Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Ind Chem Mater ; 2(3): 378-392, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39165661

RESUMEN

Antifouling liquid-infused surfaces have generated interest in multiple fields due to their diverse applications in industry and medicine. In nearly all reports to date, the liquid component consists of only one chemical species. However, unlike traditional solid surfaces, the unique nature of liquid surfaces holds the potential for synergistic and even adaptive functionality simply by including additional elements in the liquid coating. In this work, we explore the concept of multi-component liquid-infused systems, in which the coating liquid consists of a primary liquid and a secondary component or components that provide additional functionality. For ease of understanding, we categorize recently reported multi-component liquid-infused surfaces according to the size of the secondary components: molecular scale, in which the secondary components are molecules; nanoscale, in which they are nanoparticles or their equivalent; and microscale, in which the additional components are micrometer size or above. We present examples at each scale, showing how introducing a secondary element into the liquid can result in synergistic effects, such as maintaining a pristine surface while actively modifying the surrounding environment, which are difficult to achieve in other surface treatments. The review highlights the diversity of fabrication methods and provides perspectives on future research directions. Introducing secondary components into the liquid matrix of liquid-infused surfaces is a promising strategy with significant potential to create a new class of multifunctional materials. Keywords: Active surfaces; Antimicrobial; Antifouling; Interfaces; Sensing surfaces.

2.
Biointerphases ; 19(4)2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-39136648

RESUMEN

Liquid-infused polymers are recognized for their ability to repel foulants, making them promising for biomedical applications including catheter-associated urinary tract infections (CAUTIs). However, the impact of the quantity of free liquid layer covering the surface on protein and bacterial adhesion is not well understood. Here, we explore how the amount of free silicone liquid layer in infused silicone catheter materials influences the adhesion of bacteria and proteins relevant to CAUTIs. To alter the quantity of the free liquid layer, we either physically removed excess liquid from fully infused catheter materials or partially infused them. We then evaluated the impact on bacterial and host protein adhesion. Physical removal of the free liquid layer from the fully infused samples reduced the height of the liquid layer from 60 µm to below detection limits and silicone liquid loss into the environment by approximately 64% compared to controls, without significantly increasing the deposition of protein fibrinogen or the adhesion of the common uropathogen Enterococcus faecalis. Partially infused samples showed even greater reductions in liquid loss: samples infused to 70%-80% of their maximum capacity exhibited about an 85% decrease in liquid loss compared to fully infused controls. Notably, samples with more than 70% infusion did not show significant increases in fibrinogen or E. faecalis adhesion. These findings suggest that adjusting the levels of the free liquid layer in infused polymers can influence protein and bacterial adhesion on their surfaces. Moreover, removing the free liquid layer can effectively reduce liquid loss from these polymers while maintaining their functionality.


Asunto(s)
Adhesión Bacteriana , Enterococcus faecalis , Adhesión Bacteriana/efectos de los fármacos , Enterococcus faecalis/fisiología , Enterococcus faecalis/efectos de los fármacos , Polímeros/química , Siliconas/química , Propiedades de Superficie , Fibrinógeno/química , Fibrinógeno/metabolismo , Humanos
4.
medRxiv ; 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37790393

RESUMEN

Silicone urinary catheters infused with silicone liquid offer an effective alternative to antibiotic coatings, reducing microbial adhesion while decreasing bladder colonization and systemic dissemination. However, loss of free silicone liquid from the surface into the host system is undesirable. To reduce the potential for liquid loss, free silicone liquid was removed from the surface of liquid-infused catheters by either removing excess liquid from fully infused samples or by partial infusion. The effect on bacterial and host protein adhesion was then assessed. Removing the free liquid from fully infused samples resulted in a ~64% decrease in liquid loss into the environment compared to controls, with no significant increase in deposition of the host protein fibrinogen or the adhesion of the common uropathogen Enterococcus faecalis. Partially infusing samples decreased liquid loss as total liquid content decreased, with samples infused to 70-80% of their maximum capacity showing a ~85% reduction in liquid loss compared to fully infused controls. Furthermore, samples above 70% infusion showed no significant increase in fibrinogen or E. faecalis adhesion. Together, the results suggest that eliminating free liquid layer, mechanically or through partial infusion, can reduce liquid loss from liquid-infused catheters while preserving functionality.

5.
Phytochemistry ; 214: 113789, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37482264

RESUMEN

In botanical extracts, highly abundant constituents can mask or dilute the effects of other, and often, more relevant biologically active compounds. To facilitate the rational chemical and biological assessment of these natural products with wide usage in human health, we introduced the DESIGNER approach of Depleting and Enriching Selective Ingredients to Generate Normalized Extract Resources. The present study applied this concept to clinical Red Clover Extract (RCE) and combined phytochemical and biological methodology to help rationalize the utility of RCE supplements for symptom management in postmenopausal women. Previous work has demonstrated that RCE reduces estrogen detoxification pathways in breast cancer cells (MCF-7) and, thus, may serve to negatively affect estrogen metabolism-induced chemical carcinogenesis. Clinical RCE contains ca. 30% of biochanin A and formononetin, which potentially mask activities of less abundant compounds. These two isoflavonoids are aryl hydrocarbon receptor (AhR) agonists that activate P450 1A1, responsible for estrogen detoxification, and P450 1B1, producing genotoxic estrogen metabolites in female breast cells. Clinical RCE also contains the potent phytoestrogen, genistein, that downregulates P450 1A1, thereby reducing estrogen detoxification. To identify less abundant bioactive constituents, countercurrent separation (CCS) of a clinical RCE yielded selective lipophilic to hydrophilic metabolites in six enriched DESIGNER fractions (DFs 01-06). Unlike solid-phase chromatography, CCS prevented any potential loss of minor constituents or residual complexity (RC) and enabled the polarity-based enrichment of certain constituents. Systematic analysis of estrogen detoxification pathways (ERα-degradation, AhR activation, CYP1A1/CYP1B1 induction and activity) of the DFs uncovered masked bioactivity of minor/less abundant constituents including irilone. These data will allow the optimization of RCE with respect to estrogen detoxification properties. The DFs revealed distinct biological activities between less abundant bioactives. The present results can inspire future carefully designed extracts with phytochemical profiles that are optimized to increase in estrogen detoxification pathways and, thereby, promote resilience in women with high-risk for breast cancer. The DESIGNER approach helps to establish links between complex chemical makeup, botanical safety and possible efficacy parameters, yields candidate DFs for (pre)clinical studies, and reveals the contribution of minor phytoconstituents to the overall safety and bioactivity of botanicals, such as resilience promoting activities relevant to women's health.


Asunto(s)
Neoplasias de la Mama , Isoflavonas , Trifolium , Femenino , Humanos , Trifolium/química , Trifolium/metabolismo , Isoflavonas/farmacología , Isoflavonas/metabolismo , Estrógenos , Extractos Vegetales/farmacología , Extractos Vegetales/química , Neoplasias de la Mama/tratamiento farmacológico
6.
Sci Rep ; 13(1): 8734, 2023 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-37253812

RESUMEN

Breast cancer risk continues to increase post menopause. Anti-estrogen therapies are available to prevent postmenopausal breast cancer in high-risk women. However, their adverse effects have reduced acceptability and overall success in cancer prevention. Natural products such as hops (Humulus lupulus) and three pharmacopeial licorice (Glycyrrhiza) species have demonstrated estrogenic and chemopreventive properties, but little is known regarding their effects on aromatase expression and activity as well as pro-proliferation pathways in human breast tissue. We show that Gycyrrhiza inflata (GI) has the highest aromatase inhibition potency among these plant extracts. Moreover, phytoestrogens such as liquiritigenin which is common in all licorice species have potent aromatase inhibitory activity, which is further supported by computational docking of their structures in the binding pocket of aromatase. In addition, GI extract and liquiritigenin suppress aromatase expression in the breast tissue of high-risk postmenopausal women. Although liquiritigenin has estrogenic effects in vitro, with preferential activity through estrogen receptor (ER)-ß, it reduces estradiol-induced uterine growth in vivo. It downregulates RNA translation, protein biosynthesis, and metabolism in high-risk women's breast tissue. Finally, it reduces the rate of MCF-7 cell proliferation, with repeated dosing. Collectively, these data suggest that liquiritigenin has breast cancer prevention potential for high-risk postmenopausal women.


Asunto(s)
Neoplasias de la Mama , Glycyrrhiza , Femenino , Humanos , Neoplasias de la Mama/prevención & control , Neoplasias de la Mama/metabolismo , Aromatasa/metabolismo , Inhibidores de la Aromatasa/farmacología , Estrógenos/metabolismo , Glycyrrhiza/química , Receptor beta de Estrógeno/metabolismo , Biosíntesis de Proteínas
7.
ACS Appl Bio Mater ; 6(2): 519-528, 2023 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-36633595

RESUMEN

Evaluating surface bacterial growth at buried interfaces can be problematic due to the difficulties associated with obtaining samples. In this work, we present a new method to detect signals from microorganisms at buried interfaces that is nondestructive and can be conducted continuously. Inspired by vascular systems in nature that permit chemical communication between the surface and underlying tissues of an organism, we created a system in which an inert carrier fluid could be introduced into an empty vascular network embedded in a polymer matrix. When a microorganism layer was grown on top, small molecules produced by the growth process would diffuse down into the carrier fluid, which could then be collected and analyzed. We used this system to nondestructively detect signals from a surface layer of Escherichia coli using conductivity, ultraviolet-visible (UV-vis) absorbance spectroscopy, and high-performance liquid chromatography (HPLC) for organic acids, methods that ranged in sensitivity, time-to-result, and cost. Carrier fluid from sample vascularized polymers with surface bacterial growth recorded significantly higher values in both conductivity and absorbance at 350 nm compared to controls with no bacteria after 24 h. HPLC analysis showed three clear peaks that varied between the samples with bacteria and the controls without. Tests tracking the change in signals over 48 h showed clear trends that matched the bacterial growth curves, demonstrating the system's ability to monitor changes over time. A 2D finite element model of the system closely matched the experimental results, confirming the predictability of the system. Finally, tests using clinically relevant Staphylococcus aureus and Pseudomonas aeruginosa yielded differences in conductivity, absorbance, and HPLC peak areas unique to each species. This work lays the foundation for the use of vascularized polymers as an adaptive system for the continuous, nondestructive detection of surface microorganisms at buried interfaces in both industry and medicine.


Asunto(s)
Polímeros , Infecciones Estafilocócicas , Humanos , Bacterias , Escherichia coli/química
8.
ACS Appl Mater Interfaces ; 14(45): 50543-50556, 2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36331290

RESUMEN

The COVID-19 pandemic has revealed the importance of the detection of airborne pathogens. Here, we present composite air filters featuring a bioinspired liquid coating that facilitates the removal of captured aerosolized bacteria and viruses for further analysis. We tested three types of air filters: commercial polytetrafluoroethylene (PTFE), which is well known for creating stable liquid coatings, commercial high-efficiency particulate air (HEPA) filters, which are widely used, and in-house-manufactured cellulose nanofiber mats (CNFMs), which are made from sustainable materials. All filters were coated with omniphobic fluorinated liquid to maximize the release of pathogens. We found that coating both the PTFE and HEPA filters with liquid improved the rate at which Escherichia coli was recovered using a physical removal process compared to uncoated controls. Notably, the coated HEPA filters also increased the total number of recovered cells by 57%. Coating the CNFM filters did not improve either the rate of release or the total number of captured cells. The most promising materials, the liquid-coated HEPA, filters were then evaluated for their ability to facilitate the removal of pathogenic viruses via a chemical removal process. Recovery of infectious JC polyomavirus, a nonenveloped virus that attacks the central nervous system, was increased by 92% over uncoated controls; however, there was no significant difference in the total amount of genomic material recovered compared to that of controls. In contrast, significantly more genomic material was recovered for SARS-CoV-2, the airborne, enveloped virus, which causes COVID-19, from liquid-coated filters. Although the amount of infectious SARS-CoV-2 recovered was 58% higher, these results were not significantly different from uncoated filters due to high variability. These results suggest that the efficient recovery of airborne pathogens from liquid-coated filters could improve air sampling efforts, enhancing biosurveillance and global pathogen early warning.


Asunto(s)
Filtros de Aire , COVID-19 , Virus , Humanos , Pandemias , SARS-CoV-2 , COVID-19/prevención & control , Bacterias , Polvo , Politetrafluoroetileno
9.
Elife ; 112022 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-35348114

RESUMEN

Microbial adhesion to medical devices is common for hospital-acquired infections, particularly for urinary catheters. If not properly treated these infections cause complications and exacerbate antimicrobial resistance. Catheter use elicits bladder inflammation, releasing host serum proteins, including fibrinogen (Fg), into the bladder, which deposit on the urinary catheter. Enterococcus faecalis uses Fg as a scaffold to bind and persist in the bladder despite antibiotic treatments. Inhibition of Fg-pathogen interaction significantly reduces infection. Here, we show deposited Fg is advantageous for uropathogens E. faecalis, Escherichia coli, Pseudomonas aeruginosa, K. pneumoniae, A. baumannii, and C. albicans, suggesting that targeting catheter protein deposition may reduce colonization creating an effective intervention for catheter-associated urinary tract infections (CAUTIs). In a mouse model of CAUTI, host-protein deposition was reduced, using liquid-infused silicone catheters, resulting in decreased colonization on catheters, in bladders, and dissemination in vivo. Furthermore, proteomics revealed a significant decrease in deposition of host-secreted proteins on liquid-infused catheter surfaces. Our findings suggest targeting microbial-binding scaffolds may be an effective antibiotic-sparing intervention for use against CAUTIs and other medical device infections.


Asunto(s)
Infecciones Relacionadas con Catéteres , Infecciones Urinarias , Animales , Antibacterianos/farmacología , Candida albicans , Infecciones Relacionadas con Catéteres/complicaciones , Infecciones Relacionadas con Catéteres/prevención & control , Enterococcus faecalis , Escherichia coli , Klebsiella pneumoniae , Ratones , Catéteres Urinarios/efectos adversos , Infecciones Urinarias/prevención & control
10.
ACS Appl Mater Interfaces ; 14(4): 6148-6156, 2022 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-35042335

RESUMEN

Antifouling membranes that offer excellent operational lifetimes are critical technologies needed to meet the growing demand for clean water. In this study, we demonstrate antifouling membranes featuring an ultrathin oil layer that stayed immobilized on the surface and in the pore walls of poly(vinylidene fluoride) membranes for multiple cycles of operation at industrially relevant transmembrane pressures. An optimized quantity of a commercial Krytox oil with either a low (K103) or a high viscosity (K107) was infused onto the active surface and into the pores of membranes with a 0.45 µm pore size. The presence of the oil layer was qualitatively confirmed using crystal violet staining and variable pressure scanning electron microscopy. Using a dead-end stirred cell, a consistent pure water permeance value of 3000 L m-2 h-1 bar-1 was achieved for the K103 liquid-infused membranes for at least 10 operation cycles, which was expectedly lower than the permeance of bare control membranes (∼16 000 L m-2 h-1 bar-1), suggesting that a stable oil layer was formed on all membrane-active sites. To quantify if oil was lost during membrane operation, extensive thermogravimetric analysis was conducted on both the as-prepared and used membranes. When challenged with the microorganism, Escherichia coli K12, the liquid-infused membranes statistically reduced microbial attachment by ∼50% versus the control membranes. For the first time, we have demonstrated that by forming an immobilized, robust, and stable oil-coated membrane, we can generate high-performance membranes with stable permeance values that can be operated at relevant transmembrane pressures and provide long-lasting antifouling properties.

11.
Food Chem ; 374: 131773, 2022 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-34915376

RESUMEN

Cellulose nanofibril (CNF) is a natural biodegradable biopolymer with excellent mechanical and barrier properties. However, it is susceptible to moisture-induced deterioration of its properties. Attachment of phenolic acids can improve its hydrophobicity and provide additional active functionalities such as antioxidant properties. In this study, CNF films were esterified to vanillic and syringic acid through two different reaction mechanisms. The films were investigated for evidence of modification, hydrophobicity, mechanical properties, crystallinity, thermal stability, and antioxidant properties. Results indicate that esterification with vanillic and syringic acids imparted antioxidant activity to CNF films, with a significantly higher ABTS+· scavenging activity (76 ± 18%) when compared to control CNF films (30 ± 6%). Similarly, esterification of phenolic acids significantly improved the hydrophobicity of the films with a water contact angle of 94 ± 3° when compared to control CNF films (46 ± 5°). Covalent attachment of phenolic acids can improve hydrophobicity while providing additional functionality to CNF important for food packaging applications.


Asunto(s)
Celulosa , Hidroxibenzoatos , Embalaje de Alimentos , Interacciones Hidrofóbicas e Hidrofílicas
12.
ACS Appl Mater Interfaces ; 12(51): 57431-57440, 2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-33306341

RESUMEN

Filamentous fungi have been considered as candidates to replace petroleum-based adhesives and plastics in novel composite material production, particularly those containing lignocellulosic materials. However, the nature of the role of surface mycelium in the adhesion between lignocellulosic composite components is not well-known. The current study investigated the functionality of surface mycelium for wood bonding by incubating Trametes versicolor on yellow birch veneers and compared the lap-shear strengths after hot-pressing to evaluate if the presence of surface mycelium can improve the interface between two wood layers and consequently improve bonding. We found that the lap-shear strength of the samples was enhanced by the increase of surface mycelium coverage up to 8 days of incubation (up to 1.74 MPa) without a significant wood weight loss. We provide evidence that the bottom surface of the mycelium layer is more hydrophilic, contains more small-scale filamentous structure and contains more functional groups, resulting in better bonding with wood than the top surface. These observations confirm and highlight the functionality of the surface mycelium layer for wood bonding and provide useful information for future developments in fully biobased composites manufacturing.


Asunto(s)
Adhesivos/química , Micelio/química , Madera/química , Adhesivos/metabolismo , Ensayo de Materiales , Micelio/metabolismo , Polyporaceae/metabolismo , Resistencia al Corte , Propiedades de Superficie , Madera/metabolismo , Madera/microbiología
13.
PLoS One ; 15(12): e0244324, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33370381

RESUMEN

Microfluidic technologies have enormous potential to offer breakthrough solutions across a wide range of applications. However, the rate of scale-up and commercialization of these technologies has lagged significantly behind promising breakthrough developments in the lab, due at least in part to the problems presented by transitioning from benchtop fabrication methods to mass-manufacturing. In this work, we develop and validate a method to create functional microfluidic prototype devices using 3D printed masters in an industrial-scale roll-to-roll continuous casting process. There were no significant difference in mixing performance between the roll-to-roll cast devices and the PDMS controls in fluidic mixing tests. Furthermore, the casting process provided information on the suitability of the prototype microfluidic patterns for scale-up. This work represents an important step in the realization of high-volume prototyping and manufacturing of microfluidic patterns for use across a broad range of applications.


Asunto(s)
Dispositivos Laboratorio en un Chip , Impresión Tridimensional/instrumentación , Diseño de Equipo , Industrias
14.
Chem Res Toxicol ; 33(11): 2793-2803, 2020 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-32986415

RESUMEN

Botanical dietary supplements (BDS) containing hops are sold as women's health supplements due to the potent hop phytoestrogen, 8-prenylnaringenin (8-PN), and the cytoprotective chalcone, xanthohumol. Previous studies have shown a standardized hop extract to beneficially influence chemical estrogen carcinogenesis in vitro by fostering detoxified 2-hydroxylation over genotoxic 4-hydroxylation estrogen metabolism. In this study, hop extract and its bioactive compounds were investigated for its mechanism of action within the chemical estrogen carcinogenesis pathway, which is mainly mediated through the 4-hydroxylation pathway catalyzed by CYP1B1 that can form gentoxic quinones. Aryl hydrocarbon receptor (AhR) agonists induce CYP1A1 and CYP1B1, while estrogen receptor alpha (ERα) inhibits transcription of CYP1A1, the enzyme responsible for 2-hydroxylated estrogens and the estrogen detoxification pathway. An In-Cell Western MCF-7 cell assay revealed hop extract and 6-prenylnaringenin (6-PN) degraded ERα via an AhR-dependent mechanism. Reverse transcription PCR and xenobiotic response element luciferase assays showed hop extract and 6-PN-mediated activation of AhR and induction of CYP1A1. A reduction in estrogen-mediated DNA (cytosine-5)-methyltransferase 1 (DNMT1) downregulation of CYP1A1 accompanied this activity in a chromatin immunoprecipitation assay. Ultimately, hop extract and 6-PN induced preferential metabolism of estrogens to their detoxified form in vitro. These results suggest that the standardized hop extract and 6-PN activate AhR to attenuate epigenetic inhibition of CYP1A1 through degradation of ERα, ultimately increasing 2-hydroxylated estrogens. A new mechanism of action rationalizes the positive influence of hop BDS and 6-PN on oxidative estrogen metabolism in vitro and, thus, potentially on chemical estrogen carcinogenesis. The findings underscore the importance of elucidating various biological mechanisms of action and standardizing BDS to multiple phytoconstituents for optimal resilience promoting properties.


Asunto(s)
Citocromo P-450 CYP1A1/antagonistas & inhibidores , Regulación hacia Abajo/efectos de los fármacos , Receptor alfa de Estrógeno/antagonistas & inhibidores , Estrógenos/efectos adversos , Flavonoides/farmacología , Humulus/química , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Receptor alfa de Estrógeno/metabolismo , Femenino , Flavonoides/química , Flavonoides/aislamiento & purificación , Humanos , Células Tumorales Cultivadas
15.
J Agric Food Chem ; 68(39): 10651-10663, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-32945668

RESUMEN

Many botanicals used for women's health contain estrogenic (iso)flavonoids. The literature suggests that estrogen receptor beta (ERß) activity can counterbalance estrogen receptor alpha (ERα)-mediated proliferation, thus providing a better safety profile. A structure-activity relationship study of (iso)flavonoids was conducted to identify ERß-preferential structures, overall estrogenic activity, and ER subtype estrogenic activity of botanicals containing these (iso)flavonoids. Results showed that flavonoids with prenylation on C8 position increased estrogenic activity. C8-prenylated flavonoids with C2-C3 unsaturation resulted in increased ERß potency and selectivity [e.g., 8-prenylapigenin (8-PA), EC50 (ERß): 0.0035 ± 0.00040 µM], whereas 4'-methoxy or C3 hydroxy groups reduced activity [e.g., icaritin, EC50 (ERß): 1.7 ± 0.70 µM]. However, nonprenylated and C2-C3 unsaturated isoflavonoids showed increased ERß estrogenic activity [e.g., genistein, EC50 (ERß): 0.0022 ± 0.0004 µM]. Licorice (Glycyrrhiza inflata, [EC50 (ERα): 1.1 ± 0.20; (ERß): 0.60 ± 0.20 µg/mL], containing 8-PA, and red clover [EC50 (ERα): 1.8 ± 0.20; (ERß): 0.45 ± 0.10 µg/mL], with genistein, showed ERß-preferential activity as opposed to hops [EC50 (ERα): 0.030 ± 0.010; (ERß): 0.50 ± 0.050 µg/mL] and Epimedium sagittatum [EC50 (ERα): 3.2 ± 0.20; (ERß): 2.5 ± 0.090 µg/mL], containing 8-prenylnaringenin and icaritin, respectively. Botanicals with ERß-preferential flavonoids could plausibly contribute to ERß-protective benefits in menopausal women.


Asunto(s)
Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Flavonoides/química , Flavonoides/metabolismo , Extractos Vegetales/química , Extractos Vegetales/metabolismo , Epimedium/química , Receptor alfa de Estrógeno/química , Receptor beta de Estrógeno/química , Estrógenos/química , Estrógenos/metabolismo , Glycyrrhiza/química , Humanos , Humulus/química , Prenilación , Relación Estructura-Actividad
16.
Biointerphases ; 15(3): 030801, 2020 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-32486650

RESUMEN

The most common bulk acoustic wave device used in biosensing applications is the quartz crystal microbalance (QCM), in which a resonant pure shear acoustic wave is excited via electrodes on both major faces of a thin AT-cut quartz plate. For biosensing, the QCM is used to detect the capture of a target by a target-capture film. The sensitivity of the QCM is typically based solely on the detection of mechanical property changes, as electrical property change detection is limited by the electrode on its sensing surface. A modification of the QCM called the lateral field excited (LFE) QCM (LFE-QCM) has been developed with a bare sensing surface as both electrodes are now on a single face of the quartz plate. Compared to the QCM, the LFE-QCM exhibits significantly higher sensitivity to both electrical and mechanical property changes. This paper presents theoretical and experimental aspects of LFE-QCMs. In particular, the presence and strength of the usual and newfound LFE-QCM modes depend on the electrical properties of the film and/or sensing environment. This work also presents examples of experimental setups for measuring the response of an LFE-QCM, followed by results of LFE-QCMs used to detect liquid electrical and mechanical properties, chemical targets, and biological targets. Finally, details are given about the attachment of various target-capture films to the LFE-QCM surface to capture biomarkers associated with diseases such as cancer.


Asunto(s)
Técnicas Biosensibles , Tecnicas de Microbalanza del Cristal de Cuarzo , Acústica , Biomarcadores/análisis , Conductividad Eléctrica , Modelos Teóricos
17.
Adv Biosyst ; 4(1): e1900216, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-32293124

RESUMEN

Nature uses vascular systems to permit large-area control over the functionality of surfaces that lie above them. In this work, the application of this concept to the control of a hybrid living-nonliving system is demonstrated. Defined arrangements of vascular channels are created in agar using a fugitive ink printing method. The antibiotic gentamicin is then introduced into the vascular network where it diffuses to the surface and interacts with a model system of Escherichia coli cells. The cells either live or die depending on their distance from the underlying channels, permitting spatial control over the biological system. Using single-channel systems to define critical parameters, a theoretical model is developed to define the final surface pattern based solely on the arrangement of the underlying vascular channels. The model is then successfully used to create more complex arrangements of cells at the surface. Finally, by introducing different types of active compounds into separate vascular channels, a mixture of bacterial species is separated and localized at defined points. This work demonstrates the ability of bioinspired embedded vascular systems to predictably control a biological system at a surface, laying the groundwork for future spatially and temporally controlled biointerfaces in both industry and medicine.


Asunto(s)
Antibacterianos , Modelos Biológicos , Polímeros/química , Agar/química , Antibacterianos/química , Antibacterianos/farmacología , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Biopelículas/efectos de los fármacos , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Gentamicinas/química , Gentamicinas/farmacología , Propiedades de Superficie
18.
Biointerphases ; 14(4): 041005, 2019 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-31431017

RESUMEN

Point-of-care (POC) detection and diagnostic platforms provide critical information about health and safety conditions in austere and resource-limited settings in which medical, military, and disaster relief operations are conducted. In this work, low-cost paper materials commonly used in POC devices are coated with liquid-infused polymer surfaces and folded to produce geometries that precisely localize complex liquid samples undergoing concentration by evaporation. Liquid-infused polymer surfaces were fabricated by infusing silicone-coated paper with a chemically compatible polydimethylsiloxane oil to create a liquid overlayer. Tests on these surfaces showed no remaining bacterial cells after exposure to a sliding droplet containing a concentrated solution of Escherichia coli or Staphylococcus aureus, while samples without a liquid layer showed adhesion of both microdroplets and individual bacterial cells. Folding of the paper substrates with liquid-infused polymer surfaces into several functional 3D geometries enabled a clean separation and simultaneous concentration of a liquid containing rhodamine dye into discrete, predefined locations. When used with bacteria, which are known for their ability to adhere to nearly any surface type, functional geometries with liquid-infused polymer surfaces concentrated the cells at levels significantly higher than geometries with dry control surfaces. These results show the potential of synergistically combining paper-based materials with liquid-infused polymer surfaces for the manipulation and handling of complex samples, which may help the future engineering of POC devices.


Asunto(s)
Técnicas Bacteriológicas/métodos , Escherichia coli/aislamiento & purificación , Papel , Polímeros/química , Staphylococcus aureus/aislamiento & purificación , Propiedades de Superficie , Suspensiones , Adhesión Bacteriana
19.
Cancer Prev Res (Phila) ; 11(12): 819-830, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30287522

RESUMEN

Women are increasingly using botanical dietary supplements (BDS) to reduce menopausal hot flashes. Although licorice (Glycyrrhiza sp.) is one of the frequently used ingredients in BDS, the exact plant species is often not identified. We previously showed that in breast epithelial cells (MCF-10A), Glycyrrhiza glabra (GG) and G. inflata (GI), and their compounds differentially modulated P450 1A1 and P450 1B1 gene expression, which are responsible for estrogen detoxification and genotoxicity, respectively. GG and isoliquiritigenin (LigC) increased CYP1A1, whereas GI and its marker compound, licochalcone A (LicA), decreased CYP1A1 and CYP1B1 The objective of this study was to determine the distribution of the bioactive licorice compounds, the metabolism of LicA, and whether GG, GI, and/or pure LicA modulate NAD(P)H quinone oxidoreductase (NQO1) in an ACI rat model. In addition, the effect of licorice extracts and compounds on biomarkers of estrogen chemoprevention (CYP1A1) as well as carcinogenesis (CYP1B1) was studied. LicA was extensively glucuronidated and formed GSH adducts; however, free LicA as well as LigC were bioavailable in target tissues after oral intake of licorice extracts. GG, GI, and LicA caused induction of NQO1 activity in the liver. In mammary tissue, GI increased CYP1A1 and decreased CYP1B1, whereas GG only increased CYP1A1 LigC may have contributed to the upregulation of CYP1A1 after GG and GI administration. In contrast, LicA was responsible for GI-mediated downregulation of CYP1B1 These studies highlight the polypharmacologic nature of botanicals and the importance of standardization of licorice BDS to specific Glycyrrhiza species and to multiple constituents.


Asunto(s)
Suplementos Dietéticos , Estrógenos/metabolismo , Glycyrrhiza/química , Extractos Vegetales/administración & dosificación , Administración Oral , Animales , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1B1/metabolismo , Femenino , Sofocos/dietoterapia , Hígado/metabolismo , Hígado/patología , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología , Modelos Animales , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Extractos Vegetales/farmacocinética , Extractos Vegetales/normas , Ratas , Ratas Endogámicas ACI , Distribución Tisular , Regulación hacia Arriba , Útero/metabolismo , Útero/patología
20.
Biointerphases ; 13(6): 06D401, 2018 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-30092645

RESUMEN

The ability to control the properties of bio-inspired liquid-infused surfaces is of interest in a wide range of applications. Liquid layers created using oil-infused polydimethylsiloxane elastomers offer a potentially simple way of accomplishing this goal through the adjustment of parameters such as curing agent ratio and oil viscosity. In this work, the effect of tuning these compositional parameters on the properties of the infused polymer are investigated, including infusion dynamics, stiffness, longevity in the face of continuous liquid overlayer removal, and resistance to bacterial adhesion. It is found that that curing agent concentration appears to have the greatest impact on the functionality of the system, with a lower base-to-curing agent ratio resulting in both increased longevity and improved resistance to adhesion by Escherichia coli. A demonstration of how these findings may be implemented to introduce patterned wettability to the surface of the infused polymers is presented by controlling the spatial arrangement of bacteria. These results demonstrate a new degree of control over immobilized liquid layers and will facilitate their use in future applications.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Dimetilpolisiloxanos/química , Dimetilpolisiloxanos/farmacología , Propiedades de Superficie , Antibacterianos/síntesis química , Adhesión Bacteriana/efectos de los fármacos , Fenómenos Químicos , Dimetilpolisiloxanos/síntesis química , Escherichia coli/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...