RESUMO
One of the main toxicities associated to intravenous administration of amphiphilic drugs is pronounced hemolytic activity. To overcome this limitation, we investigated the anti-hemolytic properties of polymeric micelles of Pluronics, triblock copolymers of poly(ethylene oxide) and poly(propylene oxide). We studied the encapsulation of the amphiphilic compound miltefosine (HePC) into polymeric micelles of Pluronics F108, F68, F127, L44, and L64. In vitro hemolysis indicated that, among the five copolymers studied, only F127 completely inhibited hemolytic effect of HePC at 50 µg/mL, this effect was also observed for other two amphiphilic molecules (cetyltrimethylammonium bromide and cethylpyridinium chloride). To better understand this interaction, we analyzed the HC50 (concentration causing 50% of hemolysis) for HePC free and loaded into F127 micelles. Copolymer concentration influenced the hemolytic profile of encapsulated HePC; for F127 the HC50 increased relative to free HePC (40 µg/mL) up to 184, 441, 736 and 964 µg/mL, for 1, 3, 6 and 9% F127, respectively. Interestingly, a linear relationship was found between HC50-HePC and F127 concentration. At 3% of F127, it is possible to load up to 300 µg/mL of HePC with no hemolytic effect. By achieving this level of hemolysis protection, a promising application is on the view, bringing the parenteral use of HePC and other amphiphilic drugs. Additionally, small-angle X-ray scattering (SAXS) was used to asses structural information on the interactions between HePC and F127 micelles.
Assuntos
Antifúngicos/farmacologia , Portadores de Fármacos , Hemólise/efeitos dos fármacos , Fosforilcolina/análogos & derivados , Tensoativos/farmacologia , Animais , Antifúngicos/química , Cetrimônio/química , Cetrimônio/farmacologia , Cetilpiridínio/química , Cetilpiridínio/farmacologia , Relação Dose-Resposta a Droga , Composição de Medicamentos/métodos , Eritrócitos/efeitos dos fármacos , Micelas , Fosforilcolina/química , Fosforilcolina/farmacologia , Poloxâmero/química , Poloxâmero/farmacologia , Ovinos , Tensoativos/químicaRESUMO
It is known that cetylpyridinium chloride (CPC) has in vitro and in vivo antifungal action against Candida albicans, with advantages over other common antiseptics. A CPC delivery-controlled system, transported in polymer nanofibers (PVP/PMMA), was developed to increase the bioavailability of the drug in contact with the oral mucosa. The objectives of this study were to determine if CPC in nanofiber has antifungal action against C. albicans, and in what concentration it must be incorporated, so that the fraction released can yield an inhibitory concentration. The nanofiber was prepared by electrospinning, and sterilized with gamma irradiation. Nanofiber disks with 0.05%, 1.25%, 2.5% and 5% CPC, with 5% miconazole (MCZ) and with no drug, as well as filter paper disks with 5% CPC, with 5% MCZ and with no drug were used in this study. A Candida albicans suspension (ATCC 90028) was inoculated in Mueller-Hinton Agar plates. The disks were placed on the plates and the inhibition zone diameters were measured 48h later. The nanopolymeric disks contracted in contact with the agar. All the concentrations of CPC incorporated in the nanofiber presented inhibitory action against C. albicans. Concentrations of 2.5% and 5% CPC presented a significant advantage over the nanofiber with no drug, proving the antifungal action of CPC. Under these experimental conditions, 5% CPC has greater inhibitory action against C. albicans than 5% MCZ, both in nanofiber and in filter paper. A modification made in the polymer to decrease the contraction rate may allow a larger inhibition zone to be maintained, thereby increasing the clinical usefulness of the polymer.
Assuntos
Antifúngicos/administração & dosagem , Candida albicans/efeitos dos fármacos , Cetilpiridínio/administração & dosagem , Nanofibras/química , Polímeros/química , Análise de Variância , Cetilpiridínio/química , Sistemas de Liberação de Medicamentos , Teste de Materiais , Miconazol/administração & dosagem , Reprodutibilidade dos Testes , Propriedades de Superfície/efeitos dos fármacos , Fatores de TempoRESUMO
Native polysaccharide from pineapple gum (PANP) was obtained following alkaline extraction of gum and fractionation with cetylpyridinium chloride. It was characterized as a glucuronoarabinoxylan using NMR, methylation data, controlled Smith degradation, carboxy-reduction, and ESI-MS of oligosaccharides produced on mild acid hydrolysis of PANP. HSPEC-MALLS-RI of carboxy-reduced fraction showed homogeneous profile (Mw 1.943×10(5) g/mol). PANP was composed of Ara, Xyl, Gal, and GlcpA (40:23:7:30 molar ratio). Its main chain presented (1â4)-linked ß-xylan, highly substituted at O-2 and O-3 by side chains of 3-O- and 3,5-di-O-linked α-Araf, 2-O- and 4-O-linked α-GlcpA, and nonreducing end-units of α-Araf, ß-Arap, ß-Galp, and α-GlcpA. ESI-MS of a mixture of oligosaccharides formed on the mild acid hydrolysis of PANP was consistent with repetitive structures of α-GlcpA O-3 linked at ß-Xylp units, whereas in others glucuronoarabinoxylan-type gum exudates, α-GlcpA units had been previously found to be linked at O-2.
Assuntos
Ananas/química , Gomas Vegetais/química , Xilanos/química , Configuração de Carboidratos , Sequência de Carboidratos , Cetilpiridínio/química , Precipitação Fracionada , Hidrólise , Espectroscopia de Ressonância Magnética , Metilação , Dados de Sequência Molecular , Peso Molecular , Oxirredução , Gomas Vegetais/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray , Xilanos/isolamento & purificaçãoRESUMO
Chemical disinfectants are usually associated with mechanical methods to remove stains and reduce biofilm formation. This study evaluated the effect of disinfectants on release of metal ions and surface roughness of commercially pure titanium, metal alloys, and heat-polymerized acrylic resin, simulating 180 immersion trials. Disk-shaped specimens were fabricated with commercially pure titanium (Tritan), nickel-chromium-molybdenum-titanium (Vi-Star), nickel-chromium (Fit Cast-SB Plus), and nickel-chromium-beryllium (Fit Cast-V) alloys. Each cast disk was invested in the flasks, incorporating the metal disk to the heat-polymerized acrylic resin. The specimens (n=5) were immersed in these solutions: sodium hypochlorite 0.05%, Periogard, Cepacol, Corega Tabs, Medical Interporous, and Polident. Deionized water was used as a control. The quantitative analysis of metal ion release was performed using inductively coupled plasma mass spectrometry (ELAN DRC II). A surface analyzer (Surftest SJ-201P) was used to measure the surface roughness (µm). Data were recorded before and after the immersions and evaluated by two-way ANOVA and Tukey's test (α=0.05). The nickel release proved most significant with the Vi-Star and Fit Cast-V alloys after immersion in Medical Interporous. There was a significant difference in surface roughness of the resin (p=0.011) after immersion. Cepacol caused significantly higher resin roughness. The immersion products had no influence on metal roughness (p=0.388). It could be concluded that the tested alloys can be considered safe for removable denture fabrication, but disinfectant solutions as Cepacol and Medical Interporous tablet for daily denture immersion should be used with caution because it caused greater resin surface roughness and greater ion release, respectively.
Assuntos
Ligas Dentárias/química , Bases de Dentadura , Higienizadores de Dentadura/química , Resinas Acrílicas/química , Ligas/química , Alumínio/análise , Berílio/análise , Boratos/química , Cetilpiridínio/química , Clorexidina/análogos & derivados , Clorexidina/química , Cromo/análise , Ligas de Cromo/química , Ácido Cítrico/química , Desinfetantes de Equipamento Odontológico/química , Materiais Dentários/química , Humanos , Teste de Materiais , Metais/análise , Metais/química , Molibdênio/análise , Níquel/análise , Hipoclorito de Sódio/química , Espectrofotometria Atômica , Sulfatos/química , Propriedades de Superfície , Titânio/análise , Titânio/químicaRESUMO
AIMS: To compare three decontamination methods applied to paucibacillary samples for primary isolation of Mycobacterium bovis from suspect lesions. Tuberculosis caused by Myco. bovis is an important infectious disease of cattle in Brazil and also has zoonotic potential. Although a national campaign based on testing and slaughtering cattle has achieved good results, there is a strong need to develop better diagnostic methods to identify cattle with recent infections harbouring few bacilli. METHODS AND RESULTS: A dairy herd (274 adult crossbred cows) located in the state of Rio de Janeiro was tested for tuberculosis with both single intradermal tuberculin test and comparative intradermal tuberculin test. Reactive cows (n=27, 9.8%) were slaughtered and suspect lesions were collected (one sample per cow). Samples considered paucibacillary (based on microscopy) were decontaminated with 0.75% hexadecylpyridinium chloride (HPC), 4% sodium hydroxide (Petroff) or 6% sulphuric acid. Using these methods, 10, five and six, respectively, of the 27 samples yielded positive cultures. Overall, Myco.bovis was isolated from 14 of 24 cows. Although the HPC method resulted in isolation of more Myco.bovis strains than either Petroff or sulphuric acid methods (P=0.015), it did not result in the recovery of Myco.bovis from all samples. However, using both HPC and 6% sulphuric acid methods for decontamination was possible to identify 13 of 14 (92·9%) of infected cows. CONCLUSIONS: At least two methods should be used concurrently for primary isolation of Myco. bovis from bovine tissues, particularly for paucibacillary samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Detection of low numbers of Myco.bovis in tissue is an important goal in optimizing the detection of bovine tuberculosis and should assist in identification of infected cattle, in particular, those with few Myco.bovis bacilli. This was apparently the first study comparing three decontamination methods for the detection of Myco.bovis in paucibacillary samples from naturally infected cattle.
Assuntos
Descontaminação/métodos , Mycobacterium bovis/isolamento & purificação , Tuberculose Bovina/diagnóstico , Animais , Bovinos , Cetilpiridínio/química , Feminino , Pulmão/microbiologia , Pulmão/patologia , Mycobacterium bovis/genética , Teste Tuberculínico , Tuberculose Bovina/microbiologiaRESUMO
Chemical disinfectants are usually associated with mechanical methods to remove stains and reduce biofilm formation. This study evaluated the effect of disinfectants on release of metal ions and surface roughness of commercially pure titanium, metal alloys, and heat-polymerized acrylic resin, simulating 180 immersion trials. Disk-shaped specimens were fabricated with commercially pure titanium (Tritan), nickel-chromium-molybdenum-titanium (Vi-Star), nickel-chromium (Fit Cast-SB Plus), and nickel-chromium-beryllium (Fit Cast-V) alloys. Each cast disk was invested in the flasks, incorporating the metal disk to the heat-polymerized acrylic resin. The specimens (n=5) were immersed in these solutions: sodium hypochlorite 0.05%, Periogard, Cepacol, Corega Tabs, Medical Interporous, and Polident. Deionized water was used as a control. The quantitative analysis of metal ion release was performed using inductively coupled plasma mass spectrometry (ELAN DRC II). A surface analyzer (Surftest SJ-201P) was used to measure the surface roughness (µm). Data were recorded before and after the immersions and evaluated by two-way ANOVA and Tukey's test (α=0.05). The nickel release proved most significant with the Vi-Star and Fit Cast-V alloys after immersion in Medical Interporous. There was a significant difference in surface roughness of the resin (p=0.011) after immersion. Cepacol caused significantly higher resin roughness. The immersion products had no influence on metal roughness (p=0.388). It could be concluded that the tested alloys can be considered safe for removable denture fabrication, but disinfectant solutions as Cepacol and Medical Interporous tablet for daily denture immersion should be used with caution because it caused greater resin surface roughness and greater ion release, respectively.
Desinfetantes químicos são normalmente associados a métodos mecânicos para remover manchas e reduzir a formação do biofilme. Este estudo avaliou o efeito de desinfetantes na liberação de íons metálicos e na rugosidade superficial do titânio comercialmente puro, ligas metálicas e resina acrílica termopolimerizável, simulando 180 ensaios de imersões. Espécimes em formato de discos foram confeccionados com titânio comercialmente puro (Tritan), liga de níquel-cromo-molibdênio-titânio (Vi-Star), liga de níquel-cromo (Fit Cast-SB Plus) e liga de níquel-cromo-berílio (Fit Cast-V). Os espécimes (n=5) foram imersos nestas soluções: hipoclorito de sódio a 0,05%, Periogard, Cepacol, Corega Tabs, Medical Interporous e Polident. Como controle, foi utilizada a água deionizada. A análise quantitativa de liberação de íons metálicos foi realizada por meio de espectrometria de massa com plasma indutivamente acoplado (ELAN DRC II). O rugosímetro (Surftest SJ-201P) foi utilizado para medir a rugosidade superficial (µm). Os dados foram registrados antes e depois das imersões e avaliados por ANOVA com dois fatores e teste de Tukey (α=0,05). A liberação de níquel provou ser mais expressiva nas ligas Vi-Star e Fit Cast-V após a imersão em Medical Interporous. Houve diferença significante na rugosidade superficial da resina (p=0,011) após a imersão. O Cepacol causou maior rugosidade superficial de forma significativa. Os produtos de imersão não influenciaram nos resultados da rugosidade do metal (p=0,388). Pode-se concluir que as ligas metálicas testadas podem ser consideradas seguras para a fabricação de próteses removíveis, mas as soluções desinfetantes como o Cepacol e a pastilha Medical Interporous para a imersão diária da prótese devem ser utilizados com cautela, pois causaram maior rugosidade superficial da resina e maior liberação de íons, respectivamente.
Assuntos
Humanos , Bases de Dentadura , Ligas Dentárias/química , Higienizadores de Dentadura/química , Resinas Acrílicas/química , Ligas/química , Alumínio/análise , Berílio/análise , Boratos/química , Cetilpiridínio/química , Clorexidina/análogos & derivados , Clorexidina/química , Ligas de Cromo/química , Cromo/análise , Ácido Cítrico/química , Desinfetantes de Equipamento Odontológico/química , Materiais Dentários/química , Teste de Materiais , Metais/análise , Metais/química , Molibdênio/análise , Níquel/análise , Espectrofotometria Atômica , Propriedades de Superfície , Hipoclorito de Sódio/química , Sulfatos/química , Titânio/análise , Titânio/químicaRESUMO
Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey's test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD.
Assuntos
Resinas Acrílicas/química , Ligas de Cromo/química , Materiais Dentários/química , Higienizadores de Dentadura/química , Prótese Parcial Removível , Boratos/química , Cetilpiridínio/química , Clorexidina/análogos & derivados , Clorexidina/química , Ácido Cítrico/química , Corrosão , Humanos , Imersão , Teste de Materiais , Microscopia Eletrônica de Varredura , Oxirredução , Oxigênio/análise , Hipoclorito de Sódio/química , Espectrometria por Raios X , Sulfatos/química , Propriedades de Superfície , Fatores de TempoRESUMO
Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05 percent sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey’s test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD.
As próteses parciais removíveis (PPR) exigem higienização específica e a associação da escovação com imersão em soluções químicas tem sido o método mais recomendado para controle do biofilme. Entretanto, os efeitos destas soluções não são amplamente reportados em componentes metálicos. Este estudo avaliou o efeito de diferentes agentes de higienização na superfície dos componentes de uma PPR. Foram confeccionados 5 espécimes (disco metálico de 12 x 3 mm centralizado em uma tira de resina com 38 x 18 x 4 mm) para cada situação experimental: 6 soluções [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), hipoclorito de sódio 0,05 por cento (HS) e água destilada (AD) como controle)] e 2 ligas de cobalto-cromo [DeguDent (DD) e Vera PDI (VPDI)] foram utilizadas para cada situação experimental. Foram simuladas imersões de 180 dias. As aferições de rugosidade (Ra, μm) tanto em porção metálica quanto em resina acrílica termopolimerizável foram submetidos ao ANOVA e ao teste de Tukey. As alterações superficiais e manchas foram examinadas por meio de microscopia eletrônica de varredura (MEV). Áreas de interesse foram submetidas à espectrometria por energia dispersiva por raios X (EDS). Visualmente, puderam ser verificadas manchas nas superfícies metálicas quando utilizados HS e MI. A rugosidade dos materiais não foi afetada pelas soluções (p>0,05). As fotomicrografias evidenciaram que HS e MI ocasionaram alterações superficiais. As análises de EDS revelaram a presença de oxigênio nos grupos HS e MI, o que pode sugerir que estas duas soluções causaram oxidação das superfícies, provocando pontos de corrosão. Dentre as limitações do presente estudo, pode-se concluir que estas soluções não são apropriadas para a higienização das PPR.
Assuntos
Humanos , Resinas Acrílicas/química , Ligas de Cromo/química , Prótese Parcial Removível , Materiais Dentários/química , Higienizadores de Dentadura/química , Boratos/química , Corrosão , Cetilpiridínio/química , Clorexidina/análogos & derivados , Clorexidina/química , Ácido Cítrico/química , Imersão , Teste de Materiais , Microscopia Eletrônica de Varredura , Oxirredução , Oxigênio/análise , Espectrometria por Raios X , Propriedades de Superfície , Hipoclorito de Sódio/química , Sulfatos/química , Fatores de TempoRESUMO
The present work describes the development of a fast and robust sequential injection fluorimetric procedure for the determination of Sn in juices of canned fruits. The developed automatic methodology is based on the complexation of Sn with 8-hydroxyquinoline-5-sulfonic acid (HQSA) to form a fluorimetric product (lambda(exc)=354 nm; lambda(em)=510 nm). The influence of dimethylsulfoxide (DMSO) and cetylpyridinium bromide (CPB) on the sensitivity of the fluorimetric determination was evaluated. Linear calibration plots were obtained for Sn concentrations between 1 and 10 mg L(-1), with a detection limit of 0.38 mg L(-1). In each analytical cycle 0.006 mg of HQSA and 0.47 mg of CPB were consumed and 1.5 mL of effluent was generated. The developed methodology was applied to the determination of Sn in juices of canned fruits and the results complied with those furnished by an electrothermal atomic absorption spectrometry comparison procedure, with relative deviations lower than 5.2%. The automatic procedure exhibited good precision (R.S.D.<1.4%) and the sampling rate was about 70 determinations per hour.
Assuntos
Análise de Injeção de Fluxo/métodos , Fluorometria/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Conservação de Alimentos , Frutas/química , Estanho/análise , Cetilpiridínio/química , Dimetil Sulfóxido/química , Indicadores e Reagentes/química , Oxiquinolina/análogos & derivados , Oxiquinolina/química , Fatores de Tempo , Estanho/químicaRESUMO
An electroanalytical study for the amperometric determination of ascorbic acid (AA) in a human urine sample at a bare glassy carbon electrode using the CPC (cetylpyridinium chloride) surfactant is described. Under the optimized conditions of E(pa), I(pa), CPC concentration and pH, the oxidation peak potential of the AA shifts towards a less positive potential, and the peak current increase in a significant way in the presence of the surfactant. Under the best conditions, the method provided a linear calibration curve to AA in a 0.1 mol L(-1) phosphate buffer solution (pH 7.0) in the concentration range from 5.0 x 10(-7) up to 4.3 x 10(-4) mol L(-1), with a detection limit of 2.0 x 10(-7) mol L(-1) and a high correlation coefficient (r = 0.9996). The recovery test presented values of 98 - 105%, suggesting a great potential of the proposed method for AA determination in complex samples, such as urine.