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1.
Int J Biol Macromol ; 247: 125779, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37442506

RESUMO

Chitosan (Cs) was subjected to ball milling and subsequently functionalized with Dinitro salicylic acid (Cs-DNS) to enhance the efficacy of oral insulin delivery. The hydrodynamic spherical particle sizes exhibited 33.29 ± 5.08 nm for modified Cs-DNS NPs. Irrespective of insulin entrapment, zeta potential measurements revealed positively charged Cs-DNS NPs (+ 35 ± 3.5 mV). The entrapment performance (EP%) was evaluated in vitro, and insulin release patterns at various pH levels. The EP% for Cs-DNS NPs was 99.3 ± 1.6. Cs- DNS NPs retained a considerable amount of insulin (92 %) in an acidic medium, and significant quantities were released at increasing pH values over time. In vivo investigations, the diabetic rats which taken insulin-incorporated NPs had lower serum glucose levels (SGL) after 3 h to (39.4 ± 0.6 %) for Cs- DNS NPs. For insulin-incorporated Cs- DNS NPs, the bioavailability (BA%) and pharmacological availability (PA%) were 17.5 ± 0.31 % and 8.6 ± 0.8 %, respectively. The assertion above highlights the significance and effectiveness of modified chitosan in promoting insulin delivery, decreasing SGL levels, and guaranteeing safety.


Assuntos
Quitosana , Diabetes Mellitus Experimental , Nanopartículas , Ratos , Animais , Insulina , Quitosana/uso terapêutico , Portadores de Fármacos/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Micro-Ondas , Administração Oral , Tamanho da Partícula
2.
Luminescence ; 38(8): 1493-1500, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37259924

RESUMO

New fluorescent 4-alkoxyphenyl-nitrothiophene compounds 4a-d bearing diverse alkoxyl tails are described. The synthetic strategy was simply accomplished by alkali-assisted alkylation of 4-(5-nitrothiophen-2-yl)phenol (3) with propyl, hexyl, nonyl, and/or dodecyl iodide. The molecular structures were determined using infrared (IR), 1 H NMR, and mass spectroscopy. Ultraviolet-visible (UV-vis) absorption and emission spectra of the produced 4-alkoxyphenyl-nitrothiophenes revealed considerable extinction coefficients, which were shown to be controlled by the thiophene bridge in conjugation with the alkoxy donor moiety. It was found that the maximum absorbance wavelength was affected by the alkoxyl group-bonded substituents. The antioxidant efficiency obtained from the 4-alkoxyphenyl-nitrothiophene hybrids was excellent compared with that widely used drugs [butylated hydroxytoluene (BHT) and vitamin C]. Unlike 2-(4-[dodecyloxy]phenyl)-5-nitrothiophene hybrid 4d, which has made solid claims about the good effect of its reference drugs and vitamins, Docking investigations of the prepared 4-alkoxyphenyl-nitrothiophene hybrids towards the selected 5IKQ protein revealed impressive coordination and antioxidant effectiveness.


Assuntos
Antioxidantes , Ácido Ascórbico , Antioxidantes/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Fenômenos Químicos , Corantes
3.
Biotechnol J ; 18(7): e2300078, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37186139

RESUMO

To date, the long term stability of ascorbic acid (AA) under physiological conditions represents a major issue for wound healing and tissue regeneration applications. In this study, ascorbyl phosphate (AP) was loaded into silica nanoparticles (SiNPs) through a simple one step procedure, in which spherical shaped porous SiNPs were obtained via hydrolysis/condensation of tetraethylorthosilicate (TEOS) in the presence of bicarbonate salt and ammonia. The as-prepared SiNPs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier Transformer Infrared Spectrophotometer (FTIR). Incorporation of bicarbonate salt resulted in the formation of spherical SiNPs with an average diameter of 460 ± 89 nm, while further increase of bicarbonate salt led to the formation of silica sheet-like structures. The AP-loaded SiNPs exhibited high loading efficiency from 92.3- 81.5%, according to AP content and sustained release over 3 days. According to cell viability assay, the obtained AP-enriched SiNPS showed no toxicity and supportive effect to the proliferation of human skin fibroblast cells (HSF) at a concentration less than 200 µg mL-1 . Moreover, it was observed that the wound closure percentage (%) after 24 h was also shown to increase to 74.1 ± 3.1% for 20AP-loaded SiNPs compared to control samples (50.1 ± 1.8%). The obtained results clearly demonstrated that the developed SiNPs formulation exhibits optimal microstructure features to maintain a sustained release of ascorbic acid AA at wound bed for the healing of skin tissue, including acute and chronic wounds.


Assuntos
Nanopartículas , Dióxido de Silício , Humanos , Preparações de Ação Retardada , Dióxido de Silício/química , Bicarbonatos , Pele , Cicatrização , Nanopartículas/química
4.
Nanomaterials (Basel) ; 12(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36296875

RESUMO

The objective of this research was to explore the impact of corrosion inhibition of some synthetic acrylamide derivatives 2-cyano-N-(4-hydroxyphenyl)-3-(4-methoxyphenyl)acrylamide (ACR-2) and 2-cyano-N-(4-hydroxyphenyl)-3-phenylacrylamide (ACR-3) on copper in 1.0 M nitric acid solution using chemical and electrochemical methods, including mass loss as a chemical method and electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) as electrochemical methods. By Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1HNMR), and mass spectroscopy (MS) methods, the two compounds were verified and characterized. There is evidence that both compounds were effective corrosion inhibitors for copper in 1.0 M nitric acid (HNO3) solutions, as indicated by the PP curves, which show that these compounds may be considered mixed-type inhibitors. With the two compounds added, the value of the double-layer capacitance was reduced. In the case of 20 × 10-5 M, they reached maximum efficiencies of 84.5% and 86.1%, respectively. Having studied its behavior during adsorption on copper, it was concluded that it follows chemical adsorption and Langmuir isotherm. The theoretical computations and the experimental findings were compared using density functional theory (DFT) and Monte Carlo simulations (MC).

5.
Nanotoxicology ; 13(6): 717-732, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31111769

RESUMO

Careful handling of the nanomaterials (NMs) in research labs is crucial to ensure a safe working environment. As the largest university in Ireland, University College Dublin (UCD) has invested significant resources to update researchers working with NMs. Due to sizes often <100 nm, the NMs including nanoparticles, harbor unprecedented materialistic properties, for example, enhanced reactivity, conductivity, fluorescence, etc. which albeit conferring the NMs an edge over bulk materials regarding the applied aspects; depending on the dose, also render them to be toxic. Thus, a set of regulatory guidelines have emerged regarding safe handling of the NMs within occupational set-ups. Unfortunately, the current regulations based on the toxic chemicals and carcinogens are often confusing, lack clarity, and difficult to apply for the NMs. As a research-intensive university, a diverse range of research activities occur within the UCD labs, and it is difficult, at times impossible, for the UCD Safety, Insurance, Operational Risk & Compliance (SIRC) office to develop a set of common guidelines and cater throughout all its labs conducting research with the NMs. Hence, a necessity for dialog and exchange of ideas was felt across the UCD which encouraged the researchers including early stage researchers (e.g. PhDs, Postdocs) from multiple schools to participate in a workshop held on the 03 December 2018. The workshop tried to follow a pragmatic approach, where apart from discussing both the in vitro and in vivo scenarios, practical cases simulating situations faced frequently in the labs were discussed. This report summarizes the findings made during the workshop by this emerging critical mass in UCD.


Assuntos
Laboratórios/normas , Nanoestruturas/toxicidade , Exposição Ocupacional/prevenção & controle , Gestão da Segurança/normas , Manejo de Espécimes/normas , Universidades , Conferências de Consenso como Assunto , Guias como Assunto , Humanos , Irlanda
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