Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Acta Biomater ; 140: 88-101, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34852302

RESUMEN

Currently there are no potential curative therapies that can improve the central nervous system (CNS) regeneration after traumatic injuries or diseases. Indeed, the regeneration of CNS is greatly impaired by limited drug penetration across the blood brain barrier (BBB), poor drug targeting, deficient progenitor neural cells and limited proliferation of mature neural cells. To overcome these limitations, bioengineered injectable hydrogels in combination with drug and cell therapy have been proposed to mimic the complexity of the CNS microenvironment and architecture. Additionally, to enhance relevant CNS regeneration, proper biophysical and biochemical cues are needed. Recently, great efforts have been devoted to tailor stimuli-responsive hydrogels as novel carrier systems which are able to guide neural tissue regeneration. This review provides an extensive overview on the most promising injectable hydrogels for neural tissue engineering. A special emphasis is made to highlight the ability of these hydrogels to deliver bioactive compounds/cells upon the exposure to internal and external stimuli. Bioactive injectable hydrogels have a broad application in central nervous system's (CNS) regeneration. This review gives an overview of the latest pioneering approaches in CNS recovery using stimuli-responsive hydrogels for several neurodegenerative disorders. STATEMENT OF SIGNIFICANCE: This review summarizes the latest innovations on bioactive injectable hydrogels, focusing on tailoring internal/external stimuli-responsive hydrogels for the new injectable systems design, able to guide neural tissue response. The purpose is to highlight the advantages and the limitations of thermo-responsive, photo responsive, magnetic responsive, electric responsive, ultrasound responsive and enzymes-triggered injectable hydrogels in developing customizable neurotherapies. We believe that this comprehensive review will help in identifying the strengths and gaps in the existing literature and to further support the use of injectable hydrogels in stimulating CNS regeneration.


Asunto(s)
Hidrogeles , Ingeniería de Tejidos , Barrera Hematoencefálica , Sistema Nervioso Central/fisiología , Hidrogeles/uso terapéutico , Regeneración Nerviosa
2.
Food Chem ; 249: 22-29, 2018 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-29407927

RESUMEN

This study was designated to ascertain the effectiveness of polylactic acid (PLA) based packaging solution to store red fresh meat during its refrigerated shelf-life. Recently the attention in the packaging industry regarding the use of bioplastics has been shifting from compostable/biodegradable materials toward biobased materials. Steaks obtained from semimembranous muscle of Piemontese beef were packaged in PLA trays closed with a lid made of PLA film and for comparison purposed in a conventional reference package consisting of a amorphous polyethylene terephthalate/polyethylene (APET/PET) trays and wrapped in plastic film of polyvinyl chloride (PVC). The packaging under modified atmosphere MAP was carried out by using a gas mixture of 66% O2, 25% CO2 and 9%N2. By using PLA packaging combination it was possible to maintain an optimum red colour together with a reduced content of volatile compounds associated to off-flavours of meat samples particularly related to the oxidation phenomena.


Asunto(s)
Embalaje de Alimentos/métodos , Almacenamiento de Alimentos/métodos , Carne Roja , Animales , Materiales Biocompatibles , Bovinos , Color , Calidad de los Alimentos , Proyectos Piloto , Poliésteres/química , Polietileno , Cloruro de Polivinilo , Carne Roja/microbiología
3.
J Biomed Mater Res A ; 106(2): 521-530, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28960765

RESUMEN

This work describes the synthesis and characterization of new apatite phases co-doped with gallium, magnesium and carbonate, exhibiting osteogenic and antibacterial ability. The apatites are synthesized at low temperature to retain nanocrystallinity and controlled doping with the various bioactive foreign ions, as assessed by physico-chemical and crystallographic analyses, reporting the achievement of single phases with reduced crystal ordering. The analysis of single and multi-doped apatites reports to different mechanisms acting in the incorporation of gallium and magnesium ions in the apatite structure. The release of bioactive ions is correlated to the behavior of human mesenchymal stem cells and of different bacterial strands, selected among the most frequently affecting surgical procedures. Enhanced osteogenic and antibacterial ability is assessed in multi-doped apatites, thus suggesting potential future applications as new smart biomaterials integrating a significant boosting of bone regeneration with adequate protection against bacteria. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 106A: 521-530, 2018.


Asunto(s)
Antibacterianos/farmacología , Durapatita/farmacología , Nanopartículas/química , Osteogénesis , Tejido Adiposo/citología , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Bacterias/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Fenómenos Químicos , Durapatita/química , Humanos , Iones , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/enzimología , Pruebas de Sensibilidad Microbiana , Osteogénesis/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
4.
Chemosphere ; 194: 644-649, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29241139

RESUMEN

Seafood is associated with many beneficial effects on human health. However, the overall level of contaminants in biota has increased over the last two centuries and seafood is one of the source of oral exposition to contaminants. Therefore, this work aimed to evaluate cadmium, lead, mercury, arsenic, chromium and nickel presence in mussels and clams, from the Italian market, and the associated risk. The samples were from five different FAO areas. Analyses were carried out using inductively-coupled plasms-mass spectrometry. The sample concentrations were below the maximum levels stated by Commission Regulation (EC) 1881/2006, except one mussel sample, which was non-compliant for cadmium (2.13 ± 0.20 mg kg-1). For arsenic, nickel and chromium, maximum levels are not stated by the European Union. In this study, arsenic ranged from 1.29 to 13.35 mg kg-1 and nickel ranged from 1, and BMDL10 for lung bladder and skin cancer in all mussel samples was overcome, in the 100% and 25% of mussel and clam samples, respectively.


Asunto(s)
Arsénico/toxicidad , Bivalvos/química , Exposición a Riesgos Ambientales/análisis , Metales/análisis , Alimentos Marinos/análisis , Animales , Arsénico/análisis , Humanos , Italia , Espectrometría de Masas , Medición de Riesgo
5.
J Anim Physiol Anim Nutr (Berl) ; 101(5): 893-903, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27080058

RESUMEN

The Chianina, one of the oldest and most important cattle breeds of Italy, is now reared all over the world. The Chianina has been known and appreciated since ancient times because, from a nutritional point of view, its meat has no proper rivals. To date, studies have been performed to evaluate the genetic profile of the breed, but knowledge about the chemical profile is generally lacking. Due to the increased interest from farmers regarding breeding of the Chianina, this study proposes a preliminary evaluation of main endogenous urinary corticosteroids (cortisol and cortisone) and most commonly used synthetic one (dexamethasone). Moreover, after recent findings regarding the presence of endogenous prednisolone in the urine of more popular breeds, particular attention was given to analysis of the presence of prednisolone and prednisone, as well. For this aim, the urine samples of 12 young cows and 30 young bulls was collected at the farms and analysed using a fit-for-purpose LC-MS/MS method. The preliminary results of this study show that prednisolone was found only in Chianina females (3 out of 12). Cortisol and cortisone were found at concentrations that showed a high inter-individual variability, and that were higher in female urine compared to that of males.


Asunto(s)
Bovinos/fisiología , Cortisona/orina , Hidrocortisona/orina , Prednisolona/orina , Animales , Bovinos/genética , Bovinos/orina , Cromatografía Liquida , Cortisona/química , Femenino , Hidrocortisona/química , Masculino , Estructura Molecular , Prednisolona/química , Espectrometría de Masas en Tándem
6.
Drug Test Anal ; 9(4): 561-570, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27448217

RESUMEN

Under European legislation, the use of growth promoters is forbidden in food-producing livestock. The application of unofficial protocols with diverse combinations of veterinary drugs, administered in very low concentrations, hinders reliable detection and subsequent operative prevention. It was observed that nandrolone (anabolic steroid) and ractopamine (ß-adrenergic agonist) are occasionally administered to animals, but little is known about their synergic action when they are administered together. Two specific analytical methods based on liquid chromatography-tandem mass spectrometry have been developed, both of which include hydrolysis of the corresponding conjugates. For the nandrolone method, solid-phase extraction was necessary for the complete elimination of the interferences, while employment of the Quantitation Enhanced Data-Dependent scan mode during MS acquisition of ractopamine enabled the utilization of simple liquid-liquid extraction. The nandrolone method was linear in the range of 0.5-25 ng/mL, while the ractopamine calibration curve was constructed from 0.5 to 1000 ng/mL. The corresponding coefficients of correlations were >0.9907. The lower limit of quantification for both methods was 0.5 ng/mL, followed by overall recoveries >81%. Precisions expressed as relative standard deviations were <17%, while matrix effects were minimal. Urine samples taken at the slaughterhouse from veal calves enrolled in an experimental treatment consisting of intramuscular administration of ß-nandrolone-phenylpropionate accompanied with a ractopamine-enriched diet were analysed. Those methods might be useful for studying the elimination patterns of the administered compounds along with characterization of the main metabolic pathways. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Anabolizantes/orina , Bovinos/orina , Sustancias de Crecimiento/orina , Nandrolona/orina , Fenetilaminas/orina , Espectrometría de Masas en Tándem/métodos , Animales , Cromatografía Líquida de Alta Presión/métodos , Inocuidad de los Alimentos , Límite de Detección , Masculino , Detección de Abuso de Sustancias/métodos
7.
Food Chem ; 212: 296-304, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27374536

RESUMEN

This study analysed the usefulness of near infrared spectroscopy (NIRS), combined with volatile compound (VOC) and fatty acid (FA) analyses, for the authentication of the unique Italian Valle d'Aosta Arnad Protected Designation of Origin (PDO) lard. Ensuring the authenticity of high value meat products remains an emerging topic within the food sector. This study validated a FA, VOC and NIRS model for use in the authentication of Arnad PDO lard. The model showed a high potential rate to recognize patterns in lard samples. In particular the sensitivity and specificity calibration values were both 100%, and cross-validation models were performed using FAs and VOCs separately. The NIRS model obtained sensitivity and specificity values of 98.2% in the calibration data set, and 94.4% in the cross-validation step. This analytical approach may represent an effective tool to prevent food fraud, which is crucial for meat derived products with a high commercial value.


Asunto(s)
Grasas de la Dieta/análisis , Ácidos Grasos/análisis , Productos de la Carne/análisis , Espectroscopía Infrarroja Corta/métodos , Italia , Sensibilidad y Especificidad , Volatilización
8.
Chemosphere ; 154: 482-490, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27085062

RESUMEN

Bee products, such as honey, are widely consumed as food and consumer interest is currently oriented towards organic foods. Regarding this, the European Commission establishes that the qualification of organic honey and other beekeeping products as being from organic production is closely bound with the characteristics of hive treatments as well as the quality of the environment. Agricultural contamination with pesticides is a challenging problem that needs to be fully addressed, in particular in the field of organic production systems. In this study, the occurrence of different classes of contaminants selected as representative of potential contamination sources were investigated in 59 organic honeys: organochlorines, OCs; organophosphates, OPs; polychlorobiphenyls, PCBs and polybromodiphenylethers, PBDEs. A method based on Accelerated Solvent Extraction with "in line" clean-up and GC-MS/MS detection was developed to detect contaminants. Residues of many pesticides were found in most of the samples investigated. The majority of honey samples contained at least one of the pesticides, even if their concentrations were found to be lower than its MRL. Diazinon, Mevinphos, Coumaphos, Chlorpyrifos and Quinoxyfen were the residues frequently detected in samples coming from the apple and citrus orchard areas. Furthermore, the results of the present study show that the presence of the residue in organic honey may also be affected by the geographical area (e.g. the presence of an agricultural system) confirming honey bee and beehive matrices as appropriate sentinels for monitoring contamination in the environment. The optimised method proved to be simple and rapid, requiring small sample sizes and minimising solvent consumption, due to the ASE having an "in line" clean-up step.


Asunto(s)
Abejas , Contaminantes Ambientales/análisis , Contaminación de Alimentos , Miel/análisis , Plaguicidas/análisis , Compuestos Orgánicos Volátiles/análisis , Agricultura , Animales , Monitoreo del Ambiente/métodos , Italia , Espectrometría de Masas en Tándem/métodos
9.
Chemosphere ; 153: 162-9, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27016811

RESUMEN

Residues of environmental contaminants in food represent a concern in food safety programs. In this study, the distribution of persistent organic pollutants (POPs) were evaluated in 79 tuna samples from FAO areas 51 (Indian Ocean), 71 (Pacific Ocean), 34 (Atlantic Ocean), and 37 (Mediterranean Sea). 6 polychlorinated biphenyls (PCBs), 16 organochlorines (OCs) and 7 polybrominated biphenyl ethers (PBDEs) were selected as representative compounds according to EFSA POPs monitoring guidelines. An analytical method, based on Accelerated Solvent Extraction (ASE), with an "in-line" clean-up step and GC-MS/MS detection, was developed, validated and applied. PCBs were detected in all FAO areas, with a prevalence of 100% for most of them. In the FAO area 37, only, all PBDEs were detected. Only 5 OCs were detected. The results showed that POPs contamination of tuna reflects FAO area contamination; in particular FAO area 37 was the most polluted. Moreover, tuna muscle was an appropriate matrix for monitoring contamination and for obtaining information about food safety.


Asunto(s)
Éteres Difenilos Halogenados/metabolismo , Hidrocarburos Clorados/metabolismo , Atún/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas , Océanos y Mares , Bifenilos Policlorados/metabolismo , Espectrometría de Masas en Tándem
10.
J Mater Sci Mater Med ; 27(5): 96, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27003838

RESUMEN

Deposition of nanostructured and low-wear zirconia (ZrO2) thin films on the metallic component of a total joint implant is envisaged to reduce wear of the soft ultra-high molecular weight polyethylene (UHMWPE) counterpart. In this work, morphological surface features, wear resistance and in vitro-biocompatibility of zirconia thin films deposited by the novel Pulsed Plasma Deposition (PPD) method have been investigated. Film thickness, roughness and wettability were found to be strongly dependent on deposition gas pressure. Interestingly, wear rate of UHMWPE disks coupled to zirconia-coated titanium spheres was only poorly correlated to the contact angle values, while film roughness and thickness seemed not to affect it. Furthermore, wear of UHMWPE, when coupled with zirconia coated-titanium spheres, significantly decreased with respect to uncoated spheres under dry or NaCl-lubricated conditions; besides, when using bovine serum, similar results were obtained for coated and uncoated spheres. Finally, suitable mesenchymal stem and osteoblast cells adhesion, proliferation and viability were observed, suggesting good biocompatibility of the nanostructured zirconia films. Taken together, the results shown in this work indicate that zirconia thin films deposited by the PPD method deserve further investigations as low-wear materials for biomedical applications such as total joint replacement.


Asunto(s)
Ensayo de Materiales/métodos , Membranas Artificiales , Nanoestructuras/química , Circonio/química , Animales , Materiales Biocompatibles , Proliferación Celular , Supervivencia Celular , Células Madre Mesenquimatosas/fisiología , Ratones , Propiedades de Superficie
11.
Artículo en Inglés | MEDLINE | ID: mdl-25768050

RESUMEN

The debate about the origin of prednisolone in animal organisms has lasted for 5 years. Bovine species have been the most studied, but studies on humans and horses are also present in the literature. Even if prednisolone in pigs does not yet represent a problem for control agencies, interest has recently increased with regard to this species. To date, there has been just a single study in the literature about this topic, performed on 10 sows treated with prednisolone or a synthetic analogue of adrenocorticotropic hormone. We therefore initiated a study on 80 pigs, a number considered representative in relation to the expected frequency (prevalence) of prednisolone detection in urine collected at slaughter. Prednisolone was detected in urine both at the farm and at the slaughterhouse, with a concentration and frequency higher at slaughter. The presence of prednisolone was also studied in the adrenal glands, where the corticosteroids are produced in response to stress, and it was detected in 89% of the samples. These results, together with the similar behaviours of prednisolone and cortisol, i.e. a mutual rise in the two corticosteroids in urine collected at the slaughterhouse and the correlation between the concentrations of the two corticosteroids in the adrenal glands, seem to indicate an endogenous origin of prednisolone in pigs.


Asunto(s)
Glándulas Suprarrenales/química , Glucocorticoides/orina , Hidrocortisona/orina , Prednisolona/orina , Mataderos , Animales , Femenino , Cromatografía de Gases y Espectrometría de Masas , Porcinos
12.
Anal Chim Acta ; 852: 137-45, 2014 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-25441890

RESUMEN

The presence of ß-boldenone II phase metabolites and prednisolone in urine samples, owing to endogenous or natural origin or illicit treatment, is under debate within the European Union. The detection of ß-boldenone conjugates, α-boldenone conjugates at concentrations higher than 2 ng mL(-1) and prednisolone above the cut-off level of 5 ng mL(-1) in urine have been, until now, critical in deciding if illegal drug use has occurred. The use of urine sometimes is not entirely satisfactory, especially when the drug is administrated at low doses or when its metabolic conversion is very fast. This subsequently would hamper its detection in urine. The introduction of a new, advantageous matrix where the illicit treatment can be investigated would be highly appreciated. In this study, we have developed and validated a simple and unique immunoaffinity clean-up procedure, which was applied to bovine bile samples, followed by two different analytical liquid chromatography-electrospray-tandem mass spectrometry methods. The first method tests androstadienedione, α- and ß-boldenone sulphate, glucuronate and related free forms, while the other method assays prednisolone, prednisone, dexamethasone, cortisone, and cortisol. The methods were validated according to European Commission Decision 2002/657/EC. The evaluated parameters were linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit and detection capability. The decision limits (CCα) were between 0.38 and 0.45 ng mL(-1) for anabolic steroids, and 0.13 and 0.15 ng mL(-1) as far as corticosteroids were concerned. Intra- and inter-day repeatability was below 15.8 and 19.9% for all analytes, respectively. The methods were applied to the analysis of some bile samples collected from untreated young bulls in order to investigate the presence of the studied steroids in this matrix.


Asunto(s)
Corticoesteroides/análisis , Androstadienos/análisis , Bilis/química , Bovinos , Espectrometría de Masas en Tándem/métodos , Testosterona/análogos & derivados , Animales , Bovinos/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Glucurónidos/análisis , Técnicas de Inmunoadsorción , Límite de Detección , Masculino , Testosterona/análisis
13.
J Dairy Sci ; 97(7): 4029-42, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24835972

RESUMEN

Hyperuricemia is a biochemical hallmark of gout, renal urate lithiasis, and inherited purine disorders, and may be a result of enormous ATP breakdown or purine release as a result of cardiovascular disease, hypertension, kidney disease, eclampsia, obesity, metabolic syndrome, psoriasis, tumor lysis syndrome, or intense physical training. The beneficial role of dairy products on hyperuricemia management and prevention is well documented in the literature. The primary aim of our experimental study was to examine the effect of milk dietary regimen (commercial 1.5% fat UHT milk or patented depurinized milk) compared with allopurinol therapy on experimental hyperuricemia induced by oxonic acid in rats. Principal component analysis was applied on a data set consisting of 11 variables for 8 different experimental groups. Among the 11 parameters measured (plasma uric acid and the liver parameters NFκB-p65, Akt kinase/phospho-Akt kinase, ERK kinase/phospho-ERK kinase, IRAK kinase/phospho IRAK kinase, p38/phospho-p38, and DNase), Akt/phospho Akt and ERK/phospho-ERK signaling were extracted as the most discriminating. We also compared the content of various potentially toxic compounds (sulfur compounds, ketones, aldehydes, alcohols, esters, carboxylic acids, and phthalates) in untreated commercial milk and depurinized milk. Of all the compounds investigated in this study that were observed in commercial milk (24 volatile organic compounds and 4 phthalates), 6 volatile organic compounds were not detected in depurinized milk. For almost all of the other compounds, significant decreases in concentration were observed in depurinized milk compared with commercial milk. In conclusion, a depurinized milk diet may be recommended in nutritional treatment of primary and secondary hyperuricemia to avoid uric acid and other volatile, potentially toxic compounds that may slow down liver regeneration and may induce chronic liver diseases.


Asunto(s)
Alopurinol/farmacología , Alopurinol/uso terapéutico , Endonucleasas/metabolismo , Hiperuricemia/dietoterapia , Hígado/enzimología , Leche/metabolismo , FN-kappa B/metabolismo , Alimentación Animal/análisis , Animales , Dieta , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Hiperuricemia/inducido químicamente , Hiperuricemia/tratamiento farmacológico , Hiperuricemia/enzimología , Hígado/efectos de los fármacos , Masculino , Leche/química , Ácido Oxónico/toxicidad , Distribución Aleatoria , Ratas , Ratas Wistar
14.
Biosystems ; 114(3): 227-37, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24141144

RESUMEN

The mathematical prediction of cell proliferation in porous scaffold still remains a challenge. The analysis of existing models and experimental data confirms a need for a new solution, which takes into account cells" development on the scaffold pore walls as well as some additional parameters such as the pore size, cell density in cellular layers, the thickness of the growing cell layer and others. The simulations, presented below, are based on three main approaches. The first approach takes into account multilayer cell growth on the pore walls of the scaffold. The second approach is a simulation of cell proliferation in a discrete process as a continuous one. The third one is the representation of scaffold structure as a system of cylindrical channels. Oxygen (nutrient) mass transfer is realized inside these channels. The model, described below, proposes the new solution to time dependent description of cell proliferation in porous scaffold and optimized trophical conditions for tissue development.


Asunto(s)
Proliferación Celular , Modelos Biológicos , Andamios del Tejido/química , Recuento de Células , Simulación por Computador , Oxígeno/metabolismo , Porosidad , Biología de Sistemas , Factores de Tiempo
15.
Bone ; 56(2): 432-9, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23876980

RESUMEN

The fundamental elements of tissue regeneration are cells, biochemical signals and the three-dimensional microenvironment. In the described approach, biomineralized-collagen biomaterial functions as a scaffold and provides biochemical stimuli for tissue regeneration. In addition superparamagnetic nanoparticles were used to magnetize the biomaterials with direct nucleation on collagen fibres or impregnation techniques. Minimally invasive surgery was performed on 12 rabbits to implant cylindrical NdFeB magnets in close proximity to magnetic scaffolds within the lateral condyles of the distal femoral epiphyses. Under this static magnetic field we demonstrated, for the first time in vivo, that the ability to modify the scaffold architecture could influence tissue regeneration obtaining a well-ordered tissue. Moreover, the association between NdFeB magnet and magnetic scaffolds represents a potential technique to ensure scaffold fixation avoiding micromotion at the tissue/biomaterial interface.


Asunto(s)
Magnetismo , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Masculino , Conejos
16.
J Colloid Interface Sci ; 394: 590-7, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23266023

RESUMEN

Type I collagen films have been functionalized on their surfaces by plasma treatment with carboxyl and amino groups to improve their potential for grafting bioactive molecules. The physico-chemical properties of the plasma-treated films were evaluated and compared to the untreated materials by water contact angle, SEM and AFM. The presence of new functional groups on the film surfaces has been assessed by ATR-FTIR spectra after chemical derivatization. Moreover, the biocompatibility of the plasma-treated films was studied with MG-63 human osteoblast-like cells, evaluating cell proliferation, viability and morphology at 1, 3 and 7 days.


Asunto(s)
Materiales Biocompatibles/química , Colágeno Tipo I/química , Osteoblastos/citología , Adhesión Celular , Línea Celular , Proliferación Celular , Supervivencia Celular , Humanos , Ensayo de Materiales , Propiedades de Superficie , Ingeniería de Tejidos
17.
Nanotechnology ; 23(46): 465102, 2012 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-23093179

RESUMEN

A straightforward technique for functionalization of multiwalled carbon nanotubes (MWCNTs) with magnetite (Fe(3)O(4)) nanoparticles was developed. Iron oxide nanoparticles were deposited on MWCNT surfaces by a deposition-precipitation method using Fe(3+)/Fe(2+) salts precursors in basic solution. The characterizations by HRTEM, XRD, SEM/EDX, AAS and TPR analyses confirmed the successful formation of magnetic iron oxide nanoparticles on the MWCNT surface. Fe(3)O(4)/MWCNT hybrid composites were analysed in vitro by incubation with mesenchymal stem cells for 1, 3 and 7 days, either in the presence or absence of a static magnetic field. Analysis of cell proliferation was performed by the MTT assay, quantification of cellular stress was performed by the Lactate Dehydrogenase assay and analysis of cell morphology was performed by actin immunofluorescence and scanning electron microscopy. Results demonstrate that the introduction of magnetite into the MWCNT structure increases biocompatibility of oxidized MWCNTs. In addition, the presence of a static magnetic field further increases Fe(3)O(4)/MWCNT influence on cell behaviour. These results demonstrate this novel Fe(3)O(4)/MWCNT hybrid composite has good potential for tissue engineering applications.


Asunto(s)
Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Nanopartículas de Magnetita/química , Nanocompuestos/química , Nanotubos de Carbono/química , Ingeniería de Tejidos/métodos , Análisis de Varianza , Animales , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Células Cultivadas , L-Lactato Deshidrogenasa/metabolismo , Ensayo de Materiales , Células Madre Mesenquimatosas , Nanocompuestos/ultraestructura , Conejos
18.
J Biomed Mater Res A ; 100(9): 2278-86, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22499413

RESUMEN

The use of magnetism in tissue engineering is a very promising approach, in fact magnetic scaffolds are able not only to support tissue regeneration, but they can be activated and work like a magnet attracting functionalized magnetic nanoparticles (MNPs) injected close to the scaffold enhancing tissue regeneration. This study aimed to assess the in vivo biocompatibility and osteointegrative properties of novel magnetic scaffolds. Two hydroxyapatite/collagen (70/30 wt %) magnetic scaffolds were magnetized with two different techniques: direct nucleation of biomimetic phase and superparamagnetic nanoparticles (MNPs) on self-assembling collagen fibers (MAG-A) and scaffold impregnation in ferro-fluid solution (MAG-B). Magnetic scaffolds were implanted in rabbit distal femoral epiphysis and tibial mid-diaphysis. Histopathological screening showed no inflammatory reaction due to MNPs. Significantly higher bone healing rate (ΔBHR) results were observed in MAG-A in comparison to MAG-B. Significant differences were also found between experimental times with an increase in ΔBHR from 2 to 4 weeks for both scaffolds in trabecular bone, while only for MAG-B (23%, p < 0.05) in cortical bone. The proposed magnetic scaffolds seem to be promising for magnetic guiding in orthopedic tissue engineering applications and they will be suitable to treat also several pathologies in regenerative medicine area.


Asunto(s)
Regeneración Ósea , Sustitutos de Huesos/química , Colágeno/química , Durapatita/química , Imanes/química , Andamios del Tejido/química , Implantes Absorbibles , Animales , Sustitutos de Huesos/metabolismo , Colágeno/metabolismo , Diáfisis/fisiología , Diáfisis/cirugía , Diáfisis/ultraestructura , Durapatita/metabolismo , Epífisis/fisiología , Epífisis/cirugía , Epífisis/ultraestructura , Fémur/fisiología , Fémur/cirugía , Fémur/ultraestructura , Nanopartículas de Magnetita/química , Masculino , Conejos , Tibia/fisiología , Tibia/cirugía , Tibia/ultraestructura , Ingeniería de Tejidos/métodos
19.
J Mech Behav Biomed Mater ; 10: 197-205, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22520431

RESUMEN

Multi-principal-element (TiZrNbHfTa)N and (TiZrNbHfTa)C coatings were deposited on Ti6Al4V alloy by co-sputtering of Ti, Zr, Nb, Hf and Ta metallic targets in reactive atmosphere. The coatings were analyzed for elemental and phase compositions, crystalline structure, morphology, residual stress, hardness, friction performance, wear-corrosion resistance and cell viability. For all the films, only simple fcc solid solutions with (111) preferred orientations were found, with crystallite sizes in the range 7.2-13.5 nm. The coatings were subjected to compressive stress, with values ranging from 0.8 to 1.6 GPa. The carbide coating with the highest carbon content (carbon/metal ≈1.3) exhibited the highest hardness of about 31 GPa, the best friction behavior (µ = 0.12) and the highest wear resistance (wear rate K=0.2×10(-6)mm(3)N(-1)m(-1)), when testing in simulated body fluids (SBFs). Cell viability tests proved that the osteoblast cells were adherent to the coated substrates, and a very high percentage of live cells were observed on sample surfaces, after 72 h incubation time.


Asunto(s)
Aleaciones/química , Materiales Biocompatibles Revestidos/química , Aleaciones/metabolismo , Aleaciones/toxicidad , Materiales Biomiméticos/metabolismo , Líquidos Corporales/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/metabolismo , Materiales Biocompatibles Revestidos/toxicidad , Corrosión , Hafnio/química , Humanos , Fenómenos Mecánicos , Niobio/química , Propiedades de Superficie , Tantalio/química , Titanio/química , Circonio/química
20.
Vet Res Commun ; 34 Suppl 1: S167-70, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20461461

RESUMEN

Control of the composition of products that are intended for use as packaging material is essential, particularly when these products come into direct contact with food. It is well known that plastics are not inert and that their residual monomers, starting substances, and additives are able to migrate into the food they contact. Among plastics, styrene is a common compound found in many plastic containers that can also be produced by the oxidation of Penicillium roqueforti used in gorgonzola Protected Denomination of Origin cheese manufacturing. Therefore, solid-phase microextraction combined with gas chromatography/mass spectrometry was applied in the present work to determine the styrene content in packaged and unpackaged gorgonzola cheese samples to understand styrene migration phenomena from plastic containers.


Asunto(s)
Proteínas Bacterianas/química , Queso/análisis , Análisis de los Alimentos/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Microextracción en Fase Sólida/métodos , Embalaje de Alimentos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...