Upgrading CO2 to sustainable aromatics via perovskite-mediated tandem catalysis.

The directional transformation of carbon dioxide (CO2) with renewable hydrogen into specific carbon-heavy products (C6+) of high value presents a sustainable route for net-zero chemical manufacture. However, it is still challenging to simultaneously achieve high activity and selectivity due to the unbalanced CO2 hydrogenation and C-C coupling rates on complementary active sites in a bifunctional catalyst, thus causing unexpected secondary reaction. Here we report LaFeO3 perovskite-mediated directional tandem conversion of CO2 towards heavy aromatics with high CO2 conversion (> 60%), exceptional aromatics selectivity among hydrocarbons (> 85%), and no obvious deactivation for 1000 hours. This is enabled by disentangling the CO2 hydrogenation domain from the C-C coupling domain in the tandem system for Iron-based catalyst. Unlike other active Fe oxides showing wide hydrocarbon product distribution due to carbide formation, LaFeO3 by design is endowed with superior resistance to carburization, therefore inhibiting uncontrolled C-C coupling on oxide and isolating aromatics formation in the zeolite. In-situ spectroscopic evidence and theoretical calculations reveal an oxygenate-rich surface chemistry of LaFeO3, that easily escape from the oxide surface for further precise C-C coupling inside zeolites, thus steering CO2-HCOOH/H2CO-Aromatics reaction pathway to enable a high yield of aromatics.

Silanol-Assisted High-Yield Nanofabrication of SnO2 Single Crystals with Highly Tunable and Ordered Mesoporosity.

Highly ordered mesoporous materials with a single-crystalline structure have attracted broad interest due to their wide applications from catalysis to energy conversion/storage, but constructing them with good controllability and high yields remains a highly daunting task. Herein, we construct a new class of three-dimensionally ordered mesoporous SnO2 single crystals (3DOm-SnO2) with well-defined facets and excellent mesopore tunability. Mechanism studies demonstrate that the silanol groups on ordered silica nanospheres (3DO-SiO2) can induce the efficient heterogeneous crystallization of uniform SnO2 single crystals in its periodic voids by following the hard and soft acid and base theory, affording a much higher yield of ∼96% for 3DOm-SnO2 than that of its solid counterpart prepared in the absence of 3DO-SiO2 (∼1.5%). Benefiting from its permanent ordered mesopores and favorable electronic structure, Pd-supported 3DOm-SnO2 can efficiently catalyze the unprecedented sequential hydrogenation of 4-nitrophenylacetylene to produce 4-nitrostyrene, then 4-nitroethylbenzene, and finally 4-aminoethylbenzene. DFT calculations further reveal the favorable synergistic effect between Pd and 3DOm-SnO2 via moderate electron transfer for realizing this sequential hydrogenation reaction. Our work underlines the crucial role of silanol groups in inducing the high-yield heterogeneous crystallization of 3DOm-SnO2, shedding light on the rational design and construction of various 3DO single crystals that are of great practical significance.

Atomically Dispersed ZnN4 Sites Anchored on P-Functionalized Carbon with Hierarchically Ordered Porous Structures for Boosted Electroreduction of CO2.

Tuning the coordination structures of metal sites is intensively studied to improve the performances of single-atom site catalysts (SASC). However, the pore structure of SASC, which is highly related to the accessibility of active sites, has received little attention. In this work, single-atom ZnN4 sites embedded in P-functionalized carbon with hollow-wall and 3D ordered macroporous structure (denoted as H-3DOM-ZnN4 /P-C) are constructed. The creation of hollow walls in ordered macroporous structures can largely increase the external surface area to expose more active sites. The introduction of adjacent P atoms can optimize the electronic structure of ZnN4 sites through long-rang regulation to enhance the intrinsic activity and selectivity. In the electrochemical CO2 reduction reaction, H-3DOM-ZnN4 /P-C exhibits high CO Faradaic efficiency over 90% in a wide potential window (500 mV) and a large turnover frequency up to 7.8 × 104  h-1 at -1.0 V versus reversible hydrogen electrode, much higher than its counterparts without the hierarchically ordered structure or P-functionalization.

High rapamycin-loaded hollow mesoporous Prussian blue nanozyme targets lesion area of spinal cord injury to recover locomotor function.

Scavenging free radicals and reducing inflammatory reaction to relieve the secondary damage are important issues in the spinal cord injury (SCI) therapeutic strategy. Nanozymes attract more attention in the drug development of SCI due to the high stability, long-lasting catalytic capacity, and multienzyme-like properties. Herein, we constructed a Rapamycin (Rapa)-loaded and hollow mesoporous Prussian blue (HMPB)-based nanozyme (RHPAzyme) to realize the combined antioxidation and anti-inflammation combination therapy of SCI. Furthermore, activated cell penetrating peptide (ACPP) is modified onto nanozyme to endow the effectively ability of lesion area-targeting. This RHPAzyme exhibits ROS scavenging capacity with the transformation of Fe2+/Fe3+ valance and cyanide group of HMPB to achieve multienzyme-like activity. As expected, RHPAzyme scavenges the ROS overproduction and reduces inflammation in oxygen-glucose deprivation (OGD)-induced damage via inhibiting MAPK/AKT signaling pathway. Furtherly, RHPAzyme exhibits the combined antioxidant and anti-inflammatory activity in vivo, which can effectively alleviate neuronal damage and promote motor function recovery in SCI mice. Overall, this study demonstrates the RHPAzyme induces an effective treatment of SCI by inhibiting oxygen-mediated cell apoptosis and suppressing inflammation-induced injury, thus reduces the nervous impairment and promotes motor function recovery.

Defect Engineered Metal-Organic Framework with Accelerated Structural Transformation for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) have been increasingly applied in oxygen evolution reaction (OER), and the surface of MOFs usually undergoes structural transformation to form metal oxyhydroxides to serve as catalytically active sites. However, the controllable regulation of the reconstruction process of MOFs remains as a great challenge. Here we report a defect engineering strategy to facilitate the structural transformation of MOFs to metal oxyhydroxides during OER with enhanced activity. Defective MOFs (denoted as NiFc'x Fc1-x ) with abundant unsaturated metal sites are constructed by mixing ligands of 1,1'-ferrocene dicarboxylic acid (Fc') and defective ferrocene carboxylic acid (Fc). NiFc'x Fc1-x series are more prone to be transformed to metal oxyhydroxides compared with the non-defective MOFs (NiFc'). Moreover, the as-formed metal oxyhydroxides derived from defective MOFs contain more oxygen vacancies. NiFc'Fc grown on nickel foam exhibits excellent OER catalytic activity with an overpotential of 213 mV at the current density of 100 mA cm-2 , superior to that of undefective NiFc'. Experimental results and theoretical calculations suggest that the abundant oxygen vacancies in the derived metal oxyhydroxides facilitate the adsorption of oxygen-containing intermediates on active centers, thus significantly improving the OER activity.

Metal-Organic Frameworks as a New Platform to Construct Ordered Mesoporous Ce-Based Oxides for Efficient CO2 Fixation under Ambient Conditions.

Metal-organic frameworks (MOFs) are proved to be good precursors to derive various nanomaterials with desirable functions, but so far the controllable synthesis of ordered mesoporous derivatives from MOFs has not been achieved. Herein, this work reports, for the first time, the construction of MOF-derived ordered mesoporous (OM) derivatives by developing a facile mesopore-inherited pyrolysis-oxidation strategy. This work demonstrates a particularly elegant example of this strategy, which involves the mesopore-inherited pyrolysis of OM-CeMOF into a OM-CeO2 @C composite, followed by the oxidation removal of its residual carbon, affording the corresponding OM-CeO2 . Furthermore, the good tunability of MOFs helps to allodially introduce zirconium into OM-CeO2 to regulate its acid-base property, thus boosting its catalytic activity for CO2 fixation. Impressively, the optimized Zr-doped OM-CeO2 can achieve above 16 times higher catalytic activity than its solid CeO2 counterpart, representing the first metal oxide-based catalyst to realize the complete cycloaddition of epichlorohydrin with CO2 under ambient temperature and pressure. This study not only develops a new MOF-based platform for enriching the family of ordered mesoporous nanomaterials, but also demonstrates an ambient catalytic system for CO2 fixation.

A Janus heteroatom-doped carbon electrocatalyst for hydrazine oxidation.

The trade-off between the intrinsic activity and electronic conductivity of carbon materials is a major barrier for electrocatalysis. We report a Janus-type carbon material combining electrically conductive nitrogen-doped carbon (NC) and catalytically active boron, nitrogen co-doped carbon (BNC). The integration of NC with BNC can not only ensure high electronic conductivity of the hybrid, but also achieve an enhancement in the intrinsic activity of the BNC side due to the electron redistribution on their coupling interfaces. In the electrocatalytic hydrazine oxidation reaction (HzOR), the Janus carbon electrocatalyst exhibits superior activity than their single counterparts and simple physical mixtures. Density functional theory calculations reveal that the NC/BNC interfaces simultaneously promote efficient electron transport and decrease the free energy of the rate-determining step in the HzOR process.

Hierarchically Ordered Macro-Mesoporous Electrocatalyst with Hydrophilic Surface for Efficient Oxygen Reduction Reaction.

Metal-organic frameworks (MOFs) offer versatile templates/precursors to prepare supported metal catalysts. However, the afforded catalysts usually exhibit microporous structures and unsuitable wettability, which will restrict the accessibility of active sites in liquid-phase reactions. Herein, an etching-functionalization strategy is developed for the construction of a tannic-acid-functionalized MOF with a unique hollow-wall and 3D-ordered macroporous (H-3DOM) structure. The functional MOF can be further employed as an ideal precursor for the synthesis of cobalt supported on oxygen/nitrogen-co-doped carbon composites with H-3DOM structures, and hydrophilic surface. The H-3DOM structure can improve the external surface area to maximize the exposure of active sites. Moreover, the oxygen-containing functional groups can enhance the surface wettability to guarantee the external active sites to be more electrochemically accessible in aqueous electrolyte. Benefitting from these outstanding characteristics, H-3DOM-Co/ONC exhibits high electrocatalytic activity in the oxygen reduction reaction, superior to its counterparts without the hierarchically ordered structure and surface functionalization.

New era of medical education: asynchronous and synchronous online teaching during and after COVID-19.

COVID-19 struck the world suddenly and unexpectedly. Since traditional education requires face-to-face communication, to avoid further spreading of the virus a majority part of that education has moved online. Our study attempts to compare the differences between online medical education with a unique course design and traditional face-to-face education. We conducted a retrospective analysis of a total of 4,098 medical students between 2019 and 2020, including two groups of students who received online education and classroom education for the same subjects, respectively. Freshmen enrolled in September 2018 received traditional classroom physiology and pharmacology education in the spring semester of 2019. Because of the impact of the COVID-19 pandemic, freshmen who were enrolled in September 2019 received online physiology and pharmacology education in the spring semester of 2020. The final marks of the two groups of students were recorded and compared. Data on students participating in online discussions, learning, homework, and watching instructional videos were also recorded. There was no significant difference in the final academic performance between the two groups [average mark: 55.93 (online education) vs. 56.27 (classroom education), P = 0.488]. Further analysis showed that student participation rates in online discussions, online learning, and online viewing of instructional videos were closely correlated with final grades in online courses (P < 0.01). In conclusion, our results suggest that the pedagogical effects of online education during COVID-19 were promising, and we provide a well-designed medical online course to inspire further improvements in online education.NEW & NOTEWORTHY The COVID-19 pandemic has led to a massive temporary conversion of offline education to online education worldwide. Previous studies have noted that more students believed they had better learning experience in face-to-face learning. However, with our method of online teaching, we still showed a relatively similar performance result compared with offline education.

Morphology-Engineering Construction of Anti-Aggregated Co/N-Doped Hollow Carbon from Metal-Organic Frameworks for Efficient Biomass Upgrading.

The controlled pyrolysis of metal/carbon-containing precursors is commonly used for fabricating multifunctional metal/carbon-based catalysts, nevertheless, the inevitable agglomeration of these precursors in pyrolysis is extremely negative for efficient catalysis. This study reports the first example of suppressing the interfacial fusion and agglomeration of metal/carbon-based catalyst in its pyrolysis-involved fabrication process by developing a facile morphology-engineering strategy. Metal-organic framework precursors are chosen as a proof of concept and five Co/N-doped hollow carbons with different morphologies (rhombic dodecahedron, cube, plate, interpenetration twin, and rod) are synthesized via the pyrolysis of their corresponding core-shell ZIF-8@ZIF-67 precursors. It is demonstrated that the interpenetration twin precursor shows the minimum interfacial contact of interparticles due to its partly-concave morphology with abundant facets, which endows it with the best resistibility from interfacial fusion and thus aggregation of interparticles during pyrolysis. Benefiting from its unique anti-aggregated structure with high specific surface area, abundant fully-exposed active sites, and good dispersibility, the resultant 36-facet Co/N-doped hollow carbon exhibit remarkably improved catalytic property for biomass upgrading as compared with its aggregated counterparts. This study highlights the crucial role of engineering morphology to prevent metal/carbon-containing precursors from detrimental agglomeration during pyrolysis, demonstrating a new approach to constructing anti-aggregated metal/carbon-based catalysts.

Near- and Long-Range Electronic Modulation of Single Metal Sites to Boost CO2 Electrocatalytic Reduction.

Tuning the electronic structure of the active center is effective to improve the intrinsic activity of single-atom catalysts but the realization of precise regulation remains challenging. Herein, a strategy of "synergistically near- and long-range regulation" is reported to effectively modulate the electronic structure of single-atom sites. ZnN4 sites decorated with axial sulfur ligand in the first coordination and surrounded phosphorus atoms in the carbon matrix are successfully constructed in the hollow carbon supports (ZnN4 S1 /P-HC). ZnN4 S1 /P-HC exhibits excellent performance for CO2 reduction reaction (CO2 RR) with a Faraday efficiency of CO close to 100%. The coupling of the CO2 RR with thermodynamically favorable hydrazine oxidation reaction to replace oxygen evolution reaction in a two-electrode electrolyzer can greatly lower the cell voltage by 0.92 V at a current density of 5 mA cm-2 , theoretically saving 46% of energy consumption. Theoretical calculation reveals that the near-range regulation with axial thiophene-S ligand and long-range regulation with neighboring P atoms can synergistically lead to the increase of electron localization around the Zn sites, which strengthens the adsorption of *COOH intermediate and therefore boosts the CO2 RR.

Coupling Hydrazine Oxidation with Seawater Electrolysis for Energy-Saving Hydrogen Production over Bifunctional CoNC Nanoarray Electrocatalysts.

Seawater electrolysis is a promising method to produce H2 without relying on scarce freshwater resource, but its high energy consumption and inevitable accompany of competitive chlorine oxidation reaction (ClOR) are still great technological challenges. Herein, a metal-organic framework (MOF)-templated pyrolysis strategy to prepare uniform cobalt/nitrogen-codoped carbon nanosheet arrays on carbon cloth (CC@CoNC) as highly-efficient but low-cost bifunctional electrocatalysts for hydrazine-assisted seawater electrolysis is explored. The optimized CoNC nanosheet arrays can be used as an efficient bifunctional electrocatalyst to catalyze hydrazine oxidation reaction and hydrogen evolution reaction, remarkably reducing the energy consumption and nicely overcome the undesired anodic corrosion problems caused by ClOR. Impressively, a hydrazine-assisted water electrolysis system is successfully assembled by using the optimized CC@CoNC as both cathode and anode, which only needs an ultra-low cell voltage of 0.557 V and an electricity consumption of 1.22 kW h per cubic meter of H2 to achieve 200 mA cm-2 . Furthermore, the optimized CC@CoNC can also show greatly improved stability in the hydrazine-assisted seawater electrolysis system for H2 production, which can work steadily for above 40 h at ≈10 mA cm-2 . This study may offer great opportunities for obtaining hydrogen energy from infinite ocean resource by an eco-friendly method.

Monodispersed Eu2O3-Modified Fe3O4@NCG Composites as Highly Efficient and Ultra-stable Catalysts for Rechargeable Zn-Air Batteries.

Constructing highly efficient cathode catalysts for Zn-air batteries (ZABs) is an attractive research topic in sustainable energy storage area. Herein, the rare-earth metal oxide modification strategy has been proposed to construct the highly efficient and ultra-stable catalysts for ZABs. Accordingly, a graphene oxide-doped carbon-supported Eu2O3-modified Fe3O4 (Fe3O4/Eu2O3@NCG) catalyst is developed with layered Fe-Eu-MOF/GO as a precursor. Detailed characterization reveals that Fe3O4/Eu2O3@NCG possesses unique structural properties, including carbon-metal-carbon configuration, plentiful oxygen vacancies, and variable metal-active sites, which endows the catalyst with strong conductivity, high activity, and ultra-long stability. The optimal Fe3O4/Eu2O3@NCG catalyst exhibits an outstanding electrochemical performance, and the potential difference (Egap) between oxygen reduction reaction and oxygen evolution reaction is merely 0.68 V at 0.1 M KOH condition. Moreover, density functional theory calculations are employed to investigate the reaction mechanism and the synergetic effect between Fe and Eu atoms. Most importantly, the Fe3O4/Eu2O3@NCG-based aqueous ZAB delivers a high power density (218 mW/cm2), specific capacity (854 mA h/g@5 mA/cm2), and an impressive ultra-long cycle property with more than 1000 h (>6000 cycles) charge-discharge cycle life. In addition, the Fe3O4/Eu2O3@NCG-based all-solid-state ZAB also exhibits an outstanding performance, achieving >460 h cycle life (>2760 cycles) and strong practical application capability.

Controllable Synthesis of Ultrathin Defect-Rich LDH Nanoarrays Coupled with MOF-Derived Co-NC Microarrays for Efficient Overall Water Splitting.

Water electrolysis has attracted immense research interest, nevertheless the lack of low-cost but efficient bifunctional electrocatalysts for both hydrogen and oxygen evolution reactions greatly hinders its commercial applications. Herein, the controllable synthesis of ultrathin defect-rich layered double hydroxide (LDH) nanoarrays assembled on metal-organic framework (MOF)-derived Co-NC microarrays for boosting overall water splitting is reported. The Co-NC microarrays can not only provide abundant nucleation sites to produce a large number of LDH nuclei for favoring the growth of ultrathin LDHs, but also help to inhibit their tendency to aggregate. Impressively, five types of ultrathin bimetallic LDH nanoarrays can be electrodeposited on the Co-NC microarrays, forming desirable nanoarray-on-macroarray architectures, which show high uniformity with thicknesses from 1.5 to 1.9 nm. As expected, the electrocatalytic performance is significantly enhanced by exploiting the respective advantages of Co-NC microarrays and ultrathin LDH nanoarrays as well as the potential synergies between them. Especially, the optimal Co-NC@Ni2 Fe-LDH as both cathode and anode can afford the lowest cell voltage of 1.55 V at 10 mA cm-2 , making it one of the best earth-abundant bifunctional electrocatalysts for water electrolysis. This study provides new insights into the rational design of highly-active and low-cost electrocatalysts and facilitates their promising applications in the fields of energy storage and conversion.

Growth Pattern Control and Nanoarchitecture Engineering of Metal-Organic Framework Single Crystals by Confined Space Synthesis.

The nanoarchitecture engineering of metal-organic frameworks (MOFs) is a fascinating but intellectually challenging concept that opens up avenues for both tailoring the properties of MOFs and expanding their applications. Herein, we report the confined growth of ZIF-8 single crystals in a three-dimensionally ordered (3DO) macroporous polystyrene replica and reveal that their growth patterns, morphologies, and nanoarchitectures can be highly engineered using the concentration of the precursor. Impressively, the favorable in situ confined growth enables the successful fabrication of 3DO sphere-assembled ZIF-8 single crystals or 3DO single-crystalline ZIF-8 sphere arrays when a low- or high-concentration precursor solution, respectively, is used as the feedstock. Furthermore, our strategy can be extended to the preparation of other 3DO MOF single crystals, including ZIF-67 and HKUST-1, with similar controllable hierarchical nanoarchitectures. With the successful preparation of a series of diameter-tunable ZIF-8 single-crystalline spheres, we further unravel their interesting size-performance relationship in the Knoevenagle reaction between benzaldehyde and malononitrile, wherein the smallest spheres show the fastest first-order reaction kinetics. This study not only develops a general strategy for engineering the nanoarchitectures of MOF single crystals but also provides fundamental knowledge of the mechanism for the growth of hierarchical single crystals under confined spaces.

Main-Group Metal Single-Atomic Regulators in Dual-Metal Catalysts for Enhanced Electrochemical CO2 Reduction.

Single-atom sites can not only act as active centers, but also serve as promising catalyst regulators and/or promoters. However, in many complex reaction systems such as electrochemical CO2 reduction reaction (CO2 RR), the introduction of single-atom regulators may inevitably induce the competitive hydrogen evolution reaction (HER) and thus reduce the selectivity. Here, the authors demonstrate that introducing HER-inert main-group metal single atoms adjacent to transition-metal single atoms can modify their electronic structure to enhance the CO2 RR to CO without inducing the HER side reaction. Dual-metal Cu and In single-site atoms anchored on mesoporous nitrogen-doped carbon (denoted as Cu-In-NC) are prepared by the pyrolysis of a multimetallic metal-organic framework. Cu-In-NC shows a high faradic efficiency of 96% toward CO formation at -0.7 V versus reversible hydrogen electrode, superior to that of its monometallic single-atom counterparts. Density functional theory studies reveal that the HER-inert In sites can activate the adjacent Cu sites through electronic modifications, strengthening the binding of *COOH intermediate and thus boosting the electrochemical reduction of CO2 to CO.

Ultrathin Nanosheet Assembled Multishelled Superstructures for Photocatalytic CO2 Reduction.

Solar-driven conversion of CO2 is considered an efficient way to tackle the energy and environmental crisis. However, the photocatalytic performance is severely restricted due to the insufficient accessible active sites and inhibited electron transfer efficiency. This work demonstrates a general in situ topological transformation strategy for the integration of uniform Co-based species to fabricate a series of multishelled superstructures (MSSs) for CO2 photocatalytic conversion. Thorough characterizations reveal the obtained MSSs feature ultrathin Co-based nanosheet assembled polyhedral structures with tunable shell numbers, inner cavity sizes, and compositions. The superstructures increase the spatial density of Co-based active sites while maintaining their high accessibility. Further, the ultrathin nanosheets also facilitate the transfer of photogenerated electrons. As a result, the ZnCo bimetallic hydroxide featuring an ultrathin nanosheet assembled quadruple-shell hollow structure (ZnCo-OH QUNH) exhibits high photocatalytic efficiency toward CO2 reduction with a CO evolution rate of 134.2 µmol h-1 and an apparent quantum yield of 6.76% at 450 nm. The quasi in situ spectra and theoretical calculations disclose that Co sites in ZnCo-OH QUNH act as highly active centers to stabilize the COOH* intermediate, while Zn species play the role of adsorption sites for the [Ru(bpy)3]2+ molecules.

Diagnostic testing approaches for the identification of patients with TRK fusion cancer prior to enrollment in clinical trials investigating larotrectinib.

INTRODUCTION: NTRK gene fusions are targetable oncogenic drivers independent of tumor type. Prevalence varies from highly recurrent in certain rare tumors to <1% in common cancers. The selective TRK inhibitor larotrectinib was shown to be highly active in adult and pediatric patients with tumors harboring NTRK gene fusions. METHODS: We examined the techniques used by local sites to detect tumor NTRK gene fusions in patients enrolled in clinical trials of larotrectinib. We also report the characteristics of the detected fusions in different tumor types. RESULTS: The analysis included 225 patients with 19 different tumor types. Testing methods used were next-generation sequencing (NGS) in 196 of 225 tumors (87%); this was RNA-based in 96 (43%); DNA-based in 53 (24%); DNA/RNA-based in 46 (20%) and unknown in 1 (<1%); FISH in 14 (6%) and PCR-based in 12 (5%). NanoString, Sanger sequencing and chromosome microarray were each utilized once (<1%). Fifty-four different fusion partners were identified, 39 (72%) of which were unique occurrences. CONCLUSIONS: The most common local testing approach was RNA-based NGS. Many different NTRK gene fusions were identified with most occurring at low frequency. This supports the need for validated and appropriate testing methodologies that work agnostic of fusion partners.

Facile Synthesis of Boron and Nitrogen Dual-Doped Hollow Mesoporous Carbons for Efficient Reduction of 4-Nitrophenol.

The development of heteroatom-doped carbons with fascinating hierarchical porosity is of great significance for the improvement of catalytic properties of carbon catalysts. In this work, we report a boron and nitrogen codoped hollow mesoporous carbon (denoted as BN/HMC) via a simple synthesis route by direct pyrolysis of phenylboronic acid/melamine/ZIF-8 precursors. Thanks to their high specific surface area, unique hollow mesoporous nanoarchitecture, rich defects, and boron and nitrogen codoping, the obtained BN/HMC-0.05 can be employed as a high-efficiency carbon-based catalyst for the reduction of 4-nitrophenol. Theoretical calculations reveal that the B and N codoping in a carbon matrix are essential for the adsorption and activation of 4-nitrophenol. The present work might pave a new way in construction of metal-free carbon catalysts with both heteroatom doping and hierarchical porosity for various applications.

Anti-Inflammatory Nanotherapeutics by Targeting Matrix Metalloproteinases for Immunotherapy of Spinal Cord Injury.

Neuroinflammation is critically involved in the repair of spinal cord injury (SCI), and macrophages associated with inflammation propel the degeneration or recovery in the pathological process. Currently, efforts have been focused on obtaining efficient therapeutic anti-inflammatory drugs to treat SCI. However, these drugs are still unable to penetrate the blood spinal cord barrier and lack the ability to target lesion areas, resulting in unsatisfactory clinical efficacy. Herein, a polymer-based nanodrug delivery system is constructed to enhance the targeting ability. Because of increased expression of matrix metalloproteinases (MMPs) in injured site after SCI, MMP-responsive molecule, activated cell-penetrating peptides (ACPP), is introduced into the biocompatible polymer PLGA-PEI-mPEG (PPP) to endow the nanoparticles with the ability for diseased tissue-targeting. Meanwhile, etanercept (ET), a clinical anti-inflammation treatment medicine, is loaded on the polymer to regulate the polarization of macrophages, and promote locomotor recovery. The results show that PPP-ACPP nanoparticles possess satisfactory lesion targeting effects. Through inhibited consequential production of proinflammation cytokines and promoted anti-inflammation cytokines, ET@PPP-ACPP could decrease the percentage of M1 macrophages and increase M2 macrophages. As expected, ET@PPP-ACPP accumulates in lesion area and achieves effective treatment of SCI; this confirmed the potential of nano-drug loading systems in SCI immunotherapy.