A novel porphyrin-based two-dimensional metal–organic framework (MOF) nanodisk with small size and few layers was prepared by coordination chelation between meso-tetra(4-carboxyphenyl)porphine ligand and Zn(ii) paddlewheel metal nodes.

Insulin resistance (IR) is the primary pathological mechanism underlying type 2 diabetes mellitus (T2DM). Here, the study aimed to ascertain whether and how exercise mediates IR in T2DM. An in vivo mouse model of high-fat diet-induced IR and an in vitro high-glucose-induced IR model were constructed. High long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression was detected in T2MD and was positively correlated with HOMA-IR and resistin levels. Then, short hairpin RNA targeting MALAT1 (sh-MALAT1) or pcDNA-MALAT1 was delivered into human umbilical vein endothelial cells (HUVECs) to knock down or upregulate its expression, respectively. Silencing of MALAT1 resulted in reduced levels of resistin, Ang II, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), endothelin-1 (ET-1), and p-insulin receptor substrate-1 (p-IRS)/ISR-1, and decreased cell migration, as well as enhanced glucose uptake and levels of nitric oxide (NO) and p-Akt/Akt. In the IR mouse model, exercise was observed to downregulate MALAT1 to reduce resistin, whereby exercise reduced homeostatic model assessment-insulin resistance (HOMA-IR). Besides, exercise also elevated microRNA-382-3p (miR-382-3p) expression in the serum of IR mice. Dual-luciferase reporter and RNA binding protein immunoprecipitation (RIP) assays identified that MALAT1 could bind to miR-382-3p to upregulate resistin. Collectively, the key observations of the study provide evidence that inhibition of MALAT1 elevates miR-382-3p to repress resistin, which consequently underlies the mechanism of exercise protecting against IR, highlighting a direction for T2DM therapy development.

The low solubility of gases in aqueous solution is the major kinetic limitation of reactions that involve gases. To address this challenge, we report a nanochannel reactor with joint gas-solid-liquid interfaces and controlled wettability. As a proof of concept, a porous anodic alumina (PAA) nanochannel membrane with different wettability is used for glucose oxidase (GOx) immobilization, which contacts with glucose aqueous solution on one side, while the other side gets in touch with the gas phase directly. Interestingly, it is observed that the O could participate in the enzymatic reaction directly from gas phase through the proposed nanochannels, and a hydrophobic interface is more favorable for the enzymatic reaction due to the rearrangement of GOx structure as well as the high gas adhesion. As a result, the catalytic efficiency of GOx in the proposed interface is increased up to 80-fold compared with that of the free state in traditional aqueous air-saturated electrolyte. This triphase interface with controlled wettability can be generally applied to immobilize enzymes or catalysts with gas substrates for high efficiency.

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In this work, a simple and ultrasensitive localized surface plasmon resonance (LSPR) method that use Au nanoflowers (AuNFs) as a probe was designed for in situ monitoring of alkaline phosphatase (ALP) activity. The AuNFs were fabricated by hydrogen tetrechloroaurate-induced oxidative disruption of polydopamine-coated Au nanoparticles (AuNPs), and subsequently, growth of Au nanopetals on AuNPs occurred. The as-prepared AuNFs showed a much higher LSPR capability and stronger scattering color change than AuNPs. The strategy for in situ cellular ALP activity detection relied on the deposition of Ag on the AuNFs surface, which changed the morphology of AuNFs and led to a tremendous LSPR response and scattering color change. The deposition of Ag shell on AuNFs was related to ALP activity, where ALP catalyzed the hydrolysis of L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate to form Lascorbic acid (AA), and then AA reduced Ag + to Ag and deposited onto AuNFs. With this concept, the ALP activity could be monitored with a detection limit of 0.03 μU L −1 . Meanwhile, the ALP activity of single HepG2 cells and HEK 293 cells was tracked with a proposed approach, which indicated the trace expression level of ALP in HEK 293T cell and overexpressed level of ALP in HepG2 cells. After treatment with drugs, the cellular ALP activity of HepG2 cells was decreased with the treating time and dose increasing. Therefore, the proposed strategy could be used for tracking the cellular ALP activity, which paved a new avenue for cell studies and held great potential for discovering novel ALP-based drugs applications.