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1.
Pharmaceutics ; 12(9)2020 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-32932682

RESUMO

The delivery of bioactive agents using active wound dressings for the management of pain and infections offers improved performances in the treatment of wound complications. In this work, solid lipid microparticles (SLMPs) loaded with lidocaine hydrochloride (LID) were processed and the formulation was evaluated regarding its ability to deliver the drug at the wound site and through the skin barrier. The SLMPs of glyceryl monostearate (GMS) were prepared with different LID contents (0, 1, 2, 4, and 10 wt.%) using the solvent-free and one-step PGSS (Particles from Gas-Saturated Solutions) technique. PGSS exploits the use of supercritical CO2 (scCO2) as a plasticizer for lipids and as pressurizing agent for the atomization of particles. The SLMPs were characterized in terms of shape, size, and morphology (SEM), physicochemical properties (ATR-IR, XRD), and drug content and release behavior. An in vitro test for the evaluation of the influence of the wound environment on the LID release rate from SLMPs was studied using different bioengineered human skin substitutes obtained by 3D-bioprinting. Finally, the antimicrobial activity of the SLMPs was evaluated against three relevant bacteria in wound infections (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa). SLMPs processed with 10 wt.% of LID showed a remarkable performance to provide effective doses for pain relief and preventive infection effects.

2.
J Biomed Mater Res A ; 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32506782

RESUMO

It is well-known that fibroblasts play a fundamental role in the contraction of collagen and fibrin hydrogels when used in the production of in vitro bilayered skin substitutes. However, little is known about the contribution of other factors, such as the hydrogel matrix itself, on this contraction. In this work, we studied the contraction of plasma-derived fibrin hydrogels at different temperatures (4, 23, and 37°C) in an isotonic buffer (phosphate-buffered saline). These types of hydrogels presented a contraction of approximately 30% during the first 24 hr, following a similar kinetics irrespectively of the temperature. This kinetics continued in a slowed down manner to reach a plateau value of 40% contraction after 10-15 days. Contraction of commercial fibrinogen hydrogels was studied under similar conditions and the kinetics was completed after 8 hr, reaching values between 20 and 70% depending on the temperature. We attribute these substantial differences to a modulatory effect on the contraction due to plasma proteins which are initially embedded in, and progressively released from, the plasma-based hydrogels. The elastic modulus of hydrogels measured at a constant frequency decreased with increasing temperature in 7-day gels. Rheological measurements showed the absence of a strain-hardening behavior in the plasma-derived fibrin hydrogels. Finally, plasma-derived fibrin hydrogels with and without human primary fibroblast and keratinocytes were prepared in transwell inserts and their height measured over time. Both cellular and acellular gels showed a height reduction of 30% during the first 24 hr likely due to the above-mentioned intrinsic fibrin matrix contraction.

3.
Molecules ; 25(6)2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32192041

RESUMO

This study aimed to assess the physicochemical, nutritional and sensory properties of gluten-free breads containing isolated coffee cascara dietary fiber (ICCDF) as a food ingredient. ICCDF was obtained by aqueous extraction. The oil and water holding capacity and the nutritional profile of the novel ingredient were determined. Its safety was certificated by analysis of ochratoxin A, caffeine and gluten. Gluten-free bread formulations were prepared enriching a commercial bakery premix in rice protein (8%) and ICCDF (3% and 4.5%). Nutritional profile of the novel gluten-free breads (dietary fiber, protein, amino acids, lipids, fatty acid profile and resistant starch), as well as bread volume, crumb density, moisture, firmness, elasticity and color intensity were determined. A sensory quantitative descriptive analysis of the breads was conducted using eight trained panelists. New breads showed significantly higher (p < 0.05) content of dietary fiber and protein than the control bread. The addition of ICCDF allowed increasing dough yield, a less crumb firmness and a higher crumb elasticity. The nutrition claims "source of protein and high in dietary fiber" were assigned to the new formulations. In conclusion, a certificated gluten-free bread with improved nutritional and physicochemical properties and good sensorial profile was obtained.

4.
Methods Mol Biol ; 2140: 217-228, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32207115

RESUMO

We describe an extrusion-based method to print a human bilayered skin using bioinks containing human plasma and primary human fibroblasts and keratinocytes from skin biopsies. We generate 100 cm2 of printed skin in less than 35 min. We analyze its structure using histological and immunohistochemical methods, both in in vitro 3D cultures and upon transplantation to immunodeficient mice. We have demonstrated that the printed skin is similar to normal human skin and indistinguishable from bilayered dermo-epidermal equivalents, previously produced manually in our laboratory and successfully used in the clinic.

5.
Rev. Univ. Ind. Santander, Salud ; 50(4): 296-306, oct.-dic. 2018. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1003141

RESUMO

Resumen Introducción: Son escasos los datos del impacto de la infección por el virus de inmunodeficiencia humana (VIH) a nivel hormonal, metabólico y hematológico en pacientes hospitalizados en Colombia. Objetivo: Describir el perfil hormonal, metabólico y hematológico de los pacientes con VIH hospitalizados en una institución de tercer nivel. Material y método: Estudio observacional de corte transversal, donde se incluyeron variables sociodemográficas, clínicas, hormonales, metabólicas y hematológicas de pacientes con VIH entre el 2013 y 2014. Resultados: Se incluyeron 52 pacientes, 34 hombres, con media de edad 39,7 años (Ds 12,6, Min: 21 Max: 79). 23% habían cursado con tuberculosis, 13% con toxoplasmosis cerebral. 26 pacientes tenían historia de consumo de tóxicos: cigarrillo (58%), alcohol (27%) y sustancias alucinógenas (15%). 14% de los pacientes recibían terapia antirretroviral al ingreso, los esquemas contenían principalmente inhibidores de proteasa. Otros medicamentos usados fueron: trimetoprim-sulfametoxazol (27.2%) y antituberculosos (15%). Las principales causas de hospitalización fueron toxoplasmosis cerebral (31%) y tuberculosis (15%). 52% de la población presentó síndrome de desgaste. El tiempo de diagnóstico del VIH fue <1 de un año en el 48% de la población. 79% de los pacientes tenía recuento de CD4 <200cel/mm3 (Ds 199, Min: 3 Max: 641). En el perfil hormonal, 58% (29 pacientes) presentaron alteración del eje tiroideo, de los cuales 14 presentaron perfil de hipotiroidismo central. 55,8% de los hombres presentaron hiperprolactinemia. El perfil metabólico se caracterizó por hipertrigliceridemia (44%) y HDL bajas (81%). La alteración electrolítica de mayor frecuencia fue hiponatremia (37%). Conclusiones: En la población de pacientes hospitalizados con VIH, se encontraron alteraciones endocrinas que sugieren compromiso glandular primario hipofisiario y adrenal; alteraciones lipídicas y electrolíticas en gran medida relacionadas con enfermedad avanzada.


Abstract Introduction: Data on the impact of human immunodeficiency virus (HIV) infection on a hormonal, metabolic and haematological level in patients hospitalized in Colombia are scarce. Objective: To describe the hormonal, metabolic and haematological profile of HIV patients hospitalized in a third level institution. Material and method: Cross-sectional observational study, which included sociodemographic, clinical, hormonal, metabolic and hematological variables of patients with HIV between 2013 and 2014. Results: We included 52 patients, 34 men, with an average age of 40 years (SD 12.6, Min: 21 Max: 79). 23% had tuberculosis, 13% had cerebral toxoplasmosis. 26 patients had a history of toxic consumption: cigarette (58%), alcohol (27%) and hallucinogenic substances (15%). 14% of the patients received antiretroviral therapy at admission, mainly with protease inhibitors. Other medications used were: trimethoprim-sulfamethoxazole (27.2%) and antituberculous drugs (15%). The main causes of hospitalization were cerebral toxoplasmosis (31%) and tuberculosis (15%). 52% of the population had Wasting syndrome. The time of diagnosis of HIV was <1 year in 48% of the population. 79% of the patients had a CD4 count <200 cell/mm3 (SD 199, Min: 3 Max: 641). In the hormonal profile, 58% (29 patients) presented alteration of the thyroid axis, of which 14 session profile of central hypothyroidism. 55.8% of men had hyperprolactinemia. The metabolic profile was characterized by hypertriglyceridemia (44%) and low HDL (81%). The most frequent electrolyte alteration was hyponatremia (37%). Conclusions: In the population of patients hospitalized with HIV, endocrine alterations were found suggesting primary glandular, pituitary and adrenal involvement, with lipid and electrolyte alterations largely related to advanced disease.


Assuntos
Humanos , HIV , Colômbia , Eletrólitos , Hormônios , Hospitalização
6.
Molecules ; 23(9)2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-30223585

RESUMO

Non-planar amides are usually transitional structures, that are involved in amide bond rotation and inversion of the nitrogen atom, but some ground-minimum non-planar amides have been reported. Non-planar amides are generally sensitive to water or other nucleophiles, so that the amide bond is readily cleaved. In this article, we examine the reactivity profile of the base-catalyzed hydrolysis of 7-azabicyclo[2.2.1]heptane amides, which show pyramidalization of the amide nitrogen atom, and we compare the kinetics of the base-catalyzed hydrolysis of the benzamides of 7-azabicyclo[2.2.1]heptane and related monocyclic compounds. Unexpectedly, non-planar amides based on the 7-azabicyclo[2.2.1]heptane scaffold were found to be resistant to base-catalyzed hydrolysis. The calculated Gibbs free energies were consistent with this experimental finding. The contribution of thermal corrections (entropy term, ⁻TΔS‡) was large; the entropy term (ΔS‡) took a large negative value, indicating significant order in the transition structure, which includes solvating water molecules.


Assuntos
Amidas/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Nitrogênio/química , Catálise , Entropia , Hidrólise , Cinética , Modelos Moleculares , Estrutura Molecular
7.
Biofabrication ; 9(1): 015006, 2016 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-27917823

RESUMO

Significant progress has been made over the past 25 years in the development of in vitro-engineered substitutes that mimic human skin, either to be used as grafts for the replacement of lost skin, or for the establishment of in vitro human skin models. In this sense, laboratory-grown skin substitutes containing dermal and epidermal components offer a promising approach to skin engineering. In particular, a human plasma-based bilayered skin generated by our group, has been applied successfully to treat burns as well as traumatic and surgical wounds in a large number of patients in Spain. There are some aspects requiring improvements in the production process of this skin; for example, the relatively long time (three weeks) needed to produce the surface required to cover an extensive burn or a large wound, and the necessity to automatize and standardize a process currently performed manually. 3D bioprinting has emerged as a flexible tool in regenerative medicine and it provides a platform to address these challenges. In the present study, we have used this technique to print a human bilayered skin using bioinks containing human plasma as well as primary human fibroblasts and keratinocytes that were obtained from skin biopsies. We were able to generate 100 cm2, a standard P100 tissue culture plate, of printed skin in less than 35 min (including the 30 min required for fibrin gelation). We have analysed the structure and function of the printed skin using histological and immunohistochemical methods, both in 3D in vitro cultures and after long-term transplantation to immunodeficient mice. In both cases, the generated skin was very similar to human skin and, furthermore, it was indistinguishable from bilayered dermo-epidermal equivalents, handmade in our laboratories. These results demonstrate that 3D bioprinting is a suitable technology to generate bioengineered skin for therapeutical and industrial applications in an automatized manner.


Assuntos
Bioimpressão/métodos , Pele/patologia , Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Diferenciação Celular , Sobrevivência Celular , Células Cultivadas , Fibrina/química , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Camundongos , Camundongos Nus , Próteses e Implantes , Regeneração
8.
Cytometry B Clin Cytom ; 90(6): 543-545, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-25612555

RESUMO

Double-hit lymphoma (DHL) is a rare type of lymphoma with concurrent chromosomal translocations of C-MYC with BCL2 or BCL6, associated with unfavorable prognosis. We describe a case of DHL in a 79-year-old female patient previously diagnosed with diffuse large B-cell lymphoma (DLBCL) with an early relapse in the ascitic fluid. A seven-color multiparametric flow cytometry immunophenotyping study of the ascitic fluid was carried out, and revealed 99.78% of large in size and high cellular complexity B-cells positive for CD19, CD10 (64.27%), CD45 dim, CD22 dim, CD25 (60%), CD43 bright, CD38 bright, and IgM (18.53%); and negative for CD20, CD5, CD23, CD79b, CD103, CD200, CD11c, and FMC7, and 78.99% without light chain expression and 21% with Lambda chain restriction. Due to the expression of CD19 and CD10 with overexpression of BCL-2 protein and due to CD43 and CD38 positivity detected, those cells showed features between DLBCL and Burkitt lymphoma. Fluorescence in situ hybridization (FISH) confirmed both c-MYC/IGH and BCL2/IGH rearrangement. Our findings may help to identify cases requiring additional cytogenetic analysis. © 2015 International Clinical Cytometry Society.


Assuntos
Líquido Ascítico/patologia , Citometria de Fluxo/métodos , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/patologia , Idoso , Linfoma de Burkitt/diagnóstico , Linfoma de Burkitt/patologia , Feminino , Humanos , Imunofenotipagem/métodos
9.
Clin Chem Lab Med ; 54(4): 553-60, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26485748

RESUMO

BACKGROUND: Structural hemoglobinopathies do not usually have a clinical impact, but they can interfere with the analytical determination of some parameters, such as the glycated hemoglobin in diabetic patients. Thalassemias represent a serious health problem in areas where their incidence is high. The defects in the post-translational modifications produce hyper-unstable hemoglobin that is not detected by most of electrophoretic or chromatographic methods that are available so far. METHODS: We studied seven patients who belong to six unrelated families. The first two families were studied because they had peak abnormal hemoglobin (Hb) during routine analytical assays. The other four families were studied because they had microcytosis and hypochromia with normal HbA2 and HbF without iron deficiency. HbA2 and F quantification and abnormal Hb separation were performed by chromatographic and electrophoretic methods. The molecular characterization was performed using specific sequencing. RESULTS: The Hb Puerta del Sol presents electrophoretic mobility and elution in HPLC that is different from HbA and similar to HbS. The electrophoretic and chromatographic profiles of the four other variants are normal and do not show any anomalies, and their identification was only possible with sequencing. CONCLUSIONS: Some variants, such as Hb Valdecilla, Hb Gran Vía, Hb Macarena and Hb El Retiro, have significant clinical impact when they are associated with other forms of α-thalassemia, which could lead to more serious forms of this group of pathologies as for HbH disease. Therefore, it is important to maintain an adequate program for screening these diseases in countries where the prevalence is high to prevent the occurrence of severe forms.


Assuntos
Hemoglobinopatias/genética , Hemoglobinas/análise , Hemoglobinas/genética , Adulto , Idoso de 80 Anos ou mais , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Testes Hematológicos , Hemoglobinopatias/sangue , Hemoglobinas/química , Humanos , Lactente , Masculino , Pessoa de Meia-Idade
10.
Med. clín (Ed. impr.) ; 144(1): 26-29, ene. 2015. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-131127

RESUMO

Fundamento y objetivo: El control de la diabetes mellitus se realiza mediante la determinación de hemoglobina glucosilada (HbA1c) por cromatografía líquida de alta resolución. Algunas variantes estructurales de la hemoglobina (Hb) son conocidas por causar interferencia analítica en la medición de la HbA1c. Pacientes y métodos: En este estudio se ha caracterizado una nueva variante de Hb en 4 pacientes, que se detectó al realizarse un control de HbA1c. Resultados: La secuenciación selectiva del gen α1 mostró una mutación responsable del cambio de ácido aspártico (Asp) por asparagina (Asn) en el codón 64. El cambio de Asp por Asn no produce ninguna alteración funcional de la Hb y se comporta como una hemoglobinopatía silente. Conclusión: Las variantes estructurales de la Hb se pueden detectar durante la medición de la HbA1c y pueden alterar sus valores. Estos casos, aunque poco frecuentes, requieren examinar a fondo los cromatogramas para detectar posibles interferencias (AU)


Background and objective: The glycated hemoglobin (HbA1c) test by high performance liquid chromatography is a useful tool for the follow-up of diabetes mellitus patients. Some structural hemoglobin (Hb) variants are known to cause interference in the analytical measurement of HbA1c. Patients and methods: In this study, it has been characterized a new Hb variant in 4 patients during their regular control of HbA1c. Results: Selective α1 gene sequencing showed a mutation GAC > AAC at codon 64 within exon 2. This produces a change of aspartic acid (Asp) by asparagine (Asn) that does not produce any functional alteration so the resultant molecule behaves as a silent hemoglobinopathy. Conclusion: The structural Hb variants can be detected during the analysis of HbA1c and may alter its values. Though rare, this occurrence signals the need to being aware when measuring HbA1 (AU)


Assuntos
Humanos , Diabetes Mellitus/fisiopatologia , Hemoglobina A Glicada/análise , Hemoglobinopatias/fisiopatologia , Sequência de Bases/genética , Cromatografia Líquida de Alta Pressão
11.
J Colloid Interface Sci ; 441: 90-7, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25490568

RESUMO

HYPOTHESIS: Microfluidic techniques are expected to provide narrower particle size distribution than conventional methods for the preparation of poly (lactic-co-glycolic acid) (PLGA) microparticles. Besides, it is hypothesized that the particle size distribution of poly (lactic-co-glycolic acid) microparticles influences the settling behavior and rheological properties of its aqueous dispersions. EXPERIMENTS: For the preparation of PLGA particles, two different methods, microfluidic and conventional oil-in-water emulsification methods were employed. The particle size and particle size distribution of PLGA particles prepared by microfluidics were studied as a function of the flow rate of the organic phase while particles prepared by conventional methods were studied as a function of stirring rate. In order to study the stability and structural organization of colloidal dispersions, settling experiments and oscillatory rheological measurements were carried out on aqueous dispersions of PLGA particles with different particle size distributions. FINDINGS: Microfluidics technique allowed the control of size and size distribution of the droplets formed in the process of emulsification. This resulted in a narrower particle size distribution for samples prepared by MF with respect to samples prepared by conventional methods. Polydisperse samples showed a larger tendency to aggregate, thus confirming the advantages of microfluidics over conventional methods, especially if biomedical applications are envisaged.


Assuntos
Ácido Láctico/química , Microfluídica , Ácido Poliglicólico/química , Emulsões , Ácido Láctico/síntese química , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Ácido Poliglicólico/síntese química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Reologia , Água/química
12.
Med Clin (Barc) ; 144(1): 26-9, 2015 Jan 06.
Artigo em Espanhol | MEDLINE | ID: mdl-25458507

RESUMO

BACKGROUND AND OBJECTIVE: The glycated hemoglobin (HbA1c) test by high performance liquid chromatography is a useful tool for the follow-up of diabetes mellitus patients. Some structural hemoglobin (Hb) variants are known to cause interference in the analytical measurement of HbA1c. PATIENTS AND METHODS: In this study, it has been characterized a new Hb variant in 4 patients during their regular control of HbA1c. RESULTS: Selective α1 gene sequencing showed a mutation GAC>AAC at codon 64 within exon 2. This produces a change of aspartic acid (Asp) by asparagine (Asn) that does not produce any functional alteration so the resultant molecule behaves as a silent hemoglobinopathy. CONCLUSION: The structural Hb variants can be detected during the analysis of HbA1c and may alter its values. Though rare, this occurrence signals the need to being aware when measuring HbA1c.


Assuntos
Substituição de Aminoácidos , Diabetes Mellitus/sangue , Hemoglobina A Glicada/análise , Hemoglobinas Anormais/genética , Mutação de Sentido Incorreto , Mutação Puntual , alfa-Globinas/genética , Idoso , Idoso de 80 Anos ou mais , Artefatos , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Códon/genética , Diabetes Mellitus/genética , Éxons/genética , Genótipo , Hemoglobina A Glicada/química , Hemoglobinas Anormais/química , Humanos , Masculino , Análise de Sequência de DNA
13.
Carbohydr Polym ; 111: 348-55, 2014 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-25037360

RESUMO

The preparation of composite biopolymer hydrogels offers the capability to produce biocompatible and biodegradable materials with cooperative properties. In this paper, two natural polymers, namely, chitosan and agarose were employed to prepare composite hydrogels with dual pH and temperature properties. The elastic modulus of the composite hydrogels increased with agarose concentration reaching the value of 1 kPa for the chitosan/agarose gel with a 2% (w/v) concentration of agarose. In addition, composite gels exhibited a higher stability in acidic aqueous solutions, in comparison with agarose gels. The drug release properties of the composite hydrogels were tested by loading a model anticancer drug, 5-Fluorouracil, in the hydrogel interior. At pH=7.4, the cumulative release of 5-FU was ∼ 50% within 96 h and decreased to ∼ 33% at pH = 5.2, which was attributed to the different solubility of 5-FU as a function of pH. The preparation of composite microgels with controllable dimensions in the range from 42 to 18 µm and with narrow size distribution (polidispersity not exceeding 1.5%) was achieved by the microfluidic emulsification of an aqueous mixture of chitosan and agarose and subsequent gelation of the precursor droplets by cooling.


Assuntos
Quitosana/química , Hidrogéis/química , Sefarose/química , Portadores de Fármacos/química , Fluoruracila/química , Técnicas Analíticas Microfluídicas
14.
Biomacromolecules ; 15(7): 2419-25, 2014 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-24931723

RESUMO

To develop an understanding of the nature of complex, spatiotemporal interactions between cells and the extracellular matrix (ECM), artificial ECMs formed from hydrogels with a particular spectrum of properties are being developed at a rapid pace. We report the microfluidic generation of small, monodisperse composite agarose-gelatin hydrogel modules (microgel particles) that can be used for cell encapsulation and can serve as instructive cellular microenvironments. The agarose component of the microgels gelled under reduced temperature, while gelatin modified with phenolic hydroxyl groups underwent peroxidase-catalyzed gelation. Microgel composition, structure, morphology, and rigidity were tuned in a high-throughput manner. The results of this work are important for the generation of libraries of cell-laden polymer microgels for single-cell analysis, tissue engineering, and fundamental studies of the role of local microenvironments in cell fate.


Assuntos
Biopolímeros/química , Hidrogéis/química , Fenômenos Mecânicos , Microfluídica , Matriz Extracelular/química , Gelatina/química , Sefarose/química , Análise de Célula Única , Engenharia Tecidual
15.
J Biomater Sci Polym Ed ; 24(3): 253-68, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23565646

RESUMO

A series of poly-(N-isopropyl acrylamide)-based copolymers were developed with a view to biomedical applications, specifically cell cultivation and recovery. Ethylpyrrolidone methacrylate (EPM), the monomer of poly-(ethylpyrrolidone methacrylate) (pEPM), which is itself thermoresponsive, was copolymerized with N-isopropylacrylamide in varying ratios to create this novel thermoresponsive copolymer series. Characterization indicated a moderate increase of copolymer lower critical solution temperature with increasing EPM content. Films of the copolymers successfully hosted cells to monolayer. Cells detached from the copolymers upon temperature reduction with cell to cell junctions maintained, avoiding the damage which can be caused using conventional detachment techniques. These results indicate that these copolymers are highly cell compatible and may be useful for a range of biomedical applications.


Assuntos
Resinas Acrílicas/síntese química , Resinas Acrílicas/farmacologia , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Temperatura , Células 3T3 , Resinas Acrílicas/química , Animais , Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Técnicas de Química Sintética , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Camundongos
16.
Lab Chip ; 13(13): 2547-53, 2013 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-23407698

RESUMO

Microfluidics (MFs) offers a promising method for the preparation of polymer microgels with exquisite control over their dimensions, shapes and morphologies. A challenging task in this process is the generation of droplets (precursors for microgels) from highly viscous polymer solutions. Spatial separation of MF emulsification and gelation of the precursor droplets on chip can address this challenge. In the present work, we explored the application of the "direct injection" method for the preparation of microgels by adding a highly concentrated polymer solution or a gelling agent directly into the precursor droplets. In the first system, primary droplets were generated from a dilute aqueous solution of agarose, followed by the injection of the concentrated agarose solution directly in the primary droplets. The secondary droplets served as precursors for microgels. In the second system, primary droplets were generated from the low-viscous solution of methyl-ß-cyclodextrin and poly(ethylene glycol) end-terminated with octadecyl hydrophobic groups. Addition of surfactant directly into the primary droplets led to the binding of methyl-ß-cyclodextrin to the surfactant, thereby releasing hydrophobized poly(ethylene glycol) to form polymer microgels. Our results show that, when optimized, the direct injection method can be used for microgel preparation from highly viscous liquids and thus this method expands the range of polymers used for MF generation of microgels.


Assuntos
Géis/química , Microfluídica/métodos , Polímeros/química , Microfluídica/instrumentação , Polietilenoglicóis/química , Sefarose/química , Tensoativos/química , beta-Ciclodextrinas/química
18.
Endodoncia (Madr.) ; 30(4): 171-177, oct.-dic. 2012.
Artigo em Espanhol | IBECS | ID: ibc-117495

RESUMO

Objetivo: Calibrar y determinar cuál es el diámetro apical adecuado en función del caso y del tipo de conducto. Para llegar a determinar el diámetro apical adecuado nos propusimos, por un lado, valorar si el preflaring facilita la instrumentación apical, y por otro, verificar si los conductos pueden ser instrumentados a tamaños ISO mayores a los que habitualmente lo son. Material y métodos: Después de realizar una preparación del tercio coronal de 40 conductos mesiales (mv-ml) de 23 molares inferiores exodonciados mediante instrumentación rotatoria, se determinó la longitud de trabajo (LT) tras la cual se llevó a cabo la preparación apical. Para ello, se instrumentó (manualmente) en primer lugar, el conducto a LT-1 mm para eliminar cualquier tipo de interferencia posterior entre las limas y el propio conducto. Una vez finalizado dicho ensanchamiento, se procedió a repermeabilizar el conducto y continuar con la preparación apical a LT (manualmente). Nuestros datos se analizaron estadísticamente por medio del test de ANOVA y t de Student. Resultados: De la muestra estudiada, los datos obtenidos fueron que de un 87,5% de los conductos (35) su diámetro apical se encontraba entre 0,30 y 0,35 mm (30-35 ISO) (15 y 20 conductos respectivamente), el 10% de los conductos (4) tenían un diámetro apical de 0,40 mm (40 ISO) y el 2,5% restante de los conductos (1) se correspondían con un diámetro apical de 0,25 mm (25 ISO). Conclusiones: Se debe tratar de alcanzar un diámetro apical adecuado que nos permite el paso de irrigantes y conseguir así un desbridamiento químico y mécanico del conducto y del periápice, pero sin debilitar en exceso el conducto, De ahí la importancia del ensanche del tercio coronal (preflaring) y del equilibrio de los binomios instrumentación-irrigantes y limpieza-debilitamiento (AU)


Objetive: To calibrate and determine the appropriate apical diameter regarding to the case and the type of root canal. In other to determine the appropriate apical diameter, first of all we set out to assess whether or not the apical instrumentation facilitates preflaring and secondly, to verify if root canal can be instrumented to ISO sizes larger than the ones usually used. Material and Methods: After performing an expansion of the coronal third of 40 mesial root canals (mv-ml) of 23 extracted lower molars done by mechanical instrumentation, we investigated the working length (WL) in which the apical preparation was conducted. To that end, the duct first was implemented (manually) to 1mm above the working length WL) so any further interference between the files and the duct itself would be eliminated. Having completed this enlargement, we continue to working the canal and proceed to the apical preparation to WL (manually). Results. Of the sample studied, data obtained was that 87.5% of the ducts (35) apical diameter was between 0,30 and 0,35 mm (30-35 ISO) (15 and 20 channels respectively), 10% of the ducts (4) had an apical diameter of 0,40 mm the remaining 2.5% of the tubes (1) correspond to apical diameter of 0,25 mm (25 ISO). Conclusions. Proper apical diameter should be obtain in order to let the irrigants flow trough the canal and thereby achieving a chemical and mechanical debridement of the canal and the periapical, but without excessively weaken the canal. That is the reason of the importance of widening the coronal third of the duct (opreflaring) and the balance of the binomial-instrumentation irrigants and cleaning-weakening (AU)


Assuntos
Humanos , Tecido Periapical/anatomia & histologia , Obturação do Canal Radicular/métodos , Tratamento do Canal Radicular/métodos , Preparo de Canal Radicular/instrumentação , Materiais Restauradores do Canal Radicular/uso terapêutico , Instrumentos Odontológicos
20.
Small ; 8(11): 1633-42, 2012 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-22467645

RESUMO

In this Concept article, recent advances in microfluidic platforms for the generation of cell-laden hydrogel particles (microgels) are reported. Advances in the continuous microfluidic encapsulation of cells in droplets and microgels are critically reviewed, and currently used methods for the encapsulation of cells in polymer microgels are discussed. An outlook on current applications and future directions in this field of research are also presented. This article will be of interest to chemists, materials scientists, cell biologists, bioengineers, and pharmacologists.


Assuntos
Hidrogel de Polietilenoglicol-Dimetacrilato/química , Microfluídica/métodos , Polímeros/química
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