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1.
Food Chem ; 351: 129226, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33639430

RESUMEN

The effect of three drying methods (hot air, freeze and spray drying) on the solubility and amphiphilicity of gelatin were investigated and compared. Results showed spray drying gelatin (SDG) and hot air drying gelatin (HDG) showed the lowest and best solubility, respectively. This phenomenon was attributed to the degree of subunits degradation and hydrophobicity. The HDG showed an obvious degradation during the hot air drying and displayed the strongest hydrophilicity, while SDG showed a slight degradation and strongest hydrophobicity. The results of wettability showed that SDG had a better amphiphilicity (92.48°) in comparison with HDG (57.7°) and freeze drying gelatin (VDG, 77.53°), which can effectively reduce the interfacial tension of gelatin, thus significantly improving the stability of foam and emulsion (p < 0.05). These results suggested the drying methods can adjust the amphiphilicity of gelatin, and the SDG displayed a better amphiphilicity, showing good potential applications in foam and emulsion.


Asunto(s)
Desecación/métodos , Congelación , Gelatina/química , Gelatina/aislamiento & purificación , Interacciones Hidrofóbicas e Hidrofílicas , Microondas , Solubilidad , Factores de Tiempo , Humectabilidad
2.
Food Chem ; 349: 129112, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33581437

RESUMEN

Zein/low-acyl gellan gum (GG) composite particles (ZGPs) were fabricated to stabilize Pickering emulsions (termed "ZGPEs"). The wettability of ZGPs was manipulated simply by adjusting the concentration of GG. The effects of GG concentration, oil fraction and pH on ZGPEs were systematically evaluated by confocal laser scanning microscopy (CLSM), cryo-scanning electron microscopy (cryo-SEM), dynamic light scattering technique, stimulated emission depletion (STED) nanoscopy and rheology. The results showed that ZGPEs exhibited robust colloidal properties and distinct advantage over other previously reported zein-polysaccharide-based Pickering emulsions. CLSM, STED and cryo-SEM analyses revealed that the network structures formed by GG and ZGPs at the continuous phase and oil-water interface were the main contributors to the emulsion's characteristics. This study provides insights into the fabrication of food-grade Pickering emulsions with distinct characteristics that impart favorable properties to various foods and bioactive delivery systems.


Asunto(s)
Nanoestructuras/química , Polisacáridos Bacterianos/química , Zeína/química , Emulsiones , Geles , Tamaño de la Partícula , Reología , Humectabilidad
3.
Int J Nanomedicine ; 16: 667-682, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33531806

RESUMEN

Background: Nanostructured surface modifications of Ti-based biomaterials are moving up from a highly-promising to a successfully-implemented approach to developing safe and reliable implants. Methods: The study's main objective is to help consolidate the knowledge and identify the more suitable experimental strategies related to TiO2 nanotubes-modified surfaces. In this sense, it proposes the thorough investigation of two optimized nanotubes morphologies in terms of their biological activity (cell cytotoxicity, alkaline phosphatase activity, alizarin red mineralization test, and cellular adhesion) and their electrochemical behavior in simulated body fluid (SBF) electrolyte. Layers of small-short and large-long nanotubes were prepared and investigated in their amorphous and crystallized states and compared to non-anodized samples. Results: Results show that much more than the surface area development associated with the nanotubes' growth; it is the heat treatment-induced change from amorphous to crystalline anatase-rutile structures that ensure enhanced biological activity coupled to high corrosion resistance. Conclusion: Compared to both non-anodized and amorphous nanotubes layers, the crystallized nano-structures' outstanding bioactivity was related to the remarkable increase in their hydrophilic behavior, while the enhanced electrochemical stability was ascribed to the thickening of the dense rutile barrier layer at the Ti surface beneath the nanotubes.


Asunto(s)
Nanotubos/química , Prótesis e Implantes , Titanio/química , Fosfatasa Alcalina/metabolismo , Adhesión Celular , Línea Celular Tumoral , Supervivencia Celular , Corrosión , Electroquímica , Electrólitos/química , Humanos , Nanotubos/ultraestructura , Humectabilidad
4.
Food Chem ; 350: 129251, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33588282

RESUMEN

The pea protein isolate-high methoxyl pectin-epigallocatechin gallate (PPI-HMP-EGCG) complex was used to stabilize Pickering emulsions (PEs) and high internal phase PEs (HIPPEs), and the effect of interfacial rheology on the microstructure, bulk rheology and stability of these emulsions was investigated. The PPI-HMP-EGCG complex with PPI to EGCG 30:1 exhibited partial wettability (81.6 ± 0.4°) and optimal viscoelasticity for the formation of stable interfacial layer. The microstructure demonstrated that the PPI-HMP-EGCG complex acted as an interfacial layer and surrounded the oil droplets, and continuous phases were mainly filled with excessive HMP, which enhanced emulsion stability. The formation of a firm gel-like network structure required a dense interfacial layer to provide the PEs (complex concentration of 0.1%) and HIPPEs (oil-phase up to 0.83) with ideal viscoelasticity and stability. The results provide the guidelines for the rational design of EGCG-loaded HIPPEs stabilized by water-soluble protein/polysaccharide complexes.


Asunto(s)
Catequina/análogos & derivados , Proteínas de Guisantes/química , Pectinas/química , Catequina/química , Emulsiones , Reología , Viscosidad , Agua/química , Humectabilidad
5.
Carbohydr Polym ; 256: 117506, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483028

RESUMEN

Direct deposition of the negatively charged polyelectrolyte, carboxymethyl cellulose (CMC), into a bacterial cellulose (BC) matrix was used as a simple route to fabricate a re-swellable and biocompatible cellulose-based hydrogel. As a result of this non-destructive approach, the physical and mechanical property of the original BC were well-preserved within the resulting BC/CMC hydrogel. As a BC/CMC-based colorimetric pH sensor, it exhibited a rapid response with an easy color differentiation between each pH by the naked eye, and wide linear range of pH 4.0-9.0 with good linearity. For the detection of glucose in sweat, the BC/CMC-based colorimetric glucose sensor provided a low limit of detection (25 µM) with a wide linear detection range (0.0-0.5 mM) and high accuracy. These BC/CMC based sensors could potentially be applied as non-invasive semi-quantitative sensors for on-skin health monitoring.


Asunto(s)
Técnicas Biosensibles , Celulosa/química , Colorimetría/métodos , Gluconacetobacter xylinus/química , Glucosa/análisis , Sudor/química , Carboximetilcelulosa de Sodio/química , Color , Humanos , Hidrogeles , Concentración de Iones de Hidrógeno , Límite de Detección , Electricidad Estática , Agua/química , Humectabilidad
6.
Carbohydr Polym ; 256: 117507, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483029

RESUMEN

A series of vegetable oil-based waterborne polyurethane composites were prepared through construction of novel semi-interpenetrating polymers network using carboxymethyl chitosan (CA) as the secondary polymer phase. The effects of CA contents on storage stability, and particle size distribution of the composite dispersions and thermal stability, mechanical properties and surface wettability of composite films were investigated and discussed. The results showed that the composite dispersions displayed excellent storage stability and the biomass contents of resulting films were high up to 80 %. A significant increase in crosslinking density and glass transition temperature of the composite films were observed as the CA contents increased, which was attributed to the increasing hard segment of films and strong hydrogen bonding interaction between polyurethanes and CA. This work provided a simple method to tailor the performance of environmentally friendly vegetable oil-based waterborne polyurethane, which could find application in the field of coatings, adhesives, ink and so on.


Asunto(s)
Aceite de Ricino/química , Quitosano/análogos & derivados , Poliuretanos/química , Agua/química , Quitosano/química , Estabilidad de Medicamentos , Humanos , Enlace de Hidrógeno , Ensayo de Materiales , Tamaño de la Partícula , Transición de Fase , Resistencia a la Tracción , Temperatura de Transición , Humectabilidad
7.
Carbohydr Polym ; 256: 117520, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483041

RESUMEN

Xylan and gelatin-based hydrogels are prepared in different molar ratios using ethylene glycol diglycidyl ether cross-linker. The hydrogels are characterized by Fourier transform infrared spectroscopy, morphology, thermal analysis, and swelling ratio. The rheological experiment shows the gels are cross-linked successfully by revealing the viscoelastic nature. The xylan-gelatin gel synthesized in a 5:1 molar ratio (hence XG5) has higher storage modulus, gelation temperature, and time among the synthesized gels. The adsorption behaviour of the synthesized gels is studied for the removal of methylene blue, by varying adsorbate concentration, pH, and temperature. Among the synthesized hydrogels, XG5 shows the highest adsorption capacity of 26.04 mg g-1 at pH = 5.84 and 25 °C. The kinetics of the adsorption process follows the pseudo-second-order model, and monolayer adsorption is adequately represented by the Langmuir isotherm model. The adsorption process is established as spontaneous, exothermic, and physisorption from the thermodynamic parameters.


Asunto(s)
Gelatina/química , Hidrogeles/química , Azul de Metileno/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Xilanos/química , Adsorción , Reactivos de Enlaces Cruzados/química , Elasticidad , Resinas Epoxi/química , Concentración de Iones de Hidrógeno , Cinética , Azul de Metileno/química , Reología , Temperatura , Termodinámica , Viscosidad , Contaminantes Químicos del Agua/química , Humectabilidad
8.
Carbohydr Polym ; 256: 117524, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483045

RESUMEN

Curdlan hydrogel obtained after thermal gelling exhibits elasticity and high water-absorbing capacity. However, its modifications leading to the increase of biofunctionality usually alter its solubility and reduce mechanical parameters. Therefore, curdlan hydrogel was modified by deposition of polydopamine to improve its capacity to bind biologically active molecules with free amino groups. It exhibited the unchanged structure, mechanical properties and increased soaking capacity. Aminoglycoside antibiotic (gentamicin) as a model molecule was effectively immobilized to such modified curdlan via quinone moiety (but not amino groups) of polydopamine. Approximately 50 % of the immobilized drug was released following Fickian diffusion and inhibited the bacterial growth in matrix-surrounding medium in prolonged manner. The remaining drug amount was stably attached and prevented the hydrogel against bacterial adhesion even when all the mobile drug has been released. Therefore, polydopamine-modified curdlan hydrogel shows the potential for fabrication of functional materials for different purposes, including drug-loaded biomaterials.


Asunto(s)
Antibacterianos/metabolismo , Materiales Biocompatibles Revestidos/síntesis química , Gentamicinas/metabolismo , Hidrogeles/síntesis química , Indoles/química , Polímeros/química , beta-Glucanos/química , Antibacterianos/farmacología , Adhesión Bacteriana/efectos de los fármacos , Materiales Biocompatibles Revestidos/farmacología , Portadores de Fármacos , Composición de Medicamentos/métodos , Liberación de Fármacos , Elasticidad , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Gentamicinas/farmacología , Humanos , Hidrogeles/farmacología , Cinética , Pruebas de Sensibilidad Microbiana , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/crecimiento & desarrollo , Humectabilidad
9.
ACS Appl Mater Interfaces ; 13(3): 3631-3644, 2021 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-33448783

RESUMEN

Three-dimensional (3D) scaffolds with optimum physicochemical properties are able to elicit specific cellular behaviors and guide tissue formation. However, cell-material interactions are limited in scaffolds fabricated by melt extrusion additive manufacturing (ME-AM) of synthetic polymers, and plasma treatment can be used to render the surface of the scaffolds more cell adhesive. In this study, a hybrid AM technology, which combines a ME-AM technique with an atmospheric pressure plasma jet, was employed to fabricate and plasma treat scaffolds in a single process. The organosilane monomer (3-aminopropyl)trimethoxysilane (APTMS) and a mixture of maleic anhydride and vinyltrimethoxysilane (MA-VTMOS) were used for the first time to plasma treat 3D scaffolds. APTMS treatment deposited plasma-polymerized films containing positively charged amine functional groups, while MA-VTMOS introduced negatively charged carboxyl groups on the 3D scaffolds' surface. Argon plasma activation was used as a control. All plasma treatments increased the surface wettability and protein adsorption to the surface of the scaffolds and improved cell distribution and proliferation. Notably, APTMS-treated scaffolds also allowed cell attachment by electrostatic interactions in the absence of serum. Interestingly, cell attachment and proliferation were not significantly affected by plasma treatment-induced aging. Also, while no significant differences were observed between plasma treatments in terms of gene expression, human mesenchymal stromal cells (hMSCs) could undergo osteogenic differentiation on aged scaffolds. This is probably because osteogenic differentiation is rather dependent on initial cell confluency and surface chemistry might play a secondary role.


Asunto(s)
Células Madre Mesenquimatosas/citología , Gases em Plasma/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Adhesión Celular , Línea Celular , Proliferación Celular , Humanos , Osteogénesis , Silanos/química , Compuestos de Vinilo/química , Humectabilidad
10.
Food Chem ; 342: 128380, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33508904

RESUMEN

The utilization of oils in the food industry can be facilitated by converting into a powdered form using microencapsulation technologies. In this study, coatings formed from macadamia protein isolate (MPI) and chitosan hydrochloride (CHC) were assessed for their ability to facilitate the microencapsulation of macadamia oil by spray dried, and all encapsulation efficiency was higher than 87.0%. The physicochemical properties of macadamia oil powders were then characterized. In addition, changes in the particle size, aggregation state, and creaming stability of rehydrated emulsions were analyzed during storage. The addition of CHC significantly enhanced the water-solubility and wettability but decreased the flowability of microencapsulated oil. Powdered macadamia oil produced at MPI/CHC = 5:1 had the highest encapsulation efficiency (94.2%), best oxidation stability (<4 meq/kg), and best rehydration properties. Overall, MPI/CHC could be used as a good emulsifier for producing stable rehydrated emulsion, which may therefore be useful in certain food applications.


Asunto(s)
Quitosano/química , Emulsiones/química , Macadamia/metabolismo , Proteínas de Plantas/química , Almacenamiento de Alimentos , Macadamia/química , Aceites/química , Oxidación-Reducción , Tamaño de la Partícula , Polvos/química , Solubilidad , Temperatura , Agua/química , Humectabilidad
11.
ACS Appl Mater Interfaces ; 13(3): 4740-4749, 2021 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-33370088

RESUMEN

Superhydrophobic conductive materials have received a great amount of interest due to their wide applications in oil-water separation, electrically driven smart surface, electromagnetic shielding, and body motion detection. Herein, a highly conductive superhydrophobic cotton cloth is prepared by a facile method. A layer of polydopamine/reduced graphene oxide (PDA/rGO) was first coated on the cotton fabric, and then copper nanoparticles were in situ grown on the prepared surface. After further modification with stearic acid (STA), the wettability of the cotton surface changed from superhydrophilic to superhydrophobic (water contact angle (WCA) = 153°). The electrical conductivity of the PDA/rGO/Cu/STA cotton is as high as 6769 S·m-1, while the stearic acid effectively protects Cu NPs from oxidation. As a result, the superhydrophobic PDA/rGO/Cu/STA cotton has shown excellent electrical stability and can be used in detecting human motions in both ambient and underwater conditions. The sensor can recognize human motion from air into water and other underwater activities (e.g., underwater bending, stretching, and ultrasound). This multifunctional cotton device can be used as an ideal sensor for underwater intelligent devices and provides a basis for further research.


Asunto(s)
Técnicas Biosensibles/instrumentación , Fibra de Algodón/análisis , Grafito/química , Indoles/química , Polímeros/química , Dispositivos Electrónicos Vestibles , Técnicas Biosensibles/métodos , Conductividad Eléctrica , Diseño de Equipo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Movimiento (Física) , Oxidación-Reducción , Ácidos Esteáricos/química , Agua/química , Humectabilidad
12.
ACS Appl Mater Interfaces ; 13(1): 1979-1987, 2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33351582

RESUMEN

It is a great challenge to fabricate a surface with Cassie-Baxter wettability that can be continuously adjusted from hydrophilicity to superhydrophobicity by changing of geometric parameters. In this paper, we propose and demonstrate a bioinspired surface fabricated by using a projection micro-stereolithography (PµSL) based 3D printing technique to address the challenge. Independent of materials, the bioinspired textured surface has a maximum contact angle (CA) of 171°, which is even higher than that of the omniphobic springtail skin we try to imitate. Most significantly, we are able to control the CA of the bioinspired surface in the range of 55-171° and the adhesion force from 71 to 99 µN continuously by only changing the geometric parameters of the bioinspired microstructures. The underlying mechanisms of the CA control of our bioinspired surface are also revealed by using a multi-phase lattice Boltzmann model. Furthermore, we demonstrate potential applications in droplet-based microreactors, nonloss water transportation, and coalescence of water droplets by employing our 3D-printed bioinspired structures with their remarkable precise Cassie-Baxter wettability control and petal effects. The present results potentially pave a new way for designing next generation functional surfaces for microdroplet manipulation, droplet-based biodetection, antifouling surfaces, and cell culture.


Asunto(s)
Plásticos/química , Estereolitografía , Agua/química , Humectabilidad , Animales , Artrópodos/química , Biomimética/métodos , Interacciones Hidrofóbicas e Hidrofílicas , Impresión Tridimensional
13.
Food Chem ; 339: 127976, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33152855

RESUMEN

Innovative biocomposite coating powders based on soy protein isolate or whey protein isolate, both containing sunflower oil (SO) were fabricated by freeze drying technique. The influences of concentration of SO and using different protein isolate types on the physicochemical, thermal and morphological properties of the powders were investigated. The Fourier transform infrared spectroscopy and thermal analysis revealed that SO interacted with protein isolates through hydrogen bonding resulted a strong network structure of the powders. It was found that amorphous structure and morphology of the powders was not significantly influenced by oil addition. Moisture content and water activity values of SPI powders were found higher than those of WPI. All powders were wettable, and solubility values were in the range of 91-99%. Preservative-free powders were reconstituted and applied to coat sliced cakes, a bakery product. Coating application showed effective protection on textural structure of cake by high moisture preservation ability.


Asunto(s)
Liofilización , Proteínas de Soja/química , Aceite de Girasol/química , Proteína de Suero de Leche/química , Desecación , Polvos , Solubilidad , Humectabilidad
14.
Int J Mol Sci ; 21(24)2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33353050

RESUMEN

Recently, extreme ultraviolet (EUV) radiation has been increasingly used to modify polymers. Properties such as the extremely short absorption lengths in polymers and the very strong interaction of EUV photons with materials may play a key role in achieving new biomaterials. The purpose of the study was to examine the impact of EUV radiation on cell adhesion to the surface of modified polymers that are widely used in medicine: poly(tetrafluoroethylene) (PTFE), poly (vinylidene fluoride) (PVDF), and poly-L-(lactic acid) (PLLA). After EUV surface modification, which has been performed using a home-made laboratory system, changes in surface wettability, morphology, chemical composition and cell adhesion polymers were analyzed. For each of the three polymers, the EUV radiation differently effects the process of endothelial cell adhesion, dependent of the parameters applied in the modification process. In the case of PVDF and PTFE, higher cell number and cellular coverage were obtained after EUV radiation with oxygen. In the case of PLLA, better results were obtained for EUV modification with nitrogen. For all three polymers tested, significant improvements in endothelial cell adhesion after EUV modification have been demonstrated.


Asunto(s)
Adhesión Celular , Células Endoteliales/fisiología , Microvasos/fisiología , Poliésteres/farmacología , Politetrafluoroetileno/farmacología , Polivinilos/farmacología , Rayos Ultravioleta , Células Cultivadas , Células Endoteliales/efectos de los fármacos , Humanos , Microvasos/efectos de los fármacos , Poliésteres/química , Poliésteres/efectos de la radiación , Politetrafluoroetileno/química , Politetrafluoroetileno/efectos de la radiación , Polivinilos/química , Polivinilos/efectos de la radiación , Propiedades de Superficie , Humectabilidad
15.
Chemosphere ; 254: 126873, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32957285

RESUMEN

The removal of organic pollutants from water is highly desired because of the development of industrial and social economy. Superhydrophilic and underwater superoleophobic membranes are emerging materials for effective oil/water separation. In this paper, superhydrophilic and underwater superoleophobic polypropylene (PP) melt-blown membranes were prepared through melt-blown and in situ growth method, achieving highly efficient oil/water separation. After in situ growth, polydopamine (PDA) grows on the surface of PP fibers, and the addition of coupling agent (3-aminopropyltriethoxysilane, APTES) can improve the stability of the membrane in harsh environments (1 M HCl, 1 M NaOH, 1 M NaCl). The PDA/APTES@PP membrane could dramatically enhance the wetting (water contact angle ∼0, underwater oil contact angle∼154°) compare with the pristine PP melt-blown membrane (water contact angle ∼130°, underwater oil contact angle ∼0). Moreover, the filtration performance is at a high level (∼99%). The behaviors are comparable or even superior to the typical reported results in the references (such as the mussel-inspired superhydrophilic PVDF membrane and copper mesh). This method provides a facile route to prepared multi-functional membrane for highly efficiency oil/water separation and industrial oily wastewater remediation.


Asunto(s)
Indoles/análisis , Polímeros/análisis , Cobre , Interacciones Hidrofóbicas e Hidrofílicas , Membranas Artificiales , Aceites , Aguas Residuales , Agua , Purificación del Agua , Humectabilidad
16.
Adv Exp Med Biol ; 1267: 101-115, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32894479

RESUMEN

Pathogenic bacteria colonize or disseminate into cells and tissues by inducing large-scale remodeling of host membranes. The physical phenomena underpinning these massive membrane extension and deformation are poorly understood. Invasive strategies of pathogens have been recently enriched by the description of a spectacular mode of opening of large transendothelial cell macroaperture (TEM) tunnels correlated to the dissemination of EDIN-producing strains of Staphylococcus aureus via a hematogenous route or to the induction of gelatinous edema triggered by the edema toxin from Bacillus anthracis. Remarkably, these highly dynamic tunnels close rapidly after they reach a maximal size. Opening and closure of TEMs in cells lasts for hours without inducing endothelial cell death. Multidisciplinary studies have started to provide a broader perspective of both the molecular determinants controlling cytoskeleton organization at newly curved membranes generated by the opening of TEMs and the physical processes controlling the dynamics of these tunnels. Here we discuss the analogy between the opening of TEM tunnels and the physical principles of dewetting, stemming from a parallel between membrane tension and surface tension. This analogy provides a broad framework to investigate biophysical constraints in cell membrane dynamics and their diversion by certain invasive microbial agents.


Asunto(s)
Bacterias/patogenicidad , Membrana Celular/microbiología , Membrana Celular/patología , Células Endoteliales/microbiología , Células Endoteliales/patología , Humectabilidad , Membrana Celular/metabolismo , Edema/metabolismo , Edema/microbiología , Edema/patología , Células Endoteliales/metabolismo , Humanos , Tensión Superficial
17.
Int J Nanomedicine ; 15: 5813-5824, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32821103

RESUMEN

Introduction: This paper presents a novel technique for the synthesis of graphene oxide (GO) with various surface features using high-density atmospheric plasma deposition. Furthermore, to investigate the use of hydrophobic, super-hydrophobic, and hydrophilic graphene in biological applications, we synthesized hydrophobic, super-hydrophobic, and hydrophilic graphene oxides by additional heat treatment and argon plasma treatment, respectively. In contrast to conventional fabrication procedures, reduced graphene oxide (rGO) formed under low pressure and high-temperature environment using a new synthesis method-developed and described in this study-offers a convenient deposition method on any kind surface with controlled wettability. Methods: High density at atmospheric plasma is used for the synthesis of rGO and GO and its biocompatibility based on various wetting properties was evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and the viability of cells in response to rGO and GO with various surface features was investigated. Structural integrity was characterized by Raman spectroscopy, FESEM and FE-TEM. Wettability was measured via contact angle method and confirmed with XPS analysis. Results: We found that GO coating with a hydrophilic feature is more biocompatible than other surfaces as observed in case of fibroblast cells. We have shown that wettability-controlled by GO deposition-influences biocompatibilities and antibacterial effect of biomaterial surfaces. Discussion: Measuring the contact angle, it is found that contact angle for hydrophobic is increased to 150.590 and reduced to 11.580 by heat and argon plasma treatment, respectively, from 75.880 that was initially in the case of hydrophobic surface. XPS analysis confirmed various oxygen-containing functional groups transforming as deposited hydrophobic surface into superhydrophobic and hydrophilic surface. Thus, we have proposed a new, direct, cost-effective, and highly productive method for the synthesis of rGO and GO-with various surface properties-for biological applications. Similarly, for the dental implant application, the Streptococcus mutans was used as an antibacterial effect and found that S. mutans grows slowly on hydrophilic surface. Thus, antibacterial effect was prominent on GO with hydrophilic surface.


Asunto(s)
Atmósfera/química , Grafito/síntesis química , Gases em Plasma/farmacología , Animales , Muerte Celular/efectos de los fármacos , Línea Celular , Grafito/química , Ratones , Viabilidad Microbiana/efectos de los fármacos , Oxidación-Reducción , Streptococcus mutans/efectos de los fármacos , Agua , Humectabilidad
18.
PLoS One ; 15(7): e0236837, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32730369

RESUMEN

Recent developments propose renewed use of surface-modified nanoparticles (NPs) for enhanced oil recovery (EOR) due to improved stability and reduced porous media retention. The enhanced surface properties render the nanoparticles more suitable compared to bare nanoparticles, for increasing the displacement efficiency of waterflooding. However, the EOR mechanisms using NPs are still not well established. This work investigates the effect of in-situ surface-modified silica nanoparticles (SiO2 NPs) on interfacial tension (IFT) and wettability behavior as a prevailing oil recovery mechanism. For this purpose, the nanoparticles have been synthesized via a one-step sol-gel method using surface-modification agents, including Triton X-100 (non-ionic surfactant) and polyethylene glycol (polymer), and characterized using various techniques. These results exhibit the well-defined spherical particles, particularly in the presence of Triton X-100 (TX-100), with particle diameter between 13 to 27 nm. To this end, SiO2 nanofluids were formed by dispersing nanoparticles (0.05 wt.%, 0.075 wt.%, 0.1 wt.%, and 0.2 wt.%) in 3 wt.% NaCl to study the impact of surface functionalization on the stability of the nanoparticle suspension. The optimal stability conditions were obtained at 0.1 wt.% SiO2 NPs at a basic pH of 10 and 9.5 for TX-100/ SiO2 and PEG/SiO nanofluids, respectively. Finally, the surface-treated SiO2 nanoparticles were found to change the wettability of treated (oil-wet) surface into water-wet by altering the contact angle from 130° to 78° (in case of TX-100/SiO2) measured against glass surface representing carbonate reservoir rock. IFT results also reveal that the surfactant treatment greatly reduced the oil-water IFT by 30%, compared to other applied NPs. These experimental results suggest that the use of surface-modified SiO2 nanoparticles could facilitate the displacement efficiency by reducing IFT and altering the wettability of carbonate reservoir towards water-wet, which is attributed to more homogeneity and better dispersion of surface-treated silica NPs compared to bare-silica NPs.


Asunto(s)
Nanopartículas/química , Aceites/aislamiento & purificación , Dióxido de Silicio/química , Tensoactivos/química , Aceites/análisis , Aceites/química , Tensión Superficial , Humectabilidad
19.
Environ Sci Process Impacts ; 22(8): 1759-1767, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-32697206

RESUMEN

Magnesium and calcium chloride salts contribute to the global atmospheric aerosol burden via emission of sea spray and mineral dust. Their influence on aerosol hygroscopicity and cloud forming potential is important but uncertain with ambiguities between results reported in the literature. To address this, we have conducted measurements of the hygroscopic growth and critical supersaturation of dried, size selected nano-particles made from aqueous solution droplets of MgCl2 and CaCl2, respectively, and compare experimentally derived values with results from state-of-the-art thermodynamic modelling. It is characteristic of both MgCl2 and CaCl2 salts that they bind water in the form of hydrates under a range of ambient conditions. We discuss how hydrate formation affects the particles' water uptake and provide an expression for hydrate correction factors needed in calculations of hygroscopic growth factors, critical super-saturations, and derived κ values of particles containing hydrate forming salts. We demonstrate the importance of accounting for hydrate forming salts when predicting hygroscopic properties of sea spray aerosol.


Asunto(s)
Sales (Química) , Agua , Aerosoles , Polvo , Humectabilidad
20.
Int J Nanomedicine ; 15: 4471-4481, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32606689

RESUMEN

Background: Ineffective integration has been recognized as one of the major causes of early orthopedic failure of titanium-based implants. One strategy to address this problem is to develop modified titanium surfaces that promote osteoblast differentiation. This study explored titanium surfaces modified with TiO2 nanotubes (TiO2 NTs) capable of localized drug delivery into bone and enhanced osteoblast cell differentiation. Materials and Methods: Briefly, TiO2 NTs were subjected to anodic oxidation and loaded with Metformin, a widely used diabetes drug. To create surfaces with sustainable drug-eluting characteristics, TiO2 NTs were spin coated with a thin layer of chitosan. The surfaces were characterized via scanning electron microscopy, atomic force microscopy, and contact angle measurements. The surfaces were then exposed to mesenchymal bone marrow stem cells (MSCs) to evaluate cell adhesion, growth, differentiation, and morphology on the modified surfaces. Results: A noticeable increase in drug release time (3 days vs 20 days) and a decrease in burst release characteristics (85% to 7%) was observed in coated samples as compared to uncoated samples, respectively. Chitosan-coated TiO2 NTs exhibited a considerable enhancement in cell adhesion, proliferation, and genetic expression of type I collagen, and alkaline phosphatase activity as compared to uncoated TiO2 NTs. Conclusion: TiO2 NT surfaces with a chitosan coating are capable of delivering Metformin to a bone site over a sustained period of time with the potential to enhance MSCs cell attachment, proliferation, and differentiation.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Quitosano/química , Liberación de Fármacos , Metformina/farmacología , Nanotubos/química , Osteoblastos/citología , Titanio/química , Fosfatasa Alcalina/metabolismo , Animales , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Nanotubos/ultraestructura , Osteoblastos/efectos de los fármacos , Osteoblastos/ultraestructura , Osteogénesis/efectos de los fármacos , Ratas Wistar , Humectabilidad
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