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1.
ACS Biomater Sci Eng ; 9(12): 6632-6643, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37982239

RESUMO

Atmospheric pressure plasma treatments are nowadays gaining importance to improve the performance of biomaterials in the orthopedic field. Among those, magnesium phosphate-based cements (MPCs) have recently shown attractive features as bone repair materials. The effect of plasma treatments on such cements, which has not been investigated so far, could represent an innovative strategy to modify MPCs' physicochemical properties and to tune their interaction with cells. MPCs were prepared and treated for 5, 7.5, and 10 min with a cold atmospheric pressure plasma jet. The reactive nitrogen and oxygen species formed during the treatment were characterized. The surfaces of MPCs were studied in terms of the phase composition, morphology, and topography. After a preliminary test in simulated body fluid, the proliferation, adhesion, and osteogenic differentiation of human mesenchymal cells on MPCs were assessed. Plasma treatments induce modifications in the relative amounts of struvite, newberyite, and farringtonite on the surfaces on MPCs in a time-dependent fashion. Nonetheless, all investigated scaffolds show a good biocompatibility and cell adhesion, also supporting osteogenic differentiation of mesenchymal cells.


Assuntos
Osteogênese , Fosfatos , Humanos , Teste de Materiais , Fosfatos/farmacologia , Fosfatos/química , Pressão Atmosférica
2.
J Colloid Interface Sci ; 598: 24-35, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33892441

RESUMO

HYPOTHESIS: Among all the materials used so far to replace and repair damaged bone tissues, magnesium silicate bioceramics are one of the most promising, thanks to their biocompatibility, osteoinductive properties and good mechanical stability. EXPERIMENTS: Magnesium silicate cement pastes were prepared by hydration of MgO mixed with different SiO2 batches at different Mg/Si molar ratios. Pastes were either moulded or 3D printed to obtain set cements that were then calcined at 1000 °C to produce biologically relevant ceramic materials. Both cements and ceramics were characterized by means of X-ray diffraction, while two selected formulations were thoroughly characterized by means of injectability tests, Raman confocal microscopy, scanning electron microscopy, atomic force microscopy, gas porosimetry, X-ray microtomography and compressive tests. FINDINGS: The results show that bioceramic scaffolds, namely forsterite and clinoenstatite, can be effectively obtained by 3D printing MgO/SiO2 cement pastes, paving the way towards important advances in the field of bone tissue engineering.


Assuntos
Magnésio , Alicerces Teciduais , Materiais Biocompatíveis , Cerâmica , Teste de Materiais , Dióxido de Silício , Engenharia Tecidual
3.
J Colloid Interface Sci ; 589: 367-377, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33476891

RESUMO

HYPOTHESIS: Endogenous Amorphous Magnesium-Calcium Phosphates (AMCPs) form in the human body and, besides their biomedical implications, the development of effective stabilization strategies is an open challenge. An interesting approach consists of stabilizing amorphous phosphates with macromolecules that have beneficial effects from a nutritional/medical point of view, for a potential application of the hybrid particles in nutraceutics or drug delivery. EXPERIMENTAL: We investigated the effect of proteins extracted from Moringa oleifera seeds (MO) on the features of synthetic analogs of AMCPs and on their crystallization pathway. The stability of the amorphous phase was studied using infrared spectroscopy and X-ray diffraction. To unravel the effect of the protein on the nano-scale structure of the inorganic particles, we also studied how MO affects the features of the amorphous phase using thermal analysis, small angle X-ray scattering and confocal Raman microscopy. FINDINGS: We observed that MO markedly delays the transition from amorphous to crystalline phosphate in a concentration-dependent fashion. Interestingly, MO not only enhances the lifetime of the amorphous phase, but also influences the type and amount of crystalline material formed. The results are relevant from both a fundamental and an applied perspective, paving the way for the use of these hybrids in the field of nutraceutics and drug delivery.


Assuntos
Moringa oleifera , Nanopartículas , Preparações Farmacêuticas , Fosfatos de Cálcio , Cristalização , Humanos , Magnésio , Fosfatos , Sementes , Difração de Raios X
4.
Materials (Basel) ; 13(14)2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679758

RESUMO

The ingress of water, as a vehicle for many harmful substances, is the main cause of all the major physical and chemical degradation processes affecting concrete buildings. To prevent damage and protect concrete surfaces, coatings are generally used. Cement-based coatings in particular can act as a physical barrier and reduce the permeability of surfaces. In case of chloride-induced corrosion, corrosion inhibitors are also generally used, and nano-carriers have been proven to provide a long-term protective effect. In this work, we designed a surface protection cementitious coating enhanced with nano-silica and halloysite nanotubes (HNTs). HNTs were loaded with a corrosion inhibitor, benzotriazole (BTA), and used as nano-reservoir, while nano-silica was used to improve the structure of the protective coating and to strengthen its adhesion to the surface of application. The cementitious coatings were characterized with a multi-technique approach including thermal and spectroscopic analysis, scanning electron microscopy, specific surface area and pore size distribution, and Vickers hardness test. The release of BTA was monitored through UV-vis analysis, and the transportation of BTA through coated mortars was studied in simulated rain conditions. We evidenced that the presence of silica densifies the porous structure and increases the interfacial bond strength between the protective coating and the surface of application. We report here, for the first time, that HNTs can be used as nano-carriers for the slow delivery of anti-corrosion molecules in cement mortars.

6.
Rheumatol Int ; 38(Suppl 1): 251-258, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29637324

RESUMO

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Italian language.The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents.The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability, and construct validity (convergent and discriminant validity).A total of 1296 JIA patients (7.2% systemic, 59.5% oligoarticular, 21.4% RF negative polyarthritis, 11.9% other categories) and 100 healthy children, were enrolled in 18 centres. The JAMAR components discriminated well healthy subjects from JIA patients except for the Health Related Quality of Life (HRQoL) Psychosocial Health (PsH) subscales. All JAMAR components revealed good psychometric performances.In conclusion, the Italian version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research.


Assuntos
Artrite Juvenil/diagnóstico , Avaliação da Deficiência , Medidas de Resultados Relatados pelo Paciente , Reumatologia/métodos , Adolescente , Idade de Início , Artrite Juvenil/fisiopatologia , Artrite Juvenil/psicologia , Artrite Juvenil/terapia , Estudos de Casos e Controles , Criança , Pré-Escolar , Características Culturais , Feminino , Nível de Saúde , Humanos , Itália , Masculino , Pais/psicologia , Pacientes/psicologia , Valor Preditivo dos Testes , Prognóstico , Psicometria , Qualidade de Vida , Reprodutibilidade dos Testes , Tradução
7.
Langmuir ; 34(6): 2205-2218, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29035549

RESUMO

Cement is produced by mixing mineral phases based on calcium silicates and aluminates with water. The hydration reaction of the mixture leads to a synthetic material with outstanding properties that can be used as a binder for construction applications. Despite the importance of cement in society, for a long time, the chemical reactions involved in its hydration remained poorly understood as a result of the complexity of hydration processes, nanostructure, and transport phenomena. This feature article reviews the recently obtained results using water as a probe to detail the essential features in the setting process. By examining the peculiar physicochemical properties of water, fundamental information on the evolving inorganic colloid matrix can be deduced, ranging from the fractal nanostructure of the inorganic silicate framework to the transport phenomena inside the developing porosity. A similar approach can be transferred to the investigation of a plethora of other complex systems, where water plays the main role in determining the final structural and transport properties (i.e., biomaterials, hydrogels, and colloids).

8.
Nat Commun ; 7: 13646, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27929089

RESUMO

A challenge in molecular spintronics is to control the magnetic coupling between magnetic molecules and magnetic electrodes to build efficient devices. Here we show that the nature of the magnetic ion of anchored metal complexes highly impacts the exchange coupling of the molecules with magnetic substrates. Surface anchoring alters the magnetic anisotropy of the cobalt(II)-containing complex (Co(Pyipa)2), and results in blocking of its magnetization due to the presence of a magnetic hysteresis loop. In contrast, no hysteresis loop is observed in the isostructural nickel(II)-containing complex (Ni(Pyipa)2). Through XMCD experiments and theoretical calculations we find that Co(Pyipa)2 is strongly ferromagnetically coupled to the surface, while Ni(Pyipa)2 is either not coupled or weakly antiferromagnetically coupled to the substrate. These results highlight the importance of the synergistic effect that the electronic structure of a metal ion and the organic ligands has on the exchange interaction and anisotropy occurring at the molecule-electrode interface.

9.
Respiration ; 77(3): 265-72, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19075557

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by a combination of 3 different disorders, namely chronic asthma, chronic bronchitis and pulmonary emphysema, sometimes simultaneously present in the same subject. OBJECTIVES: The aim of our study was to compare sputum inflammatory markers in patients with different phenotypes of chronic airway obstruction. METHODS: Forty-five subjects (forced expiratory volume in 1 s/vital capacity, FEV(1)/VC: 58.8 +/- 12.2%; FEV(1): 49.8 +/- 11.5% of predicted) were classified as chronic asthma (n = 10) or COPD patients (n = 35); the latter were further divided into patients with prevalent chronic bronchitis (n = 24) or prevalent pulmonary emphysema (n = 11) according to clinical history and functional evaluation, and underwent sputum induction and analysis of inflammatory cell and soluble mediators. RESULTS: Patients with chronic asthma showed higher sputum eosinophil percentages and eosinophilic cationic protein levels, and lower neutrophil percentages and neutrophil elastase levels than COPD patients. Neutrophil chemotactic activity in sputum supernatant was higher than the pool of normal subjects both in chronic asthma and COPD patients. No difference in sputum cell composition and levels of soluble mediators was observed between patients with chronic bronchitis and patients with pulmonary emphysema. CONCLUSIONS: The pattern of airway inflammation in induced sputum of patients with chronic asthma is different from that of COPD patients with a similar FEV(1). Among COPD patients, however, the pattern of airway inflammation shows no difference between chronic bronchitis and patients with pulmonary emphysema, suggesting that these two clinically and functionally distinct phenotypes share a common inflammatory pattern as detected by induced sputum.


Assuntos
Asma/diagnóstico , Biomarcadores/metabolismo , Bronquite Crônica/diagnóstico , Enfisema Pulmonar/diagnóstico , Escarro/metabolismo , Idoso , Asma/imunologia , Asma/metabolismo , Bronquite Crônica/imunologia , Bronquite Crônica/metabolismo , Proteína Catiônica de Eosinófilo/metabolismo , Feminino , Granulócitos/citologia , Humanos , Interleucina-8/metabolismo , Elastase de Leucócito/metabolismo , Masculino , Pessoa de Meia-Idade , Fenótipo , Enfisema Pulmonar/imunologia , Enfisema Pulmonar/metabolismo , Escarro/citologia , Escarro/imunologia
10.
Pulm Pharmacol Ther ; 16(6): 355-60, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14580927

RESUMO

The aim of this study was to assess the distribution of the occurrence of tolerance to the protective effect of salmeterol on allergen challenge in a large sample of asthmatic subjects. We investigated 53 subjects (45 male and eight female), mean age 24+/-8.2 years, with mild intermittent asthma, in stable phase of the disease, never previously treated with regular beta2-agonists. All subjects with a previous positive early airway response (EAR) to a screening allergen challenge underwent, in double blind randomized, cross-over manner, three further allergen challenges: after placebo (T0), after a single dose (50 microg) of inhaled salmeterol (T1), and after regular treatment with inhaled salmeterol (50 microg bid) for 1 week (T2). All subjects showed an EAR after placebo treatment (T0), and were completely protected against EAR by the single dose of salmeterol (T1). After 1-week regular treatment with salmeterol (T2). 24 out of 53 subjects (45%) were still protected, whereas 29 subjects (55%) showed a significant EAR. The distribution of the response to allergen challenge, which was quite homogeneous at T0 and T1, showed considerable heterogeneity at T2. Tolerance to the protective effect of salmeterol on allergen challenge can be observed in a large group of previously untreated mild asthmatic subjects. This phenomenon is heterogeneously distributed, with some subjects still showing a complete protection similar to that obtained after a single dose of salmeterol and others showing a response similar to that obtained after placebo. The reason of this heterogeneity needs to be elucidated.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Albuterol/análogos & derivados , Albuterol/farmacologia , Asma/tratamento farmacológico , Tolerância a Medicamentos , Administração por Inalação , Agonistas Adrenérgicos beta/administração & dosagem , Adulto , Resistência das Vias Respiratórias , Albuterol/administração & dosagem , Testes de Provocação Brônquica , Estudos Cross-Over , Método Duplo-Cego , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Xinafoato de Salmeterol
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