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Id: biblio-1285573
Autor: Kelte Filho, Irineo; Machado, Christiane Schineider; Diedrich, Camila; Karam, Thaysa Ksiaskiewcz; Nakamura, Celso Vataru; Khalil, Najeh Maissar; Mainardes, Rubiana Mara.
Título: Optimized Chitosan-Coated Gliadin Nanoparticles Improved the Hesperidin Cytotoxicity over Tumor Cells
Fonte: Braz. arch. biol. technol;64(spe):e21200795, 2021. tab, graf.
Idioma: en.
Projeto: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; . Conselho Nacional de Desenvolvimento Científico e Tecnológico.
Resumo: Abstract Hesperidin is a natural compound which is found in citric fruits and presents antitumor and antimicrobial activities. However, the in vivo efficacy of Hesperidin is reduced due to its low oral bioavailability. Protein-based nanoparticles have been applied to improve biological parameters of drugs and natural compounds. Gliadin is a monomeric protein present in wheat. In this study, gliadin-based nanoparticles containing hesperidin were obtained by desolvation technique and a Taguchi orthogonal array design was employed to optimize the formulation. The independent variables were set as concentration of CaCl2 (0.5; 1 or 2%) and stabilizing agent (Pluronic F68, Tween 80 or sodium caseinate). The dependent variables consisted of mean diameter, polydispersity index, zeta potential, and encapsulation efficiency. The results showed significant effects on the dependent variables when 1% CaCl2 and Pluronic F68 were used. The optimized formulation was coated with chitosan to increase the physical stability of the nanoparticles. The final nanoparticles presented a mean diameter of 321 nm and polydispersity index of 0.217, and spherical shape. After coating, the Zeta potential was +21 mV, and the encapsulation efficiency was 73 %. The in vitro release assay showed that about 98% of the drug was released from the nanoparticles after 48 h. Moreover, the nanoparticles reduced hesperidin cytotoxicity on healthy cells (Vero cells) and improved the cytotoxicity on tumor cells (HeLa, PC-3 and Caco-2 cells). Results showed that the chitosan-coated gliadin nanoparticles are potential carriers for hesperidin delivery for cancer treatment.
Descritores: Quitosana/química
Gliadina/química
Hesperidina/farmacologia
Neoplasias/tratamento farmacológico
-Nanopartículas
Responsável: BR1.1 - BIREME


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Id: biblio-1249176
Autor: Gonçalves, Melissa Marques; Carneiro, Jaqueline; Justus, Barbara; Espinoza, Joel Toribio; Budel, Jane Manfron; Farago, Paulo Vitor; Paula, Josiane Padilha de.
Título: Preparation and characterization of a novel antimicrobial film dressing for wound healing application
Fonte: Braz. J. Pharm. Sci. (Online);56:e18784, 2020. tab, graf.
Idioma: en.
Resumo: Antibacterial activity and good mechanical properties are some of the characteristics required for an appropriate film dressing. A novel polymer blend was developed for wound healing application. Twenty-four formulations using the polymers chitosan, poly(vinyl alcohol) and/or É›-Polylysine and the plasticizer glycerol were designed using factorial design and then the films were prepared by the casting/solvent evaporation method. Seventeen films were obtained among the twenty-four proposed formulations that were characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Mechanical properties, such as tensile strength (σ), elongation at break (É›) and Young's modulus (Y) as well as antibacterial properties were determined. The best candidate was then further analyzed with regard to porosity, Water Vapor Transmission Rate (WVTR), swelling and cytotoxicity experiments. The results showed a film with semi-occlusive characteristics, good mechanical properties and no toxic. Incorporation of É›-Polylysine increased antibacterial activity against gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria
Descritores: Bandagens
Quitosana/farmacologia
-Polilisina/farmacologia
Cicatrização/efeitos dos fármacos
Microscopia Eletrônica de Varredura/métodos
Espectroscopia de Infravermelho com Transformada de Fourier
Glicerol/farmacologia
Responsável: BR40.1 - DBD - Divisão de Biblioteca e Documentacão do Conjunto das Químicas


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Id: biblio-1224659
Autor: Mello, Daphne de Camargo Reis.
Título: Hidrogel de quitosana com nanofibras de Policaprolactona (PCL) associado a extratos fitoterápicos no metabolismo celular e ação antimicrobiana: estudo in vitro / Evaluation of the chitosan hydrogel with PCL nanofibers associated with phytotherapeutic extracts in cellular and microbiological activity: in vitro study.
Fonte: São José dos Campos; s.n; 2020. 119 p. il., graf., tab..
Idioma: pt.
Tese: Apresentada a Universidade Estadual Paulista (Unesp), Instituto de Ciência e Tecnologia para obtenção do grau de Doutor.
Resumo: O objetivo neste estudo foi produzir hidrogel de quitosana (CH) com PCL e fitoterápicos para uso preventivo de úlcera de pressão. Os hidrogéis de CH foram produzidos com glicerofosfato (GP) e com xantana (X), associados ao PCL e foram caracterizados por estereomicroscopio, intumescimento, molhabilidade e MEV. Posteriormente foram submetidos ao teste de viabilidade (MTT) com fibroblastos HFF-1 e queratinócitos HaCat. O hidrogel que apresentou melhor resultado foi escolhido para continuar na pesquisa. Posteriormente, extratos de Pfaffia panculata K, Juglans regia L, Rosmarinus officinalis L, Zingiber officinale, Própolis e Hamamelis foram colocados em contato com cepas de Staphylococcus aureus (S.a) (ATCC 6538), Streptococcus pyogenes (S.p) (ATCC 19615), Staphylococcus epidermidis (S.e) (ATCC 12228), Pseudomonas aeruginosa (P.a) (ATCC 15442), Escherichia coli (E.c) (ATCC 25922) e Klebsiella Pneumoniae (K.p) (ATCC 4352) na forma planctônica nos testes de CIM e CMM. Os dois melhores extratos fitoterápicos foram avaliados quanto ao sinergismo no teste checkerboard e posteriormente associados ao hidrogel anteriormente eleito. A seguir, o comportamento da HaCat e HFF-1 com os hidrogéis foi analisado por MTT, proteína total, ELISA, genotoxicidade e formação de biofilme monotípico com suspensões padronizadas (107 cel/mL) de S.a, S.e, S.p, P.a, E.c e K.p. Na caracterização e viabilidade o hidrogel CHX PCL apresentou os melhores resultados. Os extratos selecionados após CIM, CMM e checkerboard foram gengibre (G) e própolis (P). O extrato G se destacou na CIM com inibição de K. p e P. a. Os extratos de G e P demonstraram ação microbicida para K. p e P. a e somente o extrato P obteve ação microbicida para S. a na CMM. Houve ação aditiva dos extratos associados no checkerboard para S.p e ação aditiva e sinérgica para S. e. Os grupos de hidrogéis foram compostos por: quitosana xantana (CHX), CHX própolis (CHXP), CHX gengibre (CHXG) e CHX própolis e gengibre associados (CHXPG), todos associados ao PCL. Todos os hidrogéis demonstraram viabilidade celular acima de 70% do grupo controle, permitindo metabolismo celular observado na proteína total. Houve quantificação de IL-6 maior no grupo CHX nas duas linhagens de células enquanto a quantificação de IL-10 não exibiu diferença estatística entre os grupos. Todos os hidrogéis promoveram redução acentuada de biofilme de K.p e E.c. Os grupos CHX, CHXP e CHXG reduziram biofilme de S.e. O grupo CHXG reduziu biofilme de S.p. Para S.a e P.a o grupo CHXPG foi mais eficaz reduzindo biofilme. Concluímos que os hidrogéis apresentaram resultados satisfatórios e promissores, trazendo inovação por associação de biopolímeros e associação de extratos fitoterápicos pouco estudados. Os resultados positivos justificam a continuidade dos estudos com esse biomaterial(AU)

The aim of this study was to produce chitosan hydrogel (CH) with PCL and herbal medicines for preventive use of pressure ulcers. The CH hydrogels were produced with glycerophosphate (GP) and xanthan (X), associated with PCL and were characterized by stereomicroscope, swelling, wettability and SEM. Subsequently, they were submitted to a viability test (MTT) with HFF-1 fibroblasts and HaCat keratinocytes. The hydrogel that presented the best result was chosen to continue the research. Subsequently, extracts of Pfaffia panculata K, Juglans regia L, Rosmarinus officinalis L, Zingiber officinale, Propolis and Hamamelis were placed in contact with strains of Staphylococcus aureus (Sa) (ATCC 6538), Streptococcus pyogenes (Sp) (ATCC 19615), epidermidis (Se) (ATCC 12228), Pseudomonas aeruginosa (Pa) (ATCC 15442), Escherichia coli (Ec) (ATCC 25922) and Klebsiella Pneumoniae (Kp) (ATCC 4352) in planktonic form in CIM and CMM tests. The two best herbal extracts were evaluated for synergism in the checkerboard test and subsequently associated with the previously elected hydrogel. Next, the behavior of HaCat and HFF-1 with hydrogels was analyzed by MTT, total protein, ELISA, genotoxicity and monotypic biofilm formation with standardized suspensions (107 cel / mL) of Sa, Se, Sp, Pa, Ec and Kp In the characterization and viability the CHX PCL hydrogel presented the best results. The extracts selected after MIC, CMM and checkerboard were ginger (G) and propolis (P). The G extract stood out in the MIC with inhibition of K. p and P. a. The extracts of G and P showed microbicidal action for K. p and P. a and only the extract P obtained microbicidal action for S. a in CMM. There was an additive action of the associated extracts on the checkerboard for S.p and an additive and synergistic action for S. e. The hydrogel groups were composed of: xanthan chitosan (CHX), CHX propolis (CHXP), CHX ginger (CHXG) and CHX propolis and ginger associated (CHXPG), all associated with PCL. All hydrogels demonstrated cell viability above 70% of the control group, allowing cellular metabolism observed in the total protein. There was a greater quantification of IL-6 in the CHX group in the two cell lines while the quantification of IL-10 did not show statistical difference between the groups. All hydrogels promoted a marked reduction in the biofilm of K.p and E.c. The CHX, CHXP and CHXG groups reduced S.e biofilm. The CHXG group reduced S.p. For S.a and P.a, the CHXPG group was more effective in reducing biofilm. We conclude that the hydrogels presented satisfactory and promising results, bringing innovation through association of biopolymers and association of phytotherapic extracts little studied. The positive results justify the continuity of studies with this biomaterial(AU)
Descritores: Quitosana/uso terapêutico
-Queratinócitos/imunologia
Biofilmes
Hidrogéis/administração & dosagem
Medicamentos Fitoterápicos
Nanofibras/efeitos adversos
Fibroblastos/microbiologia
Responsável: BR243.1 - Serviço Técnico de Biblioteca e Documentação
BR243.1


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Id: biblio-1132174
Autor: Parvin, Zargham; Kowsar, Mansouri; Jafar, Amani; Jafar, Salimian; Ali, Ahmadi.
Título: A Therapeutic Oral Vaccine Candidate against Propionibacterium acnes: Preparation and Immunological Evaluation of Nanoparticles Encapsulated Sialidase-CAMP Fusion Protein
Fonte: Braz. arch. biol. technol;63:e20190427, 2020. tab, graf.
Idioma: en.
Resumo: Abstract Acne Vulgaris is a common skin disease caused by Propionibacterium acnes, an anaerobic microbiota of human skin that plays a vital role in the pathology of acne. The aim of this study was to prepare nanoparticles containing an acne recombinant protein and determine its ability as an oral acne vaccine in mice. The recombinant Sialidase-CAMP gene was expressed and purified in a prokaryotic host. The chitosan nanoparticles containing the recombinant protein were prepared, encapsulated, and administered by both oral and subcutaneous routes to Balb/c mice. Sera IgA and IgG and stool IgA titers were measured by ELISA, and the immunized mice were challenged against P. acnes. A 65 kDa recombinant protein was confirmed by SDS-PAGE and western blot. The size and zeta potential of nanoparticles were 80 nm and +18 mV, respectively. After oral immunization, the serum IgG and IgA titers were 1:3200 and 1:16, respectively, and the stool IgA titer was 1:8. In the subcutaneous route, the serum IgG titer was 1:51200. Immunized mice showed no inflammation in the ear of challenged mice. It is the first study that examines a chitosan-nanoparticulated acne fusion protein as an applicable acne vaccine candidate with appropriate immunogenicity potential. Further studies are required to validate the clinical usefulness of this vaccine candidate.
Descritores: Propionibacterium acnes/efeitos dos fármacos
Acne Vulgar/prevenção & controle
Quitosana/administração & dosagem
Nanopartículas/administração & dosagem
-Proteínas Recombinantes
Ensaio de Imunoadsorção Enzimática
Western Blotting
Imunização/métodos
Modelos Animais de Doenças
Eletroforese em Gel de Poliacrilamida
Camundongos Endogâmicos BALB C
Neuraminidase
Limites: Animais
Feminino
Camundongos
Responsável: BR1.1 - BIREME


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Id: lil-735016 LILACS-Express
Autor: Tejeda Benítez, Lesly; Tejada Tovar, Candelaria; Marimón Bolívar, Wilfredo; Villabona Ortiz, Ángel.
Título: ESTUDIO DE MODIFICACIÓN QUÍMICA Y FÍSICA DE BIOMASA (Citrus sinensis Y Musa paradisiaca) PARA LA ADSORCIÓN DE METALES PESADOS EN SOLUCIÓN / STUDY OF PHYSICAL AND CHEMICAL MODIFICATION OF BIOMASS (Citrus sinensis AND Musa paradisiaca) FOR THE ADSORPTION OF HEAVY METALS IN SOLUTION
Fonte: Rev. luna azul;(39):124-142, jul.-dic. 2014. ilus, tab.
Idioma: es.
Resumo: Se estudia el efecto de las modificaciones a carbón activado y recubrimiento con quitosano de biomasa lignocelulósica obtenida de cáscaras de plátano y naranja, para la adsorción de Cr (VI). La caracterización de los grupos funcionales en las biomasas aptos para la adsorción se verificó mediante un análisis elemental (CHON) y espectroscopia de infrarrojo (IR), mientras que para los carbones activados se determinó su área superficial por medio de un análisis BET. El contenido de Cr (VI) en solución se midió mediante espectrofotometría UV-vis, usando el método de la difenilcarbazida. Los resultados mostraron una remoción de los iones de Cr (VI) de 66,6 y 93 ppm para las cáscaras de naranja y plátano respectivamente, los carbones activados removieron 85 y 95 ppm, mientras que las biomasas modificadas con quitosano presentaron una adsorción 61,24 y 88,2 ppm. Se observa que la cinética de adsorción fue mejor descrita por la ecuación de Pseudo Segundo Orden, y el efecto de competitividad bimetálica se vio afectada de mayor forma por iones de níquel, y en menor proporción por iones de plomo.

The effect of changes to activated charcoal and chitosan coating of lignocellulosic biomass obtained from banana and orange peels for the absorption of Cr (VI) was studied. Characterization of the functional groups in the biomass suitable for the adsorption was monitored by elemental analysis (CHON) and infrared spectroscopy (IR), while for activated carbon surface area was determined by BET analysis. The Cr (VI) content in solution was measured by UV-vis spectrophotometer, using the diphenylcarbazide method. The results showed a removal of Cr (VI) ions of 66.6 and 93 ppm for orange peels and banana peels respectively; the activated carbons removed 85 and 95 ppm, while the modified biomasses with chitosan showed an adsorption of 61.24 and 88.2 ppm. It was observed that the adsorption kinetics was best described by the Pseudo Second Order equation, and the bimetallic competitiveness effect was affected more by nickel ions and to a lesser extent by lead ions.
Descritores: Biomassa
-Carvão Vegetal
Adsorção
Quitosana
Limites: Humanos
Tipo de Publ: Artigo Clássico
Responsável: CO54.1 - Centro de Biblioteca e Información Científica


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Id: biblio-1132244
Autor: Lima, Maria de Morais; Carneiro, Lucia Cesar; Machado, Mírian Ribeiro Galvão; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa; Prentice, Carlos; Moreira, Angelita da Silveira.
Título: Application of Films Based on Chitosan and Xanthan Gum in Refrigerated Fish Conservation
Fonte: Braz. arch. biol. technol;63:e20190046, 2020. tab, graf.
Idioma: en.
Resumo: Abstract This research aims to determine the efficiency of chitosan and xanthan gum films in conservation of croaker fillets kept in refrigeration for 9 days. Proximal composition, loss of mass, color, pH, TVB-N (Total Volatile Bases) and microbiological profile were assessed. The films were prepared with chitosan and xanthan gum in varying mass proportions 100:0, m:m (C100XG0); 60:40, m:m (C60XG40); 50:50, m:m (C50XG50). They presented the respective values for moisture content, water solubility, thickness and water vapor permeability: 24.59%, 19.50%, 0.086 mm and 11.45gm-1.s-1.Pa-1for C100XG0; 24.58%; 20.27%, 0.091 mm and 10.41 gm-1.s-1.Pa-1for C60XG40; 22.11%, 22.06%, 0.089 mm and 10.68 gm-1.s-1.Pa-1 forC50XG50.The films were made in small bags format capable to hold about 20 g of fish fillets. A control sample was prepared in parallel, using polyethylene bags under the same storage conditions. The results showed that the chitosan films combined with xanthan gum had excellent antimicrobial properties, capable of preserving the quality of chilled fish fillets during the studied period, since it inhibited the growth of Staphylococcus coagulase-positive, Salmonella spp and coliforms at 45 ° C. Mass loss of the croaker fillets was not significantly affected by xanthan gum addition to the films. On the other hand, xanthan gum addition affected pH and color parameters of the corvina fillets. It was also verified that the combination of these two polymers promoted the reduction of N-BVT, being the C50XG50 film that presented the best response.
Descritores: Xanthomonas/química
Embalagem de Alimentos/métodos
Quitosana/química
Peixes/microbiologia
Conservação de Alimentos/métodos
-Polissacarídeos Bacterianos/química
Anti-Infecciosos
Limites: Animais
Responsável: BR1.1 - BIREME


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Id: biblio-1132216
Autor: Leonardelli, Cristiane; Silvestre, Wendel Paulo; Baldasso, Camila.
Título: Effect of Chitosan Addition in Whey-based Biodegradable Films
Fonte: Braz. arch. biol. technol;63:e20200178, 2020. tab, graf.
Idioma: en.
Resumo: Abstract Whey, a by-product of dairy industry, is a feedstock widely employed in the production of biodegradable films. However, these films present some limitations when considering the performance of synthetic polymers, especially biological transformation by decomposition. This work aimed to evaluate the effects of chitosan addition to whey-based films to improve films physical-chemical properties and resistance to microbial degradation. The results showed that there was an interaction effect between the chitosan concentration and the storage time for the physical-chemical properties of elongation at break and opacity. There was statistical difference among the formulations; however, for the moisture content and film thickness, there was no interaction effect between the formulation and the storage time. The films with 1.5 and 3.0 wt.% chitosan presented a yellowish hue, characteristic of the polysaccharide; this could also be detected by SEM analysis. The films presented an excellent biodegradability, being decomposed in about 8 days. Considering all chitosan contents tested had similar performances, the chitosan content of 0.15 wt.% was the one with the better cost-benefit relation.
Descritores: Biotransformação/efeitos dos fármacos
Quitosana/farmacologia
Soro do Leite/efeitos dos fármacos
Filmes Comestíveis
Antibacterianos/farmacologia
-Fatores de Tempo
Armazenamento de Produtos
Fenômenos Químicos
Responsável: BR1.1 - BIREME


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Id: biblio-1150986
Autor: Andueza Galeno, Isabel Cecilia.
Título: Desarrollo de un nanosistema para la liberación de fármacos intravítreo / Development of intravitreal nanosistema for drugs release.
Fonte: Caracas; s.n; oct. 2012. ilus, tab, graf.
Idioma: es.
Tese: Apresentada a Universidad Central de Venezuela. Facultad de Farmacia para obtenção do grau de Doctor.
Resumo: La inyección intravítrea ha sido la vía de administración más eficaz para el tratamiento de enfermedades vitreorretinianas. Su práctica continua, no es agradable para los pacientes y a su vez podría causar complicaciones indeseadas. El presente trabajo tuvo como objetivo desarrollar un nanosistema de liberación polímero-terapéutico (conjugado)/nanopartícula, utilizando Dextrano y Quitosano como polímeros transportadores biodegradables, hidrosolubles y compatibles a nivel ocular así como Hemisuccinato de Metilprednisolona como fármaco modelo. Primeramente, el fármaco fue capaz de unirse covalentemente a dos Dextranos de pesos moleculares 10 y 70 kDa. En función del contenido del componente activo y perfil de liberación, se seleccionó el Hemisuccinato de Metilprednisolona-Dextrano 10 kDa para elaborar las nanopartículas de Quitosano por el método de gelificación iónica empleando tripolifosfato sódico como agente entrecruzante. Por último, las nanopartículas fueron cubiertas con lactosa aplicando el secado por atomización. Se evaluó morfología, distribución de tamaño de las partículas, carga superficial, contenido y eficacia de captura del fármaco. Las partículas esféricas presentaron superficies lisas y uniformes. El pH tuvo influencia en el tamaño de las partículas observándose una distribución bimodal a pHs ≈ pKa del Quitosano y unimodal con un rango entre 130 - 170 nm a pHs < pKa. La variación de los potenciales Zeta entre los compuestos involucrados en la reacción, indicaron la posible ocurrencia de la misma. Al comparar la liberación del conjugado con las Nanopartículas a pH fisiológico, se observó que la encapsulación retrasó la liberación del fármaco alrededor de un 50%. Las nanopartículas recubiertas formaron micropartículas de 1.780 ± 0,5 nm, lo que favoreció su dispersibilidad en agua. Este nuevo nanosistema, evidenció su posible potencial en el desarrollo de formulaciones de liberación intravítrea, que reduzca la frecuencia de administración, ofreciendo una excelente alternativa que proporcione un mayor grado de satisfacción y mejore la calidad de vida del paciente.
Descritores: Doenças Retinianas/tratamento farmacológico
Nanotecnologia/organização & administração
Liberação Controlada de Fármacos/efeitos dos fármacos
-Polímeros/farmacologia
Qualidade de Vida
Doenças Retinianas/complicações
Metilprednisolona/uso terapêutico
Cromatografia Líquida/métodos
Dextranos/uso terapêutico
Membrana Epirretiniana/tratamento farmacológico
Preparações de Ação Retardada/farmacologia
Quitosana/uso terapêutico
Composição de Medicamentos/métodos
Material Particulado/uso terapêutico
Nanopartículas/administração & dosagem
Injeções Intravítreas/efeitos adversos
Limites: Humanos
Tipo de Publ: Estudo de Validação
Responsável: VE497.1 - Biblioteca Dr. Oswaldo Enríquez Isava
VE497.1; D-CF, An3


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Id: biblio-1177832
Autor: Vasei, Fateme; Sharafeddin, Farahnaz.
Título: Effect of chitosan treatment on shear bond strength of composite to deep dentin using self-etch and total-etch adhesive systems / Efeito do tratamento com quitosana na resistência ao cisalhamento de resina compost em dentina profunda usando sistemas adesivos autocondicionantes e condicionamento total
Fonte: Braz. dent. sci;24(2):1-9, 2021. tab, ilus.
Idioma: en.
Resumo: Objective: To assess the shear bond strength (SBS) of resin composite to deep dentin, using 1 and 2.5% chitosan pretreatment as well as different adhesive systems. Material and Methods: 80 human maxillary molars were randomly divided to eight groups according to the type of adhesive system and dentin pretreatment (n = 10): I) two-step self-etch system (Clearfil SE bond); II) two-step etch-and-rinse system (Adper single bond 2); III) 2.5% chitosan + Clearfil SE bond; IV) 2.5% chitosan +etch + Adper single bond 2; V) etch + 2.5% chitosan + Adper single bond 2; VI) 1% chitosan + Clearfil SE bond; VII) 1% chitosan + etch + Adper single bond 2; VIII) etch + 1% chitosan + Adper single bond 2 (chitosan solution (w/v): 2.5 g and 1 g of chitosan (Sigma Aldrich, USA) was dissolved in 100 ml of 1% acetic acid). Plastic molds were positioned on dentin and filled with composite (Z350, 3M ESPE, USA). SBS (MPa) was tested using a universal testing machine. ANOVA tests, Tukey's test, and independent t test were used to analyze data (p ≤ 0.05). Results: The highest SBS value among self-etch groups was observed with 1% chitosan (p = 0.001). In the etch-and-rinse group, the SBS of 1% chitosan was significantly lower than the other groups. Chitosan treatment following acid etching led to higher SBS in comparison to when chitosan was applied before etching, with the significant difference in 1% concentration (p = 0.030). A predominance of mix fractures was observed in dentin. Conclusion: Improved dentin bond strength can be achieved through immediate dentin pretreatment with 1% chitosan in self-etch adhesive systems. Chitosan Pretreatment may not be advantageous for etch-and-rinse adhesive systems. (AU)

Objetivo: Avaliar a resistência ao cisalhamento (RC) da resina composta em dentina profunda, utilizando quitosana de 1 e 2,5% como pré-tratamento, e também diferentes sistemas adesivos. Materiai e métodos: 80 molares superiores humanos foram divididos aleatoriamente em oito grupos de acordo com o tipo de sistema adesivo e pré-tratamento dentinário (n = 10): I) sistema autocondicionante de dois passos (Clearfil SE bond); II) sistema convencional de dois passos (Adper Single Bond II); III) quitosana 2,5% + Clearfil SE bond; IV) quitosana 2,5% + ácido + Adper single bond; V) ácido + quitosana 2,5% + Adper single bond II; VI) quitosana 1% + Clearfil SE bond; VII) quitosana 1% + ácido + Adper single bond II; VIII) ácido + quitosana 1% + Adper single bond II (solução de quitosana (w/w): 2,5 ge 1 g de quitosana (Sigma Aldrich, EUA) foi dissolvido em 100 ml de ácido acético a 1%). Moldeiras foram posicionados na dentina e preenchidos com resina composta (Z350, 3M ESPE, EUA). O RC (MPa) foi testado em uma máquina de teste universal. Os testes ANOVA, teste de Tukey e teste t foram usados para analisar os dados (p ≤ 0,05). Resultados: O maior valor de RC entre os grupos autocondicionantes foi observado com quitosana a 1% (p = 0,001). No grupo do condicionamento total a RC da quitosana a 1% foi significativamente menor do que nos outros grupos. O tratamento com quitosana após o condicionamento ácido levou a um maior RC em comparação a quitosana aplicada antes do condicionamento, com diferença significativa na concentração de 1% (P = 0,030). Observou-se predomínio de fraturas na dentina. Conclusão: A resistência de união à dentina pode ser alcançada por meio do pré-tratamento imediato da dentina com quitosana a 1% em sistemas adesivos autocondicionantes. O pré-tratamento com quitosana pode não ser vantajoso para sistemas adesivos de condicionamento total. (AU)
Descritores: Resinas Compostas
Resistência ao Cisalhamento
Dentina
Quitosana
Limites: Humanos
Tipo de Publ: Estudo Comparativo
Responsável: BR243.1 - Serviço Técnico de Biblioteca e Documentação


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Id: biblio-950859
Autor: Cao, Xuebing; Hou, Dongzhi; Wang, Lei; Li, Sai; Sun, Shengang; Ping, Qineng; Xu, Yan.
Título: Effects and molecular mechanism of chitosan-coated levodopa nanoliposomes on behavior of dyskinesia rats
Fonte: Biol. Res;49:1-9, 2016. ilus, graf.
Idioma: en.
Projeto: National Natural Science Foundation of China; . National Natural Science Foundation of China.
Resumo: BACKGROUND: Chitosan, the N-deacetylated derivative of chitin, is a cationic polyelectrolyte due to the presence of amino groups, one of the few occurring in nature. The use of chitosan in protein and drug delivery systems is being actively researched and reported in the literature RESULTS: In this study, we used chitosan-coated levodopa liposomes to investigate the behavioral character and the expression of phosphorylated extracellular signal-regulated kinase (ERK1/2), dopamine- and cAMP-regulated phos-phoprotein of 32 kDa (DARPP-32) and FosB/AFosB in striatum of rat model of levodopa-induced dyskinesia (LID). We found that scores of abnormal involuntary movement (AIM) decreased significantly in liposome group (P < 0.05), compared with levodopa group. Levels of phospho-ERK1/2, phospho-Thr34 DARPP-32 and FosB/AFosB in striatum decreased significantly in liposome group lesion side compared with levodopa group (P < 0.05). However, both of two groups above have significantly differences compared with the control group (P < 0.05). CONCLUSION: Chitosan-coated levodopa liposomes may be useful in reducing dyskinesias inducing for Parkinson disease. The mechanism might be involved the pathway of signaling molecular phospho-ERK1/2, phospho-Thr34 DARPP-32 and AFosB in striatum
Descritores: Dopaminérgicos/farmacologia
Levodopa/farmacologia
Proteínas Proto-Oncogênicas c-fos/metabolismo
Quitosana/farmacologia
Discinesia Induzida por Medicamentos/metabolismo
Discinesia Induzida por Medicamentos/prevenção & controle
Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo
-Doença de Parkinson/tratamento farmacológico
Fosforilação/efeitos dos fármacos
Materiais Biocompatíveis/farmacologia
Imuno-Histoquímica
Distribuição Aleatória
Western Blotting
Reprodutibilidade dos Testes
Resultado do Tratamento
Proteínas Proto-Oncogênicas c-fos/análise
Proteínas Proto-Oncogênicas c-fos/efeitos dos fármacos
Ratos Sprague-Dawley
Corpo Estriado/efeitos dos fármacos
Sistema de Sinalização das MAP Quinases
MAP Quinases Reguladas por Sinal Extracelular/análise
MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos
Discinesia Induzida por Medicamentos/etiologia
Fosfoproteína 32 Regulada por cAMP e Dopamina/análise
Fosfoproteína 32 Regulada por cAMP e Dopamina/efeitos dos fármacos
Nanopartículas
Lipossomos
Limites: Animais
Masculino
Tipo de Publ: Estudo de Avaliação
Responsável: CL1.1 - Biblioteca Central



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