Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
J Microencapsul ; 40(2): 67-81, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36722704

RESUMO

The objectives of this work are to develop nanocarrier systems for the Ru(II)-p-cymene naproxen antitumor metallodrug, [Ru(η6-p-cymene)(npx)Cl] or Rupcy, based on polymeric nanoparticles (NPs) composed by the biodegradable poly(lactic acid) (PLA) and the hydrophilic polymerised ß-cyclodextrin (PolyCD); to validate an analytical method for determination of Ru incorporated into the metallodrug loaded-NPs. The PolyCD was prepared by single step condensation and polymerisation reaction and incorporated as a polymer blend during the fabrication of PLA/PolyCD blends NPs and also as a core/shell structure built by adsorption of the PolyCD onto the surface of PLA NPs to give PLA(core)/PolyCD(shell) NPs. Three different loaded-systems incorporating the metallodrug (Rupcy-PLA NPs (1), Rupcy-PLA/PolyCD blends (2), and Rupcy-PLA(core)/PolyCD(shell) NPs (3)) were prepared by nanoprecipitation. The characterisation was performed by Proton Nuclear Magnetic Resonance, Matrix Assisted Laser Desorption/Ionization Time-of-Flight, Fourier-Transform Infra-red and UV-VIS Electronic Absorption Spectroscopies, Thermogravimetric Analysis, Differential Scanning Calorimetry, Dynamic Light Scattering, and Electrophoretic Light Scattering. Ru was determined by Microwave Induced Plasma Optical Emission Spectrometry (MIP-OES) with validation of the method. The metallodrug entrapment efficiency was around 90% (w/w) and drug loading was at 3-4% (w/w). The characterised metallodrug-loaded systems exhibited monomodal size distributions and appropriate hydrodynamic diameters [218.3 ± 13.5 (1), 205.4 ± 14.4 (2), 231.5 ± 22.0 (3) nm] and zeta potential values [-31.5 ± 2.2 (1), -26.1 ± 4.5 (2), -28.8 ± 6.1 (3) mV]. The validation of the MIP-OES method by evaluating selectivity, linearity, precision, accuracy, and limits of detection and quantification succeeded. The NPs parameters are compatible with colloidally stable systems. The MIP-OES method showed to be simple, reliable, and feasible to quantify indirectly the amount of the metallodrug-loaded into the PLA NPs.


Assuntos
Nanopartículas , Rutênio , Naproxeno , Micro-Ondas , Poliésteres/química , Polímeros/química , Nanopartículas/química , Análise Espectral , Tamanho da Partícula , Portadores de Fármacos/química
2.
Prep Biochem Biotechnol ; 53(9): 1154-1163, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36794850

RESUMO

Lignocellulosic residues, such as cocoa bean shell (FI), are generated in large quantities during agro-industrial activities. Proper management of residual biomass through solid state fermentation (SSF) can be effective in obtaining value-added products. The hypothesis of the present work is that the bioprocess promoted by P. roqueforti can lead to structural changes in the fibers of the fermented cocoa bean shell (FF) that confer characteristics of industrial interest. To unveil such changes, the techniques of FTIR, SEM, XRD, TGA/TG were used. After SSF, an increase of 36.6% in the crystallinity index was observed, reflecting the reduction of amorphous components such as lignin in the FI residue. Furthermore, an increase in porosity was observed through the reduction of the 2θ angle, which gives the FF a potential candidate for applications of porous products. The FTIR results confirm the reduction in hemicellulose content after SSF. The thermal and thermogravimetric tests showed an increase in the hydrophilicity and thermal stability of FF (15% decomposition) in relation to the by-product FI (40% decomposition). These data provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures.


This work presents a new approach for solid state fermentation based on the study of structural changes caused by Penicillium roquefort, which is important to understand the changes in the lignocellulosic matrix after the fungus growth. The results provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures. Consequently, they can help in proposals for the total use of the residual solid after fermentation, as well as contribute to reducing the lack of this information in the literature.


Assuntos
Penicillium , Penicillium/metabolismo , Lignina/metabolismo , Fermentação
3.
HIV Med ; 23(6): 639-649, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34964226

RESUMO

OBJECTIVES: HIV outcomes centre primarily around clinical markers with limited focus on patient-reported outcomes. With a global trend towards capturing the outcomes that matter most to patients, there is agreement that standardizing the definition of value in HIV care is key to their incorporation. This study aims to address the lack of routine, standardized data in HIV care. METHODS: An international working group (WG) of 37 experts and patients, and a steering group (SG) of 18 experts were convened from 14 countries. The project team (PT) identified outcomes by conducting a literature review, screening 1979 articles and reviewing the full texts of 547 of these articles. Semi-structured interviews and advisory groups were performed with the WG, SG and people living with HIV to add to the list of potentially relevant outcomes. The WG voted via a modified Delphi process - informed by six Zoom calls - to establish a core set of outcomes for use in clinical practice. RESULTS: From 156 identified outcomes, consensus was reached to include three patient-reported outcomes, four clinician-reported measures and one administratively reported outcome; standardized measures were included. The WG also reached agreement to measure 22 risk-adjustment variables. This outcome set can be applied to any person living with HIV aged > 18 years. CONCLUSIONS: Adoption of the HIV360 outcome set will enable healthcare providers to record, compare and integrate standardized metrics across treatment sites to drive quality improvement in HIV care.


Assuntos
Infecções por HIV , Adulto , Consenso , Infecções por HIV/terapia , Pessoal de Saúde , Humanos , Avaliação de Resultados em Cuidados de Saúde , Medidas de Resultados Relatados pelo Paciente , Resultado do Tratamento
4.
Polymers (Basel) ; 16(13)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-39000613

RESUMO

Vegetable fibers are increasingly used in biocomposites, but there is a need for further development in utilizing by-products like cocoa husks. Three-dimensional printing, through Fused Filament Fabrication (FFF), is advancing rapidly and may be of great interest for applying biocomposite materials. This study focuses on developing innovative and fully biodegradable filaments for the FFF process. PLA filaments were prepared using cellulose fibers derived from cocoa husks (5% mass ratio). One set of filaments incorporated fibers from untreated husks (UCFFs), while another set utilized fibers from chemically treated husks (TCFFs). The fabricated materials were analyzed using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) techniques, and they were also tested for tensile strength. ANOVA reveals that both UCFFs and TCFFs significantly predict tensile strength, with the UCFFs demonstrating an impressive R2 value of 0.9981. The optimal tensile strength for the filament test specimens was 16.05 MPa for TCFF8 and 13.58 MPa for UCFF8, utilizing the same printing parameters: 70% infill and a layer thickness of 0.10 mm. Additionally, there was an 18% improvement in the tensile strength of the printed specimens using the filaments filled with chemically treated cocoa husk fibers compared to the filaments with untreated fibers.

5.
Z Naturforsch C J Biosci ; 68(5-6): 181-90, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23923614

RESUMO

Linalool is a monoterpene alcohol and constituent of several Brazilian aromatic medicinal plants, popularly used against hypertension. Cardiovascular effects induced by linalool were evaluated. In normotensive rats, (+/-)-linalool [1, 5, 10, and 20 mg/kg body weight (BW); intravenous (i.v.)]-induced hypotension was associated with tachycardia, which was attenuated by atropine (2 mg/kg BW) and N(G)-nitro-L-arginine methyl ester (20 mg/kg BW), but was not modified after indomethacin (5 mg/kg BW) administration. In hypertensive rats, linalool [200 mg/kg BW; oral (v.o.)] reduced blood pressure without changing the heart rate. In intact rings of rat mesenteric artery precontracted with 10 microM phenylephrine, linalool (from 6.4 x 10(-6) to 6.4 x 10(-3) M) induced relaxations in a concentration-dependent manner [E(max) = (115 +/- 13)%] that were not changed after atropine administration [E(max) = (105 +/- 2)%], and were not different from those obtained in endothelium-denuded rings precontracted with phenylephrine [E(max) = (108 +/- 7)%] or 80 mM KCl [E(max) = (113 +/- 7)%] or tetraethylammonium incubation [E(max) = (105 +/- 12)%]. Linalool (1.9 x 10(-3) M) antagonized the contractions induced by CaCl2 (3 x 10(-6)-10(-2) M) (maximal inhibition, 81%). Furthermore, linalool inhibited the contractions induced by 10 microM phenylephrine or 20 mM caffeine. In conclusion, these results demonstrate that linalool reduces blood pressure probably due to a direct effect on the vascular smooth muscle leading to vasodilation.


Assuntos
Sistema Cardiovascular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Monoterpenos/farmacologia , Monoterpenos Acíclicos , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Masculino , Monoterpenos/uso terapêutico , Ratos , Ratos Wistar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA