Latest ArticlesProtein S-sulfenylation (protein sulfenic acid), as one of the most significant oxidative post-translational modifications (OxiPTMs), plays a vital role in regulating protein function. A variety of activity-based probes have been developed to profile sulfenic acid in living cells. However, due to the transient presence and low content of sulfenic acid in living cell, high doses of probes are needed to achieve efficient labeling. More importantly, current probes have no temporal control over sulfenic acid labeling. To overcome these limitations, two caged cysteine sulfenic acid probes DYn-2-ONB and DYn-2-Cou with either an o-nitrobenzyl or coumarin protecting group were developed in this study. Both probes can be efficiently uncaged via irradiation to produce the active C-nucleophile probe DYn-2. Labeling assay in living cells demonstrated DYn-2-ONB exhibited better labeling capacity compared with DYn-2, providing it as a powerful tool for improved monitoring of protein S-sulfenylation in living cells.
DNA nanomaterials hold great promise in biomedical fields due to its excellent sequence programmability, molecular recognition ability and biocompatibility. Hybridization chain reaction (HCR) is a simple and efficient isothermal enzyme-free amplification strategy of DNA, generating nicked double helices with repeated units. Through the design of HCR hairpins, multiple nanomaterials with desired functions are assembled by DNA, exhibiting great potential in biomedical applications. Herein, the recent progress of HCR-based DNA nanomaterials for biosensing, bioimaging and therapeutics are summarized. Representative works are exemplified to demonstrate how HCR-based DNA nanomaterials are designed and constructed. The challenges and prospects of the development of HCR-based DNA nanomaterials are discussed. We envision that rationally designing HCR-based DNA nanomaterials will facilitate the development of biomedical applications.
Paclitaxel (PTX) is widely applied for the treatment of unresectable and metastasis breast carcinoma as well as other cancers, whereas its efficacy is always impeded by poor solubility. Liposomes are one kind of the most successful drug carriers which are capable of solubilizing PTX and improving patients' tolerance owing to excellent biocompatibility and biodegradability. However, poor compatibility between PTX and liposomes compromises the stability, drug loading and anti-tumor capacity of liposomal formulations. To address this issue, three lipids with various chain lengths, namely, myristic acid (MA, 14C), palmitic acid (PA, 16C) and stearic acid (SA, 18C), were conjugated to PTX via ester bonds and the synthesized prodrugs with high lipophilicity were further formulated into liposomes, respectively. All liposomes show high stability and drug loadings, as well as sustained drug release. The chain lengths of lipids are negatively correlated with drug release and enzymatic conversion rates, which further impact the pharmacokinetics, tumor accumulation, and anti-tumor efficacy of liposomal PTX. Neither rapid nor slow drug release facilitates high tumor accumulation as well as anti-tumor efficacy of PTX. Among all liposomes, PTX-PA-loaded liposomes show the longest circulation and highest tumor accumulation of PTX and exert the most potent anti-tumor capacities in vivo, owing to its moderate drug release and enzymatic conversion rate. Witnessing its superior safety, PTX-PA liposomes hold potential for further clinical translation.
Small interfering RNA (siRNA)-based gene silencing has been considered as a potential therapy modality against inflammatory diseases. Nevertheless, the effective delivery of siRNA to desired destination still remains challenging due to poor stability, high molecular weight and negative charge. Currently, ionizable lipid nanoparticle (LNP) has been extensively used as vector for effective delivery of siRNA. Herein, we report a mannose-modified LNP (M-MC3 LNP@TNFα) loading tumor necrosis factor α (TNFα) siRNA for targeting liver macrophages, achieving effectively inhibit acute liver injury. The M-MC3 LNP@TNFα not only increases the internalization of LNP by macrophages, but also enhances the gene silencing efficiency of TNFα in vitro. Additionally, the M-MC3 LNP@TNFα exhibits higher accumulation in liver of healthy mice than that of MC3 LNP@TNFα (un-modified LNP) owing to the targeting effect of mannose. As expected, the M-MC3 LNP@TNFα significantly suppresses the expression of TNFα and ameliorates liver damage in acute liver injury model. Such a LNP targeting siRNA delivery holds great potential for the treatment of diseases associated with liver in the future.
We report SiO2-supported monometallic Pt, Pd, Au, Ni, Cu and Co catalysts for proton-driven NAD+ regeneration, co-producing H2. All metals are fully selective to NAD+ where the order of turnover frequencies (Pt > Pd > Cu > Au, Ni and Co) coincides with those otherwise observed in electrochemical hydrogen evolution reactions. This has revealed that NADH is capable of converting the metal sites into a "cathode" without an external potential and the NADH to NAD+ reaction involves transferring electron and hydrogen atom separately. Electron-deficient Ptδ+ (on CeO2) enhances TOF and the heterogeneous Pt/CeO2 catalyst is recyclable without losing any activity/selectivity.
Two-dimensional (2D) MXenes have emerged as an archetypical layered material combining the properties of an organic-inorganic hybrid offering materials sustainability for a range of applications. Their surface functional groups and the associated chemical properties' tailorability through functionalizing MXenes with other materials as well as hydrophilicity and high conductivity enable them to be the best successor for various applications in textile industries, especially in the advancement of smart textiles and remediation of textile wastewater. MXene-based textile composite performs superb smartness in high-performance wearables as well as in the reduction of textile dyes from wastewater. This article critically reviews the significance of MXenes in two sectors of the textile industry. Firstly, we review the improvement of textile raw materials such as fiber, yarn, and fabric by using MXene as electrodes in supercapacitors, pressure sensors. Secondly, we review advancements in the removal of dyes from textile wastewater utilizing MXene as an absorbent by the adsorption process. MXene-based textiles demonstrated superior strength through the strong bonding between MXene and textile structures as well as the treatment of adsorbate by adsorbent (MXene in the adsorption process). We identify critical gaps for further research to enable their real-life applications.
Lithium-rich layered cathode material (LLM) can meet the requirement of power lithium-ion energy storage devices due to the great energy density. However, the de/intercalation of Li+ will cause the irreversible loss of lattice oxygen and trigger transition metal (TM) ions migrate to Li+ vacancies, resulting in capacity decay. Here we brought Ti4+ in substitution of TM ions in Li1.2Mn0.54Ni0.13Co0.13O2, which could stabilize structure and expand the layer spacing of LLM. Moreover, optimized Ti-substitution can regulate the anions and cations of LLM, enhance the interaction with lattice oxygen, increase Ni3+ and Co3+, and improve Mn4+ coordination, improving reversibility of oxygen redox activation, maintaining the stable framework and facilitating the Li+ diffusion. Furthermore, we found 5% Ti-substitution sample delivered a high discharge capacity of 244.2 mAh/g at 50 mA/g, an improved cycling stability to 87.3% after 100 cycles and enhanced rate performance. Thereby Ti-substitution gives a new pathway to achieve high reversible cycle retention for LLMs.
Photoreduction of CO2 to solar fuels has caused great interest, but suffers from low catalytic efficiency and poor selectivity. Herein, we designed a S-scheme heterojunction (Cu-TiO2/WO3) with Cu single atom to significantly boost the photoreduction of CO2. Notably, the developed Cu-TiO2/WO3 achieved the solar-driven conversion of CO2 to CH4 with an evolution rate of 98.69 µmol g−1 h−1, and the electron selectivity of CH4 reached 88.5%. The yield was much higher than those of pristine WO3, TiO2/WO3 and Cu-TiO2 samples. Experimental and theoretical analysis suggested that the S-scheme heterojunction accelerated charge migration and inhibited the recombination of electron-hole pairs. Importantly, the charge separation effect of the heterojunction meliorated the position of the d-band. The uplifted d-band centers of Cu and Ti on Cu-TiO2/WO3 not only improved the electron interaction between Cu single atoms and substrate-TiO2, accelerated the adsorption and activation of CO2 on the active sites of Cu single atom, but also optimized the Gibbs free energies of CH4 formation pathway, leading to excellent selectivity toward CH4. This work provides new insights into the design of photocatalyst systems with high photocatalytic performance.
Antimicrobial photodynamic therapy (aPDT) has been considered a noninvasive and effective modality against the bacterial infection of peri–implantitis, especially the aPDT triggered by near-infrared (NIR) light due to the large penetration depth in tissue. However, the complexity of hypoxia microenvironments and the distance of aPDT sterilization still pose challenges before realizing the aPDT clinical application. Due to the long lifespan and transmission distance of therapeutic gas molecules, we design a multi-functional gas generator that combines aPDT as well as O2 and CO gas release function, which can solve the problem of hypoxia (O2) in PDT and the problem of inflammation regulation (CO) in the distal part of peri–implant inflammation under near-infrared (NIR) irradiation. In the composite nanoplatform that spin-coated on the surface of titanium implants, up-conversion nanoparticles (UCNPs) were involved in converting the NIR to visible, which further excites the partially oxidized stannic sulfide (SnS2), realizing the therapeutic gas release. Indocyanine green (ICG) was further integrated to enhance the aPDT performance (Ti-U@SnS2/I). Therefore, reactive oxygen species (ROS), CO, and O2 can be controllably administered via a composite nano-platform mediated by a single NIR light (808 nm). This implant surface modification strategy could achieve great self-enhancement antibacterial effectiveness and regulate the lingering questions, such as relieving the anoxic microenvironment and reaching deep infection sites, providing a viable antibiotic-free technique to combat peri–implantitis.
The presence of alkali metals in exhaust gas from stationary resources causes a grand challenge for the practical application of selective catalytic reduction (SCR) of NOx with NH3. Here, alkali-resistant NOx reduction has been successfully implemented via tailoring the electron transfer over Fe and V species on FeVO4/TiO2 catalysts. The strong interaction between Fe and V induced electron transfer from V to Fe and strengthened the adsorption and activation of NH3 and NO over active VOx sites. In the presence of K2O, the strong electron withdrawing effect of Fe offset the electron donating effect of K on the VOx species, thus protecting the active species VOx to maintain the NOx reduction ability. The enhanced adsorption and activation of NH3 allowed SCR reaction to proceed via E-R mechanism even after K2O poisoning. This work elucidated the electronic effects on the alkali metals resistance of traditional ferric vanadate SCR catalysts and provided a promising strategy to design SCR catalysts with superior alkali resistance.