RESUMO
Raloxifene HCl (RH) has poor water solubility and due to its extensive first pass metabolism; its bioavailability is only 2%. The purpose of the present study was to enhance the aqueous solubility, oral bioavailability and anti-osteoporotic effects of RH by electro-sprayed nanoparticles (NPs) in ovariectomized rats. NPs containing RH and different ratio of poly(methyl vinyl ether-co-maleic acid) (PMVEMA) were electrosprayed. The voltage, distance of needle to the collector, flow rate of the solution and polymeric percentage were optimized according to the size of NPs and drug solubility. The optimized formulation was characterized by SEM, XRD, DSC, and FTIR. The pharmacokinetic parameters were studies by oral administration of a single dose of 15mg/kg in Wistar rats. The anti-osteoporotic effects were studied in female ovariectomized rats. Animals were treated with 6mg/kg/day for 2months then serum calcium, phosphorous and alkaline phosphatase levels were measured. RH loaded electrosprayed NPs showed 10-fold enhanced solubility compared to the free drug. Moreover, the XRD and SEM tests displayed an amorphous state of drug in the NPs. FTIR and DSC tests revealed no interaction between the polymer and the drug. Serum calcium, phosphorous and alkaline phosphatase levels were significantly decreased in ovariectomized rats receiving oral RH NPs (P<0.05). No significant difference was detected between RH NPs and estradiol groups (P>0.05). Oral bioavailability of NPs showed 7.5-fold increase compared to the pure drug. The electrosprayed PMVEMA nanoparticles can enhance solubility, bioavailability and antiosteoporotic effects of RH.
Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Maleatos/administração & dosagem , Nanopartículas/administração & dosagem , Osteoporose/tratamento farmacológico , Polietilenos/administração & dosagem , Cloridrato de Raloxifeno/administração & dosagem , Administração Oral , Fosfatase Alcalina/sangue , Animais , Disponibilidade Biológica , Conservadores da Densidade Óssea/sangue , Conservadores da Densidade Óssea/química , Conservadores da Densidade Óssea/farmacocinética , Cálcio/sangue , Feminino , Maleatos/química , Maleatos/farmacocinética , Microscopia Eletrônica de Varredura , Nanopartículas/química , Nanopartículas/ultraestrutura , Osteoporose/sangue , Ovariectomia , Fósforo/sangue , Polietilenos/química , Polietilenos/farmacocinética , Cloridrato de Raloxifeno/sangue , Cloridrato de Raloxifeno/química , Cloridrato de Raloxifeno/farmacocinética , Ratos Wistar , Solubilidade , Tecnologia FarmacêuticaRESUMO
Seven new glucosyloxybenzyl 2R-benzylmalate derivatives, arundinosides A-G (1-7) were isolated from the aerial parts of the bamboo orchid Arundina graminifolia. This is the first occurrence of this class of compounds in the genus Arundina. Their planar structures and absolute configuration were determined by extensive NMR spectroscopic data as well as chemical conversion. Their neuroprotective properties were also evaluated on their potential ability to reduce the beta amyloid damage on PC12 cell model.
Assuntos
Compostos de Benzil/química , Maleatos/química , Fármacos Neuroprotetores/química , Orchidaceae/química , Animais , Compostos de Benzil/isolamento & purificação , Espectroscopia de Ressonância Magnética , Maleatos/isolamento & purificação , Estrutura Molecular , Fármacos Neuroprotetores/isolamento & purificação , Células PC12 , Componentes Aéreos da Planta/química , Ratos , TailândiaRESUMO
BACKGROUND: Peanut allergy is the most common cause of anaphylaxis and food-related death. However, there is currently no approved immunotherapy treatment. Hence, this warrants the need for relevant and convenient animal models to test for adequate immunotherapies. MATERIALS & METHODS: In this study, we compared three mouse strains: CD1, BALB/c and C57, to select a model of peanut allergy. After that, we conducted then a therapeutic study using an immunogenic peanut extract encapsulated in nanoparticles made with polymer Gantrez® following the solvent displacement method. RESULTS & CONCLUSION: After implementing a dosing schedule with oral commercial peanut butter, the antibody responses, cytokine profiles and, above all, the anaphylaxis induced after a challenge with peanut proteins, showed that the outbred CD1 strain was the most susceptible to peanut sensitization. CD1 sensitized mice were orally immunized with three doses of the nanoparticle formulation capable of protecting them against the severe anaphylactic symptoms induced by the peanut challenge.
Assuntos
Alérgenos/uso terapêutico , Anafilaxia/terapia , Dessensibilização Imunológica/métodos , Maleatos/química , Nanopartículas/uso terapêutico , Hipersensibilidade a Amendoim/terapia , Extratos Vegetais/uso terapêutico , Polivinil/química , Administração Oral , Alérgenos/química , Alérgenos/imunologia , Anafilaxia/imunologia , Animais , Formação de Anticorpos , Arachis/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Nanopartículas/química , Hipersensibilidade a Amendoim/imunologiaRESUMO
Magnetic microgels with pH- and thermo-responsive properties were developed from the pectin maleate, N-isopropyl acrylamide, and Fe3O4 nanoparticles. The hybrid materials were characterized by infrared spectroscopy, scanning electron microscope coupled with X-ray energy dispersive spectroscopy, wide angle X-ray scattering, Zeta potential, and magnetization hysteresis measurements. Curcumin (CUR) was loaded into the microgels, and release assays were carried out in simulated environments (SGF and SIF) at different conditions of temperature (25 or 37°C). A slow and sustainability CUR release was achieved under external magnetic field influence. Loaded CUR displayed stability, bioavailability and greater solubility regarding free CUR. Besides, the cytotoxicity assays showed that magnetic microgels without CUR could suppress the Caco-2 cells growth. So, the pectin maleate, N-isopropyl acrylamide, and Fe3O4 could be tailored to elicit hybrid-based materials with satisfactory application in the medical arena.
Assuntos
Curcumina/química , Portadores de Fármacos/síntese química , Magnetismo , Maleatos/química , Nanopartículas/química , Células CACO-2 , Portadores de Fármacos/química , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Pectinas/químicaRESUMO
Two new ubiquinones, named antrocinnamone and 4-acetylantrocamol LT3, were isolated along with six known ubiquinones from Antrodia cinnamomea (Polyporaceae) mycelium. The developed HPLC analysis methods successfully identified eight different ubiquinones, two benzenoids, and one maleic acid derivative from A. cinnamomea. The ubiquinones 1-8 exhibited potential and selective cytotoxic activity against three human cancer cell lines, with IC50 values ranging from 0.001 to 35.883 µM. We suggest that the different cytotoxicity levels were related to their chemical structures, especially the 4-hydroxycyclohex-2-enone ring and the presence of a free hydroxyl group in the side chain. The suppression by 4-acetylantrocamol LT3 stopped the cell cycle at the beginning of the G2-M phase thus making the cell cycle arrest at the sub-G1 phase as compared with control cells.
Assuntos
Antineoplásicos/farmacologia , Antrodia/química , Medicamentos de Ervas Chinesas/química , Micélio/química , Ubiquinona/análogos & derivados , Ubiquinona/farmacologia , Células A549 , Antineoplásicos/química , Ciclo Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Cicloexanonas/química , Descoberta de Drogas/métodos , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Maleatos/química , Ubiquinona/químicaRESUMO
Substantial amounts of industrial, agricultural, medical and domestic water worldwide are polluted by different types of contaminants. Removing these contaminants from effluent by adsorbent materials made from abundant, inexpensive polysaccharides is a feasible and promising approach to deal with this problem. In the present study, pectin blended with four other types of anionic polysaccharides, including alginate, carrageenan, xylan and xanthan, were crosslinked with zinc acetate and formed into thin films. In addition, a negatively charged polyelectrolyte, poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSMA) was coated on the film surface with the goal of increasing the capture of cationic contaminants. The average film thickness was measured by a digital micrometer. Surface morphologies and element analysis were obtained by energy dispersive spectroscopy connected with scanning electron microscopy. The swelling ratio and the mechanical properties of the films were investigated in relationship to their composition and PSSMA coating. The sorption of model cationic pollutants clearly improved for coated films and showed to be predominantly based on the interaction of positively and negatively charged groups between film/coating and contaminants.
Assuntos
Pectinas/química , Polissacarídeos/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Cinética , Maleatos/química , Poliestirenos/químicaRESUMO
Laser-mediated photothermal ablation of cancer cells aided by photothermal agents is a promising strategy for localized, externally controlled cancer treatment. We report the synthesis, characterization, and in vitro evaluation of conductive polymeric nanoparticles (CPNPs) of poly(diethyl-4,4'-{[2,5-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-1,4-phenylene] bis(oxy)}dibutanoate) (P1) and poly(3,4-ethylenedioxythiophene) (PEDOT) stabilized with 4-dodecylbenzenesulfonic acid and poly(4-styrenesulfonic acid-co-maleic acid) as photothermal ablation agents. The nanoparticles were prepared by oxidative-emulsion polymerization, yielding stable aqueous suspensions of spherical particles of <100 nm diameter as determined by dynamic light scattering and electron microscopy. Both types of nanoparticles show strong absorption of light in the near infrared region, with absorption peaks at 780 nm for P1 and 750 nm for PEDOT, as well as high photothermal conversion efficiencies (~50%), that is higher than commercially available gold-based photothermal ablation agents. The nanoparticles show significant photostability as determined by their ability to achieve consistent temperatures and to maintain their morphology upon repeated cycles of laser irradiation. In vitro studies in MDA-MB-231 breast cancer cells demonstrate the cytocompatibility of the CPNPs and their ability to mediate complete cancer cell ablation upon irradiation with an 808-nm laser, thereby establishing the potential of these systems as agents for laser-induced photothermal therapy.
Assuntos
Condutividade Elétrica , Hipertermia Induzida , Lasers , Nanopartículas/química , Neoplasias/terapia , Fototerapia , Polímeros/química , Polímeros/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Linhagem Celular Tumoral , Humanos , Maleatos/síntese química , Maleatos/química , Nanopartículas/ultraestrutura , Poliestirenos/síntese química , Poliestirenos/química , TemperaturaRESUMO
Elimination of microbial and enzyme inhibitors from pretreated lignocellulose is critical for effective cellulose conversion and yeast fermentation of liquid hot water (LHW) pretreated corn stover. In this study, xylan oligomers were hydrolyzed using either maleic acid or hemicellulases, and other soluble inhibitors were eliminated by biological detoxification. Corn stover at 20% (w/v) solids was LHW pretreated LHW (severity factor: 4.3). The 20% solids (w/v) pretreated corn stover derived liquor was recovered and biologically detoxified using the fungus Coniochaeta ligniaria NRRL30616. After maleic acid treatment, and using 5 filter paper units of cellulase/g glucan (8.3mg protein/g glucan), 73% higher cellulose conversion from corn stover was obtained for biodetoxified samples compared to undetoxified samples. This corresponded to 87% cellulose to glucose conversion. Ethanol production by yeast of pretreated corn stover solids hydrolysate was 1.4 times higher than undetoxified samples, with a reduction of 3h in the fermentation lag phase.
Assuntos
Reatores Biológicos , Etanol/síntese química , Maleatos/química , Zea mays , Ascomicetos/metabolismo , Celulose/química , Celulose/metabolismo , Fermentação , Hidrólise , Inativação Metabólica , Zea mays/química , Zea mays/metabolismoRESUMO
Cysteine is unique among the proteinogenic amino acids due to its ability to form disulfide bonds. While this property is of vital importance for protein structures and biological processes, it causes difficulties for the mass spectrometric identification of cysteine-containing peptides. A common approach to overcome these problems in bottom-up proteomics is the reduction and covalent modification of sulfhydryl groups prior to enzymatic digestion. In this study, established alkylating agents and N-maleoyl amino acids with variable hydrophobicity were characterized with respect to a variety of relevant parameters and subsequently evaluated in a large-scale analysis using different ion sources. Depending on the compound, the ion source had a profound impact on the relative and absolute identification of cysteine-containing peptides. The best results were obtained by derivatization of the cysteine residues with 4-vinylpyridine and subsequent matrix-assisted laser desorption ionization (MALDI). Modification with 4-vinylpyridine increased the number of cysteine-containing peptides identified with any other compound using LC-MALDI/MS at least by a factor of 2. This experimental observation is mirrored by differences in the gas-phase basicities, which were computed for methyl thiolate derivatives of the compounds using density functional theory. With electrospray ionization (ESI), complementary use of reagents from three different compound classes, e.g., iodoacetamide, 4-vinylpyridine, and N-maleoyl beta-alanine, was beneficial compared to the application of a single reagent.
Assuntos
Cisteína/análise , Peptídeos/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Alquilação , Sequência de Aminoácidos , Aminoácidos/química , Escherichia coli/química , Proteínas de Escherichia coli/química , Humanos , Hidrólise , Iodoacetamida/química , Maleatos/química , Modelos Moleculares , Proteômica/métodos , Piridinas/químicaRESUMO
Poly(styrene-co-maleic anhydride) was imidized with ammonium hydroxide and palm oil, resulting in an aqueous dispersion of hybrid nanoparticles with diameters 85-180 nm (dispersed) or 20-50 nm (dried). The reaction conditions were optimized for different precursors by evaluating the relative amount ammonium hydroxide and maximizing the incorporated palm oil up to 70 wt.%. The interactions between palm oil and polymer phase have been studied by TEM, IR, Raman spectroscopy and thermal analysis (TGA, [TM] DSC). From Raman spectra, the amount of imide and reacted oil were quantified. Through concurring effects of imidization and coupling of fatty acids, the imidization needs a slight excess of NH3 relatively to maleic anhydride. The oxidative stability highly depends on oxidative crosslinking of free or non-reacted oil. Comparing the imide content from spectroscopic and thermal analysis suggests that a complex rigid imide phase without strong relaxation behavior has formed in combination with oil.
Assuntos
Maleatos/química , Maleimidas/química , Nanopartículas/química , Óleos de Plantas/química , Poliestirenos/química , Hidróxido de Amônia/química , Nanopartículas/ultraestrutura , Nanotecnologia , Óleo de Palmeira , Tamanho da Partícula , Água/químicaRESUMO
Poly(lactic acid), PLA, is a biodegradable polymer, but its applications are limited by its high cost and relatively poorer properties when compared to petroleum-based plastics. The addition of starch powder into PLA is one of the most promising efforts because starch is an abundant and cheap biopolymer. However, the challenge is the major problem associated with poor interfacial adhesion between the hydrophilic starch granules and the hydrophobic PLA, leading to poorer mechanical properties. In this paper, soybean oil maleate (SOMA) was synthesized by grafting soybean oil with various weight percents of maleic anhydride (MA) using dicumyl peroxide (DCP) as an initiator. Then, SOMA was employed for the surface modifying of cassava starch powder, resulting in SOMA-g-STARCH. The obtained SOMA-g-STARCH was mixed with PLA in various weight ratios using twin-screw extruder, resulting in PLA/SOMA-g-STARCH. Finally, the obtained PLA/SOMA-g-STARCH composites were prepared by a compression molding machines. The compatibility, thermal properties, morphology properties, and mechanical properties were characterized and evaluated. The results showed that the compatibility, surface appearance, and mechanical properties at 90 : 10 and 80 : 20 ratios of PLA/SOMA-g-STARCH were the best.
Assuntos
Ácido Láctico/química , Maleatos/química , Manihot/química , Polímeros/química , Óleo de Soja/química , Amido/química , Espectroscopia de Ressonância Magnética , Poliésteres , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The present study aims to design hepatic targeted curcumin (CUR) nanoparticles using Gantrez (GZ) as a polymer. Three carbohydrate-based hepatocyte asialoglycoprotein receptor (ASGP-R) ligands were selected for the study, namely kappa carrageenan (KC), arabinogalactan (AG), and pullulan (P). AG and KC are galactose based while P is a glucose-based polymer. CUR-GZ nanoparticles were prepared by nanoprecipitation and anchored with the ligands by nonspecific adsorption onto preformed nanoparticles. The change in zeta potential values confirmed adsorption of the ligands. Docking simulation was evaluated as a tool to predict ligand ASGP-R interactions, using grid-based ligand docking with energies (Glide). Monomers and dimers were used as representative units of polymer for docking analysis. The binding of ASGP-R was validated using D-galactose as monomer. The interaction of the ligands with the receptor was evaluated based on Glide scores and E model values, both for monomers and dimers. The data of the docking study based on Glide scores and E model values suggested higher affinity of AG and P to the ASGP-R, compared to KC. At 1 h, following intravenous administration of the nanoparticles to rats, the in vivo hepatic accumulation in the order CUR-GZAG > CUR-GZKC > CUR-GZP correlated with the docking data based on Glide scores. However, at the end of 6 h, pullulan exhibited maximum hepatic accumulation and arabinogalactan minimum accumulation (p < 0.05). Nevertheless, as predicted by docking analysis, arabinogalactan and pullulan revealed maximum hepatic accumulation. Docking analysis using dimers as representative stereochemical units of polymers provides a good indication of ligand receptor affinity. Docking analysis provides a useful tool for the preliminary screening of ligands for hepatic targeting.
Assuntos
Receptor de Asialoglicoproteína/metabolismo , Simulação por Computador , Curcumina/metabolismo , Hepatócitos/metabolismo , Maleatos/metabolismo , Nanopartículas , Polivinil/metabolismo , Animais , Receptor de Asialoglicoproteína/química , Sítios de Ligação/fisiologia , Curcumina/química , Sistemas de Liberação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Ligantes , Maleatos/química , Nanopartículas/química , Polivinil/química , Ratos , Ratos Sprague-DawleyRESUMO
A new phenolic compound, 4-dehydrochebulic acid-1,6-dimethyl ester (2) was isolated from the leaves of Sapium insigne (Royle) Benth. ex Hook. fil. (Euphorbiaceae) along with three known compounds gallic acid (1), brevifolin carboxylic acid (3) and fraxin (4). Structures of those compounds were elucidated on the basis of spectroscopic data.
Assuntos
Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Folhas de Planta , Sapium , Benzopiranos/química , Benzopiranos/isolamento & purificação , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/isolamento & purificação , Maleatos/química , Maleatos/isolamento & purificação , Fenóis/química , Extratos Vegetais/químicaRESUMO
Specific immunotherapy implies certain drawbacks which could be minimized by the use of appropriate adjuvants, capable of amplifying the right immune response with minimal side effects. In this context, previous studies of our group have demonstrated the adjuvant capacity of Gantrez AN nanoparticles, which can effectively enhance the immune response. In this work, two types of nanoparticles (with and without LPS of Brucella ovis as immunomodulator) with encapsulated Lolium perenne extract are tested in a model of sensitized mice to this allergenic mixture. The results we obtained showed that Lolium-Gantrez nanoparticles with LPS of B. ovis were able to induce significative Th1 responses, characterized by the IgG(2a) isotype. Furthermore, in the challenge experiment of the sensitized mice, differences in the mortality rate and in the mMCP-1 levels were found between the treated groups and the control. Under the experimental conditions of this model of pre-sensitized mice to L. perenne, Gantrez AN nanoparticles appeared to be a good strategy for immunotherapy.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Alérgenos/administração & dosagem , Anafilaxia/terapia , Dessensibilização Imunológica , Lolium/imunologia , Nanopartículas/administração & dosagem , Anafilaxia/imunologia , Animais , Anticorpos Antibacterianos/sangue , Basófilos/imunologia , Basófilos/metabolismo , Brucella ovis/imunologia , Quimiocina CCL2/sangue , Portadores de Fármacos , Feminino , Histamina/sangue , Imunoglobulina E/sangue , Lipopolissacarídeos/imunologia , Maleatos/química , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Nanopartículas/ultraestrutura , Pólen/imunologia , Polivinil/química , Células Th1/imunologia , Células Th1/metabolismo , Células Th2/imunologia , Células Th2/metabolismoRESUMO
PURPOSE: To design bioadhesive Gantrez AN (poly[methyl vinyl ether-co-maleic anhydride], PVM/MA) nanoparticles (NP) coated with vitamin B(12) (Vit B(12)), and investigate their application in oral antigen delivery. METHODS: The association of Vit B(12) to Gantrez AN nanoparticles was performed by the direct attachment of reactive Vit B(12) to the surface of the nanoparticles (NPB), or linking to the copolymer chains in dimethylformamide prior to NP formation (NPB-DMF). Nanoparticles were characterized by measuring the size, zeta potential, Vit B(12) association efficacy, and stability of Vit B(12) on the surface of the nanoparticles. In vivo bioadhesion study was performed by the oral administration of fluorescently-labeled nanoparticle formulations to rats. Both systemic and mucosal immune responses were evaluated after oral and subcutaneous immunization with ovalbumin (OVA) containing Vit B(12)-coated nanoparticles. RESULTS: The Vit B(12) nanoparticles displayed homogenous size distribution with a mean diameter of about 200 nm and a negative surface charge. The association efficiency of Vit B(12) to NPB-DMF formulation was about two times higher than to the NPB, showing also a higher surface stability of Vit B(12). The bioadhesion study demonstrated that NPB-DMF had an important tropism to the distal portions of the gut, which was about two and 3.5 times higher than the tropism observed for NPB and control NP, respectively (p < 0.05). Oral administration of OVA-NPB-DMF induced also stronger and more balanced serum anti-OVA titers of IgG2a (Th1) and IgG1 (Th2) compared to control OVA-NP. In addition, oral immunization with OVA-NPB-DMF induced a higher mucosal IgA response than subcutaneous administration. CONCLUSIONS: These results indicate the benefits of bioadhesive Vit B(12)-coated nanoparticles in oral antigen delivery eliciting systemic and mucosal immune response.
Assuntos
Adjuvantes Imunológicos/farmacologia , Maleatos/química , Nanopartículas/química , Polivinil/química , Vitamina B 12/química , Vitamina B 12/farmacologia , Animais , Portadores de Fármacos , Feminino , Imunoglobulina A Secretora/análise , Imunoglobulina G/sangue , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Ratos , Ratos Wistar , SolubilidadeRESUMO
The objective of this work was to apply the response surface approach in the development of buccal bioadhesive tablets of 5-fluorouracil (5-FU). Experiments were performed according to a 3(2) factorial design to evaluate the effects of two polymers, Gantrez MS-955 (X(1)) and hydroxypropylmethyl cellulose (HPMC) K15M (X(2)) on the bioadhesive force, percentage drug release in 8 h (Rel(8 h)), time taken for 50% drug release (t(50%)), and diffusion coefficient (n). The effect of the two independent variables on the response variables was studied by response surface plots and contour plots generated by the Design Expert software. The compatibility between 5-FU and the tablet excipients was confirmed by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) studies. Both the polymers were found to have synergistic effect on bioadhesion but the effect of Gantrez was more pronounced. A nonlinear twisted relationship was obtained for Rel(8 h) at the intermediate and high levels of the polymers, which indicated an interaction between them at the corresponding factor levels. Kinetic treatment to the dissolution profiles revealed that the drug release ranged from Fickian to anomalous transport, which was mainly dependent on both the independent variables. The desirability function was used to optimize the response variables, and the observed responses were in agreement with the experimental values.
Assuntos
Adesivos , Antimetabólitos Antineoplásicos/administração & dosagem , Excipientes/química , Fluoruracila/administração & dosagem , Administração Bucal , Antimetabólitos Antineoplásicos/química , Varredura Diferencial de Calorimetria , Incompatibilidade de Medicamentos , Sinergismo Farmacológico , Fluoruracila/química , Derivados da Hipromelose , Cinética , Maleatos/química , Metilcelulose/análogos & derivados , Metilcelulose/química , Polivinil/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos , Fatores de TempoRESUMO
The purpose of this study was to design an experimental model that allowed extensive endodontic interim restorations to be tested for dye penetration while under simulated masticatory load. Extracted premolar teeth had standardized mesio-occluso-distal cavities prepared, and the root canals were instrumented. A cotton wool pellet was placed in the pulp chamber, and the cavities were restored with Cavit, IRM, Ketac-Fil Plus, Ketac-Silver, or composite resin (Z100). They were subjected to the equivalent of 3 months of clinical load while exposed to methylene blue dye. Results of this study could not support IRM as a suitable interim endodontic restorative material to use in extensive cavities. The dye penetration in the Ketac-Fil Plus and Ketac-Silver specimens was not predictable, and the results suggested Cavit and Z100 composite resin require further investigations as potentially useful materials for this purpose.
Assuntos
Força de Mordida , Corantes , Infiltração Dentária/classificação , Restauração Dentária Temporária/métodos , Teste de Materiais/métodos , Materiais Restauradores do Canal Radicular/uso terapêutico , Tratamento do Canal Radicular/métodos , Dente Pré-Molar , Sulfato de Cálcio/química , Sulfato de Cálcio/uso terapêutico , Cimentos Cermet/química , Cimentos Cermet/uso terapêutico , Resinas Compostas/química , Resinas Compostas/uso terapêutico , Cimentos Dentários , Combinação de Medicamentos , Desenho de Equipamento , Cimentos de Ionômeros de Vidro/química , Cimentos de Ionômeros de Vidro/uso terapêutico , Humanos , Maleatos/química , Maleatos/uso terapêutico , Mastigação , Teste de Materiais/instrumentação , Azul de Metileno , Metilmetacrilatos/química , Metilmetacrilatos/uso terapêutico , Polivinil/química , Polivinil/uso terapêutico , Materiais Restauradores do Canal Radicular/química , Preparo de Canal Radicular/métodos , Dióxido de Silício/química , Dióxido de Silício/uso terapêutico , Estresse Mecânico , Propriedades de Superfície , Óxido de Zinco/química , Óxido de Zinco/uso terapêutico , Cimento de Óxido de Zinco e Eugenol/química , Cimento de Óxido de Zinco e Eugenol/uso terapêutico , Zircônio/química , Zircônio/uso terapêuticoRESUMO
This study evaluated the surface microhardness and fluoride release of 5 restorative materials - Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom and Fluorofil - in two storage media: distilled/deionized water and a pH-cycling (pH 4.6). Twelve specimens of each material, were fabricated and the initial surface microhardness (ISM) was determined in a Shimadzu HMV-2000 microhardness tester (static load Knoop). The specimens were submitted to 6- or 18-h cycles in the tested media. The solutions were refreshed at the end of each cycle. All solutions were stored for further analysis. After 15-day storage, the final surface microhardness (FSM) and fluoride release were measured. Fluoride dose was measured with a fluoride-specific electrode (Orion 9609-BN) and digital ion analyzer (Orion 720 A). The variables ISM, FSM and fluoride release were analyzed statistically by analysis of variance and Tukey's test (p<0.05). There was significant difference in FSM between the storage media for Vitremer (pH 4.6 = 40.2 +/- 1.5; water = 42.6 +/- 1.4), Ketac-Fil Plus (pH 4.6 = 73.4 +/- 2.7; water = 58.2 +/- 1.3) and Fluorofil (pH 4.6 = 44.3 +/- 1.8; water = 38.4 +/- 1.0). Ketac-Fil Plus (9.9 +/- 18.0) and Fluorofil (4.4 +/- 1.3) presented higher fluoride release in water, whereas Vitremer (7.4 +/- 7.1), Fuji II LC (5.7 +/- 4.7) and Freedom (2.1 +/- 1.7) had higher fluoride release at pH 4.6. Microhardness and fluoride release of the tested restorative materials varied according to the storage medium.
Assuntos
Cariostáticos/química , Materiais Dentários/química , Fluoretos/química , Acetatos/química , Soluções Tampão , Cálcio/química , Compômeros/química , Resinas Compostas/química , Difusão , Cimentos de Ionômeros de Vidro/química , Dureza , Humanos , Concentração de Íons de Hidrogênio , Eletrodos Seletivos de Íons , Maleatos/química , Teste de Materiais , Fósforo/química , Resinas Sintéticas/química , Propriedades de Superfície , Trometamina/química , Água/químicaRESUMO
This study evaluated the surface microhardness and fluoride release of 5 restorative materials - Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom and Fluorofil - in two storage media: distilled/deionized water and a pH-cycling (pH 4.6). Twelve specimens of each material, were fabricated and the initial surface microhardness (ISM) was determined in a Shimadzu HMV-2000 microhardness tester (static load Knoop). The specimens were submitted to 6- or 18-h cycles in the tested media. The solutions were refreshed at the end of each cycle. All solutions were stored for further analysis. After 15-day storage, the final surface microhardness (FSM) and fluoride release were measured. Fluoride dose was measured with a fluoride-specific electrode (Orion 9609-BN) and digital ion analyzer (Orion 720 A). The variables ISM, FSM and fluoride release were analyzed statistically by analysis of variance and Tukey's test (p<0.05). There was significant difference in FSM between the storage media for Vitremer (pH 4.6 = 40.2 ± 1.5; water = 42.6 ± 1.4), Ketac-Fil Plus (pH 4.6 = 73.4 ± 2.7; water = 58.2 ± 1.3) and Fluorofil (pH 4.6 = 44.3 ± 1.8; water = 38.4 ± 1.0). Ketac-Fil Plus (9.9 ± 18.0) and Fluorofil (4.4 ± 1.3) presented higher fluoride release in water, whereas Vitremer (7.4 ± 7.1), Fuji II LC (5.7 ± 4.7) and Freedom (2.1 ± 1.7) had higher fluoride release at pH 4.6. Microhardness and fluoride release of the tested restorative materials varied according to the storage medium.
Este estudo avaliou as propriedades de microdureza de superfície e liberação de flúor de 5 materiais restauradores (Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom e Fluorofil) em dois meios de imersão: água destilada/deionizada e modelo de ciclagem de pH (4,6). Doze corpos-de-prova de cada material foram confeccionados e tiveram a microdureza de superfície inicial (MSI) determinada utilizando o microdurômetro Shimadzu HMV-2000 Micro Hardness Tester (carga estática Knoop). Os corpos-de-prova foram submetidos a ciclos de 6 e 18 h para os dois meios de imersão. A cada final de ciclo as soluções foram substituídas e armazenadas. Após 15 dias de imersão, a microdureza de superfície final (MSF) e a liberação de flúor foram determinadas. A dosagem de flúor foi feita com um eletrodo específico combinado para íon flúor (9609 BN - Orion) e analisador de íons digital (Orion 720 A). As variáveis MSI, MSF e liberação de flúor foram submetidas à análise de variância e teste de Tukey (p<0,05). Houve diferença estatisticamente significante na MSF entre os meios de imersão para o Vitremer (pH 4,6 = 40,2 ± 1,5; água = 42,6 ± 1,4), Ketac-Fil Plus (pH 4,6 = 73,4 ± 2,7; água = 58,2 ± 1,3) e Fluorofil (pH 4,6 = 44,3 ± 1,8; água = 38,4 ± 1,0). O Ketac-Fil Plus (9,9 ± 18,0) e o Fluorofil (4,4 ± 1,3) liberaram mais flúor na água; o Vitremer (7,4 ± 7,1), Fuji II LC (5,7 ± 4,7) e o Freedom (2,1 ± 1,7) no pH 4,6. A microdureza e liberação de flúor dos materiais restauradores estudados variaram de acordo com o meio de imersão.
Assuntos
Humanos , Cariostáticos/química , Materiais Dentários/química , Fluoretos/química , Acetatos/química , Soluções Tampão , Cálcio/química , Compômeros/química , Resinas Compostas/química , Difusão , Cimentos de Ionômeros de Vidro/química , Dureza , Concentração de Íons de Hidrogênio , Eletrodos Seletivos de Íons , Teste de Materiais , Maleatos/química , Fósforo/química , Resinas Sintéticas/química , Propriedades de Superfície , Trometamina/química , Água/químicaRESUMO
OBJECTIVE: To study the chemical constituents of Abelmoschus manihot. METHOD: Chromatographic methods were used to isolate compounds from A. manihot, and spectroscopic methods were used to identify the structures. RESULT: Thirteen compounds, myricetin (1), cannabiscitrin (2), myricetin-3-O-beta-D-glucopyranoside (3), glycerolmonopalmitate (4), 2, 4-dihydroxy benzoic acid (5), guanosine (6), adenosine (7), maleic acid (8), heptatriacontanoic acid (9), 1-triacontanol (10) , tetracosane (11), beta-sitosterol (12), beta-sitosterol-3-O-beta-D-glucoside (13) were obtained. CONCLUSION: 2-11 were obtained from the genus for the first time.