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1.
J Contemp Dent Pract ; 21(2): 190-196, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381826

RESUMO

AIM: The aim of the study was to evaluate the dimensional accuracy of three combinations of polyvinyl siloxane impression material by double-mix single-step impression technique. MATERIALS AND METHODS: Metal master model was made according to the ADA specification no. 19; ISO 4823:2000/AMD 2007. Impressions were made using perforated custom-made metallic trays of 2 mm and 4 mm spacing, the impression materials used were putty, heavy body, regular body and light body. A total of 30 impressions were made by single-step technique and poured in die stone to obtain resultant cast. Ten impressions were made of each combination of polyvinyl siloxane (PVS). Three dimensions (interabutment distance, height and diameter) on resultant cast were measured and compared with metal master model. The results were statistically analyzed and tabulated. RESULTS: Diameter of abutment, the height of abutment and interabutment distance in each group were larger in dimensions as compared with metal master model. The dimensional discrepancies of group I, group II and group III casts when compared with the master model were significantly different from each other. The least difference was found in group I. CONCLUSION: The one-step putty-light body combination (group I) produced the most accurate stone casts compared with one-step heavy body-light body and regular body-light body combinations. CLINICAL SIGNIFICANCE: In everyday dental practice, impression making is imperative. Hence, by doing this study, we tried to find out which material combination is suitable to give us predictable and accurate results.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Polivinil , Siloxanas
2.
Water Res ; 176: 115749, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32247996

RESUMO

Biofouling remains to be one of major obstacles in membrane bioreactors (MBRs), calling for the development of antibiofouling membranes. Silver nanoparticles (AgNPs), being a kind of broad spectrum bactericidal agent, have been widely used for modifying membrane; however, uncontrollable release of AgNPs and thus a short lifetime of modified membranes are thorny issues for the AgNPs-modified membranes. In this study, silica nanopollens were used as AgNPs nanocarriers for membrane modification (ASNP-M), which could improve silver delivery efficacy, avoid agglomeration and control Ag+ release towards bacteria. At a silver loading of 107.7 ± 10.9 µg Ag/cm2, ASNP-M effectively inhibited growth of Escherichia coli and Staphylococcus aureus, with an Ag+ release rate of 0.5 µg/(cm2 d). Long-term MBR tests showed that ASNP-M exhibited a significantly reduced transmembrane pressure increase rate of 0.88 ± 0.34 kPa/d which was much lower than that of two control membranes, i.e., pristine membrane (M0) (2.32 ± 0.86 kPa/d) and Ag@silica nanospheres (without spikes) modified membrane (ASNS-M) (2.25 ± 1.28 kPa/d). No significant adverse influences on the pollutant removal were also observed in the reactor. Foulants analysis revealed that biofilm of ASNP-M was thinner and comprised of mainly dead cells, and only organic matter with strong adhesion properties was allowed to attach onto the membrane surface. Bacterial community analysis suggested that the incorporation of Ag@silica nanopollens inhibited colonization of bacteria which are capable of causing membrane biofouling (e.g., Proteobacteria and Actinobacteria). These findings highlight the potential of the antibiofouling membrane to be used in MBRs for wastewater treatment and reclamation.


Assuntos
Incrustação Biológica , Nanopartículas Metálicas , Reatores Biológicos , Membranas Artificiais , Polivinil , Dióxido de Silício , Prata , Águas Residuárias
3.
Gene ; 740: 144534, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32145328

RESUMO

The function of tissue cells is strongly depends on the extracellular matrix (ECM) that can guide and support cell structure. This support plays a crucial role in the process of cell proliferation and differentiation. Herein, three different nanofibrous scaffolds that are highly attractive for tissue engineering were selected and then osteogenic related genes and protein expression patterns of human adipose-derived mesenchymal stem cells (AT-MSCs) were investigated when grown on substrates. Polycaprolactone, Poly (L-lactic acid) and Polyvinylidene-fluoride nanofibrous scaffolds were fabricated using Electrospinning method and then AT-MSCs viability and osteogenic differentiation were evaluated while cultured on them. The highest AT-MSCs survival rate when grown on the scaffolds was detected when grown on Polyvinylidene-fluoride. In addition, the highest ALP activity and mineralization were also observed in differentiated AT-MSCs has grown on Polyvinylidene-fluoride. The expression levels of Runx2, osteonectin and osteocalcin genes and osteocalcin protein in the AT-MSCs has grown on the Polyvinylidene-fluoride were also significantly higher than the rest of the scaffolds. Based on the results, it seems that since the studied substrate have a similar structural characteristics, their nature may have an important role in the stem cell's osteogenesis process, where the Polyvinylidene-fluoride piezoelectricity was a most distinguished characteristic.


Assuntos
Células-Tronco Mesenquimais , Nanofibras , Osteogênese , Engenharia Tecidual/métodos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Nanofibras/química , Osteocalcina/metabolismo , Osteogênese/efeitos dos fármacos , Osteogênese/fisiologia , Osteonectina/metabolismo , Poliésteres , Polivinil
4.
Chemosphere ; 250: 126236, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32088617

RESUMO

While polyphenol-based coating has been regarded as a promising alternative to functionalize membrane surface, it usually suffers from problems of low-efficient procedure and low utilization rate of the polyphenolic compounds, hindering its large-scale implementations. To solve these problems, this study provided a first report on inkjet printing of polyphenols (catechol (CA) or tannic acid (TA)) and sodium periodate (SP) on a polyvinylidene fluoride (PVDF) membrane to improve membrane performance. A series of analyses showed the efficient formation of homogenous films on the PVDF membrane surface and the improvement of hydrophilicity by the inkjet printing technique. The PVDF membranes decorated with the optimized polyphenolic coating exhibited a promising oil/water separation efficiency (higher than 99%) with a high average water permeation flux of 5.2 times higher than that of the pristine membrane. Meanwhile, the modified membranes illustrated a good stability under acidic conditions (pH = 2-7). The novel method proposed in this study is facile, cost-saving and environment-friendly. The advantages of the proposed method and the modified membranes demonstrated the great significance of the proposed method in practical applications.


Assuntos
Membranas Artificiais , Polifenóis/química , Interações Hidrofóbicas e Hidrofílicas , Polivinil , Impressão Tridimensional , Purificação da Água/métodos
5.
Pharm Res ; 37(2): 28, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912250

RESUMO

PURPOSE: This study aims to conduct an impact investigation in the hydrophobic-hydrophilic balance as an important factor for dissolution improvement of a hydrophilic carrier-based solid dispersion system. METHODS: Polymeric carriers with different hydrophobic to hydrophilic ratios were used to prepare several electrospun solid dispersion formulations. Physicochemical properties and surface morphology of the samples were assessed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), polarized light microscopy, Differential Scanning Calorimetry (DSC), X-ray Powder Diffraction (XRPD) and Scanning Electron Microscopy (SEM). Dissolution study was conducted in a non-sink condition to assess the drug release. RESULTS: Incorporation of a higher amount of hydrophilic component showed an improvement in formulating a fully amorphous system based on XRPD, yet the dissolution rate increment showed no significant difference from the lower. Hence, the degree of crystallinity is proven not to be the crucial factor contributing to dissolution rate improvement. The presence of a concomitant hydrophobic component, however, showed ability in resisting precipitation and sustaining supersaturation. CONCLUSION: Hydrophobicity in a binary carrier system plays an important role in achieving and maintaining the supersaturated state particularly for an amorphous solid dispersion. Graphical Abstract.


Assuntos
Antimaláricos/química , Atovaquona/química , Portadores de Fármacos/química , Polivinil/química , Povidona/química , Cristalização , Composição de Medicamentos , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cinética , Solubilidade , Solventes/química
6.
Prep Biochem Biotechnol ; 50(1): 18-27, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31453751

RESUMO

We report on the development of a functionalized membrane-based technology for selective enrichment of milk fat globules from raw bovine milk. Functionalization was conducted by in situ polymerization of acrylic acid within a polyvinylidene fluoride membrane, followed by the electrostatic attachment of a cationic polymer to impart a net positive charge. The functionalized membrane-based technology enabled a one-step method of selective separation of globules directly from milk-based on size and charge. The presence of globules in the eluate was confirmed by fluorescence microscopy. Quantification of the extracted phospholipids from globules in the eluant revealed a significantly higher amount of polar lipids than the permeate. Our study describes a comprehensive analysis of selective enrichment of fat globules using a functionalized membrane and demonstrates the beneficial effect of extracted phospholipids from enriched fat globules.


Assuntos
Glicolipídeos/isolamento & purificação , Glicoproteínas/isolamento & purificação , Membranas Artificiais , Leite/química , Polivinil/química , Animais , Bovinos , Fracionamento Químico/métodos , Glicolipídeos/análise , Glicoproteínas/análise , Fosfolipídeos/análise
7.
J Photochem Photobiol B ; 202: 111722, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31785445

RESUMO

Nowadays, the study of well-known sensitizers for photodynamic therapy and search for new ones are intensively conducted. In the present work supramolecular organization of crown-ether and phosphoryl-containing phthalocyanines ({Mgcr8Pc, I, and М[R4Pc] (M = Zn2+, R = -OPhP(O)(OH)(OC5H11), II; M = 2H+, R = -OPhP(O)(OH)(OC5H11), III; M = 2H+, -OPhP(O)(OH)2), IIIa}, respectively) was studied in microheterogeneous media. The role of a metal ion of a macrocycle in monomerization of phosphoryl-containing Pc in the presence of water-soluble poly(N-vinylpyrrolidone) was revealed. Some photobiological properties of compound I as possible photosensitizer with respect to human adenocarcinoma cells, HeLa, were analyzed. So, the light and dark cytotoxicity of I (IC50 dose) was 1.83 µÐœ and higher than 25 µÐœ, respectively. The reactive oxygen species (ROS) formation studied with use of fluorescent ROS detector DCFH2 revealed the plateau on the curves of fluorescence intensity vs time after 30 min of irradiation and ROS are almost not produced after the end of irradiation. In HeLa cells, accumulation of compounds I and II as well as fluorescent DCF presence were shown by confocal microscopic images. At concentration of 5 µM, compound I easily penetrates into the cell localizing primarily in the perinuclear region, whereas compound II mainly remains in the periphery of the cells in the fluorescent-active state. The results obtained allow us to continue the study of these interesting compounds.


Assuntos
Éteres de Coroa/química , Indóis/química , Metais/química , Fármacos Fotossensibilizantes/química , Polivinil/química , Pirrolidinas/química , Espécies Reativas de Oxigênio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Luz , Microscopia Confocal , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/farmacologia
8.
Chemosphere ; 241: 125068, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629244

RESUMO

This paper reports a novel nanocomposite additive for a polyvinylidene fluoride (PVDF) membrane with high hydrophilicity through the association of graphene oxide (GO) and ZnO. The influence of the hydrophilicity of GO-ZnO on the PVDF membrane was examined on different GO-ZnO loadings. The porosity and wettability (or hydrophilicity) of the membrane were improved significantly by blending GO-ZnO nanocomposite. In addition, the water flux of the GO-ZnO/PVDF membrane was 48% higher than that of bare PVDF, and the anti-fouling properties of this modified membrane were also improved. The irreversible fouling ratio (Rir) of bovine serum albumin (BSA) was reduced substantially with increasing the loading of GO-ZnO nanocomposite. The lowest irreversible fouling ratio (7.21%) was obtained for the membrane containing 0.2 wt % GO-ZnO of the nanocomposite (M6). GO-ZnO modification PVDF membranes were assumed to reduce the affinity between membrane and BSA foulant, which improved the anti-fouling properties PVDF membrane. In the activated sludge flux test, the membrane containing GO-ZnO in the polymer matrix had a higher flux than that of the bare PVDF membrane. The effluent quality after the composite membrane (0.6 NTU) was stable, indicating that the composite membrane can be used for practical applications Overall, the properties of the PVDF membrane were improved after modification due to hydrogen bonding or the hydrophilicity of the GO-ZnO nanocomposite.


Assuntos
Grafite/química , Polivinil/química , Ultrafiltração , Eliminação de Resíduos Líquidos/métodos , Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Nanocompostos , Nanopartículas/química , Polímeros , Porosidade , Soroalbumina Bovina , Óxido de Zinco/química
9.
Mater Sci Eng C Mater Biol Appl ; 106: 110056, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753372

RESUMO

Proanthocyanidins (PCs), a component of grape seed extract (GSE), have recently being used for the treatment of wounds. However, poor absorption, poor stability and rapid elimination from the systemic circulation limit its acceptance. In addressing these problems, we herein report the development of PCs based nanoformulations (PCs/SOLU) for the first time based on 1% GSE and assessed its wound healing potential in-vivo on the wistar rats. GSE and PCs/SOLU nanodispersions 1% were prepared by incorporating them into the ointment base via uniform mixing to form ointment which could be easily applied topically to wounds. The antibacterial activity of PCs/SOLU against gram positive and gram-negative bacteria strains proved that the cell membranes became more permeable with disrupted cell structure. While carrageenan and histamine induced rat paw edema analyses show there was no inflammatory signs in animals treated with 1 wt% of PCs/SOLU nanodispersion. Excision wound measuring about 3 cm in depth was created on the wistar rats. The ointment was applied topically on the wounded site and the wound contraction was measured daily. Grape seed extract (GSE) ointment, ointment base and povidone­iodine (Povi-Iod) ointment of about 1% was used as the control, positive and negative standards. PCs/SOLU nanodispersion heals the wound by mobilising the fibroblasts in the wound site and inhibits the inflammatory response through decreased expression of monocyte. The macroscopical, immunological and histopathological assessments revealed that PCs/SOLU nanodispersion ointment usage improves the cell adhesion and proliferation.


Assuntos
Nanoestruturas/química , Pomadas/farmacologia , Proantocianidinas/química , Cicatrização/efeitos dos fármacos , Administração Tópica , Animais , Edema/induzido quimicamente , Edema/tratamento farmacológico , Edema/patologia , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Feminino , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Extrato de Sementes de Uva/química , Hemólise/efeitos dos fármacos , Humanos , Masculino , Pomadas/química , Pomadas/uso terapêutico , Polietilenoglicóis/química , Polivinil/química , Proantocianidinas/farmacologia , Proantocianidinas/uso terapêutico , Ratos , Ratos Wistar , Pele/patologia
10.
Sci Total Environ ; 699: 134398, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31670038

RESUMO

A polyvinylidene fluoride plate sheet membrane coated 3D TiO2/poly (sodium styrenesulfonate) (PSS) photocatalyst layers were fabricated via dip-coating layer-by-layer (LbL) assembly. Cationic TiO2 and anionic PSS were alternately stacked on the support membrane via electrostatic interactions. The obtained modified membrane with (TiO2/PSS)7 exhibited optimal versatility under ultraviolet light irradiation in both dead-end and membrane reactor, which showed superior Lanasol Blue 3R (LB) removal rate to membrane filtration and biodegradation. The modified membranes (MM) exhibited good performance in terms of photocatalytic activity of foulant degradation and mitigation of membrane fouling in a membrane reactor. The obtained MM with (TiO2/PSS)7 exhibited optimal versatility under ultraviolet light irradiation in both dead-end and membrane reactors and superior Lanasol Blue 3R removal rate in membrane filtration and biodegradation. The MM (TiO2/PSS)7 possessed excellent antifouling properties by using bovine serum albumin (BSA), as evidenced by the extended Derjaguin-Landau-Verwey-Overbeek theory. Additionally, the TiO2/PSS membrane showed good self-cleaning ability, and the foulants on the membrane surface could be degraded using ultraviolet light irradiation.


Assuntos
Membranas Artificiais , Eliminação de Resíduos Líquidos , Incrustação Biológica , Filtração , Polivinil , Titânio , Raios Ultravioleta , Águas Residuárias
11.
Chemosphere ; 239: 124793, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726530

RESUMO

Developing an efficient and environmentally friendly strategy for oil-water separation is extremely important for practical application. In this study, a superhydrophobic and superoleophilic melamine sponge loaded with cross-linked and swellable polydivinylbenzene was successfully fabricated by a facile and effective one-step impregnation-curing method with adhesion of polydimethylsiloxane. The prepared sponge not only exhibited high oil absorption capacity, but it also enabled rapid oil collection in situ, which could be extended to practical application. Moreover, the modified superhydrophobic sponge showed excellent mechanical resistance and chemical stability. The surface morphology and chemical composition were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. This material has great development potential for large-scale oil spill clean-up and chemical spill accidents.


Assuntos
Dimetilpolisiloxanos/química , Recuperação e Remediação Ambiental/métodos , Óleos/química , Poluição por Petróleo/análise , Polivinil/química , Triazinas/química , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Nanoporos , Espectroscopia Fotoeletrônica , Polímeros/química , Água/química
12.
J Contemp Dent Pract ; 20(8): 928-934, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31797849

RESUMO

AIM: The aim of this study is to check the dimensional precision of stone models made by two different brands of polyvinyl siloxane impression materials using the monophase, one-step, and two-step putty/light-body impression techniques. MATERIALS AND METHODS: A metal model, having two crown preparations, was fabricated. With each technique, 40 impressions were made using two types of polyvinyl siloxane impression materials (Aquasil and Virtual). A total of 240 impressions were made with both the polyvinyl siloxane impression materials. Monophase impressions were made with a medium body using an acrylic custom tray. By simultaneous usage of putty and light-body, one-step impressions were made with a perforated metal stock tray. For two-step impressions, a 25-40 microns thick cellophane sheet spacer was used. The stone casts were obtained from the impressions of the stainless steel model. Three different dimensions (height, diameter, and inter-abutment distance) on these resultant stone casts were compared with the standard die. The accuracy of two different brands of impression materials was also compared. The results were then statistically analyzed. RESULTS: The resultant casts obtained from the different impression techniques had significantly larger dimensions in height and diameter, but smaller dimensions were observed for the inter-abutment distance. Larger deviation in resultant casts was observed in the monophase than one-step impression technique and the least deviation was observed in the two-step impression technique. CONCLUSION: The two-step impression technique produced the most accurate results in terms of the resultant casts. Out of the two different brands, Aquasil produced more fare results. CLINICAL SIGNIFICANCE: Adequate marginal adaptation, proper fit and least distortion of the castings, and the final prosthesis can be achieved by using the adequate impression technique and impression material.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Materiais para Moldagem Odontológica , Teste de Materiais , Polivinil , Siloxanas , Propriedades de Superfície
13.
AAPS PharmSciTech ; 21(1): 27, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31858315

RESUMO

The purpose of this study was to develop and evaluate a new formulation of ziprasidone (ZIP) for improved fasted state absorption and sustained drug release. ZIP solid dispersions were produced via spray drying using Soluplus®, an amphiphilic polymer, as the solubility enhancer. Physicochemical analysis proved that ZIP presented at amorphous state in the spray-dried microparticles and the dissolution rate of ZIP from the Soluplus®-ZIP composite microparticles was significantly increased compared with that of the physical mixtures. Commonly used encapsulation materials including Eudragit® RL, Eudragit® S100 and Ethyl Cellulose were incorporated into the solid dispersions to regulate the drug release kinetics. The formulation containing ethyl cellulose provided the most sustained release behaviors. Pharmacokinetic studies in beagle dogs confirmed that there was no significant difference in oral bioavailability of the microparticles under fasted and fed states, and a prolonged Tmax value was simultaneously achieved compared with the commercial ZIP capsules.


Assuntos
Antipsicóticos/administração & dosagem , Celulose/análogos & derivados , Interações Alimento-Droga , Piperazinas/administração & dosagem , Polietilenoglicóis/química , Polivinil/química , Tiazóis/administração & dosagem , Animais , Antipsicóticos/farmacocinética , Disponibilidade Biológica , Celulose/química , Preparações de Ação Retardada , Cães , Piperazinas/farmacocinética , Solubilidade , Tiazóis/farmacocinética
14.
Zootaxa ; 4656(3): zootaxa.4656.3.1, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31716808

RESUMO

The Chinese species of the genus Oodescelis Motschulsky, 1845 are revised. Fifteen species belonging to five subgenera are listed. O. (Acutoodescelis) emmerichi Kaszab, 1940 is proposed as subspecies of O. (A.) punctatissima (Fairmaire, 1886) [O. (A.) punctatissima emmerichi Kaszab, 1940, stat. n.]. A new synonym is established: O. (A.) pyripenis Ren, 1999 = O. (A.) punctatissima (Fairmaire, 1886), syn. n. based on the morphological characters, geographic distribution, and assessment on the molecular phylogeny [except O. (A.) pyripenis]. A new subspecies and a new species are described: O. (A.) punctatissima henanana Bai Ren, subsp. nov. from Henan and O. (Planoodescelis) lii Bai Ren, sp. nov. from Hubei. Lectotypes for the follwoing species are designated: Platyscelis punctatissima Fairmaire, 1886, Platyscelis (Oodescelis) affinis Seidlitz, 1893, Platyscelis (Oodescelis) brevipennis Kaszab, 1938, Platyscelis (Oodescelis) similis Kaszab, 1938, Oodescelis (Clavatoodescelis) acutanguloides Kaszab, 1940, Oodescelis (Clavatoodescelis) kuntzeni Kaszab, 1940 and Oodescelis (Clavatoodescelis) sachtlebeni Kaszab, 1940. Additional diagnostic characters of the subgenus Planoodescelis Egorov, 2004 are proposed. In addition, newly collected materials are examined, new distribution records, habitus of adults, images of male protibiae and aedeagus are provided, and a key to Chinese species is given. Furthermore, the first and preliminary molecular phylogeny of the genus is presented, and the used markers may be helpful to reconstitute the phylogenetic relations within the tribe Platyscelidini.


Assuntos
Besouros , Distribuição Animal , Animais , China , Masculino , Filogenia , Polivinil
15.
Eur J Pharm Biopharm ; 145: 12-26, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31622652

RESUMO

A major shortcoming of drug nanocomposites as compared with amorphous solid dispersions (ASDs) is their limited supersaturation capability in dissolution media. Here, we prepared drug hybrid nanocrystal-amorphous solid dispersions (HyNASDs) and compare their performance to ASDs. A wet-milled griseofulvin (GF, BCS II drug) nanosuspension and a GF solution, both containing the same dissolved polymer-surfactant (SDS: sodium dodecyl sulfate) with 1:1 and 1:3 GF:polymer mass ratios, were spray-dried. Hydroxypropyl cellulose (HPC) and Soluplus (Sol) were used as matrix-forming polymers. XRPD, DSC, and Raman spectroscopy reveal that ASDs were formed upon spray-drying the solution-based feed, whereas nanocomposites and nanocomposites with >10% amorphous content, HyNASDs, were formed with the nanosuspension-based feed. Sol provided higher GF relative supersaturation, up to 180% and 360% for HyNASDs and ASDs, respectively, in the dissolution tests than HPC (up to 50% for both) owing to Sol's stronger intermolecular interactions and miscibility with GF and its recrystallization inhibition. Besides the higher kinetic solubility of GF in Sol, presence of GF nanoparticles vs. micron-sized particles in the nanocomposites enabled fast supersaturation. This study demonstrates successful preparation of fast supersaturating (190% within 20 min) HyNASDs, which renders nanoparticle formulations competitive to ASDs in bioavailability enhancement of poorly soluble drugs.


Assuntos
Liberação Controlada de Fármacos/efeitos dos fármacos , Griseofulvina/química , Nanopartículas/química , Celulose/análogos & derivados , Celulose/química , Cristalização/métodos , Composição de Medicamentos/métodos , Nanocompostos/química , Tamanho da Partícula , Polietilenoglicóis/química , Polímeros/química , Polivinil/química , Dodecilsulfato de Sódio/química , Solubilidade , Tensoativos/química , Suspensões/química
16.
Environ Sci Pollut Res Int ; 26(32): 33607-33620, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31587163

RESUMO

This study aimed to improve the pore size, porosity, and hydrophobicity of polyvinylidene fluoride (PVDF) membranes for desalination by vacuum membrane distillation (VMD). New membranes were prepared via etching PVDF/calcium carbonate (CaCO3) composite membranes using hydrochloric acid (HCl), depending on the chemical reaction of CaCO3 and HCl. Etched membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), contact angle (CA), atomic force microscope (AFM), and scanning electron microscopy (SEM). The results showed that CaCO3 of composite membranes was completely reacted by 1.5 mol/L HCl after composite membranes had been etched 90 min. The crystallinity of etched membranes was the same as that of PVDF/CaCO3 composite membranes, and no new functional groups appeared in etched membranes, which indicated that etched membranes had good chemical stability. The surface roughness increased and led to the increase of contact angle, which means the hydrophobicity of etched membranes was enhanced. As a result, the increment of permeation flux had been improved in a VMD process. It was found that the maximum flux of etched membrane was enhanced and up to 1.65 times of composite membrane when the concentration of sodium chloride (NaCl) solution was 5.0 wt%, and the maximum flux reached up to 30.9 kg m-2 h-1.


Assuntos
Ácido Clorídrico/química , Membranas Artificiais , Polivinil/química , Carbonato de Cálcio/química , Destilação , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Porosidade , Cloreto de Sódio , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Int J Mol Sci ; 20(19)2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31569598

RESUMO

The interests of developing antimicrobial biomaterials based on silk sericin from Bombyx mori cocoon, have been shooting up in the last decades. Sericin is a valuable natural protein owing to its hydrophilicity, biodegradability, and biocompatibility. Here, we fabricated a sponge with antibacterial capacities for potential wound dressing application. By co-blending of sericin, polyvinyl alcohol (PVA) and zinc oxide nanoparticles (ZnONPs), the ZnONPs-sericin/PVA composite sponge (ZnONPs-SP) was successfully prepared after freeze-drying. Scanning electron microscopy showed the porous structure of ZnONPs-SP. Energy dispersive spectroscopy indicated the existence of Zn in the sponge. X-ray diffractometry revealed the hexagonal wurtzite structure of ZnONPs. Fourier transform infrared spectroscopy showed the biologic coupling of ZnONPs and sericin resulted in a decrease of α-helix and random coil contents, and an increase of ß-sheet structure in the sponge. The swelling experiment suggested ZnONPs-SP has high porosity, good hydrophilicity, and water absorption capability. The plate bacterial colony counting coupled with growth curve assays demonstrated that the composite sponge has an efficiently bacteriostatic effect against Staphylococcus aureus and Escherichia coli, respectively. Furthermore, the cell compatibility analysis suggested the composite sponge has excellent cytocompatibility on NIH3T3 cells. In all, ZnONPs-SP composite sponge has significant potentials in biomaterials such as wound dressing and tissue engineering.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Polivinil/química , Polivinil/farmacologia , Sericinas/química , Óxido de Zinco/química , Animais , Bombyx/química , Sobrevivência Celular , Nanopartículas Metálicas/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
18.
Int J Mol Sci ; 20(17)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484450

RESUMO

In this study, nanoparticle-incorporated nanofiber-covered yarns were prepared using a custom-made needle-free electrospinning system. The ultimate goal of this work was to prepare functional nanofibrous surfaces with antibacterial properties and realize high-speed production. As antibacterial agents, we used various amounts of copper oxide (CuO) and vanadium (V) oxide (V2O5) nanoparticles (NPs). Three yarn preparation speeds (100 m/min, 150 m/min, and 200 m/min) were used for the nanofiber-covered yarn. The results indicate a relationship between the yarn speed, quantity of NPs, and antibacterial efficiency of the material. We found a higher yarn speed to be associated with a lower reduction in bacteria. NP-loaded nanofiber yarns were proven to have excellent antibacterial properties against Gram-negative Escherichia coli (E. coli). CuO exhibited a greater inhibition and bactericidal effect against E. coli than V2O5. In brief, the studied samples are good candidates for use in antibacterial textile surface applications, such as wastewater filtration. As greater attention is being drawn to this field, this work provides new insights regarding the antibacterial textile surfaces of nanofiber-covered yarns.


Assuntos
Antibacterianos/química , Nanofibras/química , Polivinil/química , Cobre/química , Vanádio/química
19.
Water Res ; 165: 114982, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473356

RESUMO

In this study, an omniphobic membrane was fabricated by electrospraying fluorinated zinc oxide (ZnO) nanoparticles (NPs) mixed with polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) on the surface of an organosilane functionalized polyvinylidene difluoride (PVDF) membrane. Our results revealed that the functionalized ZnO NPs membrane exhibited a rough hierarchical re-entrant morphology with low surface energy which allowed it to achieve high omniphobic characteristics. It was observed that the addition of 30% ZnO (w/w of PVDF-HFP) was found to be optimal and imparted a high repulsive characteristic. The optimized PVDF/ZnO(30)/FAS/PVDF-HFP referred as cPFP-30Z membrane exhibited a high contact angle values of 159.0 ±â€¯3.1°, 129.6 ±â€¯2.2°, 130.4 ±â€¯4.1° and 126.1 ±â€¯1.2° for water, sodium dodecyl sulfate (SDS) saline solution (0.3 mM SDS in 3.5% NaCl), ethanol, and vegetable oil, respectively. The low surface energy and high surface roughness (Ra) of optimised membrane was assessed as 0.78 ±â€¯0.14 mN m-1 and 1.37 µm, respectively. Additionally, in contrast with the commercial PVDF membrane, the cPFP-30Z membrane exhibited superior anti-wetting/anti-fouling characteristics and high salt rejection performance (>99%) when operated with a saline oil solution (0.015 v/v) and SDS (0.4 mM) feed solutions.


Assuntos
Nanopartículas , Purificação da Água , Óxido de Zinco , Destilação , Membranas Artificiais , Polivinil , Água do Mar , Tensão Superficial
20.
World Neurosurg ; 132: 292-294, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31476459

RESUMO

BACKGROUND: Endovascular embolization is an important tool in the management of multiple pathologies as a preoperative adjunct in the care of arteriovenous malformations or vascular tumors. CASE DESCRIPTION: We report a case of delayed distal Onyx migration after surgical resection of a glomus vagale tumor, which had been preoperatively embolized. In this report, the patient underwent successful embolectomy of the migrated Onyx fragment using manual aspiration. CONCLUSIONS: This case represents the first in the literature to describe this potential delayed complication, as well as its management strategy.


Assuntos
Embolectomia/métodos , Migração de Corpo Estranho/cirurgia , Tumor Glômico/terapia , Neoplasias de Cabeça e Pescoço/terapia , Artéria Cerebral Média/cirurgia , Artéria Oftálmica/cirurgia , Polivinil , Tantálio , Adulto , Angiografia por Tomografia Computadorizada , Combinação de Medicamentos , Embolização Terapêutica , Migração de Corpo Estranho/diagnóstico por imagem , Migração de Corpo Estranho/etiologia , Humanos , Masculino , Artéria Cerebral Média/diagnóstico por imagem , Artéria Oftálmica/diagnóstico por imagem
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