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1.
J Hazard Mater ; 421: 126747, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34364210

RESUMO

The synthesis of Bi2WO6 and CeO2 photocatalytic nanomaterials exhibit a great ability to photodegrade the antibiotics and shown excellent oxidation of various organic pollutants. Heterostructure 1:1 & 2:1 Bi2WO6/CeO2 nanocomposite was successfully synthesized via the facile sono-dispersion method and exquisite photocatalytic activity. The 0.5 wt% of nanocomposites were well-grafted on PVDF membrane surface via an in-situ polymerization method using polyacrylic acid. The fourier transform infrared (FTIR) spectra demonstrated that the network formation in PVDF induced by the -COOH functional group in acrylic acid. The grafted membrane morphology and strong binding ability over the membranes were validated by scanning electron microscope with energy dispersion (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), respectively. The permeate flux of 49.2 L.m-2 h-1 and 41.65 L.m-2 h were observed for tetracycline and the humic acid solution respectively for 1 wt% of PVP and 0.5 wt% of photocatalytic nanomaterials in PVDF membrane. The tetracycline and humic acid photodegradation rate of 82% and 78% and total resistance of 1.43 × 1010 m-1 and 1.64 × 1010 m-1, 83.5% and 77% flux recovery ratio were observed with N5 membrane. The 2:1 Bi2WO6/CeO2 nanocomposite grafted membrane showed a high permeate flux and better photodegradation ability of organic pollutants in the wastewater.


Assuntos
Substâncias Húmicas , Tetraciclina , Antibacterianos , Catálise , Polivinil
2.
Part Fibre Toxicol ; 18(1): 38, 2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34663357

RESUMO

BACKGROUND: Silver nanoparticles (AgNPs) are widely used in biomedicine due to their strong antimicrobial, antifungal, and antiviral activities. Concerns about their possible negative impacts on human and environmental health directed many researchers towards the assessment of the safety and toxicity of AgNPs in both in vitro and in vivo settings. A growing body of scientific information confirms that the biodistribution of AgNPs and their toxic effects vary depending on the particle size, coating, and dose as well as on the route of administration and duration of exposure. This study aimed to clarify the sex-related differences in the outcomes of oral 28 days repeated dose exposure to AgNPs. METHODS: Wistar rats of both sexes were gavaged daily using low doses (0.1 and 1 mg Ag/kg b.w.) of polyvinylpyrrolidone (PVP)-coated small-sized (10 nm) AgNPs. After exposure, blood and organs of all rats were analysed through biodistribution and accumulation of Ag, whereas the state of the liver and kidneys was evaluated by the levels of reactive oxygen species (ROS) and glutathione (GSH), catalase (CAT) activity, superoxide dismutase (SOD) and glutathione peroxidase (GPx), expression of metallothionein (Mt) genes and levels of Mt proteins. RESULTS: In all animals, changes in oxidative stress markers and blood parameters were observed indicating the toxicity of AgNPs applied orally even at low doses. Sex-related differences were noticed in all assessed parameters. While female rats eliminated AgNPs from the liver and kidneys more efficiently than males when treated with low doses, the opposite was observed for animals treated with higher doses of AgNPs. Female Wistar rats exposed to 1 mg PVP-coated AgNPs/kg b.w. accumulated two to three times more silver in the blood, liver, kidney and hearth than males, while the accumulation in most organs of digestive tract was more than ten times higher compared to males. Oxidative stress responses in the organs of males, except the liver of males treated with high doses, were less intense than in the organs of females. However, both Mt genes and Mt protein expression were significantly reduced after treatment in the liver and kidneys of males, while they remained unchanged in females. CONCLUSIONS: Observed toxicity effects of AgNPs in Wistar rats revealed sex-related differences in response to an oral 28 days repeated exposure.


Assuntos
Nanopartículas Metálicas , Povidona , Animais , Feminino , Masculino , Nanopartículas Metálicas/toxicidade , Polivinil , Povidona/toxicidade , Ratos , Ratos Wistar , Prata/toxicidade , Distribuição Tecidual
3.
J Environ Manage ; 300: 113707, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34534759

RESUMO

Selective removal of contaminants from water by membranes is of practical importance for water purification and environmental protection. In the present study, through an in-situ polymerization process, a novel composite of Fe3O4/molecularly imprinted resorcinol -formaldehyde-melamine resin (Fe3O4/MIRFMR) was synthesized. Then, the novel membrane was prepared from a tea filter bag (TFB) as a base substrate which was subsequently coated by a casting solution containing polyvinylidene fluoride (PVDF) matrix, Prunus scoparia gum as a hydrophilic agent and Fe3O4/MIRFMR as selective filler by phase inversion technique. Resorcinol as functional monomers with multiple hydrophilic groups such as -OH, -NH2 and -NH-, were used for selective removal of Rhodamine B (RhB) as target molecule. The Fe3O4/MIRFMR/PVDF/TFB membranes were characterized by FE-SEM, XRD, FTIR, BET, VSM, water contact angle (WCA) and mechanical analysis. The filtration and adsorption of RhB on the prepared membrane was investigated parameters in a cross-module filtration setup. Casting solution containing 0.01 g of Fe3O4/MIRFMR as optimum value showed good wettability, high water flux (42.5 L/m2 h), flux recovery ratio (88.9%), RhB removal efficiency (95.8%). The selectivity of 4.9, 3.3, 2.1 and 2.5 was found to be for RhB compared to AB, MG, EB, and TB dye. It seems that the fabricated membrane could be an effective and selective option for wastewater containing pollutants. The high removal efficiency, fouling resistance, good wettability and stability of the fabricated membrane are promising for use in practical water filtration, especially for selective removal of dyes.


Assuntos
Corantes , Membranas Artificiais , Fenômenos Magnéticos , Polivinil
4.
J Chem Inf Model ; 61(9): 4537-4543, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34519202

RESUMO

The pervasive use of portable electronic devices, powered from rechargeable batteries, represents a significant portion of the electricity consumption in the world. A sustainable and alternative energy source for these devices would require unconventional power sources, such as harvesting kinetic/potential energy from mechanical vibrations, ultrasound waves, and biomechanical motion, to name a few. Piezoelectric materials transform mechanical deformation into electric fields or, conversely, external electric fields into mechanical motion. Therefore, accurate prediction of elastic and piezoelectric properties of materials, from the atomic structure and composition, is essential for studying and optimizing new piezogenerators. Here, we demonstrate the application of harmonic-covalent and reactive force fields (FF), Dreiding and ReaxFF, respectively, coupled to the polarizable charge equilibration (PQEq) model for predicting the elastic moduli and piezoelectric response of crystalline zinc oxide (ZnO) and polyvinylidene difluoride (PVDF). Furthermore, we parametrized the ReaxFF atomic interactions for Zn-F in order to characterize the interfacial effects in hybrid PVDF matrices with embedded ZnO nanoparticles (NPs). We capture the nonlinear piezoelectric behavior of the PVDF-ZnO system at different ZnO concentrations and the enhanced response that was recently observed experimentally, between 5 and 7 wt % ZnO concentrations. From our simulation results, we demonstrate that the origin of this enhancement is due to an increase in the total atomic stress distribution at the interface between the two materials. This result provides valuable insight into the design of new and improved piezoelectric nanogenerators and demonstrates the practical value of these first-principles based modeling methods in materials science.


Assuntos
Nanopartículas , Óxido de Zinco , Simulação de Dinâmica Molecular , Polivinil
5.
J Mol Graph Model ; 108: 108004, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34438240

RESUMO

Finding proper candidates for polymer-supported ionic liquid (IL)-based gas separating membranes is a challenge. The current article elucidates the quantum chemical perspective of the selective gas adsorption efficiency, from a mixture of CO2, CO, CH4, and H2, of α- and ß-polyvinylidene fluoride (PVDF)-supported imidazolium- and pyridinium-based six ionic liquid membranes. Although IL-based membrane efficiency mainly depends on the gas solubility of ILs, IL/support binding and gas adsorption on the support material are also studied to describe the overall gas adsorption properties of the PVDF/IL complexes. ß-PVDF exhibits better binding with the ILs, and better gas affinity, thus, qualified as a more suitable membrane component as compared to α-PVDF. Dispersion-corrected density functional calculations are performed to provide a detailed insight into the energetic interactions, nonbonding intermolecular interactions based on symmetry adapted perturbation theory (SAPT), natural bond orbitals (NBO), Bader's quantum theory of atoms in molecules (QTAIM), reduced density gradient (RDG), frontier orbital interactions, density of states (DOS), and thermochemical analyses of the gas-adsorbed systems. Gas molecules interact with the membrane components through weak hydrogen bonds and exhibit low interaction energies, indicating physisorption of the gases. Gas adsorption energies are more negative than the mutual interaction energies of the gas molecules, ensuring effective gas adsorption by the membrane components. All the ß-PVDF/IL systems have shown the highest and lowest affinity for CO2 and H2, respectively, leading to effective separation of CO2 and H2 from the other gases.


Assuntos
Líquidos Iônicos , Teoria da Densidade Funcional , Gases , Ligação de Hidrogênio , Polivinil
6.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361025

RESUMO

In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm-1 to 1415 cm-1 proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm-1 indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL) quenching process. An additional PL quenching process of the POPD-PVDF blends is reported to be induced in the presence of DWNTs. The studies of anisotropic PL highlight a change of the angle of the binding of the PVDF spheres onto the POPD fiber like structures surface from 50.2° to 38° when the carbon nanotubes concentration increases in the POPD-PVDF/DWNTs composites mass up to 2 wt.%.


Assuntos
Dimetilformamida/química , Nanotubos de Carbono/química , Polivinil/química , Anisotropia , Nanocompostos/química , Análise Espectral Raman
7.
BMJ Case Rep ; 14(8)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376414

RESUMO

We report transarterial Onyx embolization with flow control using rapid ventricular pacing (RVP) in a middle-aged male patient with tentorial dural arteriovenous fistulas (TDAVFs). The patient completed angiographic obliteration in one session without any complications, and the 6-month postangiographic obliteration follow-up showed no evidence of residual or recurrent dural arteriovenous fistulas. RVP may be a novel treatment option of flow control to facilitate the embolic agent penetrating into the venous side and to achieve complete cure in transarterial embolization of TDAVFs.


Assuntos
Malformações Vasculares do Sistema Nervoso Central , Embolização Terapêutica , Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Malformações Vasculares do Sistema Nervoso Central/terapia , Dimetil Sulfóxido , Humanos , Masculino , Pessoa de Meia-Idade , Polivinil , Estudos Retrospectivos , Resultado do Tratamento
8.
Sensors (Basel) ; 21(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34450718

RESUMO

In this work, new highly sensitive graphene-based flexible strain sensors are produced. In particular, polyvinylidene fluoride (PVDF) nanocomposite films filled with different amounts of graphene nanoplatelets (GNPs) are produced and their application as wearable sensors for strain and movement detection is assessed. The produced nanocomposite films are morphologically characterized and their waterproofness, electrical and mechanical properties are measured. Furthermore, their electromechanical features are investigated, under both stationary and dynamic conditions. In particular, the strain sensors show a consistent and reproducible response to the applied deformation and a Gauge factor around 30 is measured for the 1% wt loaded PVDF/GNP nanocomposite film when a deformation of 1.5% is applied. The produced specimens are then integrated in commercial gloves, in order to realize sensorized gloves able to detect even small proximal interphalangeal joint movements of the index finger.


Assuntos
Grafite , Nanocompostos , Dispositivos Eletrônicos Vestíveis , Polivinil
9.
Adv Sci (Weinh) ; 8(18): e2101498, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34272933

RESUMO

Acute kidney injury (AKI), as a common oxidative stress-related renal disease, causes high mortality in clinics annually, and many other clinical diseases, including the pandemic COVID-19, have a high potential to cause AKI, yet only rehydration, renal dialysis, and other supportive therapies are available for AKI in the clinics. Nanotechnology-mediated antioxidant therapy represents a promising therapeutic strategy for AKI treatment. However, current enzyme-mimicking nanoantioxidants show poor biocompatibility and biodegradability, as well as non-specific ROS level regulation, further potentially causing deleterious adverse effects. Herein, the authors report a novel non-enzymatic antioxidant strategy based on ultrathin Ti3 C2 -PVP nanosheets (TPNS) with excellent biocompatibility and great chemical reactivity toward multiple ROS for AKI treatment. These TPNS nanosheets exhibit enzyme/ROS-triggered biodegradability and broad-spectrum ROS scavenging ability through the readily occurring redox reaction between Ti3 C2 and various ROS, as verified by theoretical calculations. Furthermore, both in vivo and in vitro experiments demonstrate that TPNS can serve as efficient antioxidant platforms to scavenge the overexpressed ROS and subsequently suppress oxidative stress-induced inflammatory response through inhibition of NF-κB signal pathway for AKI treatment. This study highlights a new type of therapeutic agent, that is, the redox-mediated non-enzymatic antioxidant MXene nanoplatforms in treatment of AKI and other ROS-associated diseases.


Assuntos
Injúria Renal Aguda/tratamento farmacológico , Antioxidantes/farmacologia , Oxirredução/efeitos dos fármacos , Polivinil/farmacologia , Pirrolidinas/farmacologia , Titânio/farmacologia , Injúria Renal Aguda/metabolismo , Apoptose/efeitos dos fármacos , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
10.
Biomed Microdevices ; 23(3): 37, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34269869

RESUMO

Micro-reservoir based drug delivery systems have the potential to provide targeted drug release locally in the intestine, i.e. at the inflamed areas of the intestine of patients with inflammatory bowel disease (IBD). In this study, microcontainers with a diameter of 300 µm and a height of 100 µm, asymmetrical geometry and the possibility to provide unidirectional release, are fabricated in the biodegradable polymer poly-ɛ-caprolactone (PCL) using hot punching. As a first step towards local treatment of IBD, a novel method for loading of microcontainers with the corticosteroid budesonide is developed. For this purpose, a budesonide-Soluplus drug-polymer film is prepared by spin coating and loaded into the microcontainer reservoirs using hot punching. The processing parameters are optimized to achieve a complete loading of a large number of containers in a single step. A poly(lactic-co-glycolic acid) (PLGA) 50:50 lid is subsequently applied by spray coating. Solid-state characterization indicates that the drug is in an amorphous state in the drug-polymer films and the in vitro drug release profile showed a 68% release over 10 h. The results demonstrate that hot punching can be employed both as a production and loading method for PCL microcontainers with the perspective of local treatment of IBD.


Assuntos
Budesonida , Polietilenoglicóis , Sistemas de Liberação de Medicamentos , Humanos , Polivinil
11.
Molecules ; 26(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299547

RESUMO

The aspect of drug delivery is significant in many biomedical subareas including tissue engineering. Many studies are being performed to develop composites with application potential for bone tissue regeneration which at the same provide adequate conditions for osteointegration and deliver the active substance conducive to the healing process. Hydroxyapatite shows a great potential in this field due to its osteoinductive and osteoconductive properties. In the paper, hydroxyapatite synthesis via the wet precipitation method and its further use as a ceramic phase of polymer-ceramic composites based on PVP/PVA have been presented. Firstly, the sedimentation rate of hydroxyapatite in PVP solutions has been determined, which allowed us to select a 15% PVP solution (sedimentation rate was 0.0292 mm/min) as adequate for preparation of homogenous reaction mixture treated subsequently with UV radiation. Both FT-IR spectroscopy and EDS analysis allowed us to confirm the presence of both polymer and ceramic phase in composites. Materials containing hydroxyapatite showed corrugated and well-developed surface. Composites exhibited swelling properties (hydroxyapatite reduced this property by 25%) in simulated physiological fluids, which make them useful in drug delivery (swelling proceeds parallel to the drug release). The short synthesis time, possibility of preparation of composites with desired shapes and sizes and determined physicochemical properties make the composites very promising for biomedical purposes.


Assuntos
Cerâmica/química , Durapatita/química , Polímeros/química , Álcool de Polivinil/química , Polivinil/química , Pirrolidinas/química , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Engenharia Tecidual/métodos
12.
Small ; 17(36): e2102550, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34314097

RESUMO

Despite the boom in the water-triggered electric power generation technologies, few attempts have been made with a broader horizonyielding the electricity from sweat, which is of great value for low-power-consumption wearable electronics. Here, an electromechanical coupling and humidity-actuated two-in-one humidity actuator-driven piezoelectric generator (HAPG) are reported, that can yield continuous electric power from fluctuations in the ambient humidity. It is composed of polyvinyl alcohol (PVA)-wrapped highly aligned dopamine (DA)/polyvinylidene fluoride (PVDF) shell/core nanofibers (PVA@DA/PVDF NFs). As-received PVA@DA/PVDF NFs can exchange water with the ambient humidity to perform expansion and contraction and convert them into electric power. An all-fiber-based portable HAPG is fabricated and tested on human palm skin. The devices show high sensitivity and accuracy for converting the mental sweating-derived continuous moisture fluctuations into electric power. This electric power can be stored in capacitors, which is expected to power micro- and nano-electronic devices or be used in electrotherapy such as electrical stimulation to promote wound healing. Beyond this, the obtained voltage profiles exhibit unique features that can reflect the typical sweat damping oscillation curve features.


Assuntos
Nanofibras , Dopamina , Humanos , Álcool de Polivinil , Polivinil
13.
Sensors (Basel) ; 21(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207088

RESUMO

The effect of a self-pulsing non-equilibrium plasma discharge on piezoelectric PVDF nanofiber membrane was investigated. The plasma discharge was generated in air with a DC power source, with a discharge current of 0.012 mA, a nominal interelectrode separation of 1 mm, and discharge voltage of ~970 V. In a continuous fabrication process, the electrospinning method was used to generate thin nanofiber membrane with a flow rate of 0.7-1 mL h-1 and 25-27 kV voltage to obtain the nanofiber with high sensitivity and a higher degree of alignment and uniformity over a larger area. Plasma treatment was applied on both single layer and multi-layer (three layers) nanomembranes. In addition, simultaneously, the nanofiber membranes were heat-treated at a glass transition temperature (80-120 °C) and then underwent plasma treatment. Fourier-transform infrared (FTIR) spectroscopy showed that the area under the curve at 840 and 1272 cm-1 (ß phase) increased due to the application of plasma and differential scanning calorimeter (DSC) indicated an increase in the degree of crystallinity. Finally, PVDF sensors were fabricated from the nanofibers and their piezoelectric properties were characterized. The results suggested that compared to the pristine samples the piezoelectric properties in the plasma and plasma-heat-treated sensors were enhanced by 70% and 85% respectively.


Assuntos
Nanofibras , Polivinil , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
14.
J Environ Manage ; 296: 113305, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34328863

RESUMO

The present study involves a novel protocol to develop a ternary composite catalyst for an effective post-treatment technique for greywater. The ternary film of Fe2O3-TiO2/polyvinyl pyrrolidine (PVP) is coated on a glass tube using spray coating with annealing at 320 °C. The structure, thermal, microstructure, and surface properties of the coated film are characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Thermo Gravimetric Analysis (TGA). The scratch hardness of photocatalysts at different Fe2O3/TiO2 compositions is investigated based on the width measurement of scratch using FESEM analysis. Results show that at an optimum coating of 5% of Fe2O3/TiO2 composition catalytic film, the maximum scratch hardness (7.984 GPa) is obtained. Also, the photocatalyst has the highest cohesive bond strength and wearing resistance. The degradation of triclosan (TCS) in treated greywater, discharged from the anaerobic-aerobic treatment system, is investigated at a lab-scale using a solar photocatalytic reactor. The response surface analysis has been performed from the different sets of experimental trials for various optimal parameters. It is observed that the TCS degradation efficiency of 83.27% has resulted under optimum conditions.


Assuntos
Triclosan , Catálise , Polímeros , Polivinil , Pirrolidinas , Titânio
15.
Int J Biol Macromol ; 185: 543-550, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34197857

RESUMO

Controlled or slow release fertilizers have been recommended to enhance crop yield, while minimizing environmental and economic issues related from current fertilizer applications. However, alternative biodegradable and non-toxic coating material should be suggested to produce biocoated fertilizers. Here we propose the use of lignin and poly(vinyl acetate) (PVAc) as biocoating materials for preparing slow release urea fertilizer. The blend of PVAc and lignin at a mass ratio of 75:25 improved the characteristics of the formed film and increased the nitrogen release time if compared to the pure polymers. The nitrogen release time from urea granules coated with a polymeric layer of 154.3 ±â€¯5.5 µm formed by lignin and PVAc was 36 times greater than from bare urea. The increase in the polymeric coating from 52.6 ±â€¯5.2 to 80.2 ±â€¯6.1 µm decreased the curvature of the nitrogen release data by a factor of at least 1.7, while the curvature was decreased in at least 1.3 with the increase in the polymeric coating from 80.2 ±â€¯6.1 to 158.9 ±â€¯10.6 µm. The adjustment of nitrogen release data to the Peppas-Sahlin model indicated the Fickian diffusion is more predominant than relaxation contributions, since the used polymers did not present considerable swelling. Thus, the blending of PVAc and lignin at 25 wt% of lignin and 75 wt% of PVAc is suggested as a biocoating material for producing slow release fertilizers.


Assuntos
Lignina/química , Nitrogênio/química , Polivinil/química , Composição de Medicamentos , Fertilizantes , Ureia/química
16.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208563

RESUMO

Bone exhibits piezoelectric properties. Thus, electrical stimulations such as pulsed electromagnetic fields (PEMFs) and stimuli-responsive piezoelectric properties of scaffolds have been investigated separately to evaluate their efficacy in supporting osteogenesis. However, current understanding of cells responding under the combined influence of PEMF and piezoelectric properties in scaffolds is still lacking. Therefore, in this study, we fabricated piezoelectric scaffolds by functionalization of polycaprolactone-tricalcium phosphate (PCL-TCP) films with a polyvinylidene fluoride (PVDF) coating that is self-polarized by a modified breath-figure technique. The osteoinductive properties of these PVDF-coated PCL-TCP films on MC3T3-E1 cells were studied under the stimulation of PEMF. Piezoelectric and ferroelectric characterization demonstrated that scaffolds with piezoelectric coefficient d33 = -1.2 pC/N were obtained at a powder dissolution temperature of 100 °C and coating relative humidity (RH) of 56%. DNA quantification showed that cell proliferation was significantly enhanced by PEMF as low as 0.6 mT and 50 Hz. Hydroxyapatite staining showed that cell mineralization was significantly enhanced by incorporation of PVDF coating. Gene expression study showed that the combination of PEMF and PVDF coating promoted late osteogenic gene expression marker most significantly. Collectively, our results suggest that the synergistic effects of PEMF and piezoelectric scaffolds on osteogenesis provide a promising alternative strategy for electrically augmented osteoinduction. The piezoelectric response of PVDF by PEMF, which could provide mechanical strain, is particularly interesting as it could deliver local mechanical stimulation to osteogenic cells using PEMF.


Assuntos
Fosfatos de Cálcio , Materiais Revestidos Biocompatíveis , Campos Eletromagnéticos , Osteogênese , Poliésteres , Polivinil , Tecidos Suporte , Regeneração Óssea , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Expressão Gênica , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteogênese/efeitos da radiação , Poliésteres/química , Poliésteres/farmacologia , Polivinil/química , Solventes , Engenharia Tecidual , Difração de Raios X
17.
Molecules ; 26(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204150

RESUMO

The purpose of this study was to develop mixed polymeric micelles with high drug loading capacity to improve the oral bioavailability of icaritin with Soluplus® and Poloxamer 407 using a creative acid-base shift (ABS) method, which exhibits the advantages of exclusion of organic solvents, high drug loading and ease of scaling-up. The feasibility of the ABS method was successfully demonstrated by studies of icaritin-loaded polymeric micelles (IPMs). The prepared IPMs were characterized to have a spherical shape with a size of 72.74 ± 0.51 nm, and 13.18% drug loading content. In vitro release tests confirmed the faster release of icaritin from IPMs compared to an oil suspension. Furthermore, bioavailability of icaritin in IPMs in beagle dogs displayed a 14.9-fold increase when compared with the oil suspension. Transcellular transport studies of IPMs across Caco-2 cell monolayers confirmed that the IPMs were endocytosed in their intact forms through macropinocytosis, clathrin-, and caveolae-mediated pathways. In conclusion, the results suggested that the mixed micelles of Soluplus® and Poloxamer 407 could be a feasible drug delivery system to enhance oral bioavailability of icaritin, and the ABS method might be a promising technology for the preparation of polymeric micelles to encapsulate poorly water-soluble weakly acidic and alkaline drugs.


Assuntos
Flavonoides/administração & dosagem , Poloxâmero/química , Polietilenoglicóis/química , Polivinil/química , Transdução de Sinais/efeitos dos fármacos , Administração Oral , Animais , Disponibilidade Biológica , Células CACO-2 , Cavéolas/metabolismo , Clatrina/metabolismo , Cães , Estudos de Viabilidade , Flavonoides/síntese química , Flavonoides/farmacocinética , Humanos , Masculino , Micelas , Nanopartículas , Tamanho da Partícula
18.
Chemosphere ; 284: 131294, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34186221

RESUMO

Blending modification of graphene oxide (GO) and deposition of silver carbonate (Ag2CO3) on the membrane surface by suction filtration was used to prepare polyvinylidene fluoride (PVDF) composite ultrafiltration (UF) membranes (denoted as PGA membranes). The effect of this strategy on the morphology and performance of the pure PVDF membrane was investigated. Owing to an increased hydrophilicity and the formation of a more open pore, the pollution resistance and permeability of the PGA membrane were improved. The pure water flux of the PGA-3 membrane (254 LMH) was increased to more than 2-fold compared to that of the neat PVDF membrane (126 LMH). In addition, the results of antifouling experiments showed that the flux recovery rate, flux decay rate, and antibacterial performance of the PGA-3 membrane was superior to those of the other membranes synthesized in this study. Finally, after conducting multi-cycle filtration experiments with lake water, the flux and recovery rate of the PGA-3 membrane was observed to be the highest, and the water quality of the lake water filtered by the PGA-3 membrane was the best. Thus, the above results indicate that this membrane modification strategy is extraordinarily effective in improving the antifouling properties and permeability of the PVDF UF membranes in practical applications.


Assuntos
Ultrafiltração , Purificação da Água , Membranas Artificiais , Polivinil
20.
Food Chem ; 361: 130029, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34077885

RESUMO

A novel automated method was developed for the quantitative determination of nine terpenoids that could contribute to the minty notes of red wine bouquet. The method couples headspace SPME-Arrow extraction with GC-MS/MS analysis. PDMS/DVB fiber was chosen for the extraction and an ionization energy of 30 eV permitted to optimize the analyte detection. The optimal sample preparation consists of a two-fold dilution of the wine sample with addition of 4 g of sodium chloride while the most suitable extraction conditions take place at 50 °C for 1 h. The method shows good linearity, intraday variations between 2 and 25%, interday variations between 7 and 23% and recoveries between 80 and 119%. The method exhibits the required low detection (between 3 and 60 ng/L) and quantification (between 6 ng/L and 200 ng/L) limits. These limits have permitted the quantification of the pool of minty terpenoids in fourteen red Bordeaux wines.


Assuntos
Odorantes/análise , Microextração em Fase Sólida/métodos , Terpenos/isolamento & purificação , Vinho/análise , Monoterpenos Cicloexânicos/análise , Monoterpenos Cicloexânicos/isolamento & purificação , Dimetilpolisiloxanos , Eucaliptol/análise , Eucaliptol/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lactonas/análise , Lactonas/isolamento & purificação , Limoneno/análise , Limoneno/isolamento & purificação , Mentha , Mentol/análise , Mentol/isolamento & purificação , Polivinil , Espectrometria de Massas em Tandem/métodos , Terpenos/análise
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