Hemostatic and Ultrasound-Controlled Bactericidal Silk Fibroin Hydrogel via Integrating a Perfluorocarbon Nanoemulsion.

Excessive blood loss and infections are the prominent risks accounting for mortality and disability associated with acute wounds. Consequently, wound dressings should encompass adequate adhesive, hemostatic, and bactericidal attributes, yet their development remains challenging. This investigation presented the benefits of incorporating a perfluorocarbon nanoemulsion (PPP NE) into a silk-fibroin (SF)-based hydrogel. By stimulating the ß-sheet conformation of the SF chains, PPP NEs drastically shortened the gelation time while augmenting the elasticity, mechanical stability, and viscosity of the hydrogel. Furthermore, the integration of PPP NEs improved hemostatic competence by boosting the affinity between cells and biomacromolecules. It also endowed the hydrogel with ultrasound-controlled bactericidal ability through the inducement of inner cavitation by perfluorocarbon and reactive oxygen species (ROS) generated by the sonosensitizer protoporphyrin. Ultimately, we employed a laparotomy bleeding model and a Staphylococcus aureus-infected trauma wound to demonstrate the first-aid efficacy. Thus, our research suggested an emulsion-incorporating strategy for managing emergency wounds.

Ampere-Level Current Density CO2 Reduction with High C2+ Selectivity on La(OH)3-Modified Cu Catalysts.

The carbon dioxide reduction reaction (CO2RR) driven by electricity can transform CO2 into high-value multi-carbon (C2+) products. Copper (Cu)-based catalysts are efficient but suffer from low C2+ selectivity at high current densities. Here La(OH)3 in Cu catalyst is introduced to modify its electronic structure towards efficient CO2RR to C2+ products at ampere-level current densities. The La(OH)3/Cu catalyst has a remarkable C2+ Faradaic efficiency (FEC2+) of 71.2% which is 2.2 times that of the pure Cu catalyst at a current density of 1,000 mA cm-2 and keeps stable for 8 h. In situ spectroscopy and density functional theory calculations both show that La(OH)3 modifies the electronic structure of Cu. This modification favors *CO adsorption, subsequent hydrogenation, *CO─*COH coupling, and consequently increases C2+ selectivity. This work provides a guidance on facilitating C2+ product formation, and suppressing hydrogen evolution by La(OH)3 modification, enabling efficient CO2RR at ampere-level current densities.

Universal and Energy-Efficient Approach to Synthesize Pt-Rare Earth Metal Alloys for Proton Exchange Membrane Fuel Cell.

Traditional synthesis methods of platinum-rare earth metal (Pt-RE) alloys usually involve harsh conditions and high energy consumption because of the low standard reduction potentials and high oxophilicity of RE metals. In this work, a one-step strategy is developed by rapid Joule thermal-shock (RJTS) to synthesize Pt-RE alloys within tens of seconds. The method can not only realize the regulation of alloy size, but also a universal method for the preparation of a family of Pt-RE alloys (RE = Ce, La, Gd, Sm, Tb, Y). In addition, the energy consumption of the Pt-RE alloy preparation is only 0.052 kW h, which is 2-3 orders of magnitude lower than other reported methods. This method allows individual Pt-RE alloy to be embedded in the carbon substrate, endowing the alloy catalyst excellent durability for oxygen reduction reaction (ORR). The performance of alloy catalyst shows negligible decay after 20k accelerated durability testing (ADT) cycles. This strategy offers a new route to synthesize noble/non-noble metal alloys with diversified applications besides ORR.

Ligustilide Inhibits Tumor Angiogenesis by Downregulating VEGFA Secretion from Cancer-Associated Fibroblasts in Prostate Cancer via TLR4.

CAFs secrete VEGFA in the tumor microenvironment to induce angiogenesis and promote tumor growth. The downregulation of VEGFA secretion from CAFs helps block angiogenesis and exerts an anti-tumor effect. In vivo experiments showed that the angiogenesis of the tumor-bearing mice in the ligustilide group was significantly reduced. The results of MTT, tube formation, Transwell and scratch experiments showed that ligustilide did not affect the proliferation of HUVECs in a certain concentration range (<60 µM), but it inhibited the proliferation, tube formation and migration of HUVECs induced by CAFs. At this concentration, ligustilide did not inhibit CAF proliferation. The qPCR and WB results revealed that ligustilide downregulated the level of VEGFA in CAFs via the TLR4-ERK/JNK/p38 signaling pathway, and the effect was attenuated by blockers of the above molecules. Ligustilide also downregulated the autocrine VEGFA of HUVECs induced by CAFs, which inhibited angiogenesis more effectively. In addition, ligustilide inhibited glycolysis and HIF-1 expression in CAFs. Overall, ligustilide downregulated the VEGFA level in CAFs via the TLR4-ERK/JNK/p38 signaling pathway and inhibited the promotion of angiogenesis. This study provides a new strategy for the anti-tumor effect of natural active molecules, namely, blockade of angiogenesis, and provides a new candidate molecule for blocking angiogenesis in the tumor microenvironment.