A rapid synthesis of high surface area PdRu nanosponges:Composition-dependent electrocatalytic activity for formic acid oxidation

Here, Pd Ru nanoparticle networks（NPNs） with various compositions were synthesized through an inexpensive method in water as a green solvent, at different ratios of the H;PdCl;and RuCl;precursors. This is a fast, room temperature and surfactant free strategy which is able to form high surface area metal nanosponges with a three-dimensional（3D） porous structure. The structure of as-prepared nanosponges was characterized using the techniques of field emission scanning electron microscopy（FESEM）, energy dispersive spectroscopy（EDS） and cyclic voltammetry（CV）. Then, the electrocatalytic activities of Pd Ru NPNs towards formic acid oxidation were examined by electrochemical measurements including CV,chronoamperometry, and electrochemical impedance spectroscopy（EIS）. Based on studies, it was found that the current density of formic acid oxidation（FAO） is strongly dependent on the composition of Pd Ru NPNs. The best performance was realized for Pd;Ru;NPNs compared to monometallic Pd counterpart and other bimetallic NPNs which might be ascribed to the role of Ru in the decrease of CO adsorption strength on the catalyst and consequently the priority of formic acid oxidation through the direct pathway. The Pd;Ru;NPNs also showed the maximum current density and stability in chronoamperometric measurements. In addition, comparative studies were performed between as-prepared NPNs and CNTs-supported Pd nanoparticles（Pd NPs/CNTs）. The present results demonstrated the unique structural advantages of NPNs compared to individual Pd NPs supported on the CNT which leads to the promising performance of NPNs as supportless catalysts for the oxidation of formic acid.

Cytokine nanosponges suppressing overactive macrophages and dampening systematic cytokine storm for the treatment of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis(HLH)is a highly fatal condition with the positive feedback loop between continued immune cell activation and cytokine storm as the core mechanism to mediate multiple organ dysfunction.Inspired by macrophage membranes harbor the receptors with special high affinity for proin-flammation cytokines,lipopolysaccharide(LPS)-stimulated macrophage membrane-coated nanoparticles(LMNP)were developed to show strong sponge ability to both IFN-γand IL-6 and suppressed overactivation of macrophages by inhibiting JAK/STAT signaling pathway both in vitro and in vivo.Besides,LMNP also efficiently alleviated HLH-related symptoms including cytopenia,hepatosplenomegaly and hepatorenal dysfunction and save the life of mouse models.Furthermore,its sponge effect also worked well for five human HLH samples in vitro.Altogether,it’s firstly demonstrated that biocompatible LMNP could dampen HLH with high potential for clinical transformation,which also provided alternative insights for the treatment of other cytokine storm-mediated pathologic conditions such as COVID-19 infection and cytokine releasing syndrome during CAR-T therapy.

Unique and hierarchically structured novel Co3O4/NiO nanosponges with superior photocatalytic activity against organic contaminants

In the present study, novel Co3O4/NiO nanosponges designed for the photocatalytic degradation of organic contaminants were synthesized by a simple precipitation technique. The formation of sponge-like nanostructures was clearly evident through the TEM analysis. The photocatalytic efficiency was tested against rhodamine B （RhB） and congo red （CR） dye solutions. Co3O4/NiO nanosponges showed excellent and enhanced photocatalytic efficacy compared to those of Co3O4, NiO nanoparticles, and standards like Ti02 and ZnO. The influence of paramount important operational parameters was explored and the conditions for the best photocatalytic efficiency were optimized. The trapping experiment revealed that the reactive oxygen species （ROS） identified was · OH radical. These findings certainly open up a new way for synthesizing a morphology dependent photocatalyst.

Engineered Biomimetic Platelet Membrane-Coated Nanoparticles Block Staphylococcus aureus Cytotoxicity and Protect Against Lethal Systemic Infection

Staphylococcus aureus(S.aureus)is a leading human pathogen capable of producing severe invasive infections such as bacteremia,sepsis,and endocarditis with high morbidity and mortality,exacerbated by the increasingly widespread antibiotic resistance exemplified by methicillin-resistant strains(MRSA).S.aureus pathogenesis is fueled by the secretion of toxins—such as the membrane-damaging pore-forming atoxin,which have diverse cellular targets including the epithelium,endothelium,leukocytes,and platelets.Here,we examine the use of human platelet membrane-coated nanoparticles(PNPs)as a biomimetic decoy strategy to neutralize S.aureus toxins and preserve host cell defense functions.The PNPs blocked platelet damage induced by S.aureus secreted toxins,thereby supporting platelet activation and bactericidal activity.Likewise,the PNPs blocked macrophage damage induced by S.aureus secreted toxins,thus supporting macrophage oxidative burst,nitric oxide production,and bactericidal activity,and diminishing MRSA-induced neutrophil extracellular trap release.In a mouse model of MRSA systemic infection,PNP administration reduced bacterial counts in the blood and protected against mortality.Taken together,the results from the present work provide a proof of principle of the therapeutic benefit of PNPs in toxin neutralization,cytoprotection,and increased host resistance to invasive S.aureus infection.