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Background/purpose: An increasing body of evidence indicates correlations between the symptoms of temporomandibular disorder and those of eating disorder (ED). However, further investigation is required to elucidate the temporal and causal relationships between the aforementioned disorders. Materials and methods: This retrospective cohort study was conducted using data from the Taiwan National Health Insurance Research Database. Temporomandibular joint disorder (TMJD) was analyzed both as the cause and consequence of ED. We collected the data (from January 1, 1998, to December 31, 2011) of patients with antecedent TMJD (N = 15,059) or ED (N = 1219) and their respective controls (1:10), matched by age, sex, income level, residential location, and comorbidities. This study included patients who had received a new diagnosis of an ED or a TMJD between January 1, 1998, and December 31, 2013. Cox regression models were used to assess the risk of ED or TMJD development in patients with antecedent TMJD or ED. Results: TMJD patients had an approximately 3.70-fold (95 % confidence interval [CI]: 1.93-7.10) risk of ED development. Similarly, patients with ED had an approximately 4.78-fold (95 % CI: 2.52-9.09) risk of TMJD development. Subgroup analyses based on ED subtypes indicated antecedent TMJD and bulimia nervosa as the predictors of increased bulimia nervosa and TMJD risks (hazard ratios: 6.41 [95 % CI: 2.91 to 14.11] and 5.84 [95 % CI: 2.75 to 12.41]), respectively. Conclusion: Previous TMJD and ED are associated with increased risks of subsequent ED and TMJD; these findings suggest the presence of a bidirectional temporal association between TMJD and ED.
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Most microbial time-temperature indicators (TTIs) considered only one spoilage strain. This research compared single and dual spoilage strains-based microbial TTI for quality changes of chilled grouper fish (Epinephelus fuscoguttatus x E. lanceolatus) fillet products during distribution. The next-generation sequencing (NGS) and traditional plate count approach showed that Pseudomonas fragi and Vibrio parahaemolyticus were specific spoilage bacteria at 7 and 15°C. A dual-strain TTI response provides more accurate results than a single-strain TTI and provides an irreversible color change from yellow to reddish-brown, showing levels of fish freshness. The microbial TTI comprises fish spoilage bacteria strains with 3 log CFU/ml, a nutrient broth supplemented with 2% NaCl as a medium, and phenol red with 0.25 mg/ml as a pH indicator. Overall, this study points to the applicability of a dual-strain microbial TTI as a valuable tool for monitoring fish quality changes during cold chain break condition.
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Lubina , Microbiología de Alimentos , Animales , Bacterias , Frío , Refrigeración , Alimentos Marinos/microbiologíaRESUMEN
BACKGROUND: Frontal asymmetry plays a major role in depression. However, patients with treatment-resistant depression (TRD) have widespread hypofrontality. We investigated whether patients with TRD have a characteristic frontal activation pattern in functional near-infrared spectroscopy (fNIRS) findings and how the frontal cortex responds to different levels of cognitive tasks. METHODS: We enrolled 27 right-handed patients with TRD, 27 patients without TRD and 27 healthy controls. We used multichannel fNIRS to evaluate activation of the bilateral dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC) and left motor area in response to 3 tasks: finger tapping, a low cognitive-load motor task; verbal fluency, a moderate cognitive-load task; and a dual task involving simultaneous finger tapping and verbal fluency, a high cognitive-load task. RESULTS: We found significant between-group differences in left DLPFC activation for all 3 tasks. The healthy controls had cortical activation in the left motor area during finger tapping and the bilateral frontal cortex during the dual task. However, patients without TRD had right VLPFC activation during finger tapping and left DLPFC activation during the dual task. Patients with TRD had bilateral DLPFC activation during finger tapping but exhibited increased bilateral VLPFC and left motor area activation during verbal fluency and increased left motor area activation during the dual task. In healthy controls and patients without TRD, we found that the right VLPFC was positively correlated with depression severity. LIMITATIONS: Our cohort included only patients with late-onset depression. CONCLUSION: We found different patterns of abnormal frontal activation between patients with and without TRD. In patients without TRD, the right prefrontal cortex (PFC) was recruited during simple motor tasks. However, in patients with TRD, the bilateral PFC was recruited during simple tasks and motor cortical resources were used compensatorily during PFC-demanding complex cognitive tasks.
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Trastorno Depresivo Mayor , Corteza Motora , Depresión , Trastorno Depresivo Mayor/diagnóstico por imagen , Humanos , Corteza Motora/diagnóstico por imagen , Corteza Prefrontal/diagnóstico por imagen , Espectroscopía Infrarroja Corta/métodosRESUMEN
This study aimed to increase the antibacterial activity of chitosan-polylactic acid (PLA) composite film by adding nisin and ethylenediaminetetraacetic acid (EDTA). We evaluated the mechanical, physicochemical, and antibacterial properties of various PLA composite films, as well as the enhancement effect of PLA composite films with EDTA + nisin on the preservation of grouper fillets. Films of PLA alone, PLA plus chitosan (C5), PLA plus nisin + EDTA (EN2), and PLA plus chitosan plus nisin + EDTA (C5EN1 and C5EN2) were prepared. The addition of EDTA + nisin to the chitosan-PLA matrix significantly improved the antibacterial activity of the PLA composite film, with C5EN1 and C5EN2 films showing the highest antibacterial activity among the five films. Compared with the fish samples covered by C5, the counts of several microbial categories (i.e., mesophilic bacteria, psychrotrophic bacteria, coliforms, Aeromonas, Pseudomonas, and Vibrio) and total volatile basic nitrogen content in fish were significantly reduced in the samples covered by C5EN1. In addition, the counts of samples covered by C5EN1 or C5 were significantly lower compared to the uncovered and PLA film-covered samples.
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This research prepared chitosan-PLA plastic films by extrusion, analyzed the physical and mechanical properties and antibacterial activity of the fabricated plastic films, and used them to preserve grouper fillet. We added chitosan (220 kDa, 93% DD) in the weight ratio of 0.5-2% into the PLA to prepare the chitosan-PLA films. With the increasing chitosan dosage, both the water vapor transmission rate and moisture content of chitosan-PLA films increased. Among the three doses of chitosan (0.5%, 1%, and 2%) added to PLA, 0.5% chitosan-PLA film had the highest antibacterial activity. This plastic film had an inhibitory efficiency of over 95% against Escherichia coli, Pseudomonas fluorescens, and Staphylococcus aureus. The action of covering the fish fillet with 0.5% chitosan-PLA film significantly reduced several microbes' counting (i.e., mesophiles, psychrophiles, coliforms, Pseudomonas, Aeromonas, and Vibrio) and total volatile basic nitrogen (TVBN) value in the grouper fillets stored at 4 °C. Thus, such action prolongs the fish fillets' shelf life to up to at least nine days, and this 0.5% chitosan-PLA film shows promising potential for preserving refrigerated fish.
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BACKGROUND: Association of proton pump inhibitor (PPI) exposure with acute myocardial infarction (AMI) risk in the Caucasian population remains under debate. Here, we clarified whether PPI exposure might be related to an increased new-onset AMI risk in an Asian population. METHOD: Data of 27,624 patients with PPI exposure followed by new-onset AMI development were extracted from Taiwan National Health Insurance Research Database and age- and sex-matched with 27,624 controls with PPIs exposure, but without subsequent AMI and ischemic heart disease development. The amount of PPI exposure was calculated based on the cumulative defined daily dose (cDDD) during the follow-up period. Subsequent AMI risk was measured after adjustments of demographic data and indication of PPI use. RESULTS: AMI risk increased with an increase in PPI exposure: with cDDD ≤ 30 as the reference, the odds ratios (95% confidence intervals) for cDDDs of > 365 was 1.56 (1.45-1.69). All five PPI categories, including pantoprazole, lansoprazole, omeprazole, esomeprazole, and rabeprazole, increased AMI risk. CONCLUSIONS: Our study demonstrated long-term or high-dose PPI exposure associated with increased new-onset AMI risk in patients without a history of any ischemic heart disease. The underlying mechanisms of PPI-related cardiovascular effects deserve more investigation.
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Infarto del Miocardio/inducido químicamente , Inhibidores de la Bomba de Protones/efectos adversos , Adulto , Anciano , Bases de Datos Factuales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/epidemiología , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Taiwán/epidemiologíaRESUMEN
Porous scaffolds for dermal tissue engineering were fabricated by freeze-drying a mixture of chitosan and gelatin (CG) solutions. Different crosslinking agents including glutaraldehyde, 1-(3-dimethylaminopropyl)-3-ethyl-carbodimide hydrochloride (EDC), and genipin were used to crosslink the scaffolds and improve their biostability. The porous structure and mechanical properties were determined for the scaffolds. The proliferation of human fibroblasts in the scaffolds was analyzed. It was found that EDC crosslinked scaffolds had the greatest amount of cells after four days. EDC crosslinked CG scaffolds had tensile modulus in a dry state and compressive modulus in a wet state similar to commercial collagen wound dressing. They also showed appropriate pore size, high water absorption, and good dimensional stability during cell culture. When human fibroblasts were seeded on acellular porcine dermis (APD), acellular human dermis (AHD), and CG scaffolds for 3D cell culture, they were well-distributed in the centre of the CG scaffolds but stayed only on the superficial layer of APD or AHD after seven days. A gelatin-based bioglue was applied to the CG scaffolds where the keratinocytes were seeded to mimic epidermal structure. After 14 days, the bioglue degraded and keratinocytes grew to form monolayers on the scaffolds. This study showed that CG scaffolds crosslinked by EDC and seeded with human fibroblasts could serve as dermal constructs, while the bioglue coating seeded with keratinocytes could serve as an epidermal construct. Such a combination could help regenerate skin with integrated dermal and epidermal layers and a have potential use in tissue-engineered skin.
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Quitosano/química , Dermis/patología , Gelatina/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Absorción , Carbodiimidas , Técnicas de Cultivo de Célula , Reactivos de Enlaces Cruzados/farmacología , Dermis/metabolismo , Dimetilaminas , Fibroblastos/citología , Fibroblastos/metabolismo , Liofilización , Glutaral/farmacología , Humanos , Iridoides/química , Queratinocitos/citología , Estrés Mecánico , Agua/químicaRESUMEN
A novel method to exfoliate the montmorillonite clay was developed previously to generate random nanosilicate platelets (NSP), one kind of delaminated clay. To improve their dispersion in a polymer, we modified NSPs by three types of surfactants (cationic Qa, nonionic Qb, and anionic Qc) in this study and used them to prepare nanocomposites with polyurethane (PU). The zeta potential, antimicrobial ability, and biocompatibility of these surfactant-modified NSPs (abbreviated "NSQ") were characterized. It was found that the zeta potential of Qa-modified NSP (NSQa) was positive, whereas those of NSP and the other two NSQs (NSQb and NSQc) were negative. All NSQ presented less cytotoxicity than NSP. NSQa and NSQc showed excellent antimicrobial activities against S. aureus (Gram-positive strain) and E. coli (Gram-negative strain). The nanocomposites of NSQ with PU were then characterized for surface and mechanical properties, cell attachment and proliferation, antimicrobial activity in vitro, and biocompatibility in vivo. A higher surfactant to NSP ratio was found to improve the dispersion of NSQ in PU matrix. The mechanical properties of all PU/NSQ nanocomposites were significantly enhanced. Among various NSQ, only NSQa were observed to migrate to the composite surface. The attachment and proliferation of endothelial cells and fibroblasts in vitro as well as biocompatibility in vivo were significantly better for PU/NSQa containing 1% of NSQa than other materials. The microbiostasis ratios of PU/NSQ nanocomposites containing 1% NSQa or NSQc were >90%. These results proposed the safety and potential antimicrobial applications of surfactant-modified delaminated clays and their nanocomposites with PU polymer.
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Silicatos de Aluminio/química , Antibacterianos/química , Nanocompuestos/química , Poliuretanos/química , Silicatos de Aluminio/toxicidad , Antibacterianos/farmacología , Adhesión Bacteriana/efectos de los fármacos , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Adhesión Celular/efectos de los fármacos , Arcilla , Células Endoteliales/citología , Escherichia coli/efectos de los fármacos , Fibroblastos/citología , Nanocompuestos/toxicidad , Poliuretanos/farmacología , Staphylococcus aureus/efectos de los fármacosRESUMEN
Nanocomposites from a polyether-type waterborne polyurethane (PU) and 0.1 wt % of silicate materials were prepared. The individual silicate materials were natural clays (montmorillonite and mica), their exfoliated clays [nano silicate platelets (NSP) and nano mica platelets], and NSP modified with C18 fatty amine (NSP-S). The physico-chemcical properties and antimicrobial activity of the nanocomposites were characterized in vitro. The biostability and biocompatibility of the nanocomposites were evaluated in vivo. The nanocomposites exhibited various surface morphologies with phase separation of hard and soft domains in nanometric scales. The nanocomposite containing NSP (PU-NSP) showed better endothelial cell attachment and gene expression. The better biocompatibility of PU-NSP and PU-NSP-S was evidenced by the lower thickness of foreign body capsules in rat subcutaneous implantation. PU-NSP had the least surface degradation in vivo as demonstrated by the electron microscopy and infrared spectroscopy. This may be associated with the different surface structure. PU-NSP and PU-NSP-S showed strong bacteriostatic effects, which suggested that the nano clay in the polymer matrix may still interact with the microbes.
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Antiinfecciosos , Materiales Biocompatibles , Nanocompuestos/química , Poliuretanos , Silicatos , Staphylococcus aureus/efectos de los fármacos , Silicatos de Aluminio/química , Silicatos de Aluminio/metabolismo , Animales , Antiinfecciosos/química , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Bentonita/química , Bentonita/metabolismo , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Materiales Biocompatibles/farmacología , Bovinos , Humanos , Ensayo de Materiales , Microscopía de Fuerza Atómica , Estructura Molecular , Tamaño de la Partícula , Poliuretanos/química , Poliuretanos/metabolismo , Poliuretanos/farmacología , Ratas , Ratas Sprague-Dawley , Silicatos/química , Silicatos/metabolismo , Silicatos/farmacología , Difracción de Rayos XRESUMEN
Chitosan nanocomposites were prepared from chitosan and gold nanoparticles (AuNPs) or silver nanoparticles (AgNPs) of â¼5 nm size. Transmission electron microscopy (TEM) showed the NPs in chitosan did not aggregate until higher concentrations (120-240 ppm). Atomic force microscopy (AFM) demonstrated that the nanocrystalline domains on chitosan surface were more evident upon addition of AuNPs (60 ppm) or AgNPs (120 ppm). Both nanocomposites showed greater elastic modulus, higher glass transition temperature (T(g)) and better cell proliferation than the pristine chitosan. Additionally, chitosan-Ag nanocomposites had antibacterial ability against Staphylococcus aureus. The potential of chitosan-Au nanocomposites as hemostatic wound dressings was evaluated in animal (rat) studies. Chitosan-Au was found to promote the repair of skin wound and hemostasis of severed hepatic portal vein. This study indicated that a small amount of NPs could induce significant changes in the physicochemical properties of chitosan, which may increase its biocompatibility and potential in wound management.
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Antibacterianos/química , Materiales Biocompatibles/química , Quitosano/química , Nanocompuestos/química , Animales , Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Quitosano/farmacología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Oro/química , Oro/farmacología , Humanos , Masculino , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Nanocompuestos/ultraestructura , Ratas , Ratas Sprague-Dawley , Plata/química , Plata/farmacología , Piel/efectos de los fármacos , Piel/lesiones , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Temperatura de Transición , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Nanocomposites from a polyester-type waterborne polyurethane (PU) containing various low concentrations (15-75 ppm) of silver nanoparticles (nano Ag, size approximately 5 nm) were prepared. The PU-Ag nanocomposites exhibited good nanoparticle dispersion up to 30 ppm of nano Ag, confirmed by the transmission electron microscopy. Distinct surface morphology at different concentrations of nano Ag was shown by the atomic force microscopy. The oxidative degradation of PU-Ag was inhibited in all concentrations of nano Ag tested, especially at 30 ppm ("PU-Ag 30 ppm"). This may be related to the free radical scavenging ability observed for the nanocomposites. PU-Ag 30 ppm showed enhanced fibroblast attachment and endothelial cell response, as well as reduced monocyte and platelet activation, relative to PU alone or nanocomposites at the other silver contents. The rat subcutaneous implantation confirmed the better biocompatibility of the nanocomposites. The adhesion of Bacillus subtilis, Escherichia (E.) coli or Ag(+)-resistant E. coli on PU-Ag nanocomposites was significantly lower at all concentrations of nano Ag tested. Besides, the nanocomposites demonstrated microbiostatic effect while pure PU did not. The commercial catheters coated with PU-Ag 30 ppm were inserted into rat jugular veins for evaluation. The results showed milder inflammation for PU-Ag after 3 months compared to the non-coated catheters or pure PU-coated catheters. The enhanced performance of PU-Ag over that of pure PU was a result of extensively modified surface morphology in the presence of a very small amount of nano Ag. The dispersion of nano Ag was highly associated with the overall performance.
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Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Ensayo de Materiales/métodos , Nanocompuestos/química , Poliuretanos/farmacología , Plata/farmacología , Agua/química , Animales , Adhesión Bacteriana/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Humanos , Implantes Experimentales , Pruebas de Sensibilidad Microbiana , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Nanocompuestos/ultraestructura , Adhesividad Plaquetaria/efectos de los fármacos , Ratas , Piel/citología , Temperatura de Transición/efectos de los fármacosRESUMEN
Nanometer-scale silicate platelet (NSP) materials were previously developed by increasing the interlayer space and exfoliation of layered silicate clays such as montmorillonite and synthetic fluorinated mica by the process of polyamine exfoliation. In this study, the antibacterial activity and cytotoxicity of these nanometer-scale silicate clays were evaluated. The derivatives of NSP (NSP-S) which were modified by C18-fatty amine salts via ionic exchange association exhibited the highest antibacterial activity in the aqueous state among all clays. The high antibacterial activity, however, was accompanied by elevated cytotoxicity. The variations of cell surface markers (CD29 and CD44) and type I collagen expression of fibroblasts treated with the clays were measured to clarify the mechanism of the silicate-induced cytotoxicity. The signal transduction pathway involved the downregulation of extracellular-signal-regulated kinase (ERK), which appeared to participate in silicate-induced cytotoxicity. This study helped to understand the antibacterial potential of NSP and the interaction of natural and modified clays with cellular activities.
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Silicatos de Aluminio/farmacología , Aminas/química , Antiinfecciosos/farmacología , Células Endoteliales/citología , Fibroblastos/citología , Sales (Química)/química , Silicatos/farmacología , Animales , Bentonita/farmacología , Cationes , Bovinos , Muerte Celular/efectos de los fármacos , Arcilla , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Recuento de Colonia Microbiana , Células Endoteliales/efectos de los fármacos , Células Endoteliales/enzimología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Escherichia coli/ultraestructura , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Receptores de Hialuranos/metabolismo , Integrina beta1/metabolismo , Pruebas de Sensibilidad Microbiana , Fosforilación/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/ultraestructuraRESUMEN
Nanocomposites from a polyester-type water-borne polyurethane (PU) containing different amounts (17.4-174 ppm) of gold (Au) nanoparticles (approximately 5 nm) were prepared. A previous study has shown that the Au nanoparticles could induce surface morphological transformations in the PU (e.g. the mesophase transition from hard lamellae to soft micelles), which modify the physicochemical properties of the PU as well as the fibroblast response to the PU. The current study focused on the biostability and biocompatibility of the nanocomposites. The nanocomposites were characterized by transmission electron microscopy and X-ray photoelectron spectroscopy, and their oxidative stability and free radical scavenging ability were tested. The inflammatory response was evaluated by monocyte activation in vitro and rat subcutaneous implantation in vivo. It was found that the nanocomposites containing 43.5-65 ppm of Au had the least monocyte activation and tissue reactions. PU and the nanocomposites were rather resistant to oxidative degradation in vitro and biodegradation in vivo. The nanocomposites exhibited greater free radical scavenging abilities than the original PU. Based on the above results, the significantly enhanced biocompatibility of the PU-Au nanocomposites with 43.5-65 ppm of gold over the original PU appeared to be a result of the extensively modified surface morphology and greater free radical scavenging ability, instead of due to the difference in biostability.
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Materiales Biocompatibles/química , Nanopartículas del Metal/química , Nanocompuestos/química , Poliésteres/química , Poliuretanos/química , Química Física/métodos , Fibroblastos/metabolismo , Depuradores de Radicales Libres/química , Oro/química , Humanos , Inflamación , Microscopía Electrónica de Transmisión , Monocitos/metabolismo , Oxígeno/química , Poliésteres/farmacología , Poliuretanos/farmacología , Espectrometría por Rayos XRESUMEN
Nanocomposites from a hexamethylene diisocyanate (HDI)-based polyester-type waterborne polyurethane (PU) containing different amounts (17.4-174 ppm) of gold (Au) nanoparticles (approximately 5 nm) were prepared. The microstructure and physiochemical properties of the nanocomposites were characterized. The cell attachment and proliferation, platelet activation, and bacterial adhesion on the nanocomposites were evaluated. Gold nanoparticles in small amounts induced significant changes in surface morphology and domain structures, from hard segment lamellae to soft segment micelles. These changes resembled the morphological transformation among different mesophases occurred in diblock copolymers. Better cellular proliferation, lower platelet activation, and reduced bacterial adhesion were demonstrated for the PU nanocomposite with 43.5 or 65 ppm of Au than the pure PU or the nanocomposite containing a different amount of Au. The different cellular response on PU-Au nanocomposites was attributed to the extensively modified surface morphology and phase separation in the presence of a small amount of Au nanoparticles.
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Oro/química , Nanopartículas del Metal , Poliuretanos/química , Adhesión Bacteriana , Adhesión Celular , Proliferación Celular , Humanos , Activación Plaquetaria , Propiedades de SuperficieRESUMEN
We have prepared the nanocomposites of a polyether-type waterborne polyurethane (PU) incorporated with different amounts (17.4-174 ppm) of gold (Au) nanoparticles ( approximately 5 nm). The nanocomposite containing a certain amount (43.5 ppm) of gold was previously demonstrated to possess the optimal thermal and mechanical properties, as well as much reduced foreign body reactions in subcutaneous rats. In this study, the surface morphology, biocompatibility, oxidative degradation, and free radical scavenging ability of the nanocomposites were characterized in vitro. The nanocomposite at 43.5 ppm of gold ("PU-Au 43.5 ppm") exhibited different surface morphology confirmed by the atomic force microscope. PU-Au 43.5 ppm also showed enhanced cellular proliferation, reduced platelet and monocyte activation, and much less bacterial adhesion, relative to PU alone or nanocomposites at the other Au contents, in general. This better biocompatibility was associated with the surface morphological change in the presence of Au. The oxidative degradation in PU-Au 43.5 ppm was also inhibited. The increased oxidative stability corresponded to the greater free radical scavenging ability of the nanocomposites.
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Materiales Biocompatibles/química , Oro/química , Ensayo de Materiales , Nanoestructuras/química , Poliuretanos/química , Plaquetas/citología , Células Cultivadas , Células Endoteliales/citología , Humanos , Ensayo de Materiales/métodos , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Monocitos/citología , Oxidación-Reducción , Pruebas de Función Plaquetaria/métodosRESUMEN
In this work, a series of different polyurethanes based on poly(tetramethylene oxide) (PTMO, MW approximately 2000) and chain extended with butenediol were synthesized by a two-step solution polymerization. Three of them contained silanol terminated polydimethylsiloxane (PDMS, MW approximately 2000) blocks. It was shown that these polymers exhibited various degrees of micro-phase separation that further influenced their biological performances in vitro. The formulation with diphenylmethane diisocyanate/PTMO/PDMS/2-butene-1,4-diol at a molar ratio of 2: 0.75: 0.5: 1 in synthesis was favorable due to a combination of enhanced mechanical properties, biostability, cellular affinity as well as platelet nonadherence.