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1.
Anim Reprod Sci ; 252: 107227, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37027991

RESUMO

This experiment evaluated reproductive and productive responses of beef cows receiving self-fed low-moisture blocks (LMB) enriched or not with Ca salts of soybean oil (CSSO) throughout the breeding season. Non-pregnant, suckled multiparous Angus-influenced cows were assigned to a fixed-time artificial insemination (AI) protocol (day -10 to 0) followed by natural service (day 15-70). Cows were managed in 12 groups (46 ± 4 cows/group) maintained in individual pastures, and groups received LMB enriched with 25 % (as-fed basis) of CSSO or ground corn (CON) from day - 10 to 100. Both treatments were designed to yield a daily LMB intake of 0.454 kg/cow (as-fed basis). Cows receiving CSSO had greater (P < 0.01) mean concentrations of ω-6 fatty acids in plasma samples collected on days 0 and 55. Cows receiving CSSO had greater (P = 0.05) pregnancy rate to fixed-time AI (67.2 vs. 59.3 %), whereas final pregnancy rate did not differ (P = 0.92) between treatments. Pregnancy loss was less (P = 0.03) in CSSO cows (4.50 vs. 9.04 %), which also calved earlier during the calving season (treatment × week; P = 0.04). Weaning rate tended to be greater (P = 0.09) in CSSO (84.8 vs. 79.4 %), although calf weaning age and weight did not differ (P ≥ 0.72) between treatments. Kilos of calf weaned/cow exposed was greater (P = 0.04) in CSSO cows (234 vs. 215 kg). Therefore, supplementing CSSO to beef cows via LMB during the breeding season improved their reproductive and overall productivity during a cow-calf cycle.


Assuntos
Dieta , Suplementos Nutricionais , Gravidez , Feminino , Bovinos , Animais , Dieta/veterinária , Óleo de Soja/farmacologia , Sais , Melaço , Melhoramento Vegetal , Ração Animal/análise
2.
Sci Total Environ ; 808: 152164, 2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-34875333

RESUMO

The sedimentary processes play a major role in every aquatic ecosystem, however, there are few automated options for in-situ monitoring of sediment displacement in the streambed of waterways. We present an automated optical instrument for in-situ continuous monitoring of sediment deposition and erosion of the streambed that requires no calibration. With a production cost of 32€, power consumption of 300 µA in sleep mode, and capacity to monitor the bedform of a waterway, the sensor was developed to evaluate the sediment dynamics of coastal areas with a wide spatial and temporal resolution. The novel device is intended to be buried in the sand and uses 32 infrared channels to monitor the streambed sediment height. For testing purposes, a maximum measuring length of 160 mm and 5 mm resolution was chosen, but these values are scalable. Sensors can be built with different ranges and precision according to the needs of the fieldwork. A laboratory experiment was conducted to demonstrate the working principle of the instrument and its behaviour regarding the turbidity originated by suspended sediment and the settling and deposition of the suspended particles. The device was deployed for 119 days in an estuarine area and was able to detect patterns in the sediment deposition and resuspension during the tidal cycles. Also, abnormal events occurred during the experiment as floods and algae blooms. During these events, the sensor was able to record exceptional erosion and sediment deposition rates. The reported automated instrument can be broadly used in sedimentary studies or management and planning of fluvial and maritime infrastructures to provide real-time information about the changes in the bedform of the watersheds.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Ecossistema , Inundações
3.
Public Health ; 189: 54-59, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33160088

RESUMO

OBJECTIVES: Contact tracing and quarantine are common measures used in the management of infectious disease outbreaks. However, few studies have measured their impact on the control of the COVID-19 pandemic. This study aimed to assess the effectiveness of those measures on reducing transmission of severe acute respiratory syndrome coronavirus 2 in a community setting. STUDY DESIGN: The study design is a retrospective cohort study. METHODS: A retrospective cohort study of COVID-19 cases notified in Eastern Porto from March 1st to April 30th, 2020 was performed. Intervention and control cohorts were defined based on whether cases were subjected to contact tracing and quarantine measures before the laboratory confirmation of disease. The number of secondary cases per index case and the proportion of cases with subsequent secondary cases were the primary outcomes. Secondary outcomes included the time from symptom onset to specimen collection and the number of close contacts. The analysis was stratified according to whether national lockdown measures had already been implemented. RESULTS: The intervention and control cohorts comprised 98 and 453 cases, respectively. No differences were observed concerning primary outcomes. The intervention group had a shorter time between symptom onset and specimen collection (median: 3 days, interquartile range [IQR]: 1-6, vs. median: 5 days, IQR: 2-7, P-value = 0.004) and fewer close contacts (median: 0, IQR: 0-2, vs. median: 2, IQR: 1-4, P-value<0.001). The stratified analysis returned similar results. CONCLUSION: Local public health measures were effective in reducing the time between symptom onset and laboratory diagnosis and the number of close contacts per case. No effect was apparent on secondary case figures, suggesting that further measures may be required.


Assuntos
Infecções Assintomáticas/epidemiologia , COVID-19/transmissão , Busca de Comunicante/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Quarentena , SARS-CoV-2 , Adulto , Idoso , Técnicas de Laboratório Clínico , Controle de Doenças Transmissíveis/métodos , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isolamento de Pacientes , Portugal/epidemiologia , Saúde Pública , Estudos Retrospectivos
4.
Heliyon ; 6(9): e04938, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32995623

RESUMO

The aromatic nucleophilic substitution reactions of the nitro group of 4-Nitro-N-alkyl-1,8-naphthalimides by thiolate anions produce fluorescent derivatives and their rates are strongly accelerated by micelles of hexadecyltrimethylammonium chloride even at low pH. Acceleration factors of this reactions can reach million-fold. As the products are oxidant-insensible, this reaction allows the determination of SH- containing compounds such as cysteine, glutathione or proteins even in oxidative conditions. Limits of detection are as low as 5 × 10-7 M, ten times lower than the limit for the classic 5,5'-dithiobis-(2-nitrobenzoic) acid method. Moreover, this reaction can be developed at pHs between 6.5 and 7.5 thereby diminishing the rate of spontaneous oxidation of the thiols. In addition, we demonstrated that 4-Nitro-N-alkyl-1,8-naphthalimides can be used to evidence SH groups in peptides, proteins and living cells.

5.
Sensors (Basel) ; 20(11)2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32512850

RESUMO

A cost-effective optical instrument for continuous in-situ monitoring applications is presented. With a production cost in raw materials of 38 €, a power consumption of 300 A in sleep mode and 100 mA in active mode (5 ms reading), and a capacity to monitor turbidity and sedimentary displacement at eight different depths in the water column, the sensor was developed for sediment monitoring in coastal areas. Due to the extent and dynamics of the processes involved in these areas, observations require a wide spatial and temporal resolution. Each of the eight monitoring nodes uses one infrared backscatter channel, to estimate turbidity and sediment concentration, and one ultraviolet with one infrared transmitted light channels to distinguish organic/inorganic composition of the suspended material load. An in-lab calibration was conducted, using formazine to correlate turbidity with the electronic outputs of the instrument. An analysis of the influence of external light sources and correction techniques were performed. Moreover, an in-lab experiment was conducted to study the behaviour of the sensor-to-sediment transport, wash load and sediment accumulation. The device was deployed, with a water level sensor, in an estuarine area with high sediment dynamics. The monitoring data were analysed, showing the potential of the device to continuously monitor turbidity, sediment processes, and distinguish between organic and inorganic matter, at the different depths in the water column.

6.
J Clin Pediatr Dent ; 44(3): 180-184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32552448

RESUMO

Objective: Bruxism is a condition defined as a masticatory muscle activity with an unexplored genetic background. The aim of this study was to evaluate the association between genetic polymorphisms in ACTN3 and bruxism. Study design: A total of 151 biological-unrelated children, aged 7-12 years were included in a case control ratio of 1:1.5. The data collection was performed during interview and clinical examination. Saliva samples were collected from all children and 3 genetic polymorphisms in the ACTN3 (rs678397, rs1671064 and rs1815739) were selected for genotyping using real time PCR. Pearson chisquare calculation was used to assess Hardy-Weinberg equilibrium and to evaluate the association between genotypes and alleles frequencies for each genetic polymorphism in the co-dominant and recessive models. An alpha of 5% was used. Results: The genetic polymorphisms rs678397, rs1671064 and rs1815739 were associated with bruxism in the co-dominate model and in the recessive model (p<0.05). Allele distribution was also associated with bruxism for the polymorphisms rs678397 and rs1671064 (p<0.05). Conclusion: The genetic polymorphisms rs678397, rs1671064 and rs1815739 in ACTN3 are associated with bruxism and can contribute to the etiology of this condition in children.


Assuntos
Actinina/genética , Bruxismo , Genótipo , Criança , Frequência do Gene , Humanos , Polimorfismo Genético
7.
Sensors (Basel) ; 19(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31614983

RESUMO

A cost-effective optical sensor for continuous in-situ monitoring of turbidity and suspended particulate matter concentration (SPM), with a production cost in raw materials less than 20 €, is presented for marine or fluvial applications. The sensor uses an infrared LED and three photodetectors with three different positions related to the light source-135º, 90º and 0º-resulting in three different types of light detection: backscattering, nephelometry and transmitted light, respectively. This design allows monitoring in any type of environment, offering a wide dynamic range and accuracy for low and high turbidity or SPM values. An ultraviolet emitter-receiver pair is also used to differentiate organic and inorganic matter through the differences in absorption at different wavelengths. The optical transducers are built in a watertight structure with a radial configuration where a printed circuit board with the electronic signal coupling is assembled. An in-lab calibration of the sensor was made to establish a relation between suspended particulate matter (SPM) or the turbidity (NTU) to the photodetectors' electrical output value in Volts. Two different sizes of seashore sand were used (180 µm and 350 µm) to evaluate the particle size susceptibility. The sensor was tested in a fluvial environment to evaluate SPM change during sediment transport caused by rain, and a real test of 22 days continuous in-situ monitoring was realized to evaluate its performance in a tidal area. The monitoring results were analysed, showing the SPM change during tidal cycles as well as the influence of the external light and biofouling problems.

8.
ACS Appl Mater Interfaces ; 11(42): 38946-38954, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31560510

RESUMO

A flexible and ultralight planar thermoelectric generator based on 15 thermocouples composed of n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3) legs (each with 400 nm thick) connected in series, on 25 µm thick Kapton substrate, was fabricated with impressive power factor values of 2.7 and 0.8 mW K-2 m-1 (at 298 K) for Bi2Te3 and Sb2Te3 films, respectively. The p-n junction thermoelectric device can generate a maximum open-circuit voltage and output power of 210 mV and 0.7 µW (3.3 mW cm-2), respectively, for a temperature difference of 35 K, which is higher than the one observed for a conventional thermoelectric device with metallic contacts for p-n junctions. The results were combined with numerical simulations, showing a good match between the experimental and the numerical results. The current density versus voltage (J-V) characteristics of the fabricated p-n junctions revealed a diode behavior with a turn-on voltage of ≈0.3 V and an impressive rectifying ratio (I+1V/I-1V) of ≈2 × 104.

9.
Mater Sci Eng C Mater Biol Appl ; 104: 109901, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500026

RESUMO

The development of smart biomedical implants with intrinsic communication system between sensors and actuators, or between implant and patient, remains a challenge for scientific community. Titanium and its alloys, especially Ti6Al4V, are the most used materials in the implant's fabrication. The present work is concerned with implant internal communication printing process and presents a detailed study on titanium alloy (Ti6Al4V) surface texturing and their characterization (morphological and chemical) produced by a Nd: YAG laser, aiming to create localized electrical insulation zones, necessary to accommodate electrical communication systems. The characterization of the textured surface was carried out by scanning electron microscopy and the heat affected zone was analyzed by X-ray diffraction. The results showed the formation of α-Ti, Ti6O and Ti2O phases on the textured surface. Through simulations in TINA software, the outer oxide layer formed during laser texturing had efficiency above 90% as insulator when an electrical current was applied.


Assuntos
Eletricidade , Lasers , Óxidos/química , Titânio/química , Ligas , Oxirredução , Propriedades de Superfície , Difração de Raios X
10.
Nanotechnology ; 30(43): 435502, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31323652

RESUMO

Here, the ability of using p-type tin oxide (SnO x ) thin films as a thermal sensor has been investigated. Firstly, the thermoelectric performance was optimized by controlling the thickness of the SnO x film from 60 up to 160 nm. A high Seebeck coefficient of +263 µV K-1 and electrical conductivity of 4.1 × 102 (S m-1) were achieved in a 60 nm thick SnO x film, due to a compact nanostructured film and the absence of the Sn metallic phase, which was observed for the thicker SnO x film leading to a typical thermoelectric transport properties of a n-type Sn film. Moreover, x-ray photoelectron spectroscopy revealed the co-existence of SnO (79.7%) and SnO2 (20.3%) phases in the 60 nm thick SnO x film, while the optical measurements revealed an indirect gap of 1.8 eV and a direct gap of 2.7 eV, respectively. The 60 nm-SnO x thin film have been tested as a thermoelectric touch sensor, achieving a Vsignal /Vnoise  ≈ 20, with a rise time <1 s. Therefore, this work provides an efficient way for developing highly efficient thermal sensors with potential use in display technologies.

11.
J Microencapsul ; 35(4): 344-356, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29889598

RESUMO

Pharmaceutical research has been focussed on developing improved delivery systems while exploring new ways of using approved excipients. The present work investigated the potential of starch nanocapsules (StNC) as a topical delivery platform for hydrophilic antimicrobial drugs using minocycline hydrochloride (MH) as a model drug. Thus, a quality by design approach was used to assess the role of different factors that affect the main pharmaceutical properties of StNC prepared using an emulsification-solvent evaporation method. Full characterisation was performed in terms of particle size, encapsulation efficiency, morphology and physical stability at 5 ± 3 °C. Results show the surfactant and lipid contents play a major role in StNC particle size distribution. The MH loading only promoted minor changes upon StNC properties. Formulations were stable without variations on physicochemical properties. All tested formulations presented a zeta-potential of +33.6 ± 6.7 mV, indicating a good physical stability and evidencing that StNC are suitable nanocarriers for topical use.


Assuntos
Antibacterianos/administração & dosagem , Minociclina/administração & dosagem , Nanocápsulas/química , Amido/química , Administração Tópica , Antibacterianos/química , Composição de Medicamentos , Estabilidade de Medicamentos , Excipientes/química , Interações Hidrofóbicas e Hidrofílicas , Minociclina/química , Tamanho da Partícula , Solubilidade , Tensoativos/química
12.
Toxicol Appl Pharmacol ; 342: 14-21, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29407772

RESUMO

The safety profile of the ingredients used in topical dosage forms and its evaluation is an issue of utmost importance. A suitable equilibrium between safety and efficacy is crucial before promoting a dermatological product. The aim of this work was to assess the safety and biological effects of starch-based vehicles (St-BV) used in such products. The hazard, exposure and dose-response assessment were used to characterize the risk of each ingredient. The EpiSkin™ assay and human repeat insult patch tests were performed to compare the theoretical safety assessment to in vitro and in vivo data. The efficacy of the St-BV was studied using biophysical measurements in human volunteers during 28 days, showing that all ingredients and their combinations were safe for the consumer. Tissue viability determined using the EpiSkin™ testing reached values between 84.0 ±â€¯5.0% and 98.0 ±â€¯8.6% after application of St-BV, which were considered as non-irritant to the skin. These observations were confirmed by the in vivo studies where the St-BV did not induce any sensitization on the volunteers, being safe for human use. Moreover, St-BV increased skin hydration and microcirculation, emerging as an attractive alternative to chemical raw materials.


Assuntos
Alumínio/toxicidade , Cosméticos/toxicidade , Nanocápsulas/toxicidade , Pele/efeitos dos fármacos , Amido/toxicidade , Succinatos/toxicidade , Qualidade de Produtos para o Consumidor , Emulsões , Humanos , Microcirculação/efeitos dos fármacos , Testes do Emplastro , Medição de Risco , Pele/irrigação sanguínea , Pele/metabolismo , Testes de Toxicidade , Água/metabolismo
13.
Eur J Pharm Biopharm ; 127: 1-11, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29409864

RESUMO

Psoriasis and atopic dermatitis patients show an excessive amount of elastase in peripheral blood neutrophils due to an imbalance between this proteolytic enzyme and its endogenous inhibitors, the search for new human neutrophil elastase (HNE) inhibitors are required. The HNE is an attractive therapeutic target and inhibitors with new molecular architectures have been extensively investigated. In this context a promising novel synthetic human neutrophil elastase inhibitor (ER143) was associated to a starch-based nanoparticulate system (StNC) with improved pharmaceutical performance, using a quality by design approach to support product development and optimization. The resulting formulation was characterized in terms of and in vitro release, permeation and retention studies in newborn pig skin, using Franz diffusion cells revealing the StNC have the ability to control the drug release rate and contribute to a high skin retention and/or permeation profiles. The anti-inflammatory activity accessed in vivo using the croton oil-induced ear inflammation model in mice showed that erythema and edema were attenuated in 98% following local application. These observations suggest the association of ER143 to the StNC promotes a deeper skin penetration and retention, also confirming StNC as a potential topical delivery system.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Nanocápsulas/química , Neutrófilos/metabolismo , Elastase Pancreática/antagonistas & inibidores , Amido/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Dermatite Atópica/tratamento farmacológico , Edema/tratamento farmacológico , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Permeabilidade/efeitos dos fármacos , Pele/efeitos dos fármacos , Suínos
14.
J Microencapsul ; 34(2): 203-217, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28378596

RESUMO

The aim of this study was to develop a novel BCG-loaded chitosan vaccine with high association efficiency which can afford efficient interaction with APC and elicit local and Th1-type-specific immune response after intranasal administration. Chitosan-suspended BCG and BCG-loaded chitosan-alginate microparticles were prepared by ionotropic gelation. Interaction with APC was evaluated by fluorescence microscopy using rBCG-GFP. Specific immune responses were evaluated following intranasal immunisation of mice. Cellular uptake was approximately two-fold higher for chitosan-suspended BCG. A single dose of BCG-loaded microparticles or chitosan-suspended BCG by intranasal route improved Th1-type response compared with subcutaneous BCG. Chitosan-suspended BCG originated the highest mucosal response in the lungs by intranasal route. These positive results indicate that the proposed approach of whole live BCG microencapsulation in chitosan-alginate for intranasal immunisation was successful in allowing efficient interaction with APC, while improving the cellular immune response, which is of interest for local immunisation against tuberculosis.


Assuntos
Vacina BCG/química , Quitosana/química , Macrófagos/efeitos dos fármacos , Administração Intranasal , Animais , Anticorpos Antibacterianos/sangue , Vacina BCG/administração & dosagem , Feminino , Humanos , Imunoglobulina A/análise , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium bovis , Células THP-1
15.
Nanoscale ; 8(16): 8931-8, 2016 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-27074378

RESUMO

Conductance was measured in two different double stranded DNA (both with 20 bases), the more conducting poly(dG)-poly(dC) (ds-DNAc) and the less conducting poly(dA)-poly(dT) (ds-DNAi), by means of Electrochemical Capacitance Spectroscopy (ECS). The use of the ECS approach, exemplified herein with DNA nanowires, is equally a suitable and time-dependent advantageous alternative for conductance measurement of molecular systems, additionally allowing better understanding of the alignment existing between molecular scale conductance and electron transfer rate.


Assuntos
DNA/química , Espectroscopia Dielétrica/métodos , Nanofios/química , Capacitância Elétrica , Condutividade Elétrica , Transporte de Elétrons , Modelos Químicos , Nanotecnologia
16.
Eur J Pharm Biopharm ; 102: 41-50, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26925503

RESUMO

A solid lipid nanoparticle (SLN) formulation was developed with the aim of improving the oral bioavailability and the therapeutic effectiveness of glibenclamide (GLI), a poorly water-soluble drug used in the treatment of type 2 diabetes. The SLN was prepared using different lipid components (Precirol® and Compritol®) and preparation procedures. Precirol-based SLN, obtained with the emulsion of solvent evaporation technique gave the best results and was selected for drug loading. Addition of lecithin to the SLN core or PEG coating was effective in increasing the nanoparticles stability in simulated gastric solution. Both such formulations were stable after one month storage at 5±3°C, exhibited the absence of in vitro cytotoxicity, and presented a similar in vitro prolonged-release, reaching 100% release after 24h. The lecithin-containing GLI-loaded SLN formulation, selected for in vivo studies in virtue of its higher EE% than the PEG-coated formulation (70.3% vs 19.6%), showed a significantly stronger hypoglycemic effect with respect to the drug alone, in terms of both shorter onset time and longer duration of the effect. These positive results indicated that the proposed SLN approach was successful in improving GLI oral bioavailability, confirming its potential as an effective delivery system for a suitable therapy of diabetes.


Assuntos
Portadores de Fármacos/química , Glibureto/química , Glibureto/farmacocinética , Lipídeos/química , Nanopartículas/química , Administração Oral , Animais , Disponibilidade Biológica , Células CACO-2 , Linhagem Celular Tumoral , Química Farmacêutica , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diglicerídeos/administração & dosagem , Diglicerídeos/química , Diglicerídeos/farmacocinética , Estabilidade de Medicamentos , Emulsões/administração & dosagem , Emulsões/química , Emulsões/farmacocinética , Excipientes/química , Glibureto/administração & dosagem , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacocinética , Masculino , Nanopartículas/administração & dosagem , Ratos , Ratos Sprague-Dawley , Solubilidade
17.
Colloids Surf B Biointerfaces ; 143: 177-185, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27003468

RESUMO

Exploring novel applications for approved excipients with a history of safe use in therapeutics is a smart strategy to obtain improved pharmaceutical products. The present study aimed at developing a novel starch-based nanoparticulate carrier system (StNC) for topical delivery of lipophilic bioactive molecules. The role of the different factors that affect the particle size distribution and zeta potential of StNC prepared by the emulsification-solvent evaporation method was assessed using a quality by design approach. An optimal formulation was selected and fully characterized in terms of molecular interactions (DSC and FTIR), morphology (TEM and AFM), as well as in vitro and in vivo biological properties, including biological sensitivity/irritation studies performed in human volunteers. Results show the surfactant and lipid contents play a major role in StNC particle size distribution. In addition, all tested formulations presented a zeta potential of ca. +33.6±6.7 mV, indicating a good physical stability, while revealing an excellent compromise between stability, safety and cosmeticity, evidencing that StNC are suitable nanocarriers for topical use. Finally, the design planning methodology has clearly shown its usefulness for optimizing the formulation, being also crucial for the understanding of StNC formation process. The StNC proved to be a promising formulation strategy and a potential nanocarrier for topical lipophilic bioactive molecules.


Assuntos
Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Nanocápsulas/administração & dosagem , Amido/química , Administração Tópica , Varredura Diferencial de Calorimetria , Linhagem Celular , Portadores de Fármacos/química , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Lipídeos/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Nanocápsulas/química , Nanocápsulas/ultraestrutura , Tamanho da Partícula , Testes do Emplastro/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos/química
18.
Drug Dev Ind Pharm ; 42(2): 190-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25996463

RESUMO

This work aims at developing and optimizing a valuable oral delivery carrier for the cannabinoid derivative CB13, which presents a high therapeutic potential in chronic pain states that respond poorly to conventional analgesics, but also shows highly unfavorable physicochemical properties. CB13-loaded lipid nanoparticles (LNP) formulations were developed through solvent-emulsion evaporation and optimized in terms of physicochemical properties, long-term stability, integrity under gastric simulated conditions and in vitro interaction with NIH 3T3, HEK 293T and Caco-2 cells. An optimized formulation of LNP containing CB13 was obtained from a wide range of conditions assayed and analyzed. The selection of the lipid core, production conditions and the inclusion of lecithin proved to be key factors for the final properties of encapsulation, integrity and performance of the carriers. The LNP formulation proposed proved to be a promising carrier for the oral delivery of CB13, a cannabinoid with high therapeutic potential in chronic pain states that currently lack a valid oral treatment.


Assuntos
Portadores de Fármacos/química , Lipídeos/química , Nanopartículas , Naftalenos/administração & dosagem , Administração Oral , Animais , Canabinoides/administração & dosagem , Canabinoides/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Células HEK293 , Humanos , Camundongos , Células NIH 3T3 , Naftalenos/química
19.
Colloids Surf B Biointerfaces ; 135: 183-192, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26263210

RESUMO

Pickering emulsions are stabilized by solid particles instead of surfactants and have been widely investigated in pharmaceutical and cosmetic fields since they present less adverse effects than the classical emulsions. A quality by design (QbD) approach was applied to the production of w/o emulsions stabilized by starch. A screening design was conducted to identify the critical variables of the formula and the process affecting the critical quality properties of the emulsion (droplet size distribution). The optimization was made by establishing the Design Space, adjusting the concentration of starch and the quantity of the internal aqueous phase. The emulsion production process was, in turn, adjusted by varying the time and speed of stirring, to ensure quality and minimum variability. The stability was also investigated, demonstrating that an increase in starch concentration improves the stability of the emulsion. Rheological and mechanical studies indicated that the viscosity of the emulsions was enhanced by the addition of starch and, to a higher extent, by the presence of different lipids. The developed formulations was considered non-irritant, by an in vitro assay using human cells from skin (Df and HaCat) with the cell viability higher than 90% and, with self-preserving properties. Finally, the QbD approach successfully built quality in Pickering emulsions, allowing the development of hydrophilic drug-loaded emulsions stabilized by starch with desired organoleptic and structural characteristics. The results obtained suggest that these systems are a promising vehicle to be used in products for topical administration.


Assuntos
Sistemas de Liberação de Medicamentos , Excipientes/química , Amido/química , Administração Tópica , Sobrevivência Celular , Desenho de Fármacos , Emulsões , Humanos , Lipídeos , Tamanho da Partícula , Pós , Reologia , Pele/citologia , Pele/metabolismo , Viscosidade
20.
Int Endod J ; 48(6): 542-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25070009

RESUMO

AIM: To evaluate the effectiveness of Reciproc for the removal of cultivable bacteria and endotoxins from root canals in comparison with multifile rotary systems. METHODOLOGY: The root canals of forty human single-rooted mandibular pre-molars were contaminated with an Escherichia coli suspension for 21 days and randomly assigned to four groups according to the instrumentation system: GI - Reciproc (VDW); GII - Mtwo (VDW); GIII - ProTaper Universal (Dentsply Maillefer); and GIV -FKG Race(™) (FKG Dentaire) (n = 10 per group). Bacterial and endotoxin samples were taken with a sterile/apyrogenic paper point before (s1) and after instrumentation (s2). Culture techniques determined the colony-forming units (CFU) and the Limulus Amebocyte Lysate assay was used for endotoxin quantification. Results were submitted to paired t-test and anova. RESULTS: At s1, bacteria and endotoxins were recovered in 100% of the root canals investigated (40/40). After instrumentation, all systems were associated with a highly significant reduction of the bacterial load and endotoxin levels, respectively: GI - Reciproc (99.34% and 91.69%); GII - Mtwo (99.86% and 83.11%); GIII - ProTaper (99.93% and 78.56%) and GIV - FKG Race(™) (99.99% and 82.52%) (P < 0.001). No statistical difference were found amongst the instrumentation systems regarding bacteria and endotoxin removal (P > 0.01). CONCLUSION: The reciprocating single file, Reciproc, was as effective as the multifile rotary systems for the removal of bacteria and endotoxins from root canals.


Assuntos
Descontaminação/instrumentação , Instrumentos Odontológicos , Cavidade Pulpar/microbiologia , Preparo de Canal Radicular/instrumentação , Carga Bacteriana , Dente Pré-Molar , Endotoxinas , Contaminação de Equipamentos , Escherichia coli , Humanos , Técnicas In Vitro
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