RESUMEN
We investigated UV-shielding performances and biodegradation abilities under controlled hydrolytic, soil burial, and thermal conditions of transparent polylactic acids (PLA) nanocomposite films embedded with cellulose nanocrystal-zinc oxide (CNC-ZnO) hybrids. By adding high content of 15wt %CNC-ZnO hybrids into the PLA matrix, the highest UV radiation was blocked out by (85.31%) of UV-A and (95.90%) of UV-B. It is found that the weight loss of PLA nanocomposites after being hydrolytic degraded for 70â¯days increased from 9% for PLA to 25% with 15â¯wt% CNC-ZnO hybrids. Meanwhile, in soil burial test, pure PLA shows smallest degradation rate with only 8% weight loss after 110â¯days, while the PLA nanocomposite film with 15â¯wt% CNC-ZnO hybrids was degraded by about 28%. Besides, the resultant degradation byproducts from the thermally-decomposed catalysis have been identified by Fourier transform infrared spectroscopy (FT-IR). Moreover, the morphologies and appearances changes during the hydrolytic and soil degradation of PLA nanocomposite films were evaluated. This study is expected to provide meaningful insights into nanocomposite films embedded with CNC-ZnO hybrids as a result of contourable degradation and high ultraviolet protection factor value (UPF).
Asunto(s)
Biodegradación Ambiental , Celulosa/química , Nanocompuestos/química , Nanopartículas/química , Poliésteres/química , Óxido de Zinc/química , Fenómenos Químicos , Fenómenos Mecánicos , Membranas Artificiales , Nanocompuestos/ultraestructura , Nanopartículas/ultraestructura , Análisis Espectral , Rayos UltravioletaRESUMEN
Zinc oxide/cellulose nanocrystal (ZnO/CNC) hybrids with modulated morphologies were prepared by using bamboo CNC as templates via green one-step technique. The effect of pH values on the morphology, microstructure, thermal stability, antibacterial efficiency and dye absorption kinetics of hybrids were investigated. A possible mechanism for various hybrid morphologies at different pH values was provided. All the samples exhibited high antibacterial ratios of 91.4%-99.8% against both Escherichia coli and Staphylococcus aureus. ZnO/CNC8.5 gave quick removal efficiency with high dye removal ratios in methylene blue (MB, 93.55%) and malachite green (MG, 99.02%), especially >91.47% and 97.85% within 5â¯min. The absorption capacity could reach up to 46.77â¯mg/g for MB and 49.51â¯mg/g for MG. Besides, absorption kinetics showed that the absorption behavior followed the pseudo-second-order kinetic model (R2â¯>â¯0.99996). Such ZnO/CNC hybrids show outstanding and low-cost adsorbent for efficient absorption of cationic dyes in wastewater treatment field.
Asunto(s)
Absorción Fisicoquímica , Antibacterianos/química , Celulosa/química , Colorantes/química , Colorantes/aislamiento & purificación , Nanopartículas/química , Óxido de Zinc/química , Antibacterianos/farmacología , Técnicas de Química Sintética , Escherichia coli/efectos de los fármacos , Tecnología Química Verde , Concentración de Iones de Hidrógeno , Cinética , Azul de Metileno/química , Azul de Metileno/aislamiento & purificación , Colorantes de Rosanilina/química , Colorantes de Rosanilina/aislamiento & purificación , Staphylococcus aureus/efectos de los fármacos , Temperatura , Aguas Residuales/química , Purificación del Agua , Óxido de Zinc/farmacologíaRESUMEN
Mangiferin, a glucosylxanthone from Mangifera indica, has been reported to have anti-inflammatory effects. However, the protective effects and mechanisms of mangiferin on liver injury remain unclear. This study aimed to determine the protective effects and mechanisms of mangiferin on lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced acute liver injury. Mangiferin was given 1h after LPS and D-GalN treatment. The results showed that mangiferin inhibited the levels of serum ALT, AST, IL-1ß, TNF-α, MCP-1, and RANTES, as well as hepatic malondialdehyde (MDA) and ROS levels. Moreover, mangiferin significantly inhibited IL-1ß and TNF-α production in LPS-stimulated primary hepatocytes. Mangiferin was found to up-regulate the expression of Nrf2 and HO-1 in a dose-dependent manner. Furthermore, mangiferin inhibited LPS/d-GalN-induced hepatic NLRP3, ASC, caspase-1, IL-1ß and TNF-α expression. In conclusion, mangiferin protected against LPS/GalN-induced liver injury by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation.
Asunto(s)
Proteínas Portadoras/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Galactosamina/farmacología , Inflamasomas/metabolismo , Lipopolisacáridos/farmacología , Xantonas/farmacología , Enfermedad Aguda , Alanina Transaminasa/sangre , Animales , Apoptosis/efectos de los fármacos , Aspartato Aminotransferasas/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Citoprotección/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Malondialdehído/metabolismo , Ratones , Ratones Endogámicos C57BL , Factor 2 Relacionado con NF-E2/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Xantonas/uso terapéuticoRESUMEN
Forsythiaside A, an active constituent isolated from air-dried fruits of Forsythia suspensa, has been reported to have multiple pharmacological activities including anti-inflammatory, anti-oxidant, and antioxidant activities. In the present study, the hepatoprotective effect of forsythiaside A was investigated in lipopolysaccharide (LPS)/d-galactosamine (GalN)-induced acute liver injury in mice. Mice acute liver injury model was induced by LPS (50µg/kg)/GalN (800mg/kg). Forsythiaside A was administrated 1h prior to LPS/GalN exposure. The results showed that forsythiaside A attenuated hepatic pathological damage, malondialdehyde (MDA) content, and serum ALT, and AST levels induced by LPS/GalN. Moreover, forsythiaside A inhibited NF-κB activation, serum TNF-α and hepatic TNF-α levels induced by LPS/GalN. Furthermore, we found that forsythiaside A up-regulated the expression of Nrf2 and heme oxygenase-1. Our results showed that forsythiaside A protected against LPS/GalN-induced liver injury through activation of Nrf2 and inhibition of NF-κB activation.