Heterostructured metal—organic framework (MOF)‐on‐MOF thin films have the potential to cascade the various properties of different MOF layers in a sequence to produce functions that cannot be ...achieved by single MOF layers. An integration method that relies on van der Waals interactions, and which overcomes the lattice‐matching limits of reported methods, has been developed. The method deposits molecular sieving Cu‐TCPP (TCPP=5,10,15,20‐tetrakis(4‐carboxyphenyl)porphyrin) layers onto semiconductive Cu‐HHTP (HHTP=2,3,6,7,10,11‐hexahydrotriphenylene) layers to obtain highly oriented MOF‐on‐MOF thin films. For the first time, the properties in different MOF layers were cascaded in sequence to synergistically produce an enhanced device function. Cu‐TCPP‐on‐Cu‐HHTP demonstrated excellent selectivity and the highest response to benzene of the reported recoverable chemiresistive sensing materials that are active at room temperature. This method allows integration of MOFs with cascading properties into advanced functional materials.
MOF‐on‐MOF thin films were prepared from Cu‐HHTP (HHTP=hexahydrotriphenylene) and Cu‐TCPP (TCPP=tetrakis(4‐carboxyphenyl)porphyrin frameworks). The properties of the MOF layers cascade to produce functionality not achieved by a single layer. The MOF‐on‐MOF films demonstrate excellent selectivity and the highest response to benzene among reported recoverable chemiresistive sensing materials active at room temperature.
Linkage Chemistry of S(VI) Fluorides Zeng, Daming; Deng, Wei‐Ping; Jiang, Xuefeng
Chemistry : a European journal,
June 13, 2023, Letnik:
29, Številka:
33
Journal Article
Recenzirano
Sulfur(VI)‐fluoride exchange linkage as a next generation of click chemistry was introduced by Sharpless and coworkers in 2014. Distinguished from CuAAC, the SuFEx reaction proceeds under metal‐free ...conditions, and the reactive linkers are variable, enabling access to a diverse class of linkage compounds. Therein, a series of SuFEx linkers emerged has been widely prevalent in diverse fields. The SVI−F bond in comparison to SVI−Cl bond features excellent stability and chemoselectivity. The linkage chemistry primarily involves the formation of S−O and S−N bonds via commercially available phenols and amines, yet less study on C‐SuFEx linkage. This review will focus on three types of linkage for SuFEx linkers comprising S−O, S−N, and S−C bonds, and we hope to provide a practical guidance for SuFEx linkage chemistry.
Sulfur(VI)‐fluoride exchange: This review summarizes recent advances in the linkage chemistry of S(VI) fluorides since 2014, emphasizing the formation of S−O, S−N, and S−C bonds. The divergent SuFEx linkage is deployed in the assembly of S(VI)‐containing compounds library.
The NLRP3 inflammasome is a critical innate immune pathway responsible for producing active interleukin (IL)-1β, which is associated with tumor development and immunity. However, the mechanisms ...regulating the inflammatory microenvironment, tumorigenesis and tumor immunity are unclear. Herein, we show that the NLRP3 inflammasome was over-expressed in human HNSCC tissues and that the IL-1β concentration was increased in the peripheral blood of HNSCC patients. Additionally, elevated NLRP3 inflammasome levels were detected in tumor tissues of
Tgfbr1/Pten
2cKO HNSCC mice, and elevated IL-1β levels were detected in the peripheral blood serum, spleen, draining lymph nodes and tumor tissues. Blocking NLRP3 inflammasome activation using MCC950 remarkably reduced IL-1β production in an HNSCC mouse model and reduced the numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). Moreover, inhibiting NLRP3 inflammasome activation increased the numbers of CD4
+
and CD8
+
T cells in HNSCC mice. Notably, the numbers of exhausted PD-1
+
and Tim3
+
T cells were significantly reduced. A human HNSCC tissue microarray showed that NLRP3 inflammasome expression was correlated with the expression of CD8 and CD4, the Treg marker Foxp3, the MDSC markers CD11b and CD33, and the TAM markers CD68 and CD163, PD-1 and Tim3. Overall, our results demonstrate that the NLRP3 inflammasome/IL-1β pathway promotes tumorigenesis in HNSCC and inactivation of this pathway delays tumor growth, accompanied by decreased immunosuppressive cell accumulation and an increased number of effector T cells. Thus, inhibition of the tumor microenvironment through the NLRP3 inflammasome/IL-1β pathway may provide a novel approach for HNSCC therapy.
Tea plants with a specific color (white or yellow) have been studied extensively. A normal tea plant (Camellia sinensis cv. quntizhong) with one albino branch was discovered in a local tea plantation ...in Huangshan, Anhui, China. The pure albino leaves on this special branch had accumulated a fairly high content of amino acids, especially theanine (45.31 mg/g DW), and had a low concentration of polyphenols and an extremely low chlorophyll (Chl) content compared with control leaves. Ultrastructural observation of an albino leaf revealed no chloroplasts, whereas it was viable in the control leaf. RNA sequencing and differentially expressed gene (DEG) analysis were performed on the albino leaves and on control leaves from a normal green branch. The related genes involved in theanine and polyphenol biosynthesis were also investigated in this study. DEG expression patterns in Chl biosynthesis or degradation, carotenoid biosynthesis or degradation, chloroplast development, and biosynthesis were influenced in the albino leaves. Chloroplast deletion in albino leaves had probably destroyed the balance of carbon and nitrogen metabolism, leading to a high accumulation of free amino acids and a low concentration of polyphenols in the albino leaves. The obtained results can provide insight into the mechanism underlying this special albino branch phenotype, and are a valuable contribution toward understanding the albino mechanism in tea plants.
A major challenge for traditional cancer therapy, including surgical resection, chemoradiotherapy, and immunotherapy, is how to induce tumor cell death and leverage the host immune system at the same ...time. Here, a myeloid‐derived suppressor cell (MDSC) membrane‐coated iron oxide magnetic nanoparticle (MNP@MDSC) to overcome this conundrum for cancer therapy is developed. In this study, MNP@MDSC demonstrates its superior performance in immune evasion, active tumor‐targeting, magnetic resonance imaging, and photothermal therapy (PTT)‐induced tumor killing. Compared with red blood cell membrane‐coated nanoparticles (MNPs@RBC) or naked MNPs, MNP@MDSCs are much more effective in active tumor‐targeting, a beneficial property afforded by coating MNP with membranes from naturally occurring MDSC, thus converting the MNP into “smart” agents that like to accumulate in tumors as the source MDSCs. Once targeted to the tumor microenvironment, MNPs@MDSC can act as a PTT agents for enhanced antitumor response by inducing immunogenic cell death, reprogramming the tumor infiltrating macrophages, and reducing the tumor's metabolic activity. These benefits, in combination with the excellent biocompatibility and pharmacological kinetics characteristics, make MNP@MDSC a promising, multimodal agent for cancer theranostics.
Myeloid‐derived suppressor cell (MDSC) membranes are collected from tumor‐bearing mice and further used for magnetic Fe3O4 nanoparticle (MNP) coating. The resulting MDSC‐mimicking nanoparticles (MNP@MDSC) demonstrate superior performance in immune evasion, active tumor‐targeting, magnetic resonance imaging, photothermal therapy‐induced tumor killing, and excellent biocompatibility and pharmacological kinetics characteristics. These benefits make MNP@MDSC a promising, multimodal agent for cancer theranostics.
The formulation
min
x
,
y
f
(
x
)
+
g
(
y
)
,
subject
to
A
x
+
B
y
=
b
,
where
f
and
g
are extended-value convex functions, arises in many application areas such as signal processing, imaging and ...image processing, statistics, and machine learning either naturally or after variable splitting. In many common problems, one of the two objective functions is strictly convex and has Lipschitz continuous gradient. On this kind of problem, a very effective approach is the alternating direction method of multipliers (ADM or ADMM), which solves a sequence of
f
/
g
-decoupled subproblems. However, its effectiveness has not been matched by a provably fast rate of convergence; only sublinear rates such as
O
(1 /
k
) and
O
(
1
/
k
2
)
were recently established in the literature, though the
O
(1 /
k
) rates do not require strong convexity. This paper shows that global linear convergence can be guaranteed under the assumptions of strong convexity and Lipschitz gradient on one of the two functions, along with certain rank assumptions on
A
and
B
. The result applies to various generalizations of ADM that allow the subproblems to be solved faster and less exactly in certain manners. The derived rate of convergence also provides some theoretical guidance for optimizing the ADM parameters. In addition, this paper makes meaningful extensions to the existing global convergence theory of ADM generalizations.
The application of conventional metal–organic frameworks (MOFs) as electrode materials in supercapacitors is largely hindered by their conventionally poor electrical conductivity. This study reports ...the fabrication of conductive MOF nanowire arrays (NWAs) and the application of them as the sole electrode material for solid‐state supercapacitors. By taking advantage of the nanostructure and making full use of the high porosity and excellent conductivity, the MOF NWAs in solid‐state supercapacitor show the highest areal capacitance and best rate performance of all reported MOF materials for supercapacitors, which is even comparable to most carbon materials.
Conductive metal–organic framework (MOF) nanowire arrays (NWAs) are prepared as the sole electrode material for solid‐state supercapacitors. By taking advantage of their nanostructure and making full use of the high porosity and excellent conductivity, the MOF NWAs in the solid‐state supercapacitor show the highest areal capacitance and best rate performance of all reported MOF materials.
Cell membrane–based nanosystems with desirable characteristics have been studied extensively for many therapeutic applications. However, current research has focused on single cell membrane, and ...multifunctional fused membrane materials from different membrane types are still rare. Herein, a platelet–cancer stem cell (CSC) hybrid membrane‐coated iron oxide magnetic nanoparticle (MN) {CSC‐PMN} is presented for the first time for the enhanced photothermal therapy of head and neck squamous cell carcinoma (HNSCC). Inherited from the original source cells, the platelet membrane shows immune evading ability due to the surface marker comprising a number of “don't eat me” signals, and the CSC membrane has homotypic targeting capabilities due to the specific surface adhesion molecules. The CSC‐PMNs possess superior characteristics for immune evasion, active cancer targeting, magnetic resonance imaging, and photothermal therapy. Compared with single cell membrane–coated MNs, CSC‐PMNs exhibit prolonged circulation times and enhanced targeting abilities. Moreover, the CSC‐PMNs exhibit a superior photothermal ability that provides excellent HNSCC tumor growth inhibition, particularly in an immunocompetent Tgfbr1/Pten conditional double knockout HNSCC mouse model that contains a more complex tumor microenvironment that is similar to the human HNSCC microenvironment. Collectively, this biomimetic multimembrane‐coated nanoplatform may provide enhanced antitumor efficacy in the complex tumor microenvironment.
A natural cancer stem cell‐platelet hybrid mimic membrane is collected from tumor‐bearing mice and further used for magnetic nanoparticle coating. The obtained biomimetic nanoparticles are then injected into the same mice for magnetic resonance imaging and photothermal therapy. The work presents a novel design strategy for personalized cancer theranostics.
Sulfur(VI) fluoride cleavage and exchanging linkage, a new generation of linkage chemistry, exhibits enormous potential for combining a range of functional molecules in an increasing number of ...fields. Herein, we established a metal‐free linkage of unactivated alkenes and sulfonimidoyl fluorides via hydrosulfonimidoylation to construct sulfoximines within minutes. An intermolecular hydride transfer process is the key step, and it occurs via overlap of the LUMO in the sulfonimidoyl cation and HOMO in the unactivated alkene, which was confirmed via control experiments with deuterated compounds. DFT calculations further demonstrated the concerted process involving formation of the S−C(sp3) bond and hydride transfer. Remarkably, abundant natural products and pharmaceuticals with multiple heteroatoms and sensitive functional groups have been subjected to the current linkage reaction to achieve various sulfoximine linkages, furnishing the basis for drug discovery and drug conjugation.
A metal‐free linkage chemistry of unactivated alkenes and sulfonimidoyl fluorides via hydrosulfonimidoylation to construct sulfoximines within minutes is presented. An intermolecular hydride transfer process is the key step in the reaction.
PDF
