability, which could protect more than 90% of the initial activity for 8 weeks. Besides, the OLB/BSA@ZIF-8-α-amylase had high reusability, which showed a high degree of activity (more than 81%) after 20 cycles. This is the first study that uses OLB/BSA@ZIF-8 nanocomposite as immobilizing support for the immobilization of α-amylase. Improved catalytic efficiency (Vmax/Km) values, reusability, and storage stability of immobilized α-amylase can make it suitable in industrial and biotechnological applications.


Asunto(s)
Enzimas Inmovilizadas/química , Estructuras Metalorgánicas/química , Nanocompuestos/química , Albúmina Sérica Bovina/química , alfa-Amilasas/química , Animales , Biocatálisis , Biotecnología , Bovinos , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Porosidad , Zeolitas/química , alfa-Amilasas/metabolismo
17.
Food Chem ; 349: 129208, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33578247

RESUMEN

The edible films composed ofcarboxymethyl cellulose (CMC), glycerol, mucilage from Chinese yam (DOM)and ZnO nanoparticles (ZnO-NPs), were prepared by a casting method. To evaluate the applicability for food packaging, prepared films were characterised morphological, physical, rheological, mechanical and barrier properties, performed FT-IR, thermal analysis, and finally investigated the antibacterial activity and acute oral toxicity of films. The surface of films presented irregular arrangement with nanoparticles combined in the networks, suggesting the best "CMC to DOM weight ratio" of approximately 1:1 could provide a smooth surface. The films with 2.0 g ZnO-NPs presented antibacterial effects against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. With the increase of DOM, the antibacterial rate dropped at 400 and 450 µL/mL. The film-forming solutions with higher ZnO-NPs content display shear-thinning properties and liquid-like behaviour. The edible films have a great potential to be used in application in food packaging.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Carboximetilcelulosa de Sodio/química , Dioscorea/química , Películas Comestibles , Glicerol/química , Óxido de Zinc/química , Escherichia coli/efectos de los fármacos , Nanocompuestos/química , Nanopartículas/química , Staphylococcus aureus/efectos de los fármacos
18.
Food Chem ; 350: 129199, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33610843

RESUMEN

The present study aimed to develop a new bio-nanocomposite film based on gum arabic (GA) reinforced with cellulose nanocrystals (CNC). CNC was successfully fabricated and its microstructure was characterized. Subsequently, the effects of CNC on the rheological, physicochemical and functional properties of GA-based films were systematically evaluated. Results showed that the tensile strength (2.21 MPa) and elongation at break (62.79%) of film incorporated with 4% (w/w) CNC were effectively increased compared with the GA film (1.08 MPa and 42.50%). Additionally, 4% CNC reduced the water vapor and oxygen permeability by 10.61% and 25.30% respectively, while improved the ultraviolet light barrier and thermal stability of film. The well dispersion and filling effect of nanofiller contributed to form a compact and homogeneous film structure. Furthermore, the film containing 4% CNC decreased the weight loss of strawberries by 23.80% compared with the control group, thus delaying the deterioration of strawberry quality during storage.


Asunto(s)
Celulosa/química , Conservación de Alimentos/métodos , Fragaria/química , Goma Arábiga/química , Nanocompuestos/química , Nanopartículas/química , Permeabilidad , Reología , Vapor/análisis , Resistencia a la Tracción
19.
Food Chem ; 351: 129252, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33626469

RESUMEN

Herein, an innovative enzyme free electrochemiluminescence chlorpyrifos sensor was reported based on the incorporation of ternary nanocomposite (ruthenium nanobeads/silver nanoparticles/graphene oxide) on the surface of glassy carbon electrode. The silver nanoparticles as a robust signal enhancing agent were well deposited on the modified graphene oxide/glassy carbon electrode and exhibited supreme electrocatalytic proficiency. Then, Ru(bipy)32+ species in bead-like nanoparticles were uniformly anchored on the surface of the modified electrode with the help of chitosan, as a good crosslinking agent. Boron nitride quantum dots as a new coreactant species showed the excellent proficiency for signal enhancement of the fabricated electrode. The fabricated electrode was successfully used as an ultra-sensitive sensor for trace analysis of chlorpyrifos by ECL technique. The wide linear range and the low detection limit were obtained from 5.0 × 10-15 to 4.2 × 10-9 M and 6.5 × 10-16 M, respectively.


Asunto(s)
Cloropirifos/análisis , Técnicas Electroquímicas/métodos , Mediciones Luminiscentes/métodos , Nanocompuestos/química , Compuestos de Boro/química , Catálisis , Técnicas Electroquímicas/instrumentación , Electrodos , Grafito/química , Límite de Detección , Mediciones Luminiscentes/instrumentación , Nanopartículas del Metal/química , Puntos Cuánticos/química , Rutenio/química , Plata/química
20.
Int J Nanomedicine ; 16: 1157-1174, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33623380

RESUMEN

Introduction: Candida albicans is a major opportunistic pathogen that causes a wide range of human infections. Currently available therapeutic agents are limited for treating these fungal infections due to multidrug resistance as well as their nonbiodegradability, poor biocompatibility and toxicity. In order to battle these limitations, we have synthesized a polymeric system as microcarriers to deliver the antifungal drug. The objective of the present study was to immobilize MgO/CuO nanocomposite and nystatin-loaded MgO/CuO nanocomposites in nontoxic, nonimmunogenic, biodegradable and biocompatible sodium alginate microspheres for the first time. Materials and Methods: Nanoparticle-loaded sodium alginate microspheres were prepared by ionotropic gelation technique using calcium chloride as a cross-linker. Synthesized microspheres were characterized using standard characterization techniques and were evaluated for biological activity against MDR strain of C. albicans. Results: Characterization of microspheres by Fourier-transform infrared spectroscopy confirmed loading of Nys-MgO/CuO NPs, scanning electron microscopy (SEM) revealed rough spherical beads with a highly porous surface having an average size in the range of 8-10 µm. X-ray diffraction (XRD) analyzed its semicrystalline structure. Entrapment efficiency of Nys-MgO/CuO NPs was 80% and release kinetic study revealed sustained and prolonged release of drug in pH 5.5. Flow cytometry analysis showed yeast cell death caused by Nys-MgO/CuO MS exhibits late apoptotic features. In cytotoxicity assay 5-14 mg of microspheres did not cause hemolysis. Microspheres reduced virulence traits of C. albicans such as germ tube and biofilm formation were compromised at concentration of 5 mg/mL. Antimicrobial assessment results revealed a pronounced inhibitory effect against C. albicans. Conclusion: The in vitro experiments have shown promising results based on good stability, Nys-MgO/CuO NP-encapsulated microspheres can be used as a prolonged controlled release system against MDR pathogenic C. albicans.


Asunto(s)
Alginatos/química , Candida albicans/patogenicidad , Cobre/química , Resistencia a Múltiples Medicamentos , Óxido de Magnesio/química , Microesferas , Nanocompuestos/química , Nistatina/farmacología , Antiinfecciosos/farmacología , Biopelículas/efectos de los fármacos , Liberación de Fármacos , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Humanos , Cinética , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Fenotipo , Espectroscopía Infrarroja por Transformada de Fourier , Virulencia/efectos de los fármacos , Factores de Virulencia/metabolismo , Difracción de Rayos X
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