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1.
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
2.
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
3.
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
4.
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
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 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
7.
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
8.
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
9.
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
10.
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
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.
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
13.
Chem Commun (Camb) ; 57(56): 6919-6922, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34155490

RESUMO

We demonstrate an intrinsic antitumor effect of polymer nanoparticles (P-NPs), which could re-program tumor-associated macrophages to pro-inflammatory phenotype. The intrinsic effect of P-NPs on macrophage repolarization and its combination with other therapies provide new ideas for drug delivery, macrophage regulation and immunotherapy in cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Maleatos/farmacologia , Nanopartículas/química , Poliestirenos/farmacologia , Polivinil/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Maleatos/química , Maleatos/toxicidade , Camundongos , Nanopartículas/toxicidade , Poliestirenos/química , Poliestirenos/toxicidade , Polivinil/química , Polivinil/toxicidade
14.
Zhen Ci Yan Jiu ; 46(6): 474-9, 2021 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-34190450

RESUMO

In learning and evaluation of acupuncture manipulations, there are lack of quantitative physical parameters on exertion strength, duration and direction of acupuncture technique at present. Based on the tactile parameters collected during "twirling" and "lifting-thrusting" of needling, a kind of array polyvinylidene fluoride (PVDF) tactile sensor was designed. Followed by, a window segmentation method for tactile signal was proposed and the time domain features of the window were extracted. Finally, an identification method of acupuncture manipulation based on FCM (Fuzzy C-Means) was constructed. Through the experiment, it was proved that this sensor can effectively identify the four kinds of basic acupuncture manipulations, i.e. reinforcing by twirling and rotating, reducing by twirling and rotating, reinforcing by lifting and thrusting and reducing by lifting and thrusting and it was conductive to the quantification and dissemination of acupuncture manipulations.


Assuntos
Pontos de Acupuntura , Terapia por Acupuntura , Artérias , Aprendizado de Máquina , Polivinil
15.
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
16.
Colloids Surf B Biointerfaces ; 205: 111898, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34098367

RESUMO

Polyvinylidene fluoride (PVDF) coating with piezoelectric properties was prepared on surface of titanium-based materials to improve the bio inertness of the surface. The surface of titanium-based materials with piezoelectric properties similar to human bone promotes the growth of osteoblasts. However, not only new bone growth but also osseointegration are observed in the process of bone repair. The hydrophobicity of PVDF coating is unfavorable for mineralization. In this study, a PVDF coating was prepared on the titanium surface by using titanium dioxide nanotubes as a transition layer, and PVDF was attached to the wall of the titanium dioxide nanotube. The contact angle of the polarized PVDF coating decreases from 108° to 47°, which indicates that it changes from hydrophobic to hydrophilic due to the reduction in surface energy and the effect of negative surface charge. After the coating is left for a period of time, its contact angle only increases by 20° due to the loss of negative surface charge. After a physiological loading is applied to the polarized PVDF coating, the durability of its surface hydrophilicity is maintained. The mineralization ability of the polarized PVDF coating after being immersed in simulated body fluid (SBF) for 1, 7, and 14 days is significantly higher than that of the unpolarized sample. The increase in mineralization ability is mainly due to the hydrophilicity of the surface and the attraction of negative charges to calcium ions. Notably, after the polarized PVDF coating is subjected to physiological load, the mineralization ability is further improved after being immersed in SBF for 14 days, and its surface is covered with a layer of bone-like apatite. The high mineralization ability of the PVDF coating on the titanium surface after polarization can promote osseointegration and therefore shorten the bone repair cycle. Accordingly, this coating has potential application value in the clinical treatment of bone defect repair in middle-aged and elderly people.


Assuntos
Polivinil , Titânio , Idoso , Materiais Revestidos Biocompatíveis/farmacologia , Humanos , Interações Hidrofóbicas e Hidrofílicas , Pessoa de Meia-Idade , Osteoblastos , Propriedades de Superfície
17.
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
19.
AAPS PharmSciTech ; 22(5): 189, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34159457

RESUMO

Phospholipid complexation, despite being a successful, versatile, and burgeoning strategy, stickiness of phospholipids leads to suboptimal dissolution rate of drugs. This work was undertaken to fabricate simvastatin-phospholipid complex (SIM-PLC)-loaded matrix dispersion (SIM-PLC-MD) using Soluplus® as carrier material, to augment dispersibility and dissolution of SIM-PLC without altering complexation between simvastatin (SIM) and phospholipid. SIM-PLC and SIM-PLC-MD were prepared using solvent evaporation and discontinuous solvent evaporation techniques, respectively. The successful complexation was substantiated by FTIR method. Besides, PXRD and SEM studies disclosed the absence of crystallinity of SIM in both SIM-PLC and SIM-PLC-MD. The TEM analysis monitored the self-assembly of SIM-PLC and SIM-PLC-MD into colloidal structures, which could be correlated with redispersion in GIT fluids upon oral administration. The considerable increase in hydrophilicity of SIM-PLC-MD and SIM-PLC as evident from partition coefficient experiment can further be correlated with their remarkably improved solubility profiles in the following pattern: SIM-PLC-MD˃SIM-PLC˃SIM. Correspondingly, improved dispersibility of SIM-PLC-MD in comparison to SIM-PLC can be accountable for accelerated dissolution rate by 2.53-fold and 1.5-fold in pH 1.2 and 6.8 conditions, respectively. The oral pharmacokinetic evaluation in Sprague Dawley (SD) rats revealed 3.19-fold enhancement in oral bioavailability of SIM through SIM-PLC-MD when compared with plain SIM, whereas 1.83-fold increment was observed in the case of SIM-PLC. Finally, the efficacy experimentation in SD rats revealed that SIM-PLC-MD significantly reduced triglycerides and cholesterol levels in comparison to SIM and SIM-PLC. These outcomes suggest that a matrix dispersion strategy improves oral bioavailability and hypolipidemic activity of SIM.


Assuntos
Fosfolipídeos/química , Fosfolipídeos/farmacocinética , Sinvastatina/química , Sinvastatina/farmacocinética , Administração Oral , Animais , Disponibilidade Biológica , Feminino , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Polivinil/administração & dosagem , Polivinil/química , Polivinil/farmacocinética , Ratos , Ratos Sprague-Dawley , Sinvastatina/administração & dosagem , Solubilidade , Solventes/administração & dosagem , Solventes/química , Solventes/farmacocinética
20.
ACS Appl Mater Interfaces ; 13(19): 22914-22925, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-33956429

RESUMO

A flexible poly(vinylidene difluoride) (PVDF) composite film embedding LiNbO3 ceramics decorated with silver nanoparticles (Ag NPs) has been synthesized using the solvent casting method. The polar ß-phase, Ag NPs, and LiNbO3 phases were confirmed in the composite film using various characterization methods. The composite film showed promising degradation of cationic and anionic dyes using piezocatalysis under ultrasonication. Moreover, this composite film also effectively degraded two model pharmaceutical pollutants named tetracycline and ciprofloxacin using piezocatalysis under ultrasonication. In addition to this, this composite film piezocatalytically removed more than 99.999% of Escherichia coli and 96.65% of Staphylococcus aureus bacteria within 180 min of sonication. The piezocatalytic performance of the PVDF composite film embedding Ag-loaded LiNbO3 in all three applications was superior to that obtained in the case of the PVDF film embedding LiNbO3 and the bare PVDF film. This demonstrates the pronounced effect of Ag NPs in the increase of piezocatalytic activity in the composite film.


Assuntos
Bactérias/efeitos dos fármacos , Corantes/química , Nióbio/química , Óxidos/química , Preparações Farmacêuticas/química , Polivinil/química , Prata/química , Catálise , Desinfecção
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