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1.
Free Radic Biol Med ; 141: 475-482, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31349038

RESUMEN

Chronic inflammatory disorders are associated with biomolecular damage attributed partly to reactions with Reactive Oxygen Species (ROS), particularly hydroxyl radicals (•OH). However, the impacts of serum electrolytes on ROS-associated damage has received little attention. We demonstrate that the conversion of •OH to carbonate and halogen radicals via reactions with serum-relevant carbonate and halide concentrations fundamentally alters the targeting of amino acids and loss of enzymatic activity in catalase, albumin and carbonic anhydrase, three important blood proteins. Chemical kinetic modeling indicated that carbonate and halogen radical concentrations should exceed •OH concentrations by 6 and 2 orders of magnitude, respectively. Steady-state γ-radiolysis experiments demonstrated that serum-level carbonates and halides increased tyrosine, tryptophan and enzymatic activity losses in catalase up to 6-fold. These outcomes were specific to carbonates and halides, not general ionic strength effects. Serum carbonates and halides increased the degradation of tyrosines and methionines in albumin, and increased the degradation of histidines while decreasing enzymatic activity loss in carbonic anhydrase. Serum electrolytes increased the degradation of tyrosines, tryptophans and enzymatic activity in the model enzyme, ketosteroid isomerase, predominantly due to carbonate radical reactions. Treatment of a mutant ketosteroid isomerase indicated that preferential targeting of the active site tyrosine accounted for half of the total tyrosine loss. The results suggest that carbonate and halogen radicals may be more significant than •OH as drivers for protein degradation in serum. Accounting for the selective targeting of biomolecules by these daughter radicals is important for developing a mechanistic understanding of the consequences of oxidative stress.


Asunto(s)
Electrólitos/toxicidad , Radicales Libres/toxicidad , Radical Hidroxilo/toxicidad , Inflamación/sangre , Carbonatos/toxicidad , Catalasa/genética , Halógenos/toxicidad , Humanos , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/patología , Cinética , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Proteolisis/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Contaminantes Químicos del Agua
2.
Transplantation ; 103(6): 1140-1151, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30801551

RESUMEN

BACKGROUND: Storage of donor hearts in cardioplegic solutions supplemented with conditioning agents activating endogenous mitochondrial protective signaling enhanced their postreperfusion recovery. The present study investigates the role of timing and duration of cardiac exposure to cyclosporine A (CsA), another putative mitochondrial protectant, on cardiac functional recovery and potential mechanisms of CsA action in an isolated working rat heart model of donor heart retrieval and storage. METHODS: After measurement of baseline function, hearts were arrested and stored for 6 hours at 4°C in either Celsior alone or Celsior + CsA (0.2 µM), then reperfused for 45 minutes in Krebs solution, when functional recovery was assessed. Two additional groups of Celsior-alone stored hearts were exposed to 0.2 µM CsA for the initial 15 minutes (nonworking period) or the full 45-minute period of reperfusion. Coronary effluent was collected pre- and poststorage for assessment of lactate dehydrogenase release. Tissue samples were collected at the end of each study for immunoblotting and histological studies. RESULTS: CsA supplementation during cold storage or the first 15-minute reperfusion significantly improved functional recovery and significantly increased phospho-AMPKαThr172 and phospho-ULK-1Ser757. Hearts exposed to CsA for 45 minutes at reperfusion recovered poorly with no phospho-AMP-activated protein kinase α activation, decreased phospho-eNOSSer633, and decreased mitochondrial cytochrome c content with increased lactate dehydrogenase release. CONCLUSIONS: Inclusion of CsA during cold storage is cardioprotective. Effects of CsA addition to the perfusate during reperfusion were time dependent, with benefits at 15 minutes but not 45 minutes of reperfusion. The toxic effect with the presence of CsA for the full 45-minute reperfusion is associated with impaired mitochondrial integrity and decreased eNOS phosphorylation.


Asunto(s)
Soluciones Cardiopléjicas/farmacología , Ciclosporina/farmacología , Trasplante de Corazón , Corazón/efectos de los fármacos , Soluciones Preservantes de Órganos/farmacología , Preservación de Órganos , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Soluciones Cardiopléjicas/toxicidad , Isquemia Fría , Ciclosporina/toxicidad , Disacáridos/farmacología , Disacáridos/toxicidad , Electrólitos/farmacología , Electrólitos/toxicidad , Glutamatos/farmacología , Glutamatos/toxicidad , Glutatión/farmacología , Glutatión/toxicidad , Corazón/fisiopatología , Trasplante de Corazón/efectos adversos , Histidina/farmacología , Histidina/toxicidad , Preparación de Corazón Aislado , Masculino , Manitol/farmacología , Manitol/toxicidad , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/patología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Soluciones Preservantes de Órganos/toxicidad , Fosforilación , Ratas Wistar , Recuperación de la Función , Factores de Tiempo
3.
Brain Struct Funct ; 223(4): 1839-1848, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29249047

RESUMEN

Existing neuroanatomical models argue that the bed nucleus of the stria terminalis (BST) principally mediates sustained, long-lasting fear or anxiety responses, but not shorter, phasic fear responses, although recent studies paint a more complex picture. In the current study, we evaluated the effect of post-training electrolytic BST lesions in a cued fear conditioning protocol with relatively short (10 s) tones. We hypothesized that the BST would not play a crucial role in the expression of fear upon re-exposure to the conditioned tones. Tone fear memory was primarily assessed through fear-potentiated startle. In addition, freezing measurements were obtained throughout the test sessions. In a series of three experiments, we explored the effects of BST lesions, taking into consideration contextual influences on cued fear expression (using (dis)similar training and test contexts) and temporal involvement of the BST in the consolidation of fear learning (lesion induction 3 or 27 h after fear conditioning). In all three experiments, we found that post-training electrolytic lesions of the BST significantly reduced fear-potentiated startle, implying a deficit in differentiation between tone and context. These results are surprising and challenge the general consensus on the lack of BST involvement in cued fear. We discuss several alternative explanations that may account for these unexpected findings.


Asunto(s)
Condicionamiento Clásico/fisiología , Señales (Psicología) , Miedo , Reflejo de Sobresalto/fisiología , Núcleos Septales/lesiones , Núcleos Septales/fisiología , Estimulación Acústica , Animales , Electrólitos/toxicidad , Reacción Cataléptica de Congelación/fisiología , Masculino , Ratas , Ratas Wistar , Estadísticas no Paramétricas , Factores de Tiempo
4.
Anal Bioanal Chem ; 409(26): 6123-6131, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28776071

RESUMEN

A novel method based on liquid-liquid extraction with subsequent gas chromatography separation and mass spectrometric detection (GC-MS) for the quantification of organic carbonates in cell culture materials is presented. Method parameters including the choice of extraction solvent, of extraction method and of extraction time were optimised and the method was validated. The setup allowed for determination within a linear range of more than two orders of magnitude. The limits of detection (LODs) were between 0.0002 and 0.002 mmol/L and the repeatability precisions were in the range of 1.5-12.9%. It could be shown that no matrix effects were present and recovery rates between 98 and 104% were achieved. The methodology was applied to cell culture models incubated with commercial lithium ion battery (LIB) electrolytes to gain more insight into the potential toxic effects of these compounds. The stability of the organic carbonates in cell culture medium after incubation was studied. In a porcine model of the blood-cerebrospinal fluid (CSF) barrier, it could be shown that a transfer of organic carbonates into the brain facing compartment took place. Graphical abstract Schematic setup for the investigation of toxicity of lithium ion battery electrolytes.


Asunto(s)
Dioxolanos/análisis , Dioxoles/análisis , Suministros de Energía Eléctrica/efectos adversos , Formiatos/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Extracción Líquido-Líquido/métodos , Animales , Disponibilidad Biológica , Técnicas de Cultivo de Célula/métodos , Línea Celular Tumoral , Medios de Cultivo/análisis , Dioxolanos/farmacocinética , Dioxoles/farmacocinética , Electrólitos/toxicidad , Formiatos/farmacocinética , Humanos , Límite de Detección , Litio/toxicidad , Porcinos , Pruebas de Toxicidad/métodos
5.
Biointerphases ; 12(2): 02C403, 2017 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-28427270

RESUMEN

Each year, the United States spends about $20 billion to treat people who have been infected with antibiotic resistant bacteria. Even so, the development of new antibiotics has slowed considerably since the mid-20th century. As a result, researchers are looking into developing synthetic compounds and materials with antimicrobial activities such as those made by the Schanze and Whitten groups [ACS Appl. Mater. Interfaces 3, 2820 (2011)]. Previously, they have demonstrated that poly(phenylene ethynylene) (PPE) based electrolytes and oligomeric end-only phenylene ethynylene (EO-OPE) based electrolytes possess strong biocidal activity. However, before the PPE and OPE can be used with humans, skin irritation tests are required to ensure their safety. In this work, in vitro skin assays are used to predict in vivo irritation. Tissues were conditioned for 24 h, exposed to test substances for 1 h, and then tested for viability using colorimetric and cytokine assays. Concentrations up to 50 µg/ml were tested. Viability assays and cytokine (IL-1α) assays demonstrated that the two polymers, three symmetric oligomers, and three "end only" oligomers were nonirritants. In addition, electrospun mats consisting of several promising compounds, including poly(caprolactone), were evaluated. Therefore, all test substances are conservatively classified as nonirritants after a 1 h exposure time period.


Asunto(s)
Alquinos/química , Antiinfecciosos/química , Electrólitos/química , Éteres/química , Alquinos/toxicidad , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Electrólitos/toxicidad , Ensayo de Inmunoadsorción Enzimática , Éteres/toxicidad , Humanos , Interleucina-1alfa/análisis , Queratinocitos/citología , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo
6.
J Photochem Photobiol B ; 170: 40-48, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28388462

RESUMEN

Over the last few years, considerable efforts are taken, in order to find a molecular fluorescent probe fulfilling their applicability requirements. Due to a good optical properties and affinity to biological structures conjugated oligoelectrolytes (COEs) can be considered as a promising dyes for application in fluorescence-based bioimaging. In this work, we synthetized COEs with phenylenevinylene core (PV-COEs) and applied as fluorescent membranous-specific probes. Cytotoxicity effects of each COE were probed on cancerous and non-cancerous cell types and little to no toxicity effects were observed at the high range of concentrations. The intensity of cell fluorescence following the COE staining was determined by the photoluminescence analysis and fluorescence activated cell sorting method (FACS). Intercalation of tested COEs into mammalian cell membranes was revealed by fluorescent and confocal microscopy colocalization with commercial dyes specific for cellular structures including mitochondria, Golgi apparatus and endoplasmic reticulum. The phenylenevinylene conjugated oligoelectrolytes have been found to be suitable for fluorescent bioimaging of mammalian cells and membrane-rich organelles. Due to their water solubility coupled with spontaneous intercalation into cells, favorable photophysical features, ease of cell staining, low cytotoxicity and selectivity for membranous structures, PV-COEs can be applied as markers for fluorescence imaging of a variety of cell types.


Asunto(s)
Electrólitos/química , Colorantes Fluorescentes/química , Microscopía Confocal , Animales , Células 3T3 BALB , Línea Celular , Membrana Celular/química , Membrana Celular/metabolismo , Supervivencia Celular , Electrólitos/toxicidad , Citometría de Flujo , Colorantes Fluorescentes/toxicidad , Células HeLa , Humanos , Sustancias Intercalantes/química , Células K562 , Ratones
7.
J Phys Condens Matter ; 26(50): 503101, 2014 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-25388874

RESUMEN

The interaction between polymers and biological membranes has recently gained significant interest in several research areas. On the biomedical side, dendrimers, linear polyelectrolytes, and neutral copolymers find application as drug and gene delivery agents, as biocidal agents, and as platforms for biological sensors. On the environmental side, plastic debris is often disposed of in the oceans and gets degraded into small particles; therefore concern is raising about the interaction of small plastic particles with living organisms. From both perspectives, it is crucial to understand the processes driving the interaction between polymers and cell membranes. In recent times progress in computer technology and simulation methods has allowed computational predictions on the molecular mechanism of interaction between polymeric materials and lipid membranes. Here we review the computational studies on the interaction between lipid membranes and different classes of polymers: dendrimers, linear charged polymers, polyethylene glycol (PEG) and its derivatives, polystyrene, and some generic models of polymer chains. We conclude by discussing some of the technical challenges in this area and future developments.


Asunto(s)
Lípidos de la Membrana/química , Modelos Biológicos , Nanopartículas/química , Nanopartículas/toxicidad , Polímeros/química , Polímeros/toxicidad , Fenómenos Biofísicos , Simulación por Computador , Dendrímeros/química , Dendrímeros/toxicidad , Electrólitos/química , Electrólitos/toxicidad , Modelos Químicos , Simulación de Dinámica Molecular , Polietilenglicoles/química , Polietilenglicoles/toxicidad , Poliestirenos/química , Poliestirenos/toxicidad
8.
Chemosphere ; 112: 177-84, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25048904

RESUMEN

Understanding the inherent toxicity of water-soluble synthetic polyelectrolytes is critical for adequate risk management as well as enhancing product design when biological activity is a key performance index (e.g. for application in biofouling bivalves' control). The toxicity of two cationic acrylamide copolymers with different chain branching degree was evaluated. Standard ecotoxicity tests were conducted with microalgae and daphnids. The susceptibility of Corbicula fluminea, as a biofouling bivalve, was also evaluated. The effect of polyelectrolyte on the test media viscosity and the polymer chain size distributions under the experimental conditions were also examined. The susceptibility of the microalgae to both polymers was similar. As the complexity and size of the test organisms increased, differences in toxicity due to different chain architecture were noticeable. The more branched polymer was significantly less toxic to both daphnids and the bivalves, which could be linked to the distinctive features of its bimodal size chain distribution. This architecture resulted in both more compact globular molecules and the formation of aggregates, which reduce the polymer interaction with the biological surfaces. The results of this study promote the incorporation of environmental considerations in polyelectrolyte development and contribute to the design of improved solutions for controlling biofouling bivalves.


Asunto(s)
Acrilamida/química , Acrilamida/toxicidad , Organismos Acuáticos/efectos de los fármacos , Ecotoxicología , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/toxicidad , Animales , Incrustaciones Biológicas/prevención & control , Corbicula/efectos de los fármacos , Electrólitos/química , Electrólitos/toxicidad , Polímeros/química , Polímeros/toxicidad , Medición de Riesgo , Solubilidad , Relación Estructura-Actividad , Agua/química
9.
J Biomater Appl ; 28(1): 84-99, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22457040

RESUMEN

The layer-by-layer technique, which allows simple preparation of polyelectrolyte multilayers, came into the focus of research for development of functionalized medical devices. Numerous literature exist that concentrate on the film build-up and the behaviour of cells on polyelectrolyte multilayers. However, in case of very soft polyelectrolyte multilayers, studies of the cell behaviour on these films are sometimes misleading with regard to clinical applications because cells do not die due to cytotoxicity but due to apoptosis by missing cell adhesion. It turns out that the adhesion in vitro, and thus, the viability of cells on polyelectrolyte multilayers is mostly influenced by their mechanical properties. In order to decide, which polyelectrolyte multilayers are suitable for implants, we take this problem into account by putting the substrates with soft films on top of pre-cultured human primary endothelial cells ('reverse assay'). Hence, the present work aims giving a more complete and reliable study of typical polyelectrolyte multilayers with regard to clinical applications. In particular, coatings consisting of hyaluronic acid and chitosan as natural polymers and sulfonated polystyrene and polyallylamine hydrochlorite as synthetic polymers were studied. The adsorption of polyelectrolytes was characterized by physico-chemical methods which show regular buildup. Biological examination of the native or modified polyelectrolyte multilayers was based on their effect to cell adhesion and morphology of endothelial cells by viability assays, immunostaining and scanning electron microscopy. Using the standard method, which is typically applied in literature--seeding cells on top of films--shows that the best adhesion and thus, viability can be achieved using sulfonated polystyrene/polyallylamine hydrochlorite. However, putting the films on top of endothelial cells reveals that hyaluronic acid/chitosan may also be suitable for clinical applications: This result is especially remarkable, since hyaluronic acid and chitosan mediate per se no cytotoxic effects, whereas the individual polyelectrolytes, sulfonated polystyrene and polyallylamine hydrochlorite, and their complexes show slight cytotoxicity.


Asunto(s)
Materiales Biocompatibles/química , Electrólitos/química , Polímeros/química , Materiales Biocompatibles/toxicidad , Adhesión Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Quitosano/química , Quitosano/toxicidad , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/toxicidad , Electrólitos/toxicidad , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/fisiología , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/toxicidad , Ensayo de Materiales , Potenciales de la Membrana/efectos de los fármacos , Microscopía Electrónica de Rastreo , Poliaminas/química , Poliaminas/toxicidad , Polímeros/toxicidad , Poliestirenos/química , Poliestirenos/toxicidad , Tecnicas de Microbalanza del Cristal de Cuarzo , Propiedades de Superficie
10.
J Anim Physiol Anim Nutr (Berl) ; 97(1): 39-47, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21992026

RESUMEN

Foot pad dermatitis (FPD) is a very common disease affecting poultry and is mostly caused by bad litter condition. This study aimed to test the effects of poultry diets with normal levels of electrolytes compared with a surplus level of electrolytes with and without using floor heating. Eighty two-week-old ♀ turkey poults were reared over 3 weeks on wood shavings, divided randomly into four groups. Two groups were fed normal levels of electrolytes (1.60 g Na; 7.80 g K/kg diet), and the other two groups were fed surplus levels of electrolytes (3.10; 15.3 g/kg diet). In each dietary treatment, half of the birds were exposed to floor heating. Half of the birds in each group were exposed for 4 h/day to wet litter (35% water) in adjacent separate boxes. External assessment of foot pads was performed weekly. High dietary electrolytes increased the severity of FPD significantly (3.65 ± 1.03). Floor heating is likely to be highly effective in significantly reducing the severity of FPD (2.36 ± 0.588). Despite forced water intake, the litter became drier when floor heating was in use. Combining low Na and K levels with a floor heating system reduced the scores of FPD by approximately 60%, compared with high electrolyte levels without floor heating. Therefore, both dietary electrolyte levels and floor heating markedly affected FPD via litter moisture.


Asunto(s)
Alimentación Animal/análisis , Dermatitis/veterinaria , Electrólitos/toxicidad , Enfermedades del Pie/veterinaria , Enfermedades de las Aves de Corral/etiología , Pavos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dermatitis/etiología , Dermatitis/patología , Dermatitis/prevención & control , Dieta/veterinaria , Electrólitos/química , Femenino , Pisos y Cubiertas de Piso , Enfermedades del Pie/etiología , Enfermedades del Pie/patología , Enfermedades del Pie/prevención & control , Calefacción , Vivienda para Animales , Enfermedades de las Aves de Corral/patología , Enfermedades de las Aves de Corral/prevención & control
11.
Water Res ; 45(19): 6393-402, 2011 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-22000718

RESUMEN

Flocculant blocks are commonly used as a component of (passive) water treatment systems to reduce suspended sediment loads in the water column. This study investigated the potential for aquatic biological impacts of a flocculant block formulation that contained an anionic polyacrylamide (PAM) active ingredient and a polyethylene glycol (PEG) based carrier. The toxicity of the whole flocculant block was assessed and the individual components of the block were also tested separately. Five Northern Australian tropical freshwater species (i.e. Chlorella sp. Lemna aequinoctialis, Hydra viridissima, Moinodaphnia macleayi and Mogurnda mogurnda) were exposed to a range of concentrations of the whole flocculant block, and of the individual PAM and PEG components. The concentration of Total Organic Carbon (TOC) in solution was used to provide a measure of the total amount of PAM and PEG present. An extremely wide range of toxic responses were found, with the flocculant blocks being essentially non-toxic to the duckweed, fish and algae (IC(50)>1880mgl(-1)CTOC, IC(10)>460mgl(-1)CTOC), slightly toxic to the hydra (IC(50)=610-2180mgl(-1)CTOC, IC(10)=80-60mgl(-1)CTOC) and significantly more toxic to the cladoceran (IC(50)=10mgl(-1)CTOC, IC(10)=4mgl(-1)CTOC). More detailed investigation of the two components indicated that the PAM was the primary "toxicant" in the flocculant blocks. Derived Protective Concentrations (PCs) for the flocculant blocks, expressed as equivalent TOC concentrations, were found to be lower than typically measured natural environmental concentrations of TOC. It will thus be possible to use TOC as measure of the concentration of PAM only in those situations where lower levels of ecosystem protection (i.e. higher PCs) are applicable.


Asunto(s)
Ecotoxicología/métodos , Electrólitos/toxicidad , Plantas/efectos de los fármacos , Resinas Acrílicas/toxicidad , Australia , Carbono/análisis , Monitoreo del Ambiente , Floculación/efectos de los fármacos , Agua Dulce , Compuestos Orgánicos/análisis , Polietilenglicoles/toxicidad , Pruebas de Toxicidad
12.
J Am Chem Soc ; 133(18): 7054-64, 2011 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-21491937

RESUMEN

Layer-by-layer assembly of polyelectrolyte multilayer (PEM) films represents a bottom-up approach for re-engineering the molecular landscape of cell surfaces with spatially continuous and molecularly uniform ultrathin films. However, fabricating PEMs on viable cells has proven challenging owing to the high cytotoxicity of polycations. Here, we report the rational engineering of a new class of PEMs with modular biological functionality and tunable physicochemical properties which have been engineered to abrogate cytotoxicity. Specifically, we have discovered a subset of cationic copolymers that undergoes a conformational change, which mitigates membrane disruption and facilitates the deposition of PEMs on cell surfaces that are tailorable in composition, reactivity, thickness, and mechanical properties. Furthermore, we demonstrate the first successful in vivo application of PEM-engineered cells, which maintained viability and function upon transplantation and were used as carriers for in vivo delivery of PEMs containing biomolecular payloads. This new class of polymeric film and the design strategies developed herein establish an enabling technology for cell transplantation and other therapies based on engineered cells.


Asunto(s)
Materiales Biocompatibles/química , Bioingeniería , Membrana Celular/química , Trasplante de Islotes Pancreáticos , Polímeros/química , Animales , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/toxicidad , Electrólitos/síntesis química , Electrólitos/química , Electrólitos/toxicidad , Islotes Pancreáticos/química , Ratones , Poliaminas/síntesis química , Poliaminas/química , Poliaminas/toxicidad , Polielectrolitos , Polietilenglicoles/síntesis química , Polietilenglicoles/química , Polietilenglicoles/toxicidad , Polilisina/análogos & derivados , Polilisina/síntesis química , Polilisina/química , Polilisina/toxicidad , Polímeros/síntesis química , Polímeros/toxicidad
13.
Toxicol Ind Health ; 26(4): 203-16, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20203135

RESUMEN

Hydrogen-dissolved water has been suggested to be effective for alleviating the oxidative stress. In the present study, neutral-pH hydrogen-enriched electrolyzed water (NHE-water; dissolved hydrogen: 0.90-1.14 parts per million [ppm]; oxido-reduced potential: -150 approximately -80 mV), which was prepared with a water-electrolysis apparatus equipped with a non-diaphragm cell and a highly compressed activated-carbon block, was evaluated for the mutagenic and genotoxic potentials, at concentrations up to 100% dose/plate, and for the subchronic toxicity. NHE-water did not induce reverse mutations in Salmonella typhimurium strains TA100, TA1535, TA98 and TA1537, and Escherichia coli strain WP2uvrA, in either the absence or presence of rat liver S9 for exogenous metabolic activation. Similarly, NHE-water did not induce chromosome aberrations in Chinese hamster lung fibroblast cells (CHL/IU), in short-term (6-hour) tests, with or without rat liver S9, or in a continuous treatment (24-hour) test. To evaluate the subchronic toxicity, Crj:CD(SD) specific pathogen free (SPF)-rats were administered with NHE-water at a dose of 20 mL/kg/day for 28 days via intragastric infusion. NHE-water-related toxic changes were not seen in terms of any items such as clinical symptoms, body weight, food consumption, urinalysis, hematology, blood chemistry, necropsy, each organ weight and histopathology. Thus, the no-observable-adverse-effect level (NOAEL) for NHE-water was estimated to be greater than 20 mL/kg/day under the conditions examined, demonstrating the consistency with the expected safety for a human with a body weight of 60 kg to drink the NHE-water up to at least 1.2 L/day.


Asunto(s)
Electrólitos/toxicidad , Administración Oral , Animales , Línea Celular , Aberraciones Cromosómicas/efectos de los fármacos , Cricetinae , Cricetulus , Daño del ADN , Relación Dosis-Respuesta a Droga , Electrólitos/administración & dosificación , Escherichia coli/efectos de los fármacos , Concentración de Iones de Hidrógeno , Pruebas de Mutagenicidad , Nivel sin Efectos Adversos Observados , Estrés Oxidativo/efectos de los fármacos , Ratas , Salmonella typhimurium/efectos de los fármacos , Agua
14.
Artículo en Inglés | MEDLINE | ID: mdl-19757233

RESUMEN

Living cells encapsulated in polymeric shells are receiving increasing attention because of their possible biotechnological and biomedical applications. The aim of this work is to evaluate how different polyelectrolyte coatings, characterized by different numbers of polyelectrolyte layers and by different polyelectrolyte conformations, affect the viability of encapsulated biological material. We demonstrate the ability to individually encapsulate HL-60 cells as well as rat pancreatic islets within polymeric shells consisting of different PE layers using the layer-by-layer process. Coating of HL-60 cells allows for surviving and functioning of cells for all applied PE as well as for different numbers of layers. The islets encapsulated in applied polyelectrolytes exhibited the lower level of mitochondrial activity as compared to non-encapsulated islets. Nevertheless, encapsulated islets exhibited comparable absorbance values during the whole period of culture. Polyelectrolyte coating seems to be a promising way of allowing capsule void volume minimization in a model of encapsulated biological material for local production of biologically active substances.


Asunto(s)
Células/metabolismo , Electrólitos/química , Electrólitos/metabolismo , Polímeros/química , Polímeros/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Células/citología , Células/efectos de los fármacos , Electrólitos/toxicidad , Células HL-60 , Humanos , Islotes Pancreáticos/citología , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Células Jurkat , Microscopía de Fuerza Atómica , Conformación Molecular , Nanocápsulas/química , Polímeros/toxicidad , Ratas
15.
Artículo en Inglés | MEDLINE | ID: mdl-18172802

RESUMEN

The toxicity of 11 polyquaterniums used in cosmetic applications, and polydimethyldiallylammonium chloride (poly(DADMAC)) were studied for toxicity of the polyquaternium alone, and of a polyquaternium/anionic surfactant complex as occurs in some cosmetic formulations. The surfactant used in the study was sodium dodecyl sulfate (SDS), which is used in cosmetic formulations under its International Nomenclature of Cosmetic Ingredients (INCI) name Sodium Laurel Sulfate. In fish immobilization studies with Gambusia holbrooki, the EC(50) of the polyquaternium/surfactant complex was found to be the same as or similar to the EC(50) for the polyquaternium alone. The toxicity of the polyquaterniums investigated was similar to the published values for other cationic polyelectrolytes and cationic surfactants, in the range from < 1.0 to 10 mg/L, with the exception of low charge density cellulosic polyquaterniums. The anionic surfactant alone was not toxic to fish in the concentration range tested. Results thus showed the toxicity of the polyquaternium was not mitigated by the presence of the anionic surfactant.


Asunto(s)
Ciprinodontiformes/crecimiento & desarrollo , Ecotoxicología , Electrólitos/toxicidad , Polímeros/toxicidad , Compuestos de Amonio Cuaternario/toxicidad , Tensoactivos/toxicidad , Animales , Cosméticos/química , Cosméticos/toxicidad , Dodecil Sulfato de Sodio/toxicidad
16.
Cryobiology ; 56(1): 88-92, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18022150

RESUMEN

Organ preservation solutions have been designed to protect grafts against the injury inflicted by cold ischemia. However, toxicity of University of Wisconsin (UW) solution during rewarming has been reported. Therefore, we here assessed the toxicity of UW, histidine-tryptophan-ketoglutarate (HTK), Euro-Collins, histidine-lactobionate (HL), sodium-lactobionate-sucrose and Celsior solutions in cultured hepatocytes under hypothermic (4 degrees C), intermediate (21 degrees C) and physiological (37 degrees C) conditions. Marked toxicity of UW, HTK, HL and Euro-Collins solutions was observed at both 37 and 21 degrees C. With the exception of UW solution, these solutions also increased cell injury during cold incubation (LDH release after 18 h at 4 degrees C: HTK 76+/-2%, Euro-Collins 78+/-17%, HL 81+/-15%; control: Krebs-Henseleit buffer 20+/-6%). Testing of individual components using modified Krebs-Henseleit buffers suggested that histidine and phosphate are responsible for (part of) this toxicity. These potential toxicities should be taken into account in the development of future preservation solutions.


Asunto(s)
Hepatocitos/efectos de los fármacos , Soluciones Preservantes de Órganos/toxicidad , Adenosina/toxicidad , Alopurinol/toxicidad , Animales , Células Cultivadas , Frío , Disacáridos/toxicidad , Electrólitos/toxicidad , Glucosa/toxicidad , Glutamatos/toxicidad , Glutatión/toxicidad , Histidina/toxicidad , Soluciones Hipertónicas/toxicidad , Insulina/toxicidad , Masculino , Manitol/toxicidad , Cloruro de Potasio/toxicidad , Procaína/toxicidad , Rafinosa/toxicidad , Ratas , Ratas Wistar , Sacarosa/toxicidad
17.
Water Res ; 41(11): 2301-24, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17462699

RESUMEN

The use of polymers in the production of drinking water is reviewed, with emphasis on the nature of the impurities to be removed, the mechanisms of coagulation and flocculation, and the types of polymers commonly available. There is a focus on polymers for primary coagulation, their use as coagulant aids, in the recycling of filter backwash waters, and in sludge thickening. Practicalities of polymer use are discussed, with particular attention to polymer toxicity, and the presence of residual polymer in the final drinking water. The questions of polymer degradation and the formation of disinfection by-products are also addressed.


Asunto(s)
Conservación de los Recursos Naturales , Electrólitos/aislamiento & purificación , Polímeros/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Abastecimiento de Agua , Desinfectantes/química , Desinfectantes/aislamiento & purificación , Desinfectantes/toxicidad , Desinfección , Electrólitos/química , Electrólitos/toxicidad , Filtración , Floculación , Polímeros/química , Polímeros/toxicidad
18.
Biomaterials ; 28(4): 632-40, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17049374

RESUMEN

Polyethyleneimine (PEI) is a synthetic polymer commonly used as precursor base layer in polyelectrolyte multilayer films. However, the biological properties of this cationic macromolecule are poorly understood. The aim of this experimental investigation was to evaluate in vitro the biocompatibility of PEI towards two different human cell lines. The experimental investigation was undertaken on pure titanium (Ti) and nickel-titanium (NiTi) alloy samples with an average surface roughness of Ra=0.3microm. A biological study was undertaken at day 0 (2h after seeding), day 2, day 4 and day 7 to observe the cellular response of fibroblasts and osteoblasts cell lines in terms of morphology, adhesion (as observed by scanning electron microscopy), and viability (Mosmann's test). The results showed that PEI can be successfully deposited onto Ti or NiTi alloy, but generates a detrimental cellular response on both substrates as illustrated by a decrease of both fibroblast and osteoblast adhesion and proliferation over a 7-day culture period. These results suggest that PEI is potentially cytotoxic and may not be biocompatible enough in clinical applications using high molecular weight. As a consequence, polyelectrolyte multilayer films, which are promising in prosthesis and implantology fields, could not be coated with PEI at a high molecular weight. A lower molecular weight should be considered or a more biocompatible molecular base as precursor layer of polyelectrolyte multilayer films would be better to use for a good human bio-integration.


Asunto(s)
Electrólitos/toxicidad , Polietileneimina/toxicidad , Forma de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Humanos , Microscopía Electrónica de Rastreo , Osteoblastos/citología , Osteoblastos/efectos de los fármacos
19.
Methods Find Exp Clin Pharmacol ; 24(8): 493-6, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12500428

RESUMEN

A study of the different volume and infusion rates of a new maintenance fluid, Veen 3G, on the general conditions of rats was investigated during the 14 days after infusion. In Experiment I, 100 ml/kg and 200 ml/kg of Veen 3G were infused at a rate of 300 ml/kg/h in male and female rats. Results were compared with those for Gurunon Ringer solution (GRS) in male and female rats. We observed only transient polyuria in animals administered by each dose of Veen 3G and GRS for 0-15 min after infusion. Necropsy was not observed in any of the animals tested 14 days after infusion. In Experiment II, 200 ml/kg of Veen 3G was infused at rates of 200, 400, 800 and 1600 ml/kg/h in male rats. At 800 and 1600 ml/kg/h, irregular respiration and decrease in movement were observed concomitantly with polyuria. Three out of 4 rats died immediately after the infusion of Veen 3G at a rate of 1600 ml/kg/h, and one rat was still alive 14 days after the infusion. In this experiment, 200 ml/kg Veen 3G was safe when we infused at a rate of less than 400 ml/kg/h in male rats. Since this rate is about 27-80 times higher than that used clinically in maintenance treatment, Veen 3G is suggested to be safe, with the exception of polyuria, in clinical situations at the standard infusion rate (5-15 ml/kg/h).


Asunto(s)
Electrólitos/toxicidad , Fluidoterapia/efectos adversos , Glucosa/toxicidad , Poliuria/inducido químicamente , Animales , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Electrólitos/administración & dosificación , Color del Ojo/efectos de los fármacos , Femenino , Fluidoterapia/métodos , Glucosa/administración & dosificación , Bombas de Infusión/efectos adversos , Infusiones Intravenosas/métodos , Soluciones Isotónicas/administración & dosificación , Soluciones Isotónicas/toxicidad , Masculino , Dosis Máxima Tolerada , Ratas , Ratas Sprague-Dawley , Insuficiencia Respiratoria/inducido químicamente , Solución de Ringer , Convulsiones/inducido químicamente
20.
J Vet Med Sci ; 60(2): 245-50, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9524951

RESUMEN

Recently, the authors have shown that marked necrosis and fibrosis of myocardium were observed in rats given alkaline ionized water (AKW). To clarify the cause of myocardial lesions, the activities of myosin ATPase, actomyosin ATPase and creatine kinase (CK) in myocardium of rats given AKW at 15 weeks-old were compared with those in myocardium of rats given tap water (TPW). Furthermore, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of myocardiac myosin and isoelectric focusing (IEF) of myocardiac CK were performed which revealed a distinct difference between AKW and TPW groups. The activities of myosin ATPase and actomyosin ATPase in the AKW group were higher than those in the TPW group, and these elevated activities were caused by the degradation of myosin in the AKW group judging from the SDS-PAGE pattern of myosin. On the other hand, the activity of CK in the AKW group was lower than that in the TPW group, and the IEF pattern of CK showed leakage of myocardiac CK. These results indicate that increases in actomyosin ATPase activity and myosin ATPase activity, plus the decrease in CK activity caused the disorder of coupled reaction in male rats given AKW at 15 weeks-old. It is concluded that this disorder of coupled reaction may cause marked myocardiac necrosis and fibrosis in rats given AKW.


Asunto(s)
Creatina Quinasa/metabolismo , Electrólitos/toxicidad , Miocardio/metabolismo , Miosinas/metabolismo , Abastecimiento de Agua , Animales , Creatina Quinasa/aislamiento & purificación , Suplementos Dietéticos , Electrólitos/administración & dosificación , Femenino , Corazón/efectos de los fármacos , Concentración de Iones de Hidrógeno , Isoenzimas , Masculino , Miocardio/patología , Necrosis , Ratas , Ratas Sprague-Dawley , Caracteres Sexuales
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