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1.
ACS Omega ; 8(37): 33955-33965, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37744808

RESUMO

This study aims to enhance the dissolution rate of a poorly water-soluble drug physcion by producing its nanoparticles (NPs) using an antisolvent precipitation with a syringe pump (APSP) method and to assess its antioxidant and cytotoxic potential. The NPs were prepared using a simple and cost-effective APSP method and subsequently characterized by different analytical techniques including dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray powder diffractometry (XRD). They were also subjected to solubility and dissolution studies, and different parameters such as dissolution efficiency (DE), mean dissolution time (MDT), and difference (f1) and similarity factors (f2) were determined. Furthermore, physcion and its NPs were investigated for antioxidant and cytotoxic effects using various in vitro assays. SEM and DLS analysis indicated that the average size of physcion NPs was 110 and 195 ± 5.6 nm, respectively. The average ζ-potential and polydispersibility index (PDI) of the prepared NPs were -22.5 mV and 0.18, respectively, showing excellent dispersibility. XRD confirmed the amorphous nature of physcion NPs. The solubility and dissolution rates of NPs were significantly higher than those of the original powder. The antioxidant potential studied by the (DPPH), FRAP, and H2O2 assays was greater for physcion NPs than that for the raw powder. The IC50 values of physcion NPs against the aforementioned models were 57.56, 22.30, and 22.68 µg/mL, respectively. Likewise, the cytotoxic potential investigated through the MTT assay showed that physcion NPs were more cytotoxic to cancer cell lines A549 (IC50 4.12 µg/mL), HepG2 (IC50 2.84 µg/mL), and MDA-MB-231 (IC50 2.97 µg/mL), while it had less effect on HPAEpiC (IC50 8.68 µg/mL) and HRPTEpiC (IC50 10.71 µg/mL) normal human epithelial cells. These findings have proved that the APSP method successfully produced physcion NPs with enhanced solubility, dissolution rate, and antioxidant and cytotoxic activities.

2.
Opt Express ; 31(17): 27880-27893, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37710854

RESUMO

This paper presents an innovative design that combines the functionalities of a polarization convertor and an electromagnetic (EM) radiator into a single integrated metasurface. The metasurface consists of two identical metallic split-rings, a circular-shaped patch structure, a dielectric layer, and a reflective metallic ground. The polarization convertor component efficiently converts waves polarized in the x- or y-direction into cross-polarized waves within a frequency range of 8-13 GHz. It exhibits wideband resonances and achieves a high conversion efficiency. In the context of low-observable platforms, traditional high-gain antennas often suffer from a large radar cross section (RCS). To overcome this challenge, the same metasurface is utilized for EM radiation, enabling a high gain of 16.5 dBi while maintaining a low RCS. This is accomplished by strategically rotating the double-slotted metallic split-rings at 90 ∘, 180 ∘, and 270 ∘ in four distinct regions. Through this rotation, destructive interference cancellation occurs, resulting in wideband reduction of the RCS. Experimental results validate the effectiveness of the proposed metasurface in serving both applications, namely polarization conversion and EM radiation.

3.
ACS Omega ; 8(33): 30221-30230, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37636925

RESUMO

Biogenic synthesis of silver nanoparticles (AgNPs) using plant extracts is gaining attention as a substitute to the conventional physical and chemical synthesis methods. This study reports a facile, cost-effective, and ecofriendly synthesis of AgNPs using leaf extract of Alnus nitida (A. nitida) and their antioxidant and antiproliferative activities. The biosynthesized AgNPs were characterized using various analytical techniques including UV-visible spectroscopy, energy-dispersive spectrometry, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and dynamic light scattering. The antioxidant and cytotoxic potential of the extract and AgNPs was evaluated using different in vitro models. The UV-vis analysis revealed a surface plasmon resonance peak of 400 nm corresponding to the synthesis of AgNPs. SEM analysis confirmed the formation of heterogeneously dispersed particles of nano size, while the XRD and FTIR spectra confirmed the crystallinity and existence of different functional groups that helped in capping and stability of AgNPs. The antioxidant activity of AgNPs and extract, studied by 1,1-diphenyl 2-picryl hydrazyl (DPPH), fluorescence recovery after photobleaching (FRAP), 2, 2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and H2O2 scavenging assays, showed a dose-dependent effect. The AgNPs at 1000 µg/mL significantly scavenged DPPH, FRAP, ABTS, and H2O2 by 66.45, 74.65, 78.81, and 72.56% with an average IC50 value of 33.31, 18.50, 16.46, and 15.65 µg/mL, respectively. The cytotoxic potential investigated by MTT assay revealed promising antiproliferative effects against different cancer cell lines. The IC50 values of AgNPs on MDA-MB-231, A549, and Hep-G2 cells were 14.88, 3.6, and 5.38 µg/mL, respectively. The results showed that AgNPs were more effective against lung and hepatocellular carcinoma. The selectivity index showed that AgNPs remained highly selective in retarding the growth of A549 and Hep-G2 cells as compared to normal cell lines HPAEpiC and HRPTEpiC. Overall, this study showed that biosynthesized AgNPs were associated with considerable antioxidant and cytotoxic effects. Our work suggests that A. nitida-mediated AgNPs should be evaluated further in order to develop safe and effective formulations for the treatment of different degenerative diseases.

4.
Environ Res ; 215(Pt 1): 114241, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36100100

RESUMO

This study is based on the removal of methylene blue (MB) from aqueous solution by cost effective and biodegradable adsorbent carboxymethyl starch grafted polyvinyl pyrolidone (Car-St-g-PVP). The Car-St-g-PVP was synthesized by grafting vinyl pyrolidone onto carboxymethyl starch by free radical polymerization reaction. The structure and different properties of Car-St-g-PVP were determined by 1H NMR, FT-IR, XRD, TGA and SEM. A series of batch experiments were conducted for the removal of MB, The adsorption affecting factors such as temperature, contact time, initial concentration of MB dye, dose of Car-St-g-PVP and pH were studied in detail. The other parameters like the thermodynamic study, kinetics and isothermal models were fitted to the experimental data. The results showed that pseudo 2nd order kinetics and Langmuir's adsorption isotherms were best fitted to experimental data with regression coefficient R2 viz. 0.99 and 0.97. The kinetic study showed that the adsorption mechanism favored chemisorption. The Gibbs free energy (ΔG°) for the adsorption process was found to be -7.31 kJ/mol, -8.23 kJ/mol, -9.00 kJ/mol and -10.10 kJ/mol at 25 °C, 35 °C, 45 °C and 55 °C respectively. The negative values of ΔG° suggested the spontaneous nature of the adsorption process. Similarly, the positive values of entropy (ΔS°) and enthalpy (ΔH°) 91.27 J/k.mol and 19.90 kJ/mol showed the increasing randomness and endothermic nature of the adsorption process. The value of separation factor (RL) was found to be less than one (RL < 1), which supported the feasibility of the adsorption process. The maximum MB removal percentage (% R) was found to be 98.6%. So, these findings show that Car-St-g-PVP can be meritoriously used for the treatment of MB from wastewater.


Assuntos
Azul de Metileno , Poluentes Químicos da Água , Adsorção , Ácidos Carboxílicos , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno/química , Polivinil , Povidona , Espectroscopia de Infravermelho com Transformada de Fourier , Amido , Termodinâmica , Águas Residuárias
5.
Molecules ; 22(10)2017 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-29065448

RESUMO

In herbalism, botanical supplements are commonly believed to be safe remedies, however, botanical supplements and dietary ingredients interact with transport and metabolic processes, affecting drug disposition. Although a large number of studies have described that botanical supplements interfere with drug metabolism, the mode of their interaction with drug transport processes is not well described. Such interactions may result in serious undesired effects and changed drug efficacy, therefore, some studies on interaction between botanical supplement ingredients and drug transporters such as P-gp and OATPs are described here, suggesting that the interaction between botanical supplements and the drug transporters is clinically significant.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Suplementos Nutricionais/efeitos adversos , Interações Ervas-Drogas , Neoplasias Hepáticas/tratamento farmacológico , Carcinoma Hepatocelular/dietoterapia , Carcinoma Hepatocelular/patologia , Humanos , Intestinos/efeitos dos fármacos , Intestinos/patologia , Neoplasias Hepáticas/dietoterapia , Neoplasias Hepáticas/patologia , Fitoterapia/efeitos adversos , Fitoterapia/métodos
6.
Bull Environ Contam Toxicol ; 89(4): 816-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22864632

RESUMO

The estrogen pollution in the Tiaoxi River, which is the main source river for Taihu Lake, was investigated by chemical and bioassay analysis. Most estrogens species, except estrone, were not detected by the chemical analysis using liquid chromatography coupled with tandem mass spectrometry. The concentration of estrone in the samples ranged from ND (below the detection limit) to 17.25 ng/L. The estrogen activity in most water samples was also determined by the yeast estrogen screen. The 17ß-estradiol equivalent in the intake of Taihu Lake was 17.60 ng/L and was present in all water samples. This study demonstrates that combining chemical and bioassay analysis is an effective way to detect environmental contamination by estrogen species. Furthermore, the results indicate that the risk of estrogen contamination in the Tiaoxi River should not be ignored.


Assuntos
Monitoramento Ambiental/métodos , Estrogênios/análise , Rios/química , Poluentes Químicos da Água/análise , Bioensaio , Cromatografia Líquida , Espectrometria de Massas em Tandem , Poluição Química da Água/estatística & dados numéricos
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