Electrolyte Engineering via Fluorinated Siloxane Solvent for Achieving High-Performance Lithium-Metal Batteries.

Advanced solvent is of important significance to develop an excellent electrolyte that simultaneously maintains a high ionic conductivity, wide electrochemical window, and good compatibility with electrodes for high-performance lithium-metal batteries (LMBs). To realize a stable electrode/electrolyte interface and a uniform lithium (Li) deposition process, an optimal fluorinated siloxane (3,3,3-trifluoropropyltrimethoxysilane, TFTMS) is proposed as a cosolvent with 1,2-dimethoxyethane (DME) and highly antioxidative fluoroethylene carbonate (FEC) to formulate a Li-metal compatibility electrolyte. The TFTMS-based electrolyte presents high oxidization stability, high Li+ conductivity, and high Li+ transfer number, contributing to the accelerated reaction kinetics, homogeneous Li deposition behavior, and stable interfacial chemistry. Therefore, high Li stripping/plating reversibility (∼99%) and stable cycling (1400 h) are achieved in the TFTMS-based electrolyte, giving rise to the excellent electrochemical performance of practical Li-metal full cells. Moreover, an industrial 4 Ah NCM811|Gr pouch cell with the TFTMS-based electrolyte is demonstrated to display similar cycling performance with the commercial carbonate electrolyte in 120 cycles at 1 C. This work offers an approach toward high-performance LMBs through rational electrolyte design with fluorinated siloxane solvent.

Purification of total flavonoids from Ginkgo biloba flowers with resin column chromatography and evaluation of antioxidant activities in vitro.

Purification of total flavonoids from Ginkgo biloba flowers (GBF) extracts were studied using six resins. Adsorption-desorption experiments indicated that polyamide resin is the most suitable resin. The optimal purification process of total flavonoids of GBF was as follows: a loading concentration of 5.85 mg/mL, a loading volume of 1 bed volume (BV), a loading flow rate of 2 BV/h, a water volume of 2.67 BV, and a desorption solution of 40% ethanol. Under these conditions, the maximum purity of total flavonoids was 37.1 ± 1.1%. The antioxidant activity of purified flavonoids was further evaluated in vitro. It showed that the 40% ethanol purified fraction (Fr. B) group had the strongest antioxidant activity of the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity concentration for 50% of maximal effect (EC50, 145.4 ± 13.8 µg/mL) and ferric reducing ability (2.5 ± 0.2 mM FeSO4 equivalent mg-1 Fr. B). In addition, at the concentration of 160 µg/mL, the Fr. B strikingly increased the viability rate of hydrogen peroxide stimulated PC-12 cells to normal levels (***p < 0.001). This method provides a basis for the application and development of GBF resources. It indicated that the purified GBF flavonoids can be used as a source of potential antioxidant.

Engineered Organosilica Hybrid Micelles for Photothermal-enhanced Starvation Cancer Therapy.

Glucose oxidase (GOD)-based starvation therapy (ST), which inhibits the growth and proliferation of cancer cells by consuming glucose, has attracted intensive attention as an emerging non-invasive method for fighting cancers. However, the enzyme activity of GOD is greatly limited in vivo because of its optimal catalytic activity in the temperature range of 43-60 °C. Herein, a photothermal-enhanced starvation strategy is developed based on our engineered organosilica hybrid micelles (TiO2-x @POMs-GOD), in which the fluoride-doped TiO2-x with photothermal properties is encapsulated in the cores of organosilica cross-linked micelles and GOD is immobilized on the carboxyl groups of PAA segments. With its internalization by cancer cells, the conjugated GOD can effectively deplete glucose to achieve the ST effect, which can be remarkably enhanced by the loaded fluoride-doped TiO2-x with NIR laser irradiation, thus cooperatively contributing to the efficient treatment of TiO2-x @POMs-GOD on various cancer cells. This suggests great potential for TiO2-x @POMs-GOD in photothermal-enhanced ST in vivo.

One-pot fabrication of a polydopamine-based nanoplatform for GSH triggered trimodal ROS-amplification for cancer therapy.

Reactive oxygen species (ROS) based nanoplatforms have been considered as attractive and feasible candidates for cancer therapy. However, the activated endogenous antioxidant defense of cancer cells in response to the ROS attack greatly hinders their therapeutic efficacy. Although cancer-specific ROS amplification strategies have been widely explored, most of them suffer from tedious synthesis procedures and complex components, which will bring about undesired side effects and unsatisfactory results. Herein, we design a cancer-specific oxidative stress amplification nanomedicine (CA-Cu-PDA), which is simply fabricated through integrating the glutathione (GSH) responsive/depleting nanocarrier of copper-polydopamine (Cu-PDA) nanoparticles with a ROS-generating drug cinnamaldehyde (CA) via a facile one-pot polymerization route. It is verified that GSH could trigger the breakage of CA-Cu-PDA networks and the subsequent release of both copper ions and CA in cancer cells. The released copper ions efficiently oxidize GSH, thereby weakening the antioxidant system of cancer cells and increasing the ROS levels. On the other hand, extra ROS are generated by the reduced copper ions through a Fenton reaction, so that a synergistic ROS therapy with CA is achieved. Consequently, oxidative stress is specifically increased within cancer cells, leading to efficient cancer cell apoptosis, significant tumor suppression and minimized side effects. Such an ingenious structure realizes the interlocking cooperation and full utilization of each component's function, presenting promising perspectives for nanomedicine design.

Biomimic Binding Affinity Gradients Triggered GSH-Response of Core-Shell Nanoparticles for Cascade Chemo/Chemodynamic Therapy.

In eukaryotes and prokaryotes, some copper transportations driven by gradient copper-binding affinities exhibit typical glutathione (GSH)-responsive features. Inspired by these delicate endogenous processes, a biomimic copper-ion mediated GSH-responsive nanomedicine is designed based on the gradient copper-binding strengths between polydopamine (PDA) species and GSH. The nanomedicine is constructed as core-shell nanoparticles with copper-polydopamine (Cu-PDA) coordinated shell and micellar core encapsulating chemotherapeutic drug of ß-lapachone (ß-lapa). In tumor cells, the excess intracellular GSH will reduce and extract the Cu(II) from the Cu-PDA network, triggered by the binding affinity gradients between Cu-PDA and Cu-GSH, resulting in the breaking of the shell and the releasing of ß-lapa and Fenton agent copper. The additional Fenton reaction of copper ions induces excess oxidative damage of tumor cells assisted by the abundant H2 O2 amplified by ß-lapa, achieving cascade anticancer effects combining chemodynamic therapy with chemotherapy. This multilevel anticancer system exhibits an efficient tumor inhibitory rate and a negligible systematic toxicity for normal organs in vivo, presenting a new bioinspired GSH-responsive strategie to develop stimuli-responsive structures.

Are Cu2 Te-Based Compounds Excellent Thermoelectric Materials?

Most of the state-of-the-art thermoelectric (TE) materials exhibit high crystal symmetry, multiple valleys near the Fermi level, heavy constituent elements with small electronegativity differences, or complex crystal structure. Typically, such general features have been well observed in those well-known TE materials such as Bi2 X3 -, SnX-, and PbX-based compounds (X = S, Se, and Te). The performance is usually high in the materials with heavy constituent elements such as Te and Se, but it is low for light constituent elements such as S. However, there is a great abnormality in Cu2 X-based compounds in which Cu2 Te has much lower TE figure of merit (zT) than Cu2 S and Cu2 Se. It is demonstrated that the Cu2 Te-based compounds are also excellent TE materials if Cu deficiency is sufficiently suppressed. By introducing Ag2 Te into Cu2 Te, the carrier concentration is substantially reduced to significantly improve the zT with a record-high value of 1.8, 323% improvement over Cu2 Te and outperforms any other Cu2 Te-based materials. The single parabolic band model is used to further prove that all Cu2 X-based compounds are excellent TE materials. Such finding makes Cu2 X-based compounds the only type of material composed of three sequent main group elements that all possess very high zT  s above 1.5.

Enhanced Thermoelectric Performance of Quaternary Cu2-2 xAg2 xSe1- xS x Liquid-like Chalcogenides.

Liquid-like binary Cu2-δX (X = S, Se, and Te) chalcogenides and their ternary solid solutions have gained notable attention in thermoelectrics due to their interesting and abnormal thermal and electrical transport properties. However, previous studies mainly focus on a single element alloying at either an anion or cation site whereas the investigation on cation/anion co-alloying is very rare so far. Here, a series of quaternary Cu2-2 xAg2 xSe1- xS x ( x = 0.01, 0.03, 0.05, 0.1, 0.15) liquid-like copper chalcogenide materials have been fabricated and the effects of Ag/S co-alloying on the thermoelectric properties of Cu2Se have been systematically studied. It is found that all compounds are mixed phases at room temperature but single cubic phase at high temperatures. The introduction of Ag and S in Cu2Se brings about a large mass fluctuation rather than strain field fluctuation that effectively suppresses the lattice thermal conductivity. Furthermore, on increasing the Ag and S contents, the high electrical conductivity of pristine Cu2Se is well tuned to the optimal range derived from the single parabolic band model analysis. Consequently, a peak zT of 1.6 at 900 K is achieved in Cu1.8Ag0.2Se0.9S0.1, which is about 33% higher than that of binary Cu2Se.