Manipulating the Host-Guest Chemistry of Cucurbituril to Propel Highly Reversible Zinc Metal Anodes.

Rechargeable aqueous zinc-ion batteries are practically plagued by the short lifespan and low Coulombic efficiency (CE) of Zn anodes resulting from random dendrite deposition and parasitic reactions. Herein, the host-guest chemistry of cucurbituril additive with Zn2+ to achieve longstanding Zn anodes is manipulated. The macrocyclic molecule of cucurbit[5]uril (CB[5]) is delicately designed to reconstruct both the CB[5]-adsorbed electric-double layer (EDL) structure at the Zn interface and the hydrated sheath of Zn2+ ions. Especially benefiting from the desirable carbonyl rims and suitable hydrophobic cavities, the CB[5] has a strong host-guest interaction with Zn2+ ions, which exclusively permits rapid Zn2+ flux across the EDL interface but retards the H2O radicals and SO4 2-. Accordingly, such a unique particle redistributor warrants long-lasting dendrite-free deposition by homogenizing Zn nucleation/growth and significantly improved CE by inhibiting side reactions. The Zn anode can deliver superior reversibility in CB[5]-containing electrolyte with a ninefold increase of cycle lifetime and an elevated CE of 99.7% under harsh test conditions (10 mA cm-2/10 mA h cm-2). The work opens a new avenue from the perspective of host-guest chemistry to propel the development of rechargeable Zn metal batteries and beyond.

Surface Engineering of MoS2 Quantum Dots via Cyclodextrin-Based Host-Guest Chemistry as Versatile Platforms for Enhanced Cell Imaging Application.

Transition metal chalcogenide quantum dots (QDs), especially MoS2 QDs, are an emerging class of novel optical probes for versatile bioanalytical applications owing to their distinct physicochemical properties. However, the reasonable use of these QDs for biological imaging has been largely restricted due to the challenge of controllable surface functionalization. In this work, we report a new strategy to engineer the surface of MoS2 QDs by taking advantage of cyclodextrin (CD)-based host-guest chemistry. The prepared ß-CD-modified QDs (ß-CD-MoS2 QDs) exhibit enhanced fluorescence properties, excellent biocompatibility, and good stability, making them promising as novel optical probes for bioimaging. Cellular imaging experiments revealed that these ß-CD-MoS2 QDs can enter living cells through multiple internalization pathways, which differs significantly from pristine QDs. Particularly, we observed that the intracellular accumulation of MoS2 QDs in lipid droplets was enhanced owing to the specific binding of ß-CD to cholesterol, which was then harnessed for monitoring the lipid metabolism in living cells via fluorescence imaging. Furthermore, we also demonstrated the potential use of ß-CD-MoS2 QDs for targeted cell imaging and microplate-based cell recognition, which can be easily achieved via bioconjugation with functional motifs (e.g., folate acid) through host-guest chemistry. Altogether, these results illustrate the great potential of engineering the surface of MoS2 QDs and other analogous materials via CD-based host-guest chemistry for advancing their cell imaging applications.

Macrocyclic Arenes-Based Conjugated Macrocycle Polymers for Highly Selective CO2 Capture and Iodine Adsorption.

Incorporating synthetic macrocycles with unique structures and distinct conformations into conjugated macrocycle polymers (CMPs) can endow the resulting materials with great potentials in gas uptake and pollutant adsorption. Here, four CMPs (CMP-n, n=1-4) capable of reversibly capturing iodine and efficiently separating carbon dioxide are constructed from per-triflate functionalized leaning tower[6]arene (LT6-OTf) and [2]biphenyl-extended pillar[6]arene (BpP6-OTf) via Pd-catalyzed Sonogashira-Hagihara cross-coupling reaction. Intriguingly, owing to the appropriate cavity size of LT6-OTf and the numerous aromatic rings in the framework, the newly designed CMP-4 possesses an outstanding I2 affinity with a large uptake capacity of 208 wt % in vapor and a great removal efficiency of 94 % in aqueous solutions. To our surprise, with no capacity to accommodate nitrogen, CMP-2 constructed from BpP6-OTf is able to specifically capture carbon dioxide at ambient conditions.

Smart Delivery Systems Based on Poly(glycidyl methacrylate)s-Coated Organic/Inorganic Core-Shell Nanohybrids.

Smart delivery systems have gained momentum over the last few decades due to their potential to realize enhanced therapeutic efficacy. Poly(glycidyl methacrylate)s (PGMAs), which spring up like mushrooms, have drawn great attention in the theranostics field, especially in multifunctional theranostic systems. The marriage of PGMAs with functional inorganic cores is expected to integrate diagnosis (e.g., fluorescence, X-ray computed tomography, magnetic resonance, photoacoustic and upconversion luminescence imaging), treatment, or multimodal synergistic therapies (e.g., chemotherapy, gene therapy, photothermal therapy) in one pot for personalized medicine. In this review, recent progress in various PGMA-coated nanohybrids based on the type of integrated inorganic nanoparticle, including silica nanoparticles, magnetic nanoparticles, quantum dots, gold nanoparticles, gold nanorods, metal-organic frameworks, cellulose nanocrystals, and their core-shell nanostructures is systematically reviewed. Future work in this field is anticipated to be devoted to developing efficient real-time-imaging-guided multimodal synergistic therapies.

[The Effect of miR-17-5p on Vascular Lesion and Expression of VLDLR in Atherosclerotic Mice].

OBJECTIVE: To investigate the effect of miR-17-5p on vascular lesion and expression of very low density lipoprotein receptor (VLDLR) in atherosclerotic (AS) mice. METHODS: ApoE-/- mice were fed with high fat diet for 15 weeks to establish atherosclerotic mice models, and these mice were injected with miR-17-5p inhibitor antagomiR-17-5p 20 mg/kg from week 13 to week 15 to interfere the expression of miR-17-5p. AS model group (injection of normal saline) and NC miRNA group (injection of negative control inhibitors) were set and C57BL/6 mice were fed with normal diet for 15 weeks as normal control group (NC group, injection of normal saline during week 13-15). HE staining was used to detect the pathological changes of arterial vessels in each group and the vascular morphological changes were measured as well, so as to investigate the therapeutic effect of interfering miR-17-5p on AS vascular lesions. According to the prediction of Targetscan target gene prediction database, VLDLR as the target gene of miR-17-5p, the distribution of VLDLR in vascular tissues of mice in each group was observed by immunofluorescence. The effect of miR-17-5p on the expression of VLDLR mRNA in the arterial tissues of each group was detected by real-time PCR, and the changes of VLDLR protein expression caused by miR-17-5p in the arterial tissues in each group was detected by Western blot. RESULTS: The results of HE staining showed thatcompared with the NC group, the AS model group had obvious plaques in vascular endothelium, smooth muscle cell disorder and intimal hyperplasia, while the antagomiR-17-5p treated mice had significantly less lesions compared with the NC miRNA group. The intimal area of mice in the AS model group was bigger compared with NC group, but decreased after the inhibition of miR-17-5p. There was no statistically significant difference in the area of the media in each group. Vascular lumen area was smaller and intima/media ratio (I/M) values were lower in the AS model group and the NC miRNA group compared with the NC group, while the antagomiR-17-5p group alleviated this effect (P<0.05). Immunofluorescence showed that the expression of VLDLR in the AS model group was decreased, and that in the antagomiR-17-p group was higher than that in the NC miRNA group. The expression of VLDLR gene in the AS model group was lower than that in the NC group (P<0.01), while the VLDLR gene expression was higher in the antagomiR17-p group than that in the NC miRNA group (P<0.05). The results of VLDLR expression detected by Western blot were similar. CONCLUSION: miR-17-5p inhibitors may effectively alleviate the pathological changes of arterial vessels in AS mice by up-regulating the expression of VLDLR in arterial tissues, and may become a new therapeutic target for AS disease.

Zn(2+)-Triggered Drug Release from Biocompatible Zirconium MOFs Equipped with Supramolecular Gates.

A new theranostic nanoplatform, comprising of monodisperse zirconium metal-organic frameworks (MOFs) as drug carriers and carboxylatopillar[5]arene-based supramolecular switches as gating entities, is constructed, and controlled drug release triggered by bio-friendly Zn(2+) ions (abundant in synaptic vesicles) and auxiliary thermal stimulus is realized. This on-command drug delivery system exhibits large pore sizes for drug encapsulation, excellent biodegradability and biocompatibility, extremely low cytotoxicity and premature drug release, and superior dual-stimuli responsiveness, opening a new avenue in targeted drug delivery and controlled release of therapeutic agents, especially in the treatment of central nervous system diseases.

Acetylcholine-triggered cargo release from supramolecular nanovalves based on different macrocyclic receptors.

Acetylcholine (ACh), a neurotransmitter located in cholinergic synapses, can trigger cargo release from mesoporous silica nanoparticles equipped with calixarene- or pillarene-based nanovalves by removing macrocycles from the stalk components. The amount and speed of cargo release can be controlled by varying the concentration of ACh in solution or changing the type of gating macrocycle. Although this proof-of-concept study is far from a real-life application, it provides a possible route to treat diseases related to the central nervous system.

Guest-Induced Helical Superstructure from a Gold Nanocluster-Based Supramolecular Organic Framework Enables Efficient Catalysis.

Mimicking hierarchical assembly in nature to exploit atomically precise artificial systems with complex structures and versatile functions remains a long-standing challenge. Herein, we report two single-crystal supramolecular organic frameworks (MSOF-4 and MSOF-5) based on custom-designed atomically precise gold nanoclusters Au11(4-Mpy)3(PPh3)7, showing distinct and intriguing host-guest adaptation behaviors toward 1-/2-bromopropane (BPR) isomers. MSOF-4 exhibits sev topology and cylindrical channels with 4-mercaptopyridine (4-Mpy) ligands matching well with guest 1-BPR. Due to the confinement effect, solid MSOF-4 undergoes significant structural change upon selective adsorption of 1-BPR vapor over 2-BPR, resulting in strong near-infrared fluorescence. Single-crystal X-ray diffraction reveals that Au11(4-Mpy)3(PPh3)7 in MSOF-4 transforms into Au11Br3(PPh3)7 upon ligand exchange with 1-BPR, resulting in 1-BPR@MSOF-6 single crystals with a rarely reported helical assembly structure. Significantly, the double-helical structure of MSOF-6 facilitates efficient catalysis of the electron transfer (ET) reaction, resulting in a nearly 6 times increase of catalytic rates compared with MSOF-4. In sharp contrast, solid MSOF-5 possesses chb topology and cage-type channels with narrow windows, showing excellent selective physical adsorption toward 1-BPR vapor but a nonfluorescent feature upon guest adsorption. Our results demonstrate a powerful strategy for developing advanced assemblies with high-order complexity and engineering their functions in atomic precision.

Viologen-mediated assembly of and sensing with carboxylatopillar[5]arene-modified gold nanoparticles.

Carboxylatopillar[5]arene (CP[5]A), a new water-soluble macrocyclic synthetic receptor, has been employed as a stabilizing ligand for in situ preparation of gold nanoparticles (AuNPs) to gain new insights into supramolecular host-AuNP interactions. CP[5]A-modified AuNPs with good dispersion and narrow size distributions (3.1 ± 0.5 nm) were successfully produced in aqueous solution, suggesting a green synthetic pathway for the application of AuNPs in biological systems. Supramolecular self-assembly of CP[5]A-modified AuNPs mediated by suitable guest molecules was also investigated, indicating that the new hybrid material is useful for sensing and detection of the herbicide paraquat.

[Effect of RAAS antagonist on the expression of gap junction cx43 in myocardium of spontaneously hypertensive rat].

UNLABELLED: OBJECTIVE To investigate the expression of gap junction protein Cx43 in the cardiac muscle of spontaneous hypertensive rat and the effects of various antagonists against renin angiotensin aldosterone system (RAAS) on Cx43 expression. METHODS 70 spontaneous hypertensive rats of 8-week age, 200-gram weight were separated into 7 groups, as hypertension, ramipril, telmisartan, eplerenone, ramipril + telmisartan, telmisartan + eplerenone, and ramipril+eplerenone treatment group. Another 10 healthy Wistar rats of the same age and weight were used as control group. All the rats were given intragastric administration at 8 a. m. every morning, and measured arteria caudilis pressure at 0, 4 and 8 week, respectively. 8 weeks later, all the rats were sacrificed, and the hearts were taken to measure the weight of left ventricle and the ratio of left ventricle to body weight. Myocardial fibrosis was observed by H&E staining of paraffin embedded sections, and Cx43 expression was examined by RT-PCR and western blot. RESULTS: The arteria caudilis pressure of spontaneous hypertensive rats was significantly higher than that of healthy control Wistar rats (P < 0.01). The decreased blood pressure was observed in RAAS antagonists treated rats, compared with hypertension group (P < 0.05). The combined treatment of telmisartan and eplerenone had the best effect of lowering blood pressure. Moreover, the weight of left ventricle, the ratio of left ventricle to body weight, myocardial fibrosis and angiotensin 11 were all prominently decreased in telmisartan and eplerenone combination group (P < 0.01). The expression of Cx43 in spontaneous hypertensive rats was significantly lower than that of healthy control Wistar rats (P < 0.01). Increased Cx43 expression was observed in RAAS antagonists treated rats, compared with hypertension group (P < 0.05). CONCLUSION: The expression of gap junction protein Cx43 was significantly down-regulated in spontaneous hypertensive rats, while RAAS antagonists increased Cx43 expression. The combination of telmisartan and eplerenone effectively recovered the expression of Cx43 and probably reversed hypertension.

Promising Energetic Melt-Castable Material with Balanced Properties.

As one of the most widely used energetic materials to date, trinitrotoluene (TNT) suffers from several generally known drawbacks such as high toxicity, oil permeability, and poor mechanical properties, which are driving researchers to explore new high-performance energetic melt-castable materials for replacing TNT. However, it still remains a great challenge to discover a promising TNT alternative due to the multidimensional requirements for practical applications. Herein, we reported a new promising energetic melt-castable molecule, 4-methoxy-1-methyl-3,5-dinitro-1H-pyrazole (named as DMDNP). Besides a reasonable melting point (Tm: 94.8 °C), good thermostability (Td: 293.2 °C), and excellent chemical compatibility, DMDNP exhibits some obvious advantages over TNT including more environmentally friendly synthesis, high yield, low toxicity, low volume shrinkage, low mechanical and electrostatic sensitivities, etc., demonstrating well-balanced properties and great promise as a TNT replacement.

One-pot synthesis of pillar[n]arenes catalyzed by a minimum amount of TfOH and a solution-phase mechanistic study.

A practical and effective trifluoromethanesulfonic acid (TfOH)-catalyzed cyclooligomerization strategy was developed for the synthesis of functionalized pillar[n]arenes and copillar[5]arenes from 1,4-dialkoxybenzenes with paraformaldehyde under mild reaction conditions, and the reaction mechanism of solution-phase catalytic synthesis of pillararenes was investigated by room-temperature X-band ESR spectroscopy, mass spectroscopy, NMR and control experiments, suggesting a free radical process initially and a Friedel-Crafts alkylation process during the consequent coupling and ring-closure stage.

Interactions of cationic gold nanoclusters with serum proteins and effects on their cellular responses.

Cationic nanoparticles (NPs) have shown great potential in biological applications owing to their distinct features such as favorable cellular internalization and easy binding to biomolecules. However, our current knowledge of cationic NPs' biological behavior, i.e., NP-protein interactions, is still rather limited. Herein, we choose ultrasmall-sized fluorescent gold nanoclusters (AuNCs) coated by (11-mercaptoundecyl) - N, N, N - trimethylammonium bromide (MUTAB) as representative cationic NPs, and systematically study their interactions with different serum proteins at nano-bio interfaces. By monitoring the fluorescence intensity of MUTAB-AuNCs, all proteins are observed to bind with roughly micromolar affinities to AuNCs and quench their fluorescence. Transient fluorescence spectroscopy, X-ray photoelectron spectroscopy and isothermal titration calorimetry are also adopted to characterize the physicochemical properties of MUTAB-AuNCs after the protein adsorption. Concomitantly, circular dichroism spectroscopy reveals that cationic AuNCs can exert protein-dependent conformational changes of these serum proteins. Moreover, protein adsorption onto cationic AuNCs can significantly influence their cellular responses such as cytotoxicity and uptake efficiency. These results provide important knowledge towards understanding the biological behaviors of cationic nanoparticles, which will be helpful in further designing and utilizing them for safe and efficient biomedical applications.

Metal-Organic Frameworks-Mediated Assembly of Gold Nanoclusters for Sensing Applications.

Gold nanoclusters (AuNCs) are an emerging type of ultrasmall nanomaterials possessing unique physicochemical characteristics. Metal-organic frameworks (MOFs), a singular kind of porous solid and crystalline material, have attracted tremendous attention in recent years. The combination of AuNCs and MOFs can integrate and improve the prominent properties of both components, such as high catalytic activities, tunable optical properties, good biocompatibility, surface functionality and stability, which make the composites of MOFs and AuNCs promising for sensing applications. This review systematically summarizes the recent progress on the sensing of various analytes via MOFs-mediated AuNCs assemblies based on strategies of luminescence sensing, colorimetric sensing, electrochemiluminescence sensing, and electrochemical and photoelectrochemical sensing. A brief outlook regarding the future development of MOFs-mediated AuNCs assemblies for sensing application is presented as well.

Solitary plasmacytoma of the left rib misdiagnosed as angina pectoris: A case report.

BACKGROUND: Solitary plasmacytoma in the left rib is rare and can cause chest discomfort such as chest pain and tightness, and its clinical manifestations are not typical, so it is often misdiagnosed. We report a case of left costal plasmacytoma misdiagnosed as angina pectoris. We also review the literature and provide suggestions as to how to avoid misdiagnosis. CASE SUMMARY: A 77-year-old man with a history of intermittent chest tightness for 3 years presented with pain in the left chest for 1 wk and was admitted to hospital. The cardiologists initially diagnosed angina pectoris but the findings of coronary angiography were not consistent with the symptoms. Computed tomography showed that the left eighth rib mass was accompanied by bone destruction. The patient was transferred to our department for further treatment. Preoperative biopsy indicated that the lesion was possibly malignant, and elective surgery was performed to remove the lesion. The size of the tumor was about 4 cm. The tumor was spindle-shaped and protruded into the pleural cavity, without invading the lungs. Postoperative pathology confirmed that the left rib lesion was plasmacytoma. After 14 mo follow-up, the patient died of systemic metastasis. CONCLUSION: Left rib solitary plasmacytoma is a rare disease confined to a specific rib and can cause local pain. Attention should be paid to the differential diagnosis of angina pectoris to avoid misdiagnosis.

Surface chemistry regulates the optical properties and cellular interactions of ultrasmall MoS2 quantum dots for biomedical applications.

Molybdenum disulfide quantum dots (MoS2 QDs) have drawn increasing attention owing to their distinct optical properties and potential applications in many fields such as biosensing, photocatalysis and cell imaging. Elucidating the relationship between the surface chemistry of MoS2 QDs and their optical properties as well as biological behaviors is critical for their practical applications, which remain largely unclear. Herein, by adopting a sulfur vacancy modification strategy, a toolbox of MoS2 QDs functionalized with different thiolate ligands was prepared. The effect of surface chemistry on the optical properties of MoS2 QDs was systematically explored by various spectroscopic techniques, revealing the important role of surface ligands in defining their absorption band gap and luminescence quantum yield. Furthermore, cellular experiments showed that the cytotoxicity and intracellular fate (i.e., lysosomal accumulation) of MoS2 QDs are closely related to the properties of surface ligands. Our results underscore the important roles of surface ligands in regulating the properties and biological interactions of these QDs, which will facilitate the future development of MoS2-based materials with precisely controlled functions for biomedical applications.

Simultaneous regulation of optical properties and cellular behaviors of gold nanoclusters by pre-engineering the biotemplates.

Herein, we reported a new strategy to simultaneously regulate both the physicochemical properties and biological behaviors of fabricated nanomaterials. Upon precisely pre-tailoring the number of charged groups of bovine serum albumin (BSA), the resultant BSA-templated gold nanoclusters (BSA-AuNCs) exhibit remarkably different fluorescence properties and strong biotemplate-dependent cellular uptake behavior.

Novel perylene probe-encapsulated metal-organic framework nanocomposites for ratiometric fluorescence detection of ATP.

Adenosine triphosphate (ATP) plays an important role in various biological processes and the ATP level is closely associated with many diseases. Herein, a novel ratiometric fluorescence assay for ATP was developed based on the excimer-monomer transfer of a perylene probe. By encapsulating a perylene probe, N,N'-bis(6-caproic acid)-3,4:9,10-perylenediimide (PDI), into zeolitic imidazolate framework-8 (ZIF-8) nanocrystals, fluorescent nanocomposites (PDI@ZIF-8) with significant excimer emission of the perylene probe were prepared for the first time. The presence of ATP will trigger the decomposition of PDI@ZIF-8 due to much stronger coordination between ATP and Zn2+ than that of 2-methylimidazole and Zn2+. As a result, the encapsulated PDI probes were released, leading to significantly increased monomer emission accompanying the decrease in the excimer emission. The excimer-monomer transition signal was utilized for ratiometric ATP sensing and its potential application for detecting ATP in cell lysates was also successfully demonstrated.

Highly C2/C1-Selective Covalent Organic Frameworks Substituted with Azo Groups.

A series of covalent organic frameworks substituted with azo groups (AzoCOFs) have been synthesized via imine condensation. The obtained frameworks show crystallinity and high stability. More importantly, the AzoCOFs exhibit exceptionally high ideal adsorption solution theory (IAST) selectivity in adsorption of C2H2 (35-2891) over CH4 at 273 K and 1 bar, owing to the favorable interactions between azo groups and acetylene molecules. The dependence of the gas adsorption property on pore size and polarity of the frameworks was also studied. The triethylene glycol substituted Tg-AzoCOF shows the highest C2H2/CH4 selectivity (IAST selectivity of 2891), which represents the highest reported for all porous materials. The AzoCOFs also exhibit high IAST adsorption selectivity of C2H4/CH4 (11-20), C2H6/CH4 (15-22), and CO2/CH4 (12-37), which is comparable with most porous materials, thus showing their great potential in gas separation applications.

[Effect of erythropoietin on the caspase-3 subfamily in preventing apoptosis of endothelial cell].

OBJECTIVE: To explore effect of erythropoietin on the caspase-3 subfamily in preventing apoptosis of human umbilical vein endothelial cells (HUVECs) induced by oxidized-low density lipoprotein (ox-LDL). METHODS: Third-sixth passages of HUVECs were used. Two experiments were conducted. In the first experiment, there was a blank control group, ox-LDL control group (100 mg/L, incubated for 48 hours), and low, medium, and high recombinant human erythropoietin (rhEPO) groups (6.25, 25.00, 100.00 kU/L rhEPO incubated for 24 hours+100 mg/L ox-LDL incubated for 48 hours). Another experimental protocol consisted of groups of the cells pretreated with either caspase-3 inhibitor DEVD-CHO, or caspase-8 inhibitor z-IETD-fmk, or caspase-9 inhibitor z-LEHD-fmk of 25 micromol/L for 24 hours, then HUVECs were exposed ox-LDL (100 mg/L) incubated for 48 hours. The activity of caspase-3, caspase-8, or caspase 9 was determined by caspase colorimetric assay. The cell survival rate was assessed with methyl thiazolyl tetrazolium (MTT) method. The positive expression rate of caspase-3 and apoptotic rate were measured by flow cytometer. RESULTS: The activity of caspase-3 was significantly decreased and cell survival rate was increased in the caspase-3 inhibitor group (both P<0.05). The activity of caspase-8 was decreased in the caspase-8 inhibitor group (P<0.05), but the cell survival rate was not significantly different from that of ox-LDL group (P>0.05). The activity of caspase-3 or caspase-9 was lower and cell survival rate was higher in the caspase-9 inhibitor group than that of ox-LDL group (all P<0.05). The pretreatment with rhEPO led to decreased activity of caspase-3, caspase-9, positive expression rate of caspase-3 and apoptotic rate in a dose-dependent manner compared with ox-LDL group (all P<0.05), but the activity of caspase-8 showed no significant difference from rhEPO pretreatment groups (all P>0.05). CONCLUSION: These results demonstrate that rhEPO can significantly inhibit the activity of caspase-3 or caspase-9 in endothelial cell apoptosis in a dose-dependent manner. Activation of caspase-3 or caspase-9 is involved in ox-LDL-induced HUVECs apoptotic signaling pathway, but caspase-8 is not involved.