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1.
Anal Chim Acta ; 1159: 338418, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33867032

RESUMEN

Favipiravir, a promising antiviral agent, is undergoing clinical trials for the potential treatment of the novel coronavirus disease 2019 (COVID-19). This is the first report for the electrochemical activity of favipiravir and its electroanalytical sensing. For this purpose, the effect of cationic surfactant, CTAB was demonstrated on the enhanced accumulation of favipiravir at the surface of cathodically pretreated boron-doped diamond (CPT-BDD) electrode. At first, the electrochemical properties of favipiravir were investigated in the surfactant-free solutions by the means of cyclic voltammetry. The compound presented a single oxidation step which is irreversible and adsorption controlled. A systematic study of various operational conditions, such as electrode pretreatment, pH of the supporting electrolyte, concentration of CTAB, accumulation variables, and instrumental parameters on the adsorptive stripping response, was examined using square-wave voltammetry. An oxidation signal at around +1.21 V in Britton-Robinson buffer at pH 8.0 containing 6 × 10-4 M CTAB allowed to the adsorptive stripping voltammetric determination of favipiravir (after 60 s accumulation step at open-circuit condition). The process could be used in the concentration range with two linear segments of 0.01-0.1 µg mL-1 (6.4 × 10-8-6.4 × 10-7 M) and 0.1-20.0 µg mL-1 (6.4 × 10-7-1.3 × 10-4 M). The limit of detection values were found to be 0.0028 µg mL-1 (1.8 × 10-8 M), and 0.023 µg mL-1 (1.5 × 10-7 M) for the first and second segments of calibration graph, respectively. The feasibility of developed methodology was tested to the analysis of the commercial tablet formulations and model human urine samples.


Asunto(s)
Amidas/química , Antivirales/química , Boro , Diamante , Electrodos , Pirazinas/química , Tensoactivos/química , Humanos , /efectos de los fármacos
2.
J Chromatogr A ; 1642: 462045, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33735643

RESUMEN

A convenient synthetic approach to a linear alkyl-polyamine amphiphilic chromatographic selector was proposed. Successive immobilization of the amphiphile onto silica gel afforded a multimodal stationary phase for high-performance liquid chromatography (HPLC). The as-prepared silica material was studied comparatively with a conventional octadecyl (C18) and an amide-embedded C18 stationary phase. The new uniform docosyl-triamine tandem was featured by an enhanced shape selectivity towards geometric isomers, and a low silanol activity towards alkaline solutes. The presence of multiple amino groups rendered the new adsorbent operable in different modes, such as hydrophilic interaction and ion-exchange modes. The satisfactory performance of the said stationary phase in separating different classes of analytes, including polycyclic aromatic hydrocarbons, flavonoids, tricyclic antidepressants, calcium channel blockers, aromatic acids, inorganic anions, nucleosides and estrogens, revealed its great potential and high adaptability for multipurpose LC utility.


Asunto(s)
Cromatografía Liquida/métodos , Poliaminas/química , Tensoactivos/química , Estrógenos/análisis , Flavonoides/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Isomerismo , Poliaminas/síntesis química
3.
Int J Nanomedicine ; 16: 1457-1472, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33654396

RESUMEN

Purpose: Rheumatoid arthritis is an autoimmune disorder that directly affects joints. However, other body organs including heart, eyes, skin, blood vessels and lungs may also be affected. The purpose of this study was to design and evaluate a nanoemulgel formulation of diflunisal (DIF) and solubility enhanced diflunisal (DIF-IC) for enhanced topical anti-inflammatory activity. Methodology: Nanoemulsion formulations of both DIF and DIF-IC were prepared and incorporated in three different gelling agents, namely carboxymethylcellulose sodium (CMC-Na), sodium alginate (Na-ALG) and xanthan gum (XG). All the formulations were evaluated in term of particle size, pH, conductivity, viscosity, zeta potential and in vitro drug release. The formulation 2 (NE2) of both DIF and DIF-IC which expressed optimum release and satisfactory physicochemical properties was incorporated with gelling agents to produce final nanoemulgel formulations. The optimized nanoemulgel formulation was subjected to three different in vivo anti-inflammatory models including carrageenan-induced paw edema model, histamine-induced paw edema model and formalin-induced paw edema model. Results: DIF-IC-loaded nanoemulgel formulations yielded significantly enhanced in vitro skin permeation than DIF-loaded nanoemulgel. The nanoemulgel formulation of DIF-IC formulated with XG produced improved in vivo anti-inflammatory activity. Conclusion: It was recommended that DIF-IC-based nanoemulgel formulation prepared with XG could be a better option for effective topical treatment of inflammatory conditions.


Asunto(s)
Diflunisal/administración & dosificación , Sistemas de Liberación de Medicamentos , Emulsiones/química , Nanogeles/química , Polietilenglicoles/química , Polietileneimina/química , Administración Tópica , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Carragenina , Diflunisal/química , Diflunisal/farmacología , Diflunisal/uso terapéutico , Modelos Animales de Enfermedad , Composición de Medicamentos , Liberación de Fármacos , Edema/tratamiento farmacológico , Edema/patología , Conductividad Eléctrica , Concentración de Iones de Hidrógeno , Masculino , Tamaño de la Partícula , Permeabilidad , Transición de Fase , Ratas , Piel/efectos de los fármacos , Absorción Cutánea/efectos de los fármacos , Solubilidad , Tensoactivos/química , Viscosidad
4.
J Med Chem ; 64(7): 3885-3896, 2021 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-33775096

RESUMEN

Quinacrine (QC) and chloroquine (CQ) have antimicrobial and antiviral activities as well as antimalarial activity, although the mechanisms remain unknown. QC increased the antimicrobial activity against yeast exponentially with a pH-dependent increase in the cationic amphiphilic drug (CAD) structure. CAD-QC localized in the yeast membranes and induced glucose starvation by noncompetitively inhibiting glucose uptake as antipsychotic chlorpromazine (CPZ) did. An exponential increase in antimicrobial activity with pH-dependent CAD formation was also observed for CQ, indicating that the CAD structure is crucial for its pharmacological activity. A decrease in CAD structure with a slight decrease in pH from 7.4 greatly reduced their effects; namely, these drugs would inefficiently act on falciparum malaria and COVID-19 pneumonia patients with acidosis, resulting in resistance. The decrease in CAD structure at physiological pH was not observed for quinine, primaquine, or mefloquine. Therefore, restoring the normal blood pH or using pH-insensitive quinoline drugs might be effective for these infectious diseases with acidosis.


Asunto(s)
Antifúngicos/farmacología , Cloroquina/farmacología , Quinacrina/farmacología , Tensoactivos/farmacología , Antifúngicos/química , Antifúngicos/metabolismo , Membrana Celular/metabolismo , Cloroquina/química , Cloroquina/metabolismo , Concentración de Iones de Hidrógeno , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Proteínas de Transporte de Monosacáridos/antagonistas & inhibidores , Protones , Quinacrina/química , Quinacrina/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Tensoactivos/química , Tensoactivos/metabolismo
5.
Molecules ; 26(4)2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33670378

RESUMEN

Biodegradable and antimicrobial waterborne polyurethane dispersions (PUDs) and their casted solid films have recently emerged as important alternatives to their solvent-based and non-biodegradable counterparts for various applications due to their versatility, health, and environmental friendliness. The nanoscale morphology of the PUDs, dispersion stability, and the thermomechanical properties of the solid films obtained from the solvent cast process are strongly dependent on several important parameters, such as the preparation method, polyols, diisocyanates, solid content, chain extension, and temperature. The biodegradability, biocompatibility, antimicrobial properties and biomedical applications can be tailored based on the nature of the polyols, polarity, as well as structure and concentration of the internal surfactants (anionic or cationic). This review article provides an important quantitative experimental basis and structure evolution for the development and synthesis of biodegradable waterborne PUDs and their solid films, with prescribed macromolecular properties and new functions, with the aim of understanding the relationships between polymer structure, properties, and performance. The review article will also summarize the important variables that control the thermomechanical properties and biodegradation kinetics, as well as antimicrobial and biocompatibility behaviors of aqueous PUDs and their films, for certain industrial and biomedical applications.


Asunto(s)
Antiinfecciosos/química , Plásticos Biodegradables/química , Polímeros/química , Poliuretanos/química , Aniones/química , Aniones/uso terapéutico , Antiinfecciosos/uso terapéutico , Plásticos Biodegradables/uso terapéutico , Humanos , Polímeros/uso terapéutico , Poliuretanos/uso terapéutico , Solventes/química , Tensoactivos/química , Tensoactivos/uso terapéutico , Agua/química
6.
Molecules ; 26(4)2021 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-33671247

RESUMEN

In the present study, naphthyl acetohydrazide (HL) ligand was prepared and used for the synthesis of new six amorphous transition metal (Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II)) complexes. All the compounds were characterized by elemental analysis, UV-vis, FT-IR, 1H- and 13C-NMR, and Matrix-Assisted Laser Desorption Ionization (MALDI). The solubilization study was carried out by estimating the interaction between the metal complexes with surfactants viz. sodium stearate (SS) and Cetyltrimethylammonium bromide (CTAB). UV-Visible spectroscopy was employed to determine partitioning and binding parameters, whereas electrical conductivity measurements were employed to estimate critical micellar concentration (CMC), the extent of dissociation, and free energy of micellization. The CT-DNA interaction of synthesized compounds with DNA represents the major groove binding. The synthesized ligand and metal complexes were also tested against bacterial and fungal strains and it has been observed that Cu(II) complex is active against all the strains except Candida albicans, while Cd(II) complex is active against all bacterial and fungal strains except Pseudomonas. Among all compounds, only the Pd(II) complex shows reasonable activity against cervical cancer HeLa cell lines, representing 97% inhibition.


Asunto(s)
Antiinfecciosos/farmacología , Complejos de Coordinación/síntesis química , ADN/metabolismo , Hidrazonas/síntesis química , Hidrazonas/farmacología , Metales/química , Micelas , Neoplasias/patología , Bacterias/efectos de los fármacos , Espectroscopía de Resonancia Magnética con Carbono-13 , Supervivencia Celular/efectos de los fármacos , Conductividad Eléctrica , Células HeLa , Humanos , Hidrazonas/química , Ligandos , Pruebas de Sensibilidad Microbiana , Espectroscopía de Protones por Resonancia Magnética , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Tensoactivos/química
7.
Food Chem ; 349: 129203, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33581433

RESUMEN

Fabrication of food-grade water-in-oil (W/O) emulsions without surfactant, as the primary substitutes of trans-fat and saturated fat, was still a significant challenge in food science. A facial method has been adopted to fabricate W/O emulsions at 20 °C. The obtained emulsion had long-time stability, and there was no apparent phase separation or oiling-out after 60 days of storage. In this system, beeswax served as a stabilizer for both oleogels and oleogel-based emulsions. The sol-gel melting temperature of the oleogel was 37 ± 0.5 °C by regulating beeswax content to 4% w/w, and then the oleogel was used to fabricate W/O emulsion with the droplet diameter of around 9 µm. Thermo-reversible and thixotropic properties of oleogels were both retained for emulsions. Furthermore, both oleogels and oleogel-based emulsions had compact gel-like structures. The self-emulsifying W/O emulsions without surfactant would have great potential applications in food industry, pharmaceutical industry and feed industry.


Asunto(s)
Emulsionantes/química , Aceites/química , Temperatura , Agua/química , Ceras/química , Emulsiones , Compuestos Orgánicos/química , Tensoactivos/química
8.
Food Chem ; 350: 129275, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33601090

RESUMEN

Oleofoams have emerged as attractive low-calorie aeration systems, but saturated lipids or large amount of surfactants are commonly required. Herein, an innovative strategy was proposed to create oleofoams using medium-long chain diacylglycerol (MLCD) and ß-sitosterol (St). The oleofoams prepared using MLCD and St in ratios of 15:5 and 12:8 exhibited smaller bubble size and much higher stability. MLCD crystals formed rigid Pickering shell, whereby air bubbles acted as "active fillers" leading to enhanced rigidity. Both Pickering and network stabilization for the MLCD-St oleofoam provided a steric hindrance against coalescence. The gelators interacted via hydrogen bonding, causing a condensing effect in improving the gel elasticity. The oleofoams and foam-based emulsions exhibited a favorable capacity in controlling volatile release where the maximum headspace concentrations and partition coefficients showed a significantly decrease. Overall, the oleofoams have shown great potential for development of low-calorie foods and delivery systems with enhanced textural and nutritional features.


Asunto(s)
Diglicéridos/química , Sitoesteroles/química , Enlace de Hidrógeno , Tensoactivos/química
9.
Int J Nanomedicine ; 16: 905-924, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33603359

RESUMEN

Purpose: The purpose of this proposed research was to investigate a nano-formulation developed using self-nanoemulsifying drug delivery system (SNEDDS) to improve the pharmacodynamic potential of rosuvastatin by assisting its transportation through lymphatic circulation. Methods: The utilized lipids, surfactants, and co-surfactants for SNEDDS were selected on the basis of solubility studies. The SNEDDS formulation was optimized by implementing a D-optimal mixture design, wherein the effect of concentration of Capmul MCM EP (X1), Tween 20 (X2) and Transcutol P (X3) as independent variables was studied on droplet size (Y1), % cumulative drug release (Y2) and self-emulsification time (Y3) as dependent variables. The optimized formulation was evaluated via in vitro parameters and in vivo pharmacodynamic potential in Wistar rats. Results: The D-optimal mixture design and subsequent ANOVA application resulted in the assortment of the optimized SNEDDS formulation that exhibited a droplet size of nano range (14.91nm), in vitro drug release of >90% within 30 minutes, and self-emulsification time of 16 seconds. The in vivo pharmacodynamic study carried out using Wistar rats confirmed the better antihyperlipidemic potential of developed formulation in normalizing the lipidic level of serum in contrast to pure drug and marketed tablets. Conclusion: This research reports the application of D-optimal mixture design for successful and systematic development of rosuvastatin-loaded SNEDDS with distinctly enhanced in vitro and in vivo performance in comparison to marketed formulation. Eventually, improved anti-hyperlipidemic efficacy was envisaged which might be attributed to increased drug solubility and absorption. Overall, this study shows the utility of SNEDDS for improving the dissolution rate and bioavailability of poor aqueous-soluble drugs. The present SNEDDS formulation could be a promising approach and alternative to conventional dosage form.


Asunto(s)
Sistemas de Liberación de Medicamentos , Emulsiones/química , Nanopartículas/química , Rosuvastatina Cálcica/farmacología , Análisis de Varianza , Animales , Disponibilidad Biológica , Rastreo Diferencial de Calorimetría , Liberación de Fármacos , Estabilidad de Medicamentos , Lípidos/química , Masculino , Nanopartículas/ultraestructura , Tamaño de la Partícula , Transición de Fase , Ratas Wistar , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Tensoactivos/química , Comprimidos , Viscosidad
10.
Int J Nanomedicine ; 16: 1245-1259, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33633449

RESUMEN

Purpose: To enhance the oral bioavailability of revaprazan (RVP), a novel solid, supersaturable micelle (SSuM) was developed. Methods: Surfactants and solid carriers were screened based on a solubility and a flowability test, respectively. Supersaturating agents, including Poloxamer 407 (P407), were screened. The SSuM was optimized using a Box-Behnken design with three independent variables, including Gelucire 44/14:Brij L4 (G44/BL4; X1) and the amounts of Florite PS-10 (FLO; X2) and Vivapur 105 (VP105; X3), and three response variables, ie, dissolution efficiency at 30 min (Y1), dissolution enhancing capacity (Y2), and Carr's index (Y3). The solid state property was evaluated, and a dissolution test was conducted. RVP, Revanex®, solid micelle (P407-free from the composition of SSuM), and SSuM were orally administrated to rats (RVP 20 mg equivalent/kg) for in vivo pharmacokinetic study. Results: G44 and BL4 showed great solubility, with a critical micelle concentration range of 119.2-333.0 µg/mL. P407 had an excellent supersaturating effect. FLO and VP105 were selected as solid carriers, with a critical solidifying ratio (g/mL) of 0.30 and 0.91, respectively. With optimized values of X1 (-0.41), X2 (0.31), and X3 (-0.78), RVP (200 mg)-containing SSuM consisting of G44 (253.8 mg), BL4 (106.2 mg), FLO (99.3 mg), VP105 (199.8 mg), and P407 (40 mg) was developed, resulting in Y1 (40.3%), Y2 (0.008), and Y3 (12.3%). RVP existed in an amorphous state in the optimized SSuM, and the SSuM formed a nanosized dispersion in the aqueous phase, with approximately 71.7% dissolution at 2 h. The optimized SSuM improved the relative bioavailability of RVP in rats by approximately 478%, 276%, and 161% compared to raw RVP, Revanex®, and solid micelle, respectively. Conclusion: The optimized SSuM has great potential for the development of solidified formulations of poorly water-soluble drugs with improved oral absorption.


Asunto(s)
Micelas , Pirimidinonas/farmacología , Tetrahidroisoquinolinas/farmacología , Administración Oral , Animales , Disponibilidad Biológica , Composición de Medicamentos , Masculino , Modelos Teóricos , Tamaño de la Partícula , Polietilenglicoles , Pirimidinonas/farmacocinética , Ratas Sprague-Dawley , Solubilidad , Soluciones , Tensoactivos/química , Tetrahidroisoquinolinas/farmacocinética
11.
ACS Appl Mater Interfaces ; 13(7): 7825-7838, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33583172

RESUMEN

Fabry disease is a rare lysosomal storage disorder characterized by a deficiency of α-galactosidase A (GLA), a lysosomal hydrolase. The enzyme replacement therapy administering naked GLA shows several drawbacks including poor biodistribution, limited efficacy, and relatively high immunogenicity in Fabry patients. An attractive strategy to overcome these problems is the use of nanocarriers for encapsulating the enzyme. Nanoliposomes functionalized with RGD peptide have already emerged as a good platform to protect and deliver GLA to endothelial cells. However, low colloidal stability and limited enzyme entrapment efficiency could hinder the further pharmaceutical development and the clinical translation of these nanoformulations. Herein, the incorporation of the cationic miristalkonium chloride (MKC) surfactant to RGD nanovesicles is explored, comparing two different nanosystems-quatsomes and hybrid liposomes. In both systems, the positive surface charge introduced by MKC promotes electrostatic interactions between the enzyme and the nanovesicles, improving the loading capacity and colloidal stability. The presence of high MKC content in quatsomes practically abolishes GLA enzymatic activity, while low concentrations of the surfactant in hybrid liposomes stabilize the enzyme without compromising its activity. Moreover, hybrid liposomes show improved efficacy in cell cultures and a good in vitro/in vivo safety profile, ensuring their future preclinical and clinical development.


Asunto(s)
Terapia de Reemplazo Enzimático , Enfermedad de Fabry/terapia , Nanoestructuras/química , alfa-Galactosidasa/metabolismo , Enfermedad de Fabry/enzimología , Humanos , Oligopéptidos/química , Tamaño de la Partícula , Propiedades de Superficie , Tensoactivos/química
12.
Int J Mol Sci ; 22(4)2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546366

RESUMEN

The development of techniques capable of using membrane proteins in a surfactant-free aqueous buffer is an attractive research area, and it should be elucidated for various membrane protein studies. To this end, we examined a method using new solubilization surfactants that do not detach from membrane protein surfaces once bound. The designed solubilization surfactants, DKDKC12K-PAn (n = 5, 7, and 18), consist of two parts: one is the lipopeptide-based solubilization surfactant part, DKDKC12K, fand the other is the covalently connected linear polyacrylamide (PA) chain with different Mw values of 5, 7, or 18 kDa. Intermolecular interactions between the PA chains in DKDKC12K-PAn concentrated on the surfaces of membrane proteins via amphiphilic binding of the DKDKC12K part to the integral membrane domain was observed. Therefore, DKDKC12K-PAn (n = 5, 7, and 18) could maintain a bound state even after removal of the unbound by ultrafiltration or gel-filtration chromatography. We used photosystem I (PSI) from Thermosynecoccus vulcanus as a representative to assess the impacts of new surfactants on the solubilized membrane protein structure and functions. Based on the maintenance of unique photophysical properties of PSI, we evaluated the ability of DKDKC12K-PAn (n = 5, 7, and 18) as a new solubilization surfactant.


Asunto(s)
Resinas Acrílicas/química , Tampones (Química) , Proteínas de la Membrana/química , Polímeros/química , Tensoactivos/química , Fenómenos Químicos , Técnicas de Química Sintética , Concentración de Iones de Hidrógeno , Estructura Molecular , Tamaño de la Partícula , Polímeros/síntesis química , Solubilidad , Tensoactivos/síntesis química
13.
Int J Mol Sci ; 22(4)2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546426

RESUMEN

Psoriasis is a chronic autoimmune skin disease impacting the population globally. Pharmaceutical products developed to combat this condition commonly used in clinical settings are IV bolus or oral drug delivery routes. There are some major challenges for effectively developing new dosage forms for topical use: API physicochemical nature, the severity of the disease state, and low bioavailability present challenges for pharmaceutical product developers. For non-severe cases of psoriasis, topical drug delivery systems may be preferred or used in conjunction with oral or parenteral therapy to address local symptoms. Elastic vesicular systems, termed "niosomes", are promising drug delivery vehicles developed to achieve improved drug delivery into biological membranes. This study aimed to effectively incorporate a corticosteroid into the niosomes for improving the drug bioavailability of desoximetasone, used to treat skin conditions via topical delivery. Niosomes characterization measurements were drug content, pH, spreadability, specific gravity, content uniformity, rheology, and physicochemical properties. Formulations used a topical gelling agent, Carbomer 980 to test for in vitro skin permeation testing (IVPT) and accelerated stability studies. The developed niosomal test gel provided approximately 93.03 ± 0.23% to 101.84 ± 0.11% drug content with yield stresses ranging from 16.12 to 225.54 Pa. The permeated amount of desoximetasone from the niosomal gel after 24 h was 9.75 ± 0.44 µg/cm2 compared to 24.22 ± 4.29 µg/cm2 released from the reference gel tested. Furthermore, a drug retention study compared the test gel to a reference gel, demonstrating that the skin retained 30.88 ng/mg of desoximetasone while the reference product retained 26.01 ng/mg. A controlled drug release profile was obtained with a niosomal formulation containing desoximetasone for use in a topical gel formulation showing promise for potential use to treat skin diseases like psoriasis.


Asunto(s)
Desoximetasona/administración & dosificación , Portadores de Fármacos/química , Geles/química , Nanoestructuras/química , Tensoactivos/química , Administración Cutánea , Administración Tópica , Fenómenos Químicos , Química Farmacéutica , Relación Dosis-Respuesta a Droga , Sistemas de Liberación de Medicamentos , Estabilidad de Medicamentos , Humanos , Concentración de Iones de Hidrógeno , Cinética , Permeabilidad , Piel/efectos de los fármacos , Piel/metabolismo , Absorción Cutánea , Viscosidad
14.
Ecotoxicol Environ Saf ; 212: 111964, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33524909

RESUMEN

A systematic study had been carried out to get insight into the micellar behavior of anionic lipopeptide (LT) and nonionic sophorolipid (SL) in their different mass ratio mixed state using the technique of tensiometry. The models proposed by Clint, Rubingh and Gibbs et al. had been employed to interpret the formation of mixed micelles and found out synergism. The obtained experimental critical micelle concentrations (CMC) were lower than the ideal CMCs, indicating negative deviation from ideal behavior for all multi-component mixed micelles formation. A suited binary bio-surfactant mixing system was selected as the washing agents to treat the oily sludge produced from Huabei oilfield by the thermal bio-surfactant washing method. The results showed that in case of the mass ratios of 8:2 the CMC was dramatically decreased and synergism was the strongest in LT and SL bi mixed surfactant systems. The studied binary mixed bio-surfactant system showed higher washing efficiency for oily sludge than single surfactant system. In addition, the washing power of binary mixed bio-surfactants towards oily sludge was the best at below washing conditions: (a) the concentration of the mixed system (100 mg/L), (b) temperature (55 â„ƒ), (c) ratio of sludge/liquid (1:3), (d) washing time (3 h), and (e) stirring speed (300 rpm). Certainly, the washing abilities of the selected surfactants not only depend on their mixing ratio and washing conditions but also associate with microstructure and mineral components of oily sludge.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Yacimiento de Petróleo y Gas , Surfactantes Pulmonares , Lipopéptidos , Micelas , Ácidos Oléicos , Aguas del Alcantarillado , Tensoactivos/química
15.
Appl Environ Microbiol ; 87(9)2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33608298

RESUMEN

Biosurfactant production is a common trait in leaf surface-colonizing bacteria that has been associated with increased survival and movement on leaves. At the same time, the ability to degrade aliphatics is common in biosurfactant-producing leaf colonizers. Pseudomonads are common leaf colonizers and have been recognized for their ability to produce biosurfactants and degrade aliphatic compounds. In this study, we investigated the role of biosurfactants in four non-plant-pathogenic Pseudomonas strains by performing a series of experiments to characterize their surfactant properties and their role during leaf colonization and diesel degradation. The biosurfactants produced were identified using mass spectrometry. Two strains produced viscosin-like biosurfactants, and the other two produced massetolide A-like biosurfactants, which aligned with the phylogenetic relatedness between the strains. To further investigate the role of surfactant production, random Tn5 transposon mutagenesis was performed to generate knockout mutants. The knockout mutants were compared to their respective wild types with regard to their ability to colonize gnotobiotic Arabidopsis thaliana and to degrade diesel or dodecane. It was not possible to detect negative effects during plant colonization in direct competition or individual colonization experiments. When grown on diesel, knockout mutants grew significantly slower than their respective wild types. When grown on dodecane, knockout mutants were less impacted than during growth on diesel. By adding isolated wild-type biosurfactants, it was possible to complement the growth of the knockout mutants.IMPORTANCE Many leaf-colonizing bacteria produce surfactants and are able to degrade aliphatic compounds; however, whether surfactant production provides a competitive advantage during leaf colonization is unclear. Furthermore, it is unclear if leaf colonizers take advantage of the aliphatic compounds that constitute the leaf cuticle and cuticular waxes. Here, we tested the effect of surfactant production on leaf colonization, and we demonstrate that the lack of surfactant production decreases the ability to degrade aliphatic compounds. This indicates that leaf surface-dwelling, surfactant-producing bacteria contribute to degradation of environmental hydrocarbons and may be able to utilize leaf surface waxes. This has implications for plant-microbe interactions and future studies.


Asunto(s)
Arabidopsis/microbiología , Gasolina , Hojas de la Planta/microbiología , Pseudomonas/metabolismo , Tensoactivos/metabolismo , Alcanos/metabolismo , Biodegradación Ambiental , Mutagénesis , Filogenia , Pseudomonas/genética , Pseudomonas/crecimiento & desarrollo , ARN Ribosómico 16S , Tensoactivos/química
16.
Int J Mol Sci ; 22(2)2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33467613

RESUMEN

The interaction (adsorption process) of commercial ionic surfactants with non-functionalized and functionalized carbon nanotubes (CNTs) has been studied by potentiometric measurements based on the use of ion-selective electrodes. The goal of this work was to investigate the role of the CNTs' charge and structure in the CNT/surfactant interactions. Non-functionalized single- (SWCNT) and multi-walled carbon nanotubes (MWCNT), and amine functionalized SWCNT were used. The influence of the surfactant architecture on the CNT/surfactant interactions was also studied. Surfactants with different charge and hydrophobic tail length (sodium dodecyl sulfate (SDS), octyltrimethyl ammonium bromide (OTAB), dodecyltrimethyl ammonium bromide (DoTAB) and hexadecyltrimethyl ammonium bromide (CTAB)) were studied. According to the results, the adsorption process shows a cooperative character, with the hydrophobic interaction contribution playing a key role. This is made evident by the correlation between the free surfactant concentration (at a fixed [CNT]) and the critical micellar concentration, cmc, found for all the CNTs and surfactants investigated. The electrostatic interactions mainly determine the CNT dispersion, although hydrophobic interactions also contribute to this process.


Asunto(s)
Iones/química , Nanotubos de Carbono/química , Potenciometría/métodos , Tensoactivos/química , Adsorción , Cetrimonio/química , Electrodos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Electrodos de Ion-Selectivo , Luz , Micelas , Microscopía Electrónica de Transmisión , Fenómenos Físicos , Surfactantes Pulmonares , Compuestos de Amonio Cuaternario/química , Dispersión de Radiación , Dodecil Sulfato de Sodio/química , Contaminantes Químicos del Agua/química
17.
Int J Mol Sci ; 22(1)2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33406682

RESUMEN

Superparamagnetic nanoparticles have seen increased potential in medical and environmental applications. Their preparation is traditionally made by the coprecipitation method, with limited control over the particle size distribution. Microemulsion methods could be advantageous due to the efficient control of the size, shape, and composition of the nanoparticles obtained. Water-in-oil (W/O) microemulsions consist of aqueous microdomains dispersed in a continuous oil phase, stabilized by surfactant molecules. These work as nanoreactors where the synthesis of the desired nanoparticles takes place through a co-precipitation chemical reaction. In this work, superparamagnetic magnetite nanoparticles with average diameters between 5.4 and 7.2 nm and large monodispersity have been synthesized through precipitation in a W/O microemulsion, with Cetyl Trimethyl Ammonium Bromide (CTAB) as a main surfactant, 1-butanol as a cosurfactant, and with 1-hexanol as the continuous oily phase. The optimization of the corresponding washing protocol has also been established since a strict control is required when using these materials for bioapplications. Their applicability in those has been proved by their encapsulation in liposomes, being tested as signal enhancers for lateral flow immunoassays by using the affinity neutravidin-biotin model system. Due to their magnetic behaviour, they were also tested for magnetic separation. These novel materials have been found to be useful for analytical applications requiring high sensitivity and the removal of interferences.


Asunto(s)
Separación Celular/métodos , Emulsiones , Liposomas/química , Tensoactivos/química , Humanos , /química
18.
Arch Biochem Biophys ; 699: 108764, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33460582

RESUMEN

The interaction of a dirhamnolipid biosurfactant secreted by Pseudomonas aeruginosa with calcium ATPase from sarcoplasmic reticulum (SR) was studied by means of different approaches, such as enzyme activity, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and molecular docking simulations. The ATP hydrolysis activity was fully inhibited by incubation with dirhamnolipid (diRL) up to 0.1 mM concentration, corresponding to a surfactant concentration below membrane solubilization threshold. Surfactant-protein interaction induced conformational changes in the protein observed by an increase in the accessibility of tryptophan residues to the aqueous phase and by changes in the secondary structure of the protein as seen by fluorescence and FTIR spectroscopy. As a consequence, the protein become more unstable and denatured at lower temperatures, as seen by enzyme activity and DSC studies. Finally, these results were explained at molecular level throughout molecular docking simulations. It is concluded that there is a specific dirhamnolipid-protein interaction not related to the surface activity of the surfactant but to the particular physicochemical properties of the biosurfactant molecule.


Asunto(s)
Glucolípidos/metabolismo , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Tensoactivos/metabolismo , Animales , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Glucolípidos/química , Simulación del Acoplamiento Molecular , Unión Proteica , Estructura Secundaria de Proteína/efectos de los fármacos , Pseudomonas aeruginosa/química , Conejos , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/antagonistas & inhibidores , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/química , Tensoactivos/química
19.
Artículo en Inglés | MEDLINE | ID: mdl-33444076

RESUMEN

Galvanizing industries generate large amounts of effluents rich in toxic and carcinogenic chromium(VI) species. Effective and sustainable treatments are required to comply with environmental regulations. This work focused on the development of innovative treatments for Cr(VI) by its removal from a galvanizing industry wastewater (pHinitial = 5.9) containing Cr (78 mg.L-1) and Zn (2178 mg.L-1) using the liquid surfactant membranes technique. The membrane phase carrier was Alamine® 336 in Escaid™ 110. For a synthetic solution (Cr(VI) = 353mg.L-1, pHinternal phase = 1.5), 99.9% of Cr(VI) was extracted in three stages ([KOH]internal phase = 0.27 mol.L-1). For the galvanizing wastewater, two selective extractions treatments were proposed: (1) 87% of Cr(VI) and 2% of Zn(II) were extracted in a single stage ([HCl]feed phase = 0.03 mol.L-1, [KOH]internal phase = 0.6 mol.L-1); (2) 95.6% of Cr(VI) and practically no zinc were extracted in a single stage ([HCl] feed phase = 10-6mol.L-1, [HCl] internal phase = 5mol.L-1). In another treatment condition ([HCl] feed phase = 2mol.L-1 and [KOH] internal phase = 1.2 mol.L-1), the simultaneous Cr(VI) and Zn(II) extractions (95% and 70%, respectively) were obtained in a single stage and more than 99% of both metals in three stages. This resulted in a depleted feed phase with 0.01 mg.L-1 of Cr(VI), that allows its discharge, according to the Brazilian legislation (≤0.1 mg/L).


Asunto(s)
Cromo/química , Tensoactivos/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Zinc/química , Brasil , Residuos Industriales , Metalurgia
20.
ACS Appl Mater Interfaces ; 13(5): 6615-6630, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33507059

RESUMEN

The control of surface wettability through a combination of surface roughness, chemical composition, and structural modification has attracted significant attention for antifogging and antibacterial applications. Herein, a two-step spin-coating method for amphiphilic organic-inorganic hybrid materials with incorporated transition metal ions is presented. The coating solution was prepared via photochemical thiol-ene click reaction between the mercapto functional group in trimethylolpropane tris(3-mercaptopropionate) and the vinyl functionalized silica precursor 3-(trimethoxysilyl)propyl methacrylate. In the first step of coating, a glass substrate was coated using a solution of metal nitrate hydrates and subsequently showed hydrophobic properties. As the second step, the spin-coated glass substrate was further coated with silica nanoparticles (SiO2 NPs) and polycaprolactone triol (PCT) suspension, where the contents of SiO2 NPs were fixed at 0.1 wt %, unless otherwise noted. The coated substrate exhibited hydrophilic properties. For comparison, the coating was also formulated with the SiO2 NPs/PCT suspension without SiO2 NPs and with 0.5 wt % SiO2 NPs as well as by adjusting different coating layer thicknesses. The surface morphology and chemical compositions of the obtained coating materials were analyzed by field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The transparency and static contact angle of coated samples were measured by UV-visible spectrophotometry and drop shape analysis, respectively. It was concluded that our novel hybrid coating materials exhibited excellent antibacterial and antifogging properties with extremely high scratch resistance and transparency.


Asunto(s)
Antibacterianos/farmacología , Materiales Biocompatibles Revestidos/farmacología , Escherichia coli/efectos de los fármacos , Compuestos Organometálicos/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Tensoactivos/farmacología , Antibacterianos/química , Materiales Biocompatibles Revestidos/química , Interacciones Hidrofóbicas e Hidrofílicas , Estructura Molecular , Compuestos Organometálicos/química , Tamaño de la Partícula , Propiedades de Superficie , Tensoactivos/química
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