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1.
Bull Tokyo Dent Coll ; 62(4): 245-251, 2021 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-34776473

RESUMO

Here we describe a rare case of mandibular cancer involving almost the entire attached gingiva in a 71-year-old man. First, marginal resection of the entire mandible was performed, followed by one-stage reconstruction comprising application of a split-thickness skin graft onto the wound. This resulted in good alveolar ridge morphology, allowing for a mandibular prosthesis to be installed soon postoperatively. Histopathological analysis revealed a well-differentiated squamous cell carcinoma extending throughout most of the resected attached gingiva, but no malignant features in the stumps. Furthermore, no infiltration into the jawbone was observed, and no vascular or lymphatic invasion or perineural infiltration. At 3 years postoperatively, the patient's clinical course has remained uneventful, with no recurrence or problems arising in the remaining mandible. The patient is also able to eat regularly using the mandibular prosthesis provided.


Assuntos
Carcinoma de Células Escamosas , Gengiva , Idoso , Processo Alveolar , Carcinoma de Células Escamosas/cirurgia , Gengiva/cirurgia , Humanos , Masculino , Mandíbula/cirurgia
2.
Amino Acids ; 46(10): 2347-54, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24965528

RESUMO

In this study, we describe the first aqueous microwave-assisted synthesis of histidine-containing peptides in high purity and with low racemization. We have previously shown the effectiveness of our synthesis methodology for peptides including difficult sequences using water-dispersible 9-fluorenylmethoxycarbonyl-amino acid nanoparticles. It is an organic solvent-free, environmentally friendly method for chemical peptide synthesis. Here, we studied the racemization of histidine during an aqueous-based coupling reaction with microwave irradiation. Under our microwave-assisted protocol using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, the coupling reaction can be efficiently performed with low levels of racemization of histidine. Application of this water-based microwave-assisted protocol with water-dispersible 9-fluorenylmethoxycarbonyl-amino acid nanoparticles led to the successful synthesis of the histidine-containing hexapeptide neuropeptide W-30 (10-15), Tyr-His-Thr-Val-Gly-Arg-NH2, in high yield and with greatly reduced histidine racemization.


Assuntos
Aminoácidos/química , Fluorenos/química , Química Verde , Histidina/química , Neuropeptídeos/síntese química , Oligopeptídeos/síntese química , Fragmentos de Peptídeos/síntese química , Técnicas de Síntese em Fase Sólida , Animais , Indicadores e Reagentes/química , Micro-Ondas , Morfolinas/química , Nanopartículas/química , Neuropeptídeos/química , Oligopeptídeos/química , Fragmentos de Peptídeos/química , Ratos , Solubilidade , Estereoisomerismo
3.
J Nat Prod ; 77(4): 948-54, 2014 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-24689857

RESUMO

Leukemia is a hematologic malignancy with a frequent incidence and high mortality rate. Previous studies have shown that the FLT3 gene is overexpressed in leukemic blast cells, especially in acute myeloid leukemia. In this study, a commercially available curcuminoid mixture (1), pure curcumin (2), pure demethoxycurcumin (3), and pure bisdemethoxycurcumin (4) were investigated for their inhibitory effects on cell growth, FLT3 expression, and cell cycle progression in an FLT3-overexpressing EoL-1 leukemic cell line using an MTT assay, Western blotting, and flow cytometry, respectively. The mixture (1) and compounds 2-4 demonstrated cytotoxic effects with IC50 values ranging from 6.5 to 22.5 µM. A significant decrease in FLT3 protein levels was found after curcuminoid treatment with IC20 doses, especially with mixture 1 and compound 2. In addition, mixture 1 and curcumin (2) showed activity on cell cycle arrest at the G0/G1 phase and decreased the FLT3 and STAT5A protein levels in a dose-dependent manner. Compound 2 demonstrated the greatest potential for inhibiting cell growth, cell cycle progression, and FLT3 expression in EoL-1 cells. This investigation has provided new findings regarding the effect of turmeric curcuminoids on FLT3 expression in leukemic cells.


Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Curcuma/química , Curcumina/análogos & derivados , Tirosina Quinase 3 Semelhante a fms/genética , Proliferação de Células/efeitos dos fármacos , Curcumina/química , Curcumina/farmacologia , Diarileptanoides , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Estrutura Molecular
4.
Eur J Pharm Biopharm ; 170: 133-143, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34864196

RESUMO

For binder-free dry particulate coating to prepare controlled-release micron-sized particles, we designed nanocomposite coating agents with the intention to form a core-shell structure composed of two types of acrylic polymers with different glass transition temperatures (Tg) and evaluated their coating performance. A series of nanocomposite acrylic latexes synthesized by emulsion polymerization was freeze-dried after salting-out to create the powder form. An ion-exchange resin loaded with diclofenac sodium (DS, a model drug) (IER-DS) with a median diameter of approximately 100 µm was used as the core particle. Dry coating of the IER-DS with nanocomposite coating agents was carried out using a laboratory-made coating apparatus assisted with mild-intensity vibration and zirconia bead impaction. The coated particles were cured by heating at a temperature 20 °C higher than the Tg for 12 h to complete the film-forming process. It was found that the highest coating efficiency (more than 70%) and a remarkably prolonged release period of the drug (the time required for 50% release reached approximately 12 h) could be achieved when nanocomposite coating agents with a soft polymeric core (Tg = 30 °C) and a hard polymeric shell (Tg = 80 °C) were applied. In contrast, nanocomposite coating agents with a combination of a hard polymeric core and a soft polymeric shell resulted in lower coating efficiency. These results demonstrate that nanocomposite polymeric coating agents composed of a soft core and a hard shell are effective for the production of drug-loaded microparticles with a prolonged release function by a binder-free dry-coating process.


Assuntos
Acrilatos/química , Química Farmacêutica/métodos , Materiais Revestidos Biocompatíveis/química , Preparações de Ação Retardada/química , Diclofenaco/química , Liofilização , Nanocompostos , Tamanho da Partícula , Polímeros/química , Temperatura
5.
J Pept Sci ; 17(7): 487-92, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21495120

RESUMO

Regulatory pressure has compelled the chemical manufacturing industry to reduce the use of organic solvents in synthetic chemistry, and there is currently a strong focus on replacing these solvents with water. Here, we describe an efficient in-water solution-phase peptide synthesis method using Boc-amino acids. It is based on a coupling reaction utilizing suspended water-dispersible nanoparticle reactants. Using this method, peptides were obtained in good yield and with high purity.


Assuntos
Aminoácidos/química , Ésteres do Ácido Fórmico/química , Nanopartículas/química , Peptídeos/química , Peptídeos/síntese química , Água/química , Cromatografia Líquida de Alta Pressão , Encefalina Leucina/análogos & derivados , Encefalina Leucina/síntese química , Encefalina Leucina/química , Estrutura Molecular , Soluções/química , Solventes/química
6.
Appl Radiat Isot ; 169: 109407, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33444907

RESUMO

Synovial sarcoma is a rare tumor requiring new treatment methods. A 46-year-old woman with primary monophasic synovial sarcoma in the left thigh involving the sciatic nerve, declining surgery because of potential dysfunction of the affected limbs, received two courses of BNCT. The tumor thus reduced was completely resected with no subsequent recurrence. The patient is now able to walk unassisted, and no local recurrence has been observed, demonstrating the applicability of BNCT as adjuvant therapy for synovial sarcoma. Further study and analysis with more experience accumulation are needed to confirm the real impact of BNCT efficacy for its application to synovial sarcoma.


Assuntos
Terapia por Captura de Nêutron de Boro , Sarcoma Sinovial/radioterapia , Terapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Sarcoma Sinovial/diagnóstico por imagem , Sarcoma Sinovial/cirurgia
7.
Appl Radiat Isot ; 164: 109270, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819508

RESUMO

Neutron capture therapy using 157Gd (Gd-NCT) is currently under development as a cancer radiotherapy. Melanoma cells were treated with gadolinium-loaded chitosan nanoparticles (Gd-nanoCPs) for Gd-NCT. Smaller Gd-nanoCPs had higher Gd content and better cellular association of Gd and thereby made the tumor-killing effect more efficient in comparison to larger Gd-nanoCPs. This indicates that Gd-nanoCP size reduction is an efficient method for improving the cellular affinity of Gd-nanoCPs and for enhancing the tumor-killing effect of Gd-NCT.


Assuntos
Quitosana/química , Gadolínio/química , Melanoma Experimental/radioterapia , Nanopartículas/química , Terapia por Captura de Nêutron/métodos , Animais , Proliferação de Células , Melanoma Experimental/patologia , Camundongos , Peso Molecular , Tamanho da Partícula
8.
Appl Radiat Isot ; 165: 109257, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32777739

RESUMO

Bone metastasis has a major impact on the quality of life that general therapy cannot control. We established a bone metastasis model with a human breast cancer cell line and investigated the therapeutic effect of boron neutron capture therapy (BNCT). BNCT suppressed tumor growth in cases of intramedullary small tumors without damaging normal tissues, providing preliminary evidence that it is a potentially new therapeutic option for controlling tumor growth from bone metastasis. Further research is warranted for its clinical application.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Compostos de Boro/química , Terapia por Captura de Nêutron de Boro/métodos , Neoplasias da Mama/patologia , Fenilalanina/química , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Appl Radiat Isot ; 166: 109324, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32861973

RESUMO

Clear cell sarcoma of tendons and aponeuroses (CCS) is a rare, malignant tumor arising in lower extremities with no effective treatment other than wide surgical resection. Here described is a case of primary CCS in the peroneal tendon of the right foot of a 54-year-old woman enrolled to undergo BNCT. The tumor mass post-BNCT disappeared totally without damage to other normal tissue, demonstrating, for the first time, the potential efficacy of BNCT in complete local control of CCS.


Assuntos
Terapia por Captura de Nêutron de Boro/métodos , Doenças do Pé/radioterapia , Sarcoma de Células Claras/radioterapia , Tendões , Biópsia por Agulha , Feminino , Doenças do Pé/diagnóstico por imagem , Doenças do Pé/patologia , Humanos , Neoplasias Pulmonares/secundário , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Planejamento da Radioterapia Assistida por Computador , Sarcoma de Células Claras/diagnóstico por imagem , Sarcoma de Células Claras/secundário , Tendões/diagnóstico por imagem , Tendões/patologia , Resultado do Tratamento
10.
Int J Pharm ; 561: 206-218, 2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-30822506

RESUMO

We employed a new dry coating process with mild-intensity vibration to prepare a 100-µm-sized microparticle capable of prolonged release of a drug. To accomplish this without using a binder, a series of laboratory-made acrylic latexes with different glass transition temperatures (Tg) ranging from 30 °C to 80 °C were employed as coating agents, and the effects of Tg and powdering method of the coating agents on coating performance were investigated. The laboratory-made acrylic latexes were powdered by spray-drying (SD) or freeze-drying (FD). Diclofenac sodium (DS)-loaded ion-exchange-resin with particle size ∼100 µm was used as a core particle. The process utilized vibrations with amplitude of 0.5 mm and frequency of 90 Hz to form an ordered mixture composed of the core particles with the loosely-layered coating agents. Subsequently, the coating agents were fixed mechanically on the core particle by impaction of zirconia beads. The coating agents powdered by FD showed higher coating efficiencies than those powdered by SD, irrespective of the differences in Tg values. Among the coating agents powdered by FD, the particles coated at Tg = 60 °C exhibited the most prolonged drug-release, although the coating efficiency was not the highest. In our proposed process utilizing mild vibration, we demonstrated that adjusting the Tg of the coating agents is crucial to the formation of binder-free multiple coating layers for prolonged drug release.


Assuntos
Composição de Medicamentos/métodos , Polímeros/química , Pós/química , Temperatura de Transição , Vibração , Preparações de Ação Retardada/química , Dessecação/métodos , Diclofenaco/química , Liberação Controlada de Fármacos , Resinas de Troca Iônica/química , Látex/química , Tamanho da Partícula , Zircônio/química
11.
Curr Drug Deliv ; 4(2): 131-40, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17456032

RESUMO

The effects of the formulation and particle composition of gadolinium (Gd)-containing lipid nanoemulsion (Gd-nanoLE) on the biodistribution of Gd after its intravenous (IV) injection in D(1)-179 melanoma-bearing hamsters were evaluated for its application in cancer neutron-capture therapy. Gd-nanoLEs whose particles had an oily core (soybean oil, ethyl oleate, lipiodol, or triolein) and a surface layer of hydrogenated phosphatidylcholine, gadolinium-diethyl-enetriaminepentaacetic acid-distearylamide, and a cosurfactant (Myrj 53, Brij 700, or HCO-60) were prepared by a thin-layer hydration-sonication method. Biodistribution data revealed that Brij 700 and HCO-60 prolonged the retention of Gd in the blood and enhanced its accumulation in tumors. Among the core components employed, soybean oil yielded the highest Gd concentration in the blood and tumor and the lowest in the liver and spleen. Gd-nanoLEs with a Gd content of 1.5-4.5 mg/ml could be formulated by using HCO-60 and soybean oil at a constant oil-to-water ratio, and by enriching Gd in the surface layer with the particle size maintained below 100 nm. When each Gd-nanoLE was IV injected once or twice at a 24-h interval, the Gd concentration in the tumor correlated well with the total dose of Gd, and it reached a maximum of 189 microg/g wet tumor. This maximum Gd level was greater than the limit required for significantly suppressing tumor growth in neutron-capture therapy.


Assuntos
Portadores de Fármacos , Gadolínio DTPA/administração & dosagem , Gadolínio DTPA/farmacocinética , Lipídeos/química , Melanoma Experimental/metabolismo , Nanopartículas , Terapia por Captura de Nêutron/métodos , Animais , Óleo de Rícino/análogos & derivados , Óleo de Rícino/química , Linhagem Celular Tumoral , Química Farmacêutica , Cricetinae , Composição de Medicamentos , Emulsões , Feminino , Gadolínio DTPA/sangue , Gadolínio DTPA/química , Injeções Intravenosas , Óleo Iodado/química , Mesocricetus , Ácidos Oleicos/química , Fosfatidilcolinas/química , Polietilenoglicóis/química , Óleo de Soja/química , Tensoativos/química , Tecnologia Farmacêutica , Distribuição Tecidual , Trioleína/química
12.
Yakugaku Zasshi ; 127(5): 813-23, 2007 May.
Artigo em Japonês | MEDLINE | ID: mdl-17473523

RESUMO

Biologically active peptides for therapeutic use have relatively short half-lives in general, requiring appropriate controlled-release systems for better therapy. Controlled release of peptides is, however, not as easy as that of conventional drugs because their large molecular size is much more dramatic in hindering the diffusion and release from polymeric devices. From this perspective, we have been developing two types of microcapsular devices containing new acrylate-based nanogels with a specific solute-permeability for delayed- or thermosensitive-release of peptide drugs. The microcapsule preparation was accomplished by an air suspension coating process. A nanogel-particle of acrylic terpolymer, ethyl acrylate-methyl methacrylate-2-hydroxyethyl methacrylate, was newly synthesized by emulsion polymerization to construct delayed-release microcapsules. By spray-coating the insulin-loaded lactose particles with the acrylic terpolymers, microcapsules showing a pH-independent delayed-release profile can be obtained. Oral administration of the microcapsules with the lag time of 6 hours to beagle dogs resulted in significantly reduced blood glucose concentration, leading to colon-specific insulin delivery with pharmacological availability of 5%. Meanwhile, poly(N-isopropylcarylamide) (p(NIPAAm)) nanogel-particles with a reversible temperature-dependent swelling property were prepared by dispersion polymerization to fabricate microcapsular membranes with thermosensitively changeable permeability. The microcapsules constructed by coating of drug-loaded CaCO(3) particles with a blend mixture of the p(NIPAAm) nanogels and ethylcellulose pseudo-latex exhibited an 'on-off' positively thermosensitive drug-release; the release rate was remarkably enhanced at higher temperatures possibly due to the formation of voids through the shrinkage of p(NIPAAm) nanogels in the membrane. A possible application of this type of microcapsules can be found in externally temperature-activated pulsatile peptide delivery.


Assuntos
Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Hidrogéis , Nanocápsulas , Peptídeos/administração & dosagem , Preparações Farmacêuticas/administração & dosagem , Acrilamidas , Animais , Preparações de Ação Retardada , Cães , Peptídeos/farmacocinética , Polímeros , Temperatura
13.
Carbohydr Res ; 341(17): 2835-41, 2006 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-17045253

RESUMO

In order to provide a suitable device that would contain water-soluble drugs, highly water-soluble gadolinium diethylenetriaminopentaacetic acid-loaded chitosan microspheres (CMS-Gd-DTPA) were prepared by the emulsion method using glutaraldehyde as a cross-linker and Span 80 as a surfactant for gadolinium neutron-capture therapy of cancer. The gadolinium content and the mass median diameter of CMS-Gd-DTPA were estimated. The size and morphology of the CMS-Gd-DTPA were strongly influenced by the initial applied weight ratio of Gd-DTPA:chitosan. FTIR spectra showed that the electrostatic interaction between chitosan and Gd-DTPA accelerated the formation of gadolinium-enriched chitosan microspheres. Sufficient amounts of glutaraldehyde and Span 80 were necessary for producing discrete CMS-Gd-DTPA. The CMS-Gd-DTPA having a mass median diameter 11.7microm and 11.6% of gadolinium could be used in Gd-NCT following intratumoral injection.


Assuntos
Portadores de Fármacos/administração & dosagem , Gadolínio DTPA/administração & dosagem , Microesferas , Terapia por Captura de Nêutron/instrumentação , Antineoplásicos/administração & dosagem , Quitosana , Preparações de Ação Retardada , Terapia por Captura de Nêutron/métodos
14.
Int J Pharm ; 307(2): 300-7, 2006 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-16309860

RESUMO

A series of poly(ethyl acrylate (EA)/methyl methacrylate (MMA)/2-hydroxyethyl methacrylate (HEMA)) lattices were synthesized to prepare short-term delayed-release microcapsules by employing the Wurster coating process. Latex with a HEMA molar fraction exceeding 60% could not be synthesized as an aqueous suspension due to latex particle precipitation. The effects of monomer composition on the particle size of latex and the water-uptake and glass transition temperature (T(g)) of cast films were investigated. Lattices whose T(g) ranged from 40 to 80 degrees C were used to prepare the microcapsules. Most of the lattices exhibited excellent process performance while coating particles that were smaller than 100 microm: the product yields were 85.1-90.6% and the mean particle sizes were 82-85 microm. However, since the lattices with high molar ratios of EA and HEMA were highly hydrophilic and strongly adhesive, the core particles in the coating were severely agglomerated. The microcapsules coated with lattices whose HEMA molar fractions were higher than 50% were unable to retard the release of carbazochrome sodium sulfonate, a water-soluble model drug, during the initial 0.5 min. Poly(EA/MMA/HEMA) with a molar ratio of 9:9:10 appeared to be suitable for the preparation of short-term delayed-release microcapsules by the Wurster coating process.


Assuntos
Acrilatos/química , Cápsulas/química , Polímeros/química , Adesividade , Adrenocromo/análogos & derivados , Adrenocromo/química , Preparações de Ação Retardada , Látex/química , Metacrilatos/química , Metilmetacrilato/química , Tamanho da Partícula , Polímeros/síntese química , Solubilidade , Fatores de Tempo , Temperatura de Transição , Água/química
15.
Colloids Surf B Biointerfaces ; 53(2): 278-87, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17098400

RESUMO

We used the atomic force microscope to study how the cell type and the density of cells adsorbed at a substrate can affect the adhesion between a living cell and a model drug delivery system (DDS) carrier nano-particle. We used three different anchorage-dependent cells, i.e., a living mouse fibroblast cell (L929), a living human colon cancer cell (Caco2), and a living mouse malignant melanoma cell (B16F10). For the DDS model nano-particle, we used a silica colloid. In order to correlate the adhesion force with the cell types, the growth curve of the cells were determined with a haemocytometer. The shapes of the cells at the different stages were monitored by light microscopy, and the morphology of their surfaces obtained by tapping mode atomic force microscopy. Force measurements showed that the Caco2 cell bound little to a silica particle, regardless of the cell density. The L929 cell bound well to a silica particle for low and high cell densities. The B16F10 cell bound little to a silica particle for low cell densities, but bound well for high cell densities. AFM images showed that the L929 cell did not contain folds. The B16F10 cells, however, displayed folds in the cell surface for low cell densities, but no folds in the cell for high cell densities. As literature also reported that the Caco2 cell contains folds, these results suggested that cells with folds showed less adhesion to a silica particle than cells without folds. The presence of folds in the cell presumably decreased the number of sites on the cell that could hydrogen bond or undergo van der Waals binding with the silanol groups of the silica particle.


Assuntos
Adesão Celular/fisiologia , Neoplasias do Colo/metabolismo , Fibroblastos/metabolismo , Melanoma Experimental/metabolismo , Microscopia de Força Atômica , Dióxido de Silício/metabolismo , Animais , Contagem de Células , Fenômenos Fisiológicos Celulares , Neoplasias do Colo/patologia , Fibroblastos/citologia , Humanos , Melanoma Experimental/patologia , Camundongos , Dióxido de Silício/química , Propriedades de Superfície
16.
J Nutr Biochem ; 16(2): 121-8, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15681172

RESUMO

We succeeded in purifying the major glycolipid fraction in the class of sulfoquinovosyl diacylglycerol, monogalactosyl diacylglycerol and digalactosyl diacylglycerol (DGDG) from a green vegetable, spinach (Spinacia oleracea L.). This glycolipid fraction was an inhibitor of DNA polymerases and a growth inhibitor of NUGC-3 human gastric cancer cells, and, interestingly, the activities were much stronger when the fraction was hydrolyzed by lipase. Glycolipids in the hydrolyzed fraction consisted of sulfoquinovosyl monoacylglycerol (SQMG), monogalactosyl monoacylglycerol (MGMG) and DGDG. In the in vivo antitumor assay using Greene's melanoma, the fraction containing SQMG, MGMG and DGDG showed to be a promising suppressor of solid tumors. Spinach glycolipid fraction might be a potent antitumor compound if directly injected into a tumor-carrying body, and this fraction may be a healthy food material that has antitumor activity.


Assuntos
Antineoplásicos/farmacologia , Glicolipídeos/metabolismo , Glicolipídeos/farmacologia , Lipase/metabolismo , Inibidores da Síntese de Ácido Nucleico , Spinacia oleracea/química , Animais , Divisão Celular/efeitos dos fármacos , Cricetinae , Inibidores Enzimáticos/farmacologia , Galactolipídeos/farmacologia , Humanos , Hidrólise , Melanoma/tratamento farmacológico , Melanoma/patologia , Transplante de Neoplasias , Neoplasias Gástricas/patologia , Células Tumorais Cultivadas
17.
J Colloid Interface Sci ; 286(2): 433-9, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15897054

RESUMO

Chitosan, a naturally abundant biopolymer, has widely been studied for metal adsorption from various solutions, but the extension of chitosan as an adsorbent to remove organic substances from water and wastewater has seldom been explored. In this study, the adsorption of an azo dye, trisodium 2-hydroxy-1,1'-azonaphthalene-3,4',6-trisulfonate (1), from aqueous solution onto the various degrees of deacetylated chitosan has been investigated. Equilibrium studies have been carried out to determine the capacity of chitosan for dye. The experimental data were analyzed using two isotherm correlations, namely, Langmuir and Freundlich equations. The linear correlation coefficients were determined for each isotherm and the Langmuir provided the best fit. The experimental adsorption isotherms were perfectly reproduced in the simulated data obtained from numerical analysis on the basis of the Langmuir model and the isotherm constants. Adsorption of (1) onto the chitosan flakes was found to be strongly depending on degrees of deacetylation in chitosan and temperatures. Significant amounts of (1) were adsorbed by chitosan 8B (higher degree of deacetylated chitosan), but the adsorption capacity was reduced remarkably with increasing solution temperatures. Thermodynamic parameters such as change in free energy (DeltaG), enthalpy (DeltaH), and entropy (DeltaS) were also determined. In addition, kinetic study indicated that the adsorption process mechanisms were both transport- and attachment-limited.


Assuntos
Compostos Azo/química , Quitosana/química , Corantes/química , Naftalenos/química , Adsorção , Cinética , Estrutura Molecular , Termodinâmica
18.
Int J Mol Med ; 35(6): 1720-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25891482

RESUMO

The polyphenolic compound, curcumin, is a natural yellow pigment component of turmeric. It exerts various biological effects, such as anti-inflammatory effects, and we have previously demonstrated that curcumin is a specific inhibitor of DNA polymerase λ. Curcumin is characterized by poor bioavailability as it is water-insoluble, is poorly absorbed and is systemically eliminated. In order to increase the bioavailability of curcumin, in this study, we produced a curcumin-loaded lipid nanoemulsion of various particle sizes (50, 100 and 200 nm). The curcumin lipid nanoemulsion was prepared by a modified thin-film hydration method followed by sonication. To identify the optimal particle size which exhibits the strongest physiological activity, we investigated the inhibitory effects of the obtained nanoemulsions against inflammatory and allergic activities. In in vitro cell culture experiments, the 100-nm curcumin lipid nanoemulsion showed the most prominent inhibitory effect on the production of tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in RAW264.7 murine macrophages, and on the release of ß-hexosaminidase induced by the calcium ionophore, A23187, in rat basophilic leukemia RBL-2H3 cells. In an in vivo experiment, in which mice were administered the curcumin-loaded lipid nanoemulsion of various particle sizes, the 100-nm curcumin lipid nanoemulsion showed the most prominent anti-inflammatory and anti-allergic effects, inhibiting 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory ear edema and immunoglobulin E (IgE)-induced passive cutaneous anaphylactic (PCA) reaction. The effects of particle size on serum curcumin absorption were also assessed in mice, and the 100-nm lipid nanoemulsion showed the greatest absorption. The results from our study suggest that the physiological activities of curcumin lipid nanoemulsions differ depending on particle size. Our data indicate that the curcumin lipid nanoemulsion with a particle size of 100 nm has potential for use in enhancing the bioavailability and medical value of curcumin.


Assuntos
Anti-Inflamatórios , Curcumina , Portadores de Fármacos , Edema/tratamento farmacológico , Nanopartículas/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Curcumina/química , Curcumina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Edema/induzido quimicamente , Edema/metabolismo , Edema/patologia , Emulsões , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Tamanho da Partícula , Ratos , Acetato de Tetradecanoilforbol/toxicidade , Fator de Necrose Tumoral alfa/metabolismo
19.
Springerplus ; 4: 442, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26312207

RESUMO

Long-term parenteral nutrition (PN) can induce intestinal atrophy, leading to a loss of epithelial integrity in the small intestines. This change may alter the intestinal permeability of vancomycin (VCM), a non-absorbable antibiotic. The aim of the present study was to investigate the effect of PN on the pharmacokinetics of VCM in rats. VCM was intravenously (5 mg/kg) or intraduodenally (20 mg/kg) administered to control and PN rats, which were prepared by administration of PN for 9 days. After intravenous administration, there were no significant differences in any of the VCM pharmacokinetic parameters between the control and PN rats. However, after intraduodenal administration, the maximum concentration and area under the plasma concentration-time curve of VCM in PN rats was approximately 2.4- and 2.6-fold higher, respectively, than in the control rats; the calculated bioavailability was approximately 0.5 and 1.3 % in control and PN rats, respectively. These results indicated that PN administration did not affect VCM disposition, but enhanced VCM absorption; however, the enhanced oral VCM bioavailability was statistically, not clinically, significant. Therefore, while long-term PN administration may play a role in the enhancement of VCM bioavailability, this effect may be negligible without any complications.

20.
JPEN J Parenter Enteral Nutr ; 39(2): 218-27, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23894177

RESUMO

BACKGROUND: Long-term parenteral nutrition (PN) has a high risk of hepatic dysfunction and intestinal atrophy. The present study investigated the effect of PN-induced intestinal atrophy and hepatic impairment on drug pharmacokinetics by using 2 contrasting compounds: phenolsulfonphthalein (PSP) and cyclosporin A (CyA). MATERIALS AND METHODS: PSP or CyA was administered to 7-day PN-fed Rats (PN rats) and sham operated rats (control rats) via intravenous (IV) or intraloop administration of the intestine. Pharmacokinetic parameters with 2-compartment analysis including area under the concentration vs time curve (AUC) and the permeability after in situ intraloop administration (P loop) were obtained from both concentration profiles after different administration routes. RESULTS: After IV administration of PSP to control and PN rats, there was no notable difference in any of the pharmacokinetic parameters. In contrast, after intraloop administration, AUC and P loop in PN rats were approximately 2.6- and 2.0-fold higher than that in control rats, respectively. On the other hand, after IV administration of CyA, the terminal half-life and total body clearance were prolonged and decreased in PN rats, respectively, resulting in 2.0-fold increase in AUC. After intraloop administration, the AUC of PN rats was increased to approximately 1.3-fold that of control rats, whereas no notable difference was observed in P loop. CONCLUSION: The intestinal permeability of PSP was enhanced by intestinal atrophy induced by PN, while the metabolism of CyA was diminished by hepatic impairment by PN. These results revealed the physicochemical property-based pharmacokinetic alterations during PN; for a more detailed understanding, however, further studies are needed.


Assuntos
Ciclosporina/farmacocinética , Intestinos/patologia , Hepatopatias/patologia , Nutrição Parenteral/efeitos adversos , Fenolsulfonaftaleína/farmacocinética , Administração Intravenosa , Animais , Área Sob a Curva , Atrofia/etiologia , Ciclosporina/administração & dosagem , Mucosa Intestinal/metabolismo , Hepatopatias/metabolismo , Masculino , Permeabilidade/efeitos dos fármacos , Fenolsulfonaftaleína/administração & dosagem , Ratos
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