Nano Today最新文献

The development of DNA-based imaging techniques provides a promising way for theranostic applications. However, the dramatic chemical difference between DNA probes and therapeutics significantly hinders the construction of an ideal theranostic system for evaluation of therapeutic effects via in situ molecular imaging. In this work, we report a simple approach for the construction of a two-in-one DNA nanohybrid via one-step assembly of DNA probes and small molecular drugs, enabling evaluation of therapeutic effects via sensitive imaging of apoptosis-related mRNA. The nanohybrid was self-assembled from a rationally designed molecular beacon (MB) probe, doxorubicin (DOX, a chemotherapeutic drug) and Fe (II) ions through coordination interactions, which possesses anti-cancer effects from chemotherapeutics and the capability of efficient co-delivery of DNA probes without transfection agents. By tracking pro-apoptotic Bax mRNA expression with the MB, this system allows real-time monitoring of cell apoptotic process in response to drug treatment, enabling assessment of therapeutic effects of small molecular drugs. In addition, the approach is extended to the imaging of target microRNA in the drug treatment based on flexible DNA probe design, demonstrating the universality of this strategy. Moreover, the modular design of this DNA nanohybrid allows the introduction of photosensitizers into this system for efficient photodynamic therapy and simultaneous mRNA monitoring. This strategy expands the theranostic toolbox for the in situ evaluation of treatment response and screening anticancer drugs.

The in-depth blood-based proteomics is significantly limited owing to the intrinsic wide dynamic range of protein concentrations (over 10 orders of magnitude) and highly abundant proteins (albumin, etc.) in blood. Here, we developed a protein denaturation strategy to enhance the serum proteomic depth via nanoparticle-protein corona for enhanced non-small cell lung cancer (NSCLC) diagnosis. We developed an optimal denaturant panel consists of nature, 30 % acetonitrile, 40 % RapiGest, and 4 M urea respectively treated serum to form various nanoparticle-protein coronas with magnetic nanoparticles (MNPs). Based on this panel, we have identified 1846 proteins by profiling 172 NSCLC serum samples, significantly enhancing the depth of serum proteomics. Furthermore, we selected 15 key proteins with random forest algorithm to distinguish the benign and malignant nodules and achieved an ROC-AUC of 98.44 %. Differentially expressed protein-based pathway analysis revealed that metabolic and immune-related pathways were significantly enriched, in which apolipoproteins play pivotal role in the transfer from benign to malignant nodules. Our study demonstrated a facile serum denaturation strategy for enhanced depth of serum proteomics which will benefit the cancer biomarker discovery and diagnosis.

Electrochemical water splitting (EWS) is a pivotal method for sustainable hydrogen (H₂) generation, yet it faces challenges due to limited accessibility and high costs associated with precious metal electrocatalysts. Efforts in research have thus been directed toward developing cost-effective alternatives to drive widespread adoption. Transition metals (TMs) emerge as promising candidates to replace noble metal-based electrocatalysts in EWS, offering abundance and affordability. This review surveys recent advancements and innovative methodologies in designing TM-based electrocatalysts, focusing on strategies such as defect engineering of MXene. This approach demonstrates considerable potential in enhancing EWS technology. Moreover, the review underscores the necessity of comprehending the fundamental mechanisms and activity-limiting factors inherent in EWS. It advocates for catalyst engineering strategies, integration of theoretical calculations, and modern in situ characterization techniques to facilitate the commercialization of electrocatalysts for sustainable hydrogen production. By integrating recent progress and ongoing challenges, this review seeks to present insights into the frontier of TM-based electrocatalysts and their role in advancing the field of EWS toward a more sustainable future.

The precise control of nanomaterial microstructure at the atomic level relies on the comprehensive understanding of atomic structural transition during the fabrication process at the atomic level. The phase transition from protonated titanate to TiO₂ is a prevalent route to synthesize low dimensional TiO₂-based nanomaterials, which exhibit excellent photocatalytic, lithium-ion battery performances, while the detailed phase transition mechanism remains to be clarified due to lack of atomic-level in situ information. Herein, the atomic structural transitions from one-dimensional H₂Ti₃O₇ (HT) to TiO₂(B) and anatase TiO₂ (TB and TA) nanocrystals were revealed through in situ environmental transmission electron microscopy, which exhibited a two-step phase transition at 200–600 °C. (I) H₂Ti₃O₇ to TiO₂(B) transition began via an indirect pathway at ∼200 °C: The HT (200) interlayer dehydration occurred firstly with lattice shrinkage; Then TB discretely nucleated at the dehydrated H₂Ti₃O₇ nanotube wall with a crystallographic relationship of (200)_HT∥(200)_TB {[001]_HT∥[001]_TB}; At higher temperature, the separated nuclei grew up with defects and distorted crystal lattice among them, which then connected and jointed to a single crystalline TB nanotube by atomic rearrangement. (II) The further transition of TiO₂(B) to anatase TiO₂ occurred via a direct pathway above 400 °C: Scarce nucleation event of TA phase was observed, which generated within TB nanocrystal with a crystallographic relationship of (200)_TB∥(002)_TA {[001]_TB∥[010]_TA}. Once a TA nucleus formed, it grew up to a large crystal by consuming the neighbor TB nanocrystals. These findings may contribute to comprehensively understanding phase transition and precisely manipulating the atomic structure of one-dimensional TiO₂ nanocrystals.

Photodynamic therapy (PDT) and photothermal therapy (PTT) have been developed to treat tumors with potential of clinical applications due to their high spatiotemporal selectivity and non-invasiveness. Nevertheless, the hypoxia within the tumor microenvironment (TME) limits the efficacy of PDT. PTT has the risk of damaging surrounding normal tissues due to the high temperatures essential for killing tumor cells. Herein, we propose a new tumor treatment strategy based on photo-triggered ferroptosis of tumor cells, which is termed photoferroptosis therapy (PFT). The PFT agent (CuS&AIPH@PEG-PAE@PM) was synthesized by encapsulating a radical generator (2,2’-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, AIPH) and a photothermal agent (copper sulfide, CuS) into an amphiphilic polymer (poly(ethylene glycol)-poly(β-amino ester), PEG-PAE) via self-assembly and a following coating with platelet membrane (PM). Under near-infrared (NIR) irradiation, the PFT agent CuS&AIPH@PEG-PAE@PM generates abundant alkyl radicals (R●) to trigger tumor cell ferroptosis in a moderate temperature and oxygen-independent manner. Meanwhile, the PFT agent also reduces the GSH level and thus suppresses GPX4 expression to promote ferroptosis, which further consolidates the antitumor effect of PFT. The PFT is expected to establish a promising phototherapy strategy against tumors, which has the potential to overcome the limitations of PDT and PTT.

Cancer vaccines have become a milestone in immunotherapy, but inadequate activation rate of antigen presenting cells (APCs) and low delivery efficiency of specific antigen have widely limited their clinical application. Here we design an engineered vaccine platform based on targeted delivery of specific antigens to activated APCs. This vaccine platform is implemented by loading an agonist for stimulator of interferon genes and tumor lysate protein with calcium phosphate as adjuvants, and coating the surface with mannose-modified liposomes. By loading different types of tumor antigen proteins, this nanovaccine platform successfully achieves tumor immunotherapy in breast and colon cancer bearing mice. In addition, personalized nanovaccine prepared from surgically removed tumor lysate proteins also significantly suppresses postsurgical distant tumor. Through the design of nanovaccine platform, we provide an efficient multi-adjuvant delivery platform for multiple types of tumor antigens, and also offer more ideas for personalized vaccine immunization. This nanovaccine platform has great prospects for transformation due to the designability and simplicity for the preparation.

Bioorthogonal reaction refers to chemical reactions that occur within a biological system without interfering the normal biochemical process, offering the unprecedented versatility in engineering chemical reactions within cells. However, the precise regulation of bioorthogonal reaction in living systems is mired by the complexity of the physiological environment and the toxicity of catalysts. Herein, considering the deeper tissue penetration and reduced phototoxicity compared to visible light and ultraviolet, a second near infrared (NIR-II) light-activated Cu-based bioorthogonal reaction is developed to achieve precise spatiotemporal control and effective switching for Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) mediated chemical transformations in tumor, reducing the off-target effects. The catalytic activity of Cu catalyst through valence state interconversion between Cu(II) and Cu(I) can be precisely regulated in a reversible manner under NIR-II light irradiation-induced photoelectron transfer, which controls the extent of desired drug synthesis in bioorthogonal reaction. Meanwhile, the adverse effects of Cu(I) can be substantially mitigated within normal tissues due to their oxygen-rich condition. By utilizing NIR-II light and oxygen level, the Cu bioorthogonal catalyst achieves a balance between catalytic activity and biocompatibility. The ability to achieve precise spatiotemporal control and reversible catalysis makes this NIR-II light-mediated CuAAC platform an efficient and adaptable tool for bioorthogonal chemistry in living systems.

Monolayer-based electronics have emerged as a promising solution that solves the limitations of miniaturization in microelectronic circuits and paves the way for advanced electronic performance applications. Over the past few years, there have been significant advances in monolayer-based electronics from the refinement of fabrication techniques to the elucidation of fundamental mechanisms and the achievement of sophisticated electronic functionalities. In this review, we provide a timely, systematic overview of monolayer-based electronics, covering the preparation processes, charge transport mechanisms, thermoelectric effect, performance regulations, and functional applications. We also offer a detailed summary of devices that leverage either horizontal charge transport or vertical tunneling, along with their respective applications. Furthermore, we delve into the opportunities and challenges inherent in the realm of monolayer- or even single-molecule-based electronics, emphasizing potential breakthroughs that could revolutionize this swiftly evolving domain. Our review aims to provide a broad understanding of monolayer-based electronics and to inspire further research on their practical applications.