Latest ArticlesNitrogen-doped carbon (N–C) materials have demonstrated exceptional performances in activating peroxymonosulfate (PMS) for environmental remediation. However, accommodating higher nitrogen contents remains challenging in N–C due to the thermodynamic instability of C–N skeleton. In this study, we proposed an innovative epitaxial growth approach to synthesize two-dimensional N–C nanosheets. Leveraging the abundant amino groups supplied by the polymer dots as growing sites, we successfully attained a high nitrogen level and spontaneously introduced abundant structural defects in the carbon framework. The resulting N–C nanosheets exhibited outstanding catalytic activity for the activation of PMS toward selective oxidation of diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate (1,4-DHP) into diethyl 2,6-dimethylpyridine-3,5-dicarboxylate, which serves as a valuable intermediate in the synthesis of various pharmaceutical compounds. Comprehensive experimental and characterization investigations verified that the nitrogen sites and defects are the primary active sites for PMS activation and selective oxidation of 1,4-DHP. This work offered an efficient approach for the fabrication of high-nitrogen-loading carbon materials for catalytic oxidation reactions.
The low drug bioavailability of eye drops challenges the therapy of ocular disorders with high efficacy. One of solutions is to extend the corneal retention and enhance the penetration of drug into cornea. Here we synthesize two fluorophore-conjugated peptide based analogs rich in positive charges (i.e., NBD-FFKK) and with a specific ligand (i.e., NBD-FFRGD), respectively, to visualize their performances in vitro and in vivo. The peptides both can self-assemble into supramolecular hydrogels with the microstructure of nanofibers. The in vitro experiments exhibit that two peptides are both uniformly distributed in cytoplasm, and the intracellular amount of peptide rich in positive charges is significantly larger than that of peptide with a specific ligand. The living corneal fluorescence shows that two peptides enter the corneal stroma within 15 min, and the peptide rich in positive charges is accumulated more extensively throughout the entire cornea, revealing that the supramolecular hydrogel eye drops penetrate the cornea more efficiently via electrostatic interaction than that via ligand-receptor interaction. This work, as a comparative study of supramolecular hydrogel eye drops on penetrating efficiency, indicates a possible direction for the design of eye drops with efficient corneal penetration.
Chronic kidney disease (CKD) is an increasingly prevalent medical condition associated with high mortality and cardiovascular complications. The intricate interplay between kidney dysfunction and subsequent metabolic disturbances may provide insights into the underlying mechanisms driving CKD onset and progression. Herein, we proposed a large-scale plasma metabolite identification and quantification system that combines the strengths of targeted and untargeted metabolomics technologies, i.e., widely-targeted metabolomics (WT-Met) approach. WT-Met method enables large-scale identification and accurate quantification of thousands of metabolites. We collected plasma samples from 21 healthy controls and 62 CKD patients, categorized into different stages (22 in stages 1–3, 20 in stage 4, and 20 in stage 5). Using LC-MS-based WT-Met approach, we were able to effectively annotate and quantify a total of 1431 metabolites from the plasma samples. Focusing on the 539 endogenous metabolites, we identified 399 significantly altered metabolites and depicted their changing patterns from healthy controls to end-stage CKD. Furthermore, we employed machine-learning to identify the optimal combination of metabolites for predicting different stages of CKD. We generated a multiclass classifier consisting of 7 metabolites by machine-learning, which exhibited an average AUC of 0.99 for the test set. In general, amino acids, nucleotides, organic acids, and their metabolites emerged as the most significantly altered metabolites. However, their patterns of change varied across different stages of CKD. The 7-metabolite panel demonstrates promising potential as biomarker candidates for CKD. Further exploration of these metabolites can provide valuable insights into their roles in the etiology and progression of CKD.
This article reviews the latest research advances of tetrahedral framework nucleic acid (tFNA)-based systems in their fabrication, modification, and the potential applications in biomedicine. TFNA arises from the synthesis of four single-stranded DNA chains. Each chain contains brief sequences that complement those found in the other three, culminating in the creation of a pyramid-shaped nanostructure of approximately 10 nanometers in size. The first generation of tFNA demonstrates inherent compatibility with biological systems and the ability to permeate cell membrane effectively. These attributes translate into remarkable capabilities for regulating various cellular biological processes, fostering tissue regeneration, and modulating immune responses. The subsequent evolution of tFNA introduces enhanced adaptability and a relatively higher degree of biological stability. This advancement encompasses structural modifications, such as the addition of functional domains at the vertices or side arms, integration of low molecular weight pharmaceuticals, and the implementation of diverse strategies aimed at reversing multi-drug resistance in tumor cells or microorganisms. These augmentations empower tFNA-based systems to be utilized in different scenarios, thus broadening their potential applications in various biomedical fields.
A novel approach was developed to fabricate a label-free electrochemical aptasensor for specific detection of mercury ions (Hg2+). This involved modifying polylysine (PLL)-coated black phosphorus-porous graphene (BP-PG) nanocomposites (PLL/BP-PG) onto the surface of glassy carbon electrodes (GCE), which were further modified with gold nanoparticles (AuNPs) to combine with a thiolated aptamer (Apt) capable of specifically recognizing Hg2+. BP-PG was synthesized using the solvothermal method and covalently bonded to form BP-PG nanosheets, resulting in significant enhanced electrochemical properties of the PLL/BP-PG composite. Furthermore, the PLL/BP-PG composite was improved environmental stability of BP and provided a considerable quantity of -NH2 for bonding to AuNPs firmly by assembling. The physical properties and electrochemical behavior of the substrate materials were investigated using various characterization techniques, and analytical parameters were optimized. It is shown that, the Apt/AuNPs/PLL/BP-PG/GCE had a linear response (R2 = 0.999) with good selectivity and high sensitivity over the Hg2+ range of 1–10,000 nmol/L. The proposed sensor has a detection limit of 0.045 nmol/L and can be employed for detecting of Hg2+. It also obtained satisfying results in river water, soil and vegetable samples.
Silicon (Si) is considered as one of the most promising anode materials for advanced lithium-ion batteries due to its high theoretical capacity, environmental friendliness, and widespread availability. However, great challenges such as volumetric expansion, limited ionic/electronic conductivity properties and complex manufacturing processes hinder its practical applications. Herein, a novel plasma-enhanced reduced graphene oxide fibers/Si (PrGOFs/Si) composite anode is first proposed by using wet-spinning technology followed by plasma-enhanced reduction method. The PrGOFs provide large space to accommodate the volume expansion of Si nanoparticles (SiNPs) by forming a flexible 3D conductive network. Compared to the conventional thermally reduced graphene oxide fibers/Si (TrGOFs/Si) sample, the PrGOFs/Si anodes demonstrate higher conductivity, specific surface area, and superior fabrication efficiency. Accordingly, the PrGOFs/Si anodes exhibit a reversible capacity of 698.3 mAh/g, and maintain a specific capacity of 602.5 mAh/g at a current density of 200 mA/g after 100 cycles, superior to conventional TrGOFs/Si counterparts. This research presents a novel strategy for the preparation of high-performance Si/carbon anodes for energy storage applications.
The complicated and diverse deep defects, voids, and grain boundary in the CZTSSe absorber are the main reasons for carrier recombination and efficiency degradation. The further improvement of the open-circuit voltage and fill factor so as to increase the efficiency of CZTSSe device is urgent. In this work, we obtained K-doped CZTSSe absorber by a simple solution method. The medium-sized K atoms, which combine the advantages of light and heavy alkali metals, are able to enter the grain interior as well as segregate at grain boundary. The K-Se liquid phase can improve the absorber crystallinity. We find that the accumulation of the wide bandgap compound K2Sn2S5 at grain boundary can increase the contact potential difference of grain boundary, form more effective hole barriers, and enhance the charge separation ability. At the same time, K doping passivates the interface as well as bulk defects and suppresses the non-radiative recombination. The improved crystallinity, enhanced charge transport capability and reduced defect density due to K doping result in a significant enhancement of the carrier lifetime, leading to 13.04% device efficiency. This study provides a new idea for simultaneous realization of grain boundary passivation and defect suppression in inorganic kesterite solar cells.
Melanoma treatment has been revolutionized with the development of targeted therapies and immunotherapies, which shows a positive influence on the patients. However, the long-term efficaciousness of such therapy is restricted by side effects, limited clinical effects as well as quick resistance to treatment. In this work, we prepared magnetocaloric carrier-free bimetallic hydrogels, named manganese-iron oxide nanocubes@polyethylene glycol-hydrogels (MFO@PEG-Gels), to realize ion-interferential cell cycle arrest for melanoma treatment. In detail, the tumor site was exposed to alternating magnetic field (AMF) after intratumorally injected MFO@PEG-Gels, which generated hyperthermia and promoted the sol-gel phase transition for MFO sustained release. Under the tumor microenvironment, hydrogen peroxide triggered MFO degradation to induce Mn2+ and Fe3+ release. On one hand, Mn2+ blocked G1/S phase through the activation of p27 pathway. On the other hand, Fe3+ could arrest the G2/M phase by upregulating the polo-like kinase 4 (PLK4) expression as well as inhibiting autolysosome formation to achieve the enhanced cell cycle arrest, thereby promoting the apoptosis of melanoma cells. In summary, this study proposed ion-interferential cell cycle arrest strategy by a multifunctional and injectable magnetic bimetallic hydrogel for melanoma treatment, which provided a secure and sustainable regimen for enhancing anti-tumor efficacy.
Triple-negative breast cancer, due to its aggressive nature and lack of targeted treatment, faces serious challenges in breast cancer treatment. Conventional therapies, such as chemotherapy, are encumbered by a range of limitations, and there is an urgent need for more effective treatment strategies. Ferroptosis, as an iron-dependent form of cell death, has exhibited promising potential in cancer treatment. Combining ferroptosis with other cancer therapies offers new avenues for treatment. Tetrahedral DNA nanostructure (TDN), a novel DNA-based three-dimensional (3D) nanomaterial, is promising drug delivery vehicle and can be utilized for functionalizing inorganic nanomaterials. In this work, we have demonstrated the preparation of Fe3O4-PEI@TDN-DOX nanocomposites and elucidated their antitumor mechanism. The TDN facilitated the enhanced cellular uptake of polyetherimide (PEI)-modified Fe3O4, and the delivery of the chemotherapeutic drug doxorubicin (DOX) further augmented their anti-tumor effect. This novel strategy can destroy the tumor redox homeostasis and produce overwhelming lipid peroxides, consequently sensitizing the tumor to ferroptosis. The integration of ferroptosis with other cancer therapies opens up new possibilities for treatment. This research provides valuable mechanistic insights and practical strategies for leveraging nanotechnology to induce ferroptosis and amplify its impact on tumor cells.
For the first time, proteolysis-targeting chimeras (PROTAC) technology was utilized to achieve the isoform-selective degradation of class Ⅰ phosphoinositide 3-kinases (PI3Ks) in this study. Through screening and optimization, the PROTAC molecule ZM-PI05 was identified as a selective degrader of p110α in multiple breast cancer cells. More importantly, the degrader can down-regulate p85 regulatory subunit simultaneously, thereby inhibiting the non-enzymatic functions of PI3K that are independent on p110 catalytic subunits. Therefore, compared with PI3K inhibitor copanlisib, ZM-PI05 displayed the stronger anti-proliferative activity on breast cancer cells. In brief, a selective and efficient PROTAC molecule was developed to induce the degradation of p110α and concurrent reduction of p85 proteins, providing a tool compound for the biological study of PI3K-α by blocking its enzymatic and non-enzymatic functions.