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1.
Inorg Chem ; 59(17): 12632-12642, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32838518

RESUMO

Multifunctional platinumIV anticancer prodrugs have the potential to enrich the anticancer properties and overcome the clinical problems of drug resistance and side effects of platinumII anticancer agents. Herein, we develop dual and triple action platinumIV complexes with targeted and biological active functionalities. One complex (PFL) that consists of cisplatin, tegafur, and lonidamine exhibits strong cytotoxicity against triple negative breast cancer (TNBC) cells. Cellular uptake and distribution studies reveal that PFL mainly accumulates in mitochondria. As a result, PFL disrupts the mitochondrial ultrastructure and induces significant alterations in the mitochondrial membrane potential, which further leads to an increase in production of reactive oxygen species (ROS) and a decrease in ATP synthesis in MDA-MB-231 TNBCs. Western blot analysis reveals the formation of ternary complex of thymidylate synthase, which shows the intracellular conversion of tegafur into 5-FU after its release from PFL. Furthermore, treatment with PFL impairs the mitochondrial function, leading to the inhibition of glycolysis and mitochondrial respiration and induction of apoptosis through the mitochondrial pathway. The RNA-sequencing experiment shows that PFL can perturb the pathways involved in DNA synthesis, DNA damage, metabolism, and transcriptional activity. These findings demonstrate that PFL intervenes in several cellular processes including DNA damage, thymidylate synthase inhibition, and perturbation of the mitochondrial bioenergetics to kill the cancer cells. The results highlight the significance of a triple-action prodrug for efficient anticancer therapy for TNBCs.


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Inibidores Enzimáticos/química , Platina/química , Pró-Fármacos/metabolismo , Timidilato Sintase/antagonistas & inibidores , Neoplasias de Mama Triplo Negativas/patologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA , Liberação Controlada de Fármacos , Fluoruracila/metabolismo , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Pró-Fármacos/química , Espécies Reativas de Oxigênio/metabolismo , Transcrição Gênica/efeitos dos fármacos
2.
Water Sci Technol ; 76(3-4): 963-975, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28799942

RESUMO

Intermittent backwashing and relaxation are mandatory in the membrane bioreactor (MBR) for its effective operation. The objective of the current study was to evaluate the effects of run-relaxation and run-backwash cycle time on fouling rates. Furthermore, comparison of the effects of backwashing and relaxation on the fouling behavior of membrane in high rate submerged MBR. The study was carried out on a laboratory scale MBR at high flux (30 L/m2·h), treating sewage. The MBR was operated at three relaxation operational scenarios by keeping the run time to relaxation time ratio constant. Similarly, the MBR was operated at three backwashing operational scenarios by keeping the run time to backwashing time ratio constant. The results revealed that the provision of relaxation or backwashing at small intervals prolonged the MBR operation by reducing fouling rates. The cake and pores fouling rates in backwashing scenarios were far less as compared to the relaxation scenarios, which proved backwashing a better option as compared to relaxation. The operation time of backwashing scenario (lowest cycle time) was 64.6% and 21.1% more as compared to continuous scenario and relaxation scenario (lowest cycle time), respectively. Increase in cycle time increased removal efficiencies insignificantly, in both scenarios of relaxation and backwashing.


Assuntos
Reatores Biológicos , Filtração/métodos , Membranas Artificiais , Fatores de Tempo , Incrustação Biológica , Esgotos
4.
Int J Biol Macromol ; 129: 965-971, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30738165

RESUMO

In the current study, nanocomposites of bacterial cellulose (BC) and amorphous TiO2 were prepared and characterized. The nanocomposites were evaluated as adsorbent for the removal of lead (Pb) from aqueous solution. The different reactions conditions such as pH, equilibrium time, temperature, adsorbent dose and possible recycling of adsorbent were studied. The nanocomposites were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The characterization results confirmed the formation of nanocomposites. Moreover, BC modified with 3 wt% TiO2 showed best results for the removal of Pb ions from aqueous solution. TiO2-BC nanocomposites remove Pb in concentration of 100 mg/L with removal efficiency above 90% in 120 min at pH 7 and room temperature. The adsorbent was recycled, and no profound decrease of efficiency was observed till three cycles of use. Desorption studies were also carried out for the reusability of the adsorbent. The adsorbent was found efficient, stable and reusable for the removal of lead in environmental water samples.


Assuntos
Celulose/química , Gluconacetobacter xylinus/química , Chumbo/química , Chumbo/isolamento & purificação , Titânio/química , Purificação da Água/métodos , Água/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Nanocompostos/química , Temperatura , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
5.
J Hazard Mater ; 168(1): 1-12, 2009 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-19278777

RESUMO

Arsenic concentrations above acceptable standards for drinking water have been detected in many countries and this should therefore is a global issue. The presence of arsenic in subsurface aquifers and drinking water systems is a potentially serious human health hazard. The current population growth in Pakistan and other developing countries will have direct bearing on the water sector for meeting the domestic, industrial and agricultural needs. Pakistan is about to exhaust its available water resources and is on the verge of becoming a water deficit country. Water pollution is a serious menace in Pakistan, as almost 70% of its surface waters as well as its groundwater reserves have contaminated by biological, organic and inorganic pollutants. In some areas of Pakistan, a number of shallow aquifers and tube wells are contaminated with arsenic at levels which are above the recommended USEPA arsenic level of 10 ppb (10 microg L(-1)). Adverse health effects including human mortality from drinking water are well documented and can be attributed to arsenic contamination. The present paper reviews appropriate and low cost methods for the elimination of arsenic from drinking waters. It is recommended that a combination of low cost chemical treatment like ion exchange, filtration and adsorption along with bioremediation may be useful option for arsenic removal from drinking water.


Assuntos
Arsênio/isolamento & purificação , Purificação da Água/métodos , Abastecimento de Água/normas , Países em Desenvolvimento , Paquistão , Poluentes Químicos da Água , Purificação da Água/economia
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