Hydrogen-Bonded Mesoporous Frameworks with Tunable Pore Sizes and Architectures from Nanocluster Assembly Units.

Construction of mesoporous frameworks by noncovalent bonding still remains a great challenge. Here, we report a micelle-directed nanocluster modular self-assembly approach to synthesize a novel type of two-dimensional (2-D) hydrogen-bonded mesoporous frameworks (HMFs) for the first time based on nanoscale cluster units (1.0-3.0 nm in size). In this 2-D structure, a mesoporous cluster plate with ∼100 nm in thickness and several micrometers in size can be stably formed into uniform hexagonal arrays. Meanwhile, such a porous plate consists of several (3-4) dozens of layers of ultrathin mesoporous cluster nanosheets. The size of the mesopores can be precisely controlled from 11.6 to 18.5 nm by utilizing the amphiphilic diblock copolymer micelles with tunable block lengths. Additionally, the pore configuration of the HMFs can be changed from spherical to cylindrical by manipulating the concentration of the micelles. As a general approach, various new HMFs have been achieved successfully via a modular self-assembly of nanoclusters with switchable configurations (nanoring, Keggin-type, and cubane-like) and components (titanium-oxo, polyoxometalate, and organometallic clusters). As a demonstration, the titanium-oxo cluster-based HMFs show efficient photocatalytic activity for hydrogen evolution (3.6 mmol g-1h-1), with a conversion rate about 2 times higher than that of the unassembled titanium-oxo clusters (1.5 mmol g-1h-1). This demonstrates that HMFs exhibited enhanced photocatalytic activity compared with unassembled titanium-oxo clusters units.

Mannose-doped metal-organic frameworks induce tumor cell pyroptosis via the PERK pathway.

BACKGROUND: The implementation of pyroptosis exhibits significant potential as a tactic to enhance tumor immune microenvironments. Previous applications of pyroptosis inducers have encountered various limitations, such as the development of drug resistance, manifestation of toxic side effects, and a deficiency in targeting capabilities. As a result, there is a growing demand for tumor therapeutic molecules that can overcome these obstacles. Therefore, the objective of this study is to develop a multifunctional nanospheres that addresses these challenges by enabling high-precision targeting of tumor cells and inducing effective pyroptosis. RESULTS: We prepared a mannose-modified MOF called mannose-doped Fe3O4@NH2-MIL-100 (M-FNM). M-FNM could enter CAL27 cells through MR-mediated endocytosis, which caused in a significant increase in the level of intracellular ROS. This increase subsequently triggered ER stress and activated the PERK-eIF2α-ATF4-CHOP signaling pathway. CHOP then mediated the downstream cascade of Caspase-1, inducing pyroptosis. In in vivo experiments, M-FNM demonstrated excellent targeting ability and exhibited anti-tumor effects. Additionally, M-FNM reshaped the immune microenvironment by promoting the infiltration of anti-tumor immune cells, primarily T lymphocytes. CONCLUSIONS: M-FNM significantly decreased tumor growth. This novel approach to induce pyroptosis in tumor cells using M-FNM may offer new avenues for the development of effective immunotherapies against cancer.

Stable Monodisperse Pb1-x Cdx S Quantum Dots for NIR-II Bioimaging by Aqueous Coprecipitation of Bimetallic Clusters.

Aqueous lead sulfide (PbS) quantum dots (QDs) synthesized by traditional methods are unstable, so that they are usually coated with cadmium sulfide (CdS) to prevent oxidation, which are complicated and not satisfactory for mass production. Here, stable ternary Pb1-x Cdx S QDs were synthesized by in situ coprecipitation of Pb4-n Cdn O4 bimetallic clusters in an aqueous solution, which possess a uniform size of 4.0±0.2 nm and the second near-infrared (NIR-II) emission at 1100 nm with photoluminescence quantum yield (PLQY) as high as 17.72 %. Stored at 4 °C and in colloidal form, the PLQY of Pb1-x Cdx S QDs remained at 90.9 % of the initial value after 15 days, while stored as powder, the spectra did not change after 5 months. The high PLQY and good water compatibility of Pb1-x Cdx S QDs provide a good performance in vivo vasculature imaging and lymphatic system imaging at a very low power density (10 mW cm-2 ) in the NIR-II window.

General Synthesis of Hierarchically Macro/Mesoporous Fe,Ni-Doped CoSe/N-Doped Carbon Nanoshells for Enhanced Electrocatalytic Oxygen Evolution.

Constructing hierarchical porosity and designing rational hybrid composition are effective strategies for enhancing the electrocatalytic performance of hybrid catalysts for electrochemical energy conversion. Here, we develop a multistep "molecule/ion-exchange" strategy toward the synthesis of hierarchically macro/mesoporous Fe,Ni-doped CoSe/N-doped carbon nanoshells with tunable pore structures and compositions. Polystyrene (PS)@Co-based amorphous coordination polymer (Co-CP) core-shell particles with hierarchically macro/mesoporous nanoshells are first prepared by ligand-molecule-exchange etching of the outer layers in PS@Co-based metal-organic framework precursors. Afterward, a liquid-solid dual-ion-exchange reaction of PS@Co-CP particles with [Fe(CN)6]3- and [Ni(CN)4]2- ions leads to the formation of PS@Co-CP/Co-Fe Prussian blue analogue (PBA)/Co-Ni PBA particles, which are further transformed into hierarchically macro/mesoporous Fe,Ni-doped CoSe/N-doped carbon particles via a vapor-solid selenization reaction. Moreover, this approach could be extended to synthesize different hierarchically porous core-shell composites with various morphologies and tailored compositions. Because of their unique hierarchically porous nanoarchitecture, these Fe,Ni-doped CoSe/N-doped carbon particles with optimized composition show enhanced performance for electrocatalytic oxygen evolution.