Quercetin nanoparticles display antitumor activity via proliferation inhibition and apoptosis induction in liver cancer cells.

Quercetin is a potent cancer therapeutic agent and dietary antioxidant present in fruit and vegetables. Quercetin prevents tumor proliferation by inducing cell cycle arrest and is a well known cancer therapeutic agent and autophagy mediator. Recent studies showed that drug delivery by nanoparticles have enhanced efficacy with reduced side effects. In this regard, gold-quercetin into poly(DL-lactide-co-glycolide) nanoparticles was examined. In this study, we explored the role and possible underlying mechanisms of quercetin nanoparticle in regulation of antitumor activity in liver cancer cells. Treatment with quercetin nanoparticle effectively inhibited the liver cancer cell proliferation, cell migration and colony formation, thus suppressing liver cancer progression. Quercetin nanoparticle also upregulated apoptosis markedly. Further study suggested that quercetin nanoparticle accelerated the cleavage of caspase-9, caspase-3, and induced the up-releasing of cytochrome c (Cyto-c), contributing to apoptosis in liver cancer cells. Quercetin nanoparticles also promoted telomerase reverse transcriptase (hTERT) inhibition through reducing AP-2ß expression and decreasing its binding to hTERT promoter. In addition, quercetin nanoparticle had an inhibitory role in cyclooxygenase 2 (COX-2) via suppressing the NF-κB nuclear translocation and its binding to COX-2 promoter. Quercetin nanoparticle also inactivated Akt and ERK1/2 signaling pathway. Taken together, our results suggested that quercetin nanoparticle had an antitumor effect by inactivating caspase/Cyto-c pathway, suppressing AP-2ß/hTERT, inhibiting NF-κB/COX-2 and impeding Akt/ERK1/2 signaling pathways. Our results provided new mechanistic basis for further investigation of quercetin nanoparticles to find potential therapeutic strategies and possible targets for liver cancer inhibition.

Microfluidic assisted synthesis of silver nanoparticle-chitosan composite microparticles for antibacterial applications.

Silver nanoparticle (Ag NP)-loaded chitosan composites have numerous biomedical applications; however, fabricating uniform composite microparticles remains challenging. This paper presents a novel microfluidic approach for single-step and in situ synthesis of Ag NP-loaded chitosan microparticles. This proposed approach enables obtaining uniform and monodisperse Ag NP-loaded chitosan microparticles measuring several hundred micrometers. In addition, the diameter of the composites can be tuned by adjusting the flow on the microfluidic chip. The composite particles containing Ag NPs were characterized using UV-vis spectra and scanning electron microscopy-energy dispersive X-ray spectrometry data. The characteristic peaks of Ag NPs in the UV-vis spectra and the element mapping or pattern revealed the formation of nanosized silver particles. The results of antibacterial tests indicated that both chitosan and composite particles showed antibacterial ability, and Ag NPs could enhance the inhibition rate and exhibited dose-dependent antibacterial ability. Because of the properties of Ag NPs and chitosan, the synthesized composite microparticles can be used in several future potential applications, such as bactericidal agents for water disinfection, antipathogens, and surface plasma resonance enhancers.

[Effects of LED qualities on quality and antioxidation capacity of eggplant fruits].

The effects of red light, blue light, red+blue light and white light (control) generated by LED on the quality and antioxidation capacity of fruit and yield of ' Brita' eggplants were stu died. The results showed that under blue LED, the soluble protein, free amino acids contents o eggplant pulps and the anthocyanin content of eggplant peels were significantly higher by 15.1%, 27.2% and 73.6% than control respectively, but flavonoid and phenolic contents of pulps and the yield were significantly lower than those of the other treatments. Under red LED, the eggplant peels flavonoid was remarkably increased, but vitamin C (Vc) and soluble protein contents were consi derably decreased. Under red+blue LED, the soluble sugar of pulps and phenolic, red pigment yellow pigment contents, total antioxidation capacity (TAG) of peels and the yield were significantly higher than those of the other treatments, in which, the TAC of peels and the yield increased by 43.5% and 43.4% compared with control, respectively. Vc, flavonoid and phenolic contents and TAC of eggplant pulps were the highest under white LED. There was significant positive correlation between the phenol content of peels and Vc content of pulps with TAC. Under the protected cultivation condition, an appropriate amount of blue or red LED could improve the quality of eggplant fruit, and red+blue LED was more beneficial to promote the quality of eggplant peels and the yield.

Boron-doped graphene quantum dots for selective glucose sensing based on the "abnormal" aggregation-induced photoluminescence enhancement.

A hydrothermal approach for the cutting of boron-doped graphene (BG) into boron-doped graphene quantum dots (BGQDs) has been proposed. Various characterizations reveal that the boron atoms have been successfully doped into graphene structures with the atomic percentage of 3.45%. The generation of boronic acid groups on the BGQDs surfaces facilitates their application as a new photoluminescence (PL) probe for label free glucose sensing. It is postulated that the reaction of the two cis-diol units in glucose with the two boronic acid groups on the BGQDs surfaces creates structurally rigid BGQDs-glucose aggregates, restricting the intramolecular rotations and thus resulting in a great boost in the PL intensity. The present unusual "aggregation-induced PL increasing" sensing process excludes any saccharide with only one cis-diol unit, as manifested by the high specificity of BGQDs for glucose over its close isomeric cousins fructose, galactose, and mannose. It is believed that the doping of boron can introduce the GQDs to a new kind of surface state and offer great scientific insights to the PL enhancement mechanism with treatment of glucose.

Fluorescent graphene quantum dots with a boronic acid appended bipyridinium salt to sense monosaccharides in aqueous solution.

Using graphene quantum dots (GQDs) with a boronic acid-substituted bipyridinium salt (BBV), a label-free fluorescence assay for glucose detection is presented.