Latest ArticlesDiabetes mellitus considerably affects bone marrow mesenchymal stem cells (BMSCs), for example, by inhibiting their proliferation and differentiation potential, which enhances the difficulty in endogenous bone regeneration. Hence, effective strategies for enhancing the functions of BMSCs in diabetes have far-reaching consequences for bone healing and regeneration in diabetes patients. Tetrahedral framework nucleic acids (tFNAs) are nucleic acid nanomaterials that can autonomously enter cells and regulate their behaviors. In this study, we evaluated the effects of tFNAs on BMSCs from diabetic rats. We found that tFNAs could promote the proliferation, migration, and osteogenic differentiation of BMSCs from rats with type 2 diabetes mellitus, and inhibited cell senescence and apoptosis. Furthermore, tFNAs effectively scavenged the accumulated reactive oxygen species and activated the suppressed protein kinase B (Akt) signaling pathway. Overall, we show that tFNAs can recover the proliferation and osteogenic potential of diabetic BMSCs by alleviating oxidative stress and activating Akt signaling. The study provides a strategy for endogenous bone regeneration in diabetes and also paves the way for exploiting DNA-based nanomaterials in regenerative medicine.
Dry powder inhalation represents a promising approach for the treatment of lung cancer, offering several advantages such as enhanced targeting, improved bioavailability, and reduced toxicity. However, traditional dry powder formulations suffer from limitations, notably low pulmonary delivery efficiency and inadequate penetration into tumor tissues, thereby limiting their therapeutic efficacy. In response to these challenges, we have developed an innovative trojan horse strategy, harnessing an inhalable nanoparticle-in-microsphere system characterized by tunable size, reversible charge, and mucus-penetrating capabilities. The inhalable nanoparticle-in-microsphere system exhibit stable structural properties, excellent environmental responsiveness and high biocompatibility. More importantly, the therapeutic effect of MTX@PAMAM@HA@Gel (MPHG) was demonstrated in vitro and in vivo. This system offers improved pulmonary delivery efficiency, enhanced drug retention within tumor tissues, and effective penetration, thus representing a promising strategy in lung cancer treatment.
Controlling the shape and composition of Pt-based nanocrystals is essential to improve electrocatalytic performance. In this work, we have carefully investigated the evolution process of morphology and composition for Pt and Pt3M (M = Ni, Co) nanocrystals by hydrochloric acid (HCl) etching. As a result, only Pt3Ni nanocrystals successfully formed unsaturated step-like atoms on the surface and then constructed high-index facets (HIFs), while Pt and Pt3Co preserved a good octahedron shape. Density functional theory (DFT) calculation suggests that Cl− ions can be tightly adsorbed on the surface of Pt3Ni rather than other nanocrystals, which hinders the deposition of newly-reduced atoms and thus regulating the surface morphology. Besides, the etching of surface transitional metals further accelerates the formation of HIFs. Boosted by the active sites on the surface, HCl-Pt-Ni exhibited a ~10.8 and ~11.3 times higher oxygen reduction reaction (ORR) mass and specific activities than commercial Pt/C catalyst, and possessed a good durability after 10,000 cycles test. This work gives a deep insight into the design of high-performance Pt-based ORR catalysts.
Surface-enhanced Raman scattering (SERS) spectroscopy has emerged as a powerful analytical technique for detecting and identifying trace chemical and biological molecules. In this review, we present an in-depth discussion of recent advances in the field of crystal phase manipulation to achieve exceptional SERS performance. Focusing on transition metal dichalcogenides, (hydr)oxides, and carbides as exemplary materials, we illustrate the pivotal role of crystal phase regulation in enhancing SERS signals. By exploring the correlation between crystal phases and SERS responses, we uncover the underlying principles behind these strategies, thereby shedding light on their potential for future SERS applications. By addressing the current challenges and limitations, we also propose the prospects of the crystal phase strategy to facilitate the development of cutting-edge SERS-based sensing technologies.
Lung cancer is one of the most common malignant tumors with the fastest increase in the incidence rate and mortality. Even after maximum tumor resection assistance with a radiotherapy and chemotherapy combination, the recurrence of non-small cell lung cancer is still inevitable. In addition, low targeting efficiency and poor permeability of drug delivery systems strongly affect the therapeutic efficiency of anti-cancer drugs on non-small cell lung cancer. Here we designed a gemcitabine (GEM) loaded arginine-glycine-aspartic acid-cysteine (RGDc)-modified gold mineralization "hybrid nanozyme bomb" (RGTG) to overcome those obstacles. RGDc modification improved the active targeting of liposomes to the tumor tissues with the second near-infrared (NIR-II)-triggered gold-shell disruption and GEM release. The collapsed gold-shell particles with a smaller size could penetrate the tumor solid barrier and act as photothermal therapy (PTT) agents to improve PTT therapy and starvation therapy via generating gluconic acid and reactive oxygen species (ROS). Moreover, the resting reversal effect of gold particles on tumor fibroblasts can achieve accelerating tumor penetration of gold particles and GEM. Compared to monotherapy, RGTG showed significant improvement in tumor inhibition, with a tumor volume reduction of 83% compared to the control group, which provides a promising tumor treatment platform for non-small cell lung cancer (NSCLC).
Nicotinamide phosphoribosyl transferase (NAMPT) is considered as a promising target for cancer therapy to its crucial role in cancer metabolism. Despite the therapeutic potential of NAMPT enzymatic inhibitors, their effectiveness is limited by dose-related toxicity and the inability to suppress nonenzymatic functions of extracellular NAMPT (eNAMPT). Herein, we designed and synthesized the first hydrophobic tagging NAMPT degraders. Among them, compound NH-11 selectively degraded NAMPT in leukemia cells through the ubiquitin-proteasome system. Compound NH-11 effectively induced apoptosis and showed low toxicity to normal cells, representing a promising anti-leukemia lead compound.
Catalysts can significantly promote the reaction dynamics and are therefore considered crucial components for achieving high electrochemical energy conversion efficiency. However, the active sites of the catalysts, particularly for nano-level and atomic-level catalysts commonly undergo reconstruction under practical applications. Therefore, obtaining an in-depth and systematic understanding on the real active sites through in situ/operando characterization techniques is a prerequisite for establishing the structure-performance relationship and guiding the future design of more efficient electrocatalysts. Herein, we summarize the recent progress of in situ/operando characterization techniques for identifying the nature of active sites of electrocatalysts when used in electrocatalytic energy conversion reaction. Specifically, our focus lies in the fundamental principles of various in situ/operando characterization techniques, with particular emphasis on their applications for electrocatalytic reactions. Beyond that, the challenges and perspective insights are also added in the final section to highlight the future direction of this important field.
Microbial contamination in water has emerged as a critical concern and thus developing biocide materials for controlling microbial contamination is crucial. Removing all pathogenic bacteria in water is difficult when using traditional water treatment technologies. Moreover, these bacteria can easily reproduce during pipeline distribution. In this work, a facile and effective chitosan derivative biocide denoted as PCC was developed by grafting with quaternary phosphonium salt (QPS). PCC became positively charged with a wide range of pH and demonstrated antibacterial activity up to 95% and 100% against Escherichia coli and Staphylococcus aureus as model pathogens, respectively. The grafting of QPS may disrupt the cell membrane and lead to bacterial inactivation, as demonstrated by the scanning electron microscopy image and the concentration of intracellular substance leakage. MTT assay results indicate that PCC achieved good biocompatibility with negligible in vitro cytotoxicity. These findings introduce a promising approach for bacterial decontamination due to its low cytotoxicity and high biocidal activity.
Aqueous zinc ion batteries (AZIBs) are promising energy storage devices. However, the formation of dendrites, hydrogen evolution, and corrosion reaction seriously affect their electrochemical performance. Herein, the synergistic effect of ion-migration regulation and interfacial engineering has been confirmed as the potential strategy by kaolin functionalized glass fiber separator (KL-GF) to alleviate these problems. The rapid and orderly Zn2+ migration was achieved to improve the transfer kinetics and induced uniform zinc deposition by more zinc-philic sites of KL-GF. Based on the interfacial engineering, the side reactions were effectively mitigated and crystal planes were regulated through KL-GF. The hydrophilicity of KL alleviated the corrosion and hydrogen evolution. Importantly, a preferential orientation of Zn (002) crystal plane by KL-GF was induced to further realize dendrite-free deposition by density functional theory (DFT) and X-ray diffraction (XRD) characterization. Hence, the Zn|KL-GF|MnO2 cell maintained a high discharge capacity of 96.8 mAh/g at 2 A/g after 1000 cycles. This work can provide guidance enabling high-performance zinc anode for AZIBs.
Understanding the luminescence mechanisms and regulating the emission centers of carbon dots (CDs) are important for advancing their related applications. In this work, we systematically investigate the formation processes of multi-emission centers in CDs synthesized through a bottom-up approach by controlling the solvothermal reaction temperature. CDs synthesized at a lower temperature (140 ℃, 140-CDs) exhibit smaller particle sizes (3–4 nm) with dominant green–yellow emission, while CDs synthesized at a higher temperature (180 ℃, 180-CDs) exhibit larger particle sizes (8–9 nm) with enhanced red emission and emerging near-infrared (NIR) emission. The green–yellow emission and red emission originate from the core state and the surface-related state, respectively, and the emissions could be regulated by temperature-controlled dehydration and carbonization processes. The clear NIR emission center in 180-CDs is attributable to the increased content of radical defects in the cores during the increased dehydration and carbonization processes during higher-temperature solvothermal treatment.