Construction of core-shell magnetic metal-organic framework composites Fe3O4@MIL-101(Fe, Co) for degradation of RhB by efficiently activating PMS.

Low catalytic efficiency and catalyst recovery are the key factors limiting the practical application of advanced oxidation processes. In this work, a core-shell magnetic nanostructure Fe3O4@MIL-101(Fe, Co) was prepared via a simple solvothermal method. The core-shell structure and magnetic recovery performance were characterized by various technologies. The results of dye degradation experiments proved that within 10 minutes, the Fe3O4@MIL-101(Fe, Co)/PMS system can degrade more than 95% of 10 mg per L Rhodamine (RhB) at an initial pH of 7, which possesses higher catalytic activity than the Fe3O4/PMS system and the MIL-101(Fe, Co)/PMS system. The effects of initial solution pH and coexisting anions in water on the degradation of RhB were further discussed. The results showed that Fe3O4@MIL-101(Fe, Co) displayed excellent degradation efficiency in a wide pH range of 3-11 and capability of resisting coexisting anions. It is worth mentioning that after five cycles, the RhB removal rate can still be maintained at over 90% after 10 minutes of reaction. Free radical quenching experiments were further studied, confirming that ˙OH and SO4-˙ were involved in the degradation of RhB, while the dominating active free radical was SO4-˙. The possible reaction mechanism of the RhB degradation process was also inferred.

Astaxanthin attenuates cigarette smoke-induced small airway remodeling via the AKT1 signaling pathway.

BACKGROUND: Astaxanthin (AXT) is a keto-carotenoid with a variety of biological functions, including antioxidant and antifibrotic effects. Small airway remodeling is the main pathology of chronic obstructive pulmonary disease (COPD) and is caused by epithelial-to-mesenchymal transition (EMT) and fibroblast differentiation and proliferation. Effective therapies are still lacking. This study aimed to investigate the role of AXT in small airway remodeling in COPD and its underlying mechanisms. METHODS: First, the model of COPD mice was established by cigarette smoke (CS) exposure combined with intraperitoneal injection of cigarette smoke extract (CSE). The effects of AXT on the morphology of CS combined with CSE -induced emphysema, EMT, and small airway remodeling by using Hematoxylin-eosin (H&E) staining, immunohistochemical staining, and western blot. In addition, in vitro experiments, the effects of AXT on CSE induced-EMT and fibroblast function were further explored. Next, to explore the specific mechanisms underlying the protective effects of AXT in COPD, potential targets of AXT in COPD were analyzed using network pharmacology. Finally, the possible mechanism was verified through molecular docking and in vitro experiments. RESULTS: AXT alleviated pulmonary emphysema, EMT, and small airway remodeling in a CS combined with CSE -induced mouse model. In addition, AXT inhibited the EMT process in airway cells and the differentiation and proliferation of fibroblasts. Mechanistically, AXT inhibited myofibroblast activation by directly binding to and suppressing the phosphorylation of AKT1. Therefore, our results show that AXT protects against small airway remodeling by inhibiting AKT1. CONCLUSIONS: The present study identified and illustrated a new food function of AXT, indicating that AXT could be used in the therapy of COPD-induced small airway remodeling.

Impact of cervical intraepithelial neoplasia and treatment on IVF/ICSI outcomes.

STUDY QUESTION: Does treatment selection for cervical lesions affect the outcome of IVF/ICSI? SUMMARY ANSWER: There was no difference in pregnancy outcome between treated and untreated groups, or between different types of IVF/ICSI treatment. WHAT IS KNOWN ALREADY: Human papillomavirus (HPV) infection and HPV-induced cervical lesions are associated with decreased fertility, and cervical intraepithelial neoplasia (CIN) treatment may increase the risk of adverse pregnancy outcomes. STUDY DESIGN, SIZE, DURATION: Between 2018 and 2020, 190 women with infertility who had abnormal HPV screening or cytology results prior to IVF/ICSI, and were diagnosed with CIN2/CIN3 by colposcopy biopsy at a tertiary hospital, were enrolled in a retrospective cohort study with follow-up until 31 December 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients with infertility who were diagnosed with CIN2/CIN3 by colposcopy biopsy were divided into the treatment and expectant management groups. The treatment group was divided into two intervention subgroups: the ablative therapy group and the surgical treatment group. The baseline data, number of oocytes retrieved, and rates of fertilization, high-quality embryos, positive serum HCG, clinical pregnancy, abortion, live birth, and cumulative pregnancy were compared among groups. MAIN RESULTS AND THE ROLE OF CHANCE: Among the 190 patients included in the study, 152 were diagnosed with CIN2, and 38 patients had CIN3. There was no significant difference in the baseline data between the treatment and expectant groups. The time from confirmed lesions to the onset of gonadotrophin administration in the surgical treatment group was significantly longer than in the ablative therapy group and the expectant group (P = 0.007 and P = 0.024, respectively). For the treatment and expectant groups, respectively, the average number of oocytes retrieved (12.95 ± 8.77; 13.32 ± 9.16), fertilization rate (71.01 ± 23.86; 64.84 ± 26.24), and high-quality embryo rate (48.93 ± 30.72; 55.17 ± 34.13) did not differ, and no differences were detected between the different treatment subgroups. There were no differences among groups in rates of HCG positivity, clinical pregnancy, miscarriage, live birth, or cumulative pregnancy. The live birth rate in the surgical treatment group was slightly higher than that in the expectant groups (77.78% versus 66.67%), but the difference was not statistically significant. The 3-year cumulative pregnancy rates in the surgical treatment and expectant groups were 58.19% and 64.00%, respectively. LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study, which by nature can include selection bias, and the number of cases in the expectant group was <30, which may result in a false-negative result owing to the small sample size. WIDER IMPLICATIONS OF THE FINDINGS: For patients with CIN2/CIN3, the treatment of cervical lesions does not affect the outcome of IVF/ICSI. Patients with CIN2 can enroll for IVF/ICSI cycles, with close follow-up to prevent the progression of cervical lesions, in order to avoid further delay in starting ART. For patients with CIN3, ovulation induction and embryo cryopreservation can be initiated as soon as possible after cervical lesions are treated, and frozen-thawed embryo transfer can be carried out 9-12 months later. STUDY FUNDING/COMPETING INTEREST(S): This work was funded by the Key Clinical Projects of the Peking University Third Hospital (to Y.W., BYSYZD2021014). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Functionalized nanozyme with drug loading for enhanced tumour combination treatment of catalytic therapy and chemotherapy.

Nanozyme-based tumour catalytic therapy has attracted widespread attention in recent years, but the therapeutic efficacy is limited due to the trapping of hydroxyl radicals (˙OH) by endogenous glutathione (GSH) in the tumour microenvironment (TME). Zr/Ce-MOFs/DOX/MnO2 is constructed in this work to serve as a new kind of nanozyme for combination chemotherapy and catalytic treatment. Zr/Ce-MOFs can produce ˙OH in a mimic TME, and the MnO2 on the surface could deplete the GSH, further promoting the ˙OH generation. The pH/GSH dual stimulation accelerates the release of anticancer drug doxorubicin (DOX) in tumour tissue for enhanced tumour chemotherapy. Moreover, Mn2+ produced by the reaction of Zr/Ce-MOFs/DOX/MnO2 and GSH can be used as the contrast agent for T1-MRI. The potential antitumour effect of Zr/Ce-MOFs/DOX/MnO2 is demonstrated by in vitro and in vivo cancer treatment tests. This work thus provides a new nanozyme-based platform for enhanced combination chemotherapy and catalytic treatment for tumours.

Glycyl-l-histidyl-l-lysine-Cu2+ rescues cigarette smoking-induced skeletal muscle dysfunction via a sirtuin 1-dependent pathway.

BACKGROUND: Skeletal muscle dysfunction is an important co-morbidity in patients with chronic obstructive pulmonary disease (COPD) and is significantly associated with increased mortality. Oxidative stress has been demonstrated an important trigger for COPD-related skeletal muscle dysfunction. Glycine-histidine-lysine (GHK) is an active tripeptide, which is a normal component of human plasma, saliva, and urine; promotes tissue regeneration; and acts as an anti-inflammatory and antioxidant properties. The purpose of this study was to determine whether GHK is involved in COPD-related skeletal muscle dysfunction. METHODS: The plasma GHK level in patients with COPD (n = 9) and age-paired healthy subjects (n = 11) were detected using reversed-phase high-performance liquid chromatography. The complex GHK with Cu (GHK-Cu) was used in in vitro (C2C12 myotubes) and in vivo experiments (cigarette smoking [CS]-exposure mouse model) to explore the involvement of GHK in CS-induced skeletal muscle dysfunction. RESULTS: Compared with healthy control, plasma GHK levels were decreased in patients with COPD (70.27 ± 38.87 ng/mL vs. 133.0 ± 54.54 ng/mL, P = 0.009). And plasma GHK levels in patients with COPD were associated with pectoralis muscle area (R = 0.684, P = 0.042), inflammatory factor TNF-α (R = -0.696, P = 0.037), and antioxidative stress factor SOD2 (R = 0.721, P = 0.029). GHK-Cu was found to rescue CSE-induced skeletal muscle dysfunction in C2C12 myotubes, as evidenced by increased expression of myosin heavy chain, reduced expression of MuRF1 and atrogin-1, elevated mitochondrial content, and enhanced resistance to oxidative stress. In CS-induced muscle dysfunction C57BL/6 mice, GHK-Cu treatment (0.2 and 2 mg/kg) reduces CS-induced muscle mass loss (skeletal muscle weight (1.19 ± 0.09% vs. 1.29 ± 0.06%, 1.40 ± 0.05%; P < 0.05) and muscle cross-sectional area elevated (1055 ± 552.4 µm2 vs. 1797 ± 620.9 µm2 , 2252 ± 534.0 µm2 ; P < 0.001), and also rescues CS-induced muscle weakness, indicated by improved grip strength (175.5 ± 36.15 g vs. 257.6 ± 37.98 g, 339.1 ± 72.22 g; P < 0.01). Mechanistically, GHK-Cu directly binds and activates SIRT1(the binding energy was -6.1 kcal/mol). Through activating SIRT1 deacetylation, GHK-Cu inhibits FoxO3a transcriptional activity to reduce protein degradation, deacetylates Nrf2 and contribute to its action of reducing oxidative stress by generation of anti-oxidant enzymes, increases PGC-1α expression to promote mitochondrial function. Finally, GHK-Cu could protect mice against CS-induced skeletal muscle dysfunction via SIRT1. CONCLUSIONS: Plasma glycyl-l-histidyl-l-lysine level in patients with chronic obstructive pulmonary disease was significantly decreased and was significantly associated with skeletal muscle mass. Exogenous administration of glycyl-l-histidyl-l-lysine-Cu2+ could protect against cigarette smoking-induced skeletal muscle dysfunction via sirtuin 1.

Identification and Analysis of Necroptosis-Related Genes in COPD by Bioinformatics and Experimental Verification.

Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex progressive inflammatory disease. Necroptosis is a newly identified type of programmed cell death. However, the role of necroptosis in COPD is unclear. This study aimed to identify necroptosis-related genes in COPD and explore the roles of necroptosis and immune infiltration through bioinformatics. The analysis identified 49 differentially expressed necroptosis-related genes that were primarily engaged in inflammatory immune response pathways. The infiltration of CD8+ T cells and M2 macrophages in COPD lung tissue was relatively reduced, whereas that of M0 macrophages was increased. We identified 10 necroptosis-related hub genes significantly associated with infiltrated immune cells. Furthermore, 7 hub genes, CASP8, IL1B, RIPK1, MLKL, XIAP, TNFRSF1A, and CFLAR, were validated using an external dataset and experimental mice. CFLAR was considered to have the best COPD-diagnosing capability. TF and miRNA interactions with common hub genes were identified. Several related potentially therapeutic molecules for COPD were also identified. The present findings suggest that necroptosis occurs in COPD pathogenesis and is correlated with immune cell infiltration, which indicates that necroptosis may participate in the development of COPD by interacting with the immune response.

Relationship Between ACSL4-Mediated Ferroptosis and Chronic Obstructive Pulmonary Disease.

Purpose: Although cigarette smoke exposure is the major risk factor for chronic obstructive pulmonary disease (COPD), the mechanism is not completely understood. The aim of the present study was to investigate whether ACSL4-mediated ferroptosis in lung epithelial cells plays a part in the COPD development process and its association. Patients and Methods: In this study, animal and cell models of COPD were modelled using cigarette smoke extracts (CSEs), and cell viability, lipid ROS, iron ion deposition, and ferroptosis-related markers were measured in lung tissue and lung epithelial cells following CSE exposure. Morphological changes in mitochondria were observed in lung tissue and epithelial cells of the lung by transmission electron microscope. The expression levels of ACSL4 mRNA and protein in lung tissue and epithelial cells were measured by real-time PCR and Western blotting. In addition, animal-interfering lentivirus and cell-interfering RNA against ACSL4 were constructed in this study, ferroptosis in lung tissue and lung epithelial cells after ACSL4 interference was detected, and ACSL4 mRNA and protein expression levels were detected. Results: CSE induced ferroptosis in lung tissues and lung epithelial cells, and the expression levels of ACSL4 were elevated in CSE-treated lung tissues and lung epithelial cells. After ACSL4 interference, the expression of ACSL4 decreased, mitochondrial morphology was restored, and ferroptosis in lung tissues and lung epithelial cells was alleviated. Both respiratory frequency and enhanced pause of COPD mice models decreased after ACSL4 interference. Conclusion: ACSL4-mediated ferroptosis in lung epithelial cells is associated with COPD and positively correlated with ferroptosis in epithelial cells.

Construction nanoenzymes with elaborately regulated multi-enzymatic activities for photothermal-enhanced catalytic therapy of tumor.

In order to solve the limitation of tumor microenvironment on the anticancer effect of nanozymes, a multifunctional nanoenzyme Co/La-PB@MOF-199/GOx was designed in this work. By doping Co2+ and La3+ in different proportions, Co/La-PB with the optimal photothermal-enhanced catalytic performance was screened, which can catalyze H2O2 to generate more hydroxyl radicals (•OH) and oxygen, showing peroxidase (POD)-like and catalase(CAT)-like property. Through MOF-199 coating and loading glucose oxidase (GOx), a multifunctional nanoenzyme Co/La-PB@MOF-199/GOx was achieved. Due to the pH response of MOF-199, GOx can be accurately released into tumors to catalyze the reaction of glucose and oxygen to produce H2O2. In this process, the oxygen consumption can be compensated by the CAT-like property to realize continuous consumption of glucose and self-supply of H2O2 to continuously produce •OH. In the presence of high oxidation state metal ions (Co3+ and Fe3+), GSH consumption is accelerated to avoid weakening of •OH, showing the glutathione oxidase (GPx-like) activity. Besides, magnetic resonance imaging (MRI) experiments showed the potential application in imaging guided therapy. In vivo anti-tumor experiments showed a satisfactory anti-cancer effect through multi-enzymatic activities.

Synthesis of bimetal MOFs for rapid removal of doxorubicin in water by advanced oxidation method.

Doxorubicin (DOX) has been an emerging environmental pollutant due to its significant genotoxicity to mankind. Advanced oxidation processes are a potential strategy to remove DOX in water solution. To develop a highly efficient catalytic agent to remove DOX, bimetal MOFs were synthesized, with Cu2+ and Co2+ as the central ions and adenine as the organic ligand. This study investigated the degradation of DOX by Co/Cu-MOFs combined with peroxymonosulfate (PMS). It was found that the degradation of DOX by Co/Cu-MOFs can reach 80% in only 10 seconds. This can be explained by the charge transfer from Co(iii) to Co(ii) being accelerated by Cu2+, resulting in the rapid generation of free radicals, which was proved by the EIS Nyquist diagram. Co/Cu-MOFs can be reused by simply washing with water without inactivation. Therefore, Co/Cu-MOFs can be used as an efficient catalytic agent to degrade DOX in environmental water.

Achieving a "all in one" Fe/Tm-MOFs with controllable photothermal and catalytic performance for imaging-guided multi-modal synergetic therapy.

Targeting excess H2O2 in the tumor microenvironment, nanotheranostic agents for catalytic therapy are designed based on Fenton reaction, catalyzing H2O2 into oxygen and hydroxyl radical (OH). But the catalytic efficiency in tumor microenvironment is not satisfactory. In order to solve the problem, a series of bimetallic-dual ligands metal-organic frameworks Fe/Tm-MOFs were designed, that Fe3+ and Tm3+ as metalions, 2-methylimidazole and trimesic acid as ligands. Due to the doped Tm3+ in Fe/Tm-MOFs and the conjugated structures formed by two ligands, the rate of electron transfer was improved, thus promoting the generation of OH at some extent. In addition, the photothermal effect of Fe/Tm-MOFs further promotes the generation of OH, which was evidenced by the 3,3',5,5'-tetramethylbenzidine(TMB). Combining the drug loading and release capabilities of Fe/Tm-MOFs, synergetic therapy of photothermal/chemo-/catalytic therapy can be achieved. In vitro results reveal that DOX release behaviors are both pH- and thermal-responsive. In vivo anti-cancer results show that the tumors of mice almost disappeared within 10 days, which were injected with Fe/Tm-MOFs/DOX and irradiated with 808 nm for 10 min. Thus, an excellent therapeutic performance has been achieved. Besides, Fe/Tm-MOFs can serve as a multimodality bioimaging contrast agent, covering fluorescence imaging, photothermal imaging and magnetic resonance imaging. Thus, an all-in-one nanotheranostic agent is constructed, improving the catalytic efficiency and providing a novel method to design an efficient nanotheranostic agent.

Characterization of precipitation from citrus vinegar during ageing: chemical constituents, formation mechanism and anti-proliferative effect.

Precipitation formation commonly occurs in the ageing step of fermented citrus vinegar. Hitherto, the chemical characteristics and biological properties of precipitates remain unveiled. This study focused on investigating the chemical profile, formation mechanism and biological repurposing of precipitates. Nine principal components, two flavonoid glycosides and their aglycones along with five polymethoxyflavones (PMFs), were identified from a methanol extract of precipitates. Using hydrolysis models, we demonstrated that insoluble aglycones were generated through the breakage of glycosidic bonds in flavonoid glycosides under acidic condition. Moreover, soluble bound-PMFs were destroyed by yeast-acid hybrid catalysis to release insoluble free-PMFs to form precipitates. A methanol extract of precipitates exhibited a potent anti-proliferative effect on MCF-7 cells (IC50 = 0.032 µg µL-1) via inhibiting tubulin polymerization. This study will be helpful for the food industry to aid optimizing citrus vinegar brewing and for reutilizing precipitates for functional foods and health products. Furthermore, it also provides a green strategy of PMFs enrichment from citrus using an enzyme-acid hybrid system.

Effectiveness of Telemonitoring for Reducing Exacerbation Occurrence in COPD Patients With Past Exacerbation History: A Systematic Review and Meta-Analysis.

Background: Although an increasing number of studies have reported that telemonitoring (TM) in patients with chronic obstructive pulmonary disease (COPD) can be useful and efficacious for hospitalizations and quality of life, its actual utility in detecting and managing acute exacerbation of COPD (AECOPD) is less established. This meta-analysis aimed to identify the best available evidence on the effectiveness of TM targeting the early and optimized management of AECOPD in patients with a history of past AECOPD compared with a control group without TM intervention. Methods: We systematically searched PubMed, Embase, and the Cochrane Library for randomized controlled trials published from 1990 to May 2020. Primary endpoints included emergency room visits and exacerbation-related readmissions. P-values, risk ratios, odds ratios, and mean differences with 95% confidence intervals were calculated. Results: Of 505 identified citations, 17 original articles with both TM intervention and a control group were selected for the final analysis (N = 3,001 participants). TM was found to reduce emergency room visits [mean difference (MD) -0.70, 95% confidence interval (CI) -1.36 to -0.03], exacerbation-related readmissions (risk ratio 0.74, 95% CI 0.60-0.92), exacerbation-related hospital days (MD -0.60, 95% CI -1.06 to -0.13), mortality (odds ratio 0.71, 95% CI 0.54-0.93), and the St. George's Respiratory Questionnaire (SGRQ) score (MD -3.72, 95% CI -7.18 to -0.26) but did not make a difference with respect to all-cause readmissions, the rate of exacerbation-related readmissions, all-cause hospital days, time to first hospital readmission, anxiety and depression, and exercise capacity. Furthermore, the subgroup analysis by observation period showed that longer TM (≥12 months) was more effective in reducing readmissions. Conclusions: TM can reduce emergency room visits and exacerbation-related readmissions, as well as acute exacerbation (AE)-related hospital days, mortality, and the SGRQ score. The implementation of TM intervention is thus a potential protective therapeutic strategy that could facilitate the long-term management of AECOPD. Systematic Review Registration: This systematic review and meta-analysis is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement and was registered at International Prospective Register of Systematic Reviews (number: CRD42020181459).

Degradation of organic dyes by peroxymonosulfate activated with water-stable iron-based metal organic frameworks.

In this study, MIL-101(Fe) is prepared via a facile solvent-thermal method, and then applied as catalyst for activating PMS, thus generating reactive radicals for organic dyes removal in aqueous solution. Rhodamine B (RhB), Malachite Green (MG) and Methylene Blue (MB) were selected as model pollutants. The experiments showed that MIL-101(Fe)/PMS had higher removal efficiency for dyes than MIL-101(Fe), indicating that MIL-101(Fe) can be simultaneously used as adsorbent and PMS-activating catalyst for dyes removal. The effects of initial pH and the coexisted negative ions on MB degradation were further discussed, showing that MIL-101(Fe) can degrade MB with excellent stability. Furthermore, the reactive species in MIL-101(Fe)/PMS system were deduced as sulfate radicals and hydroxyl radicals. Finally, the degradation intermediates and possible degradation pathway were investigated by LC-MS.

Facile Strategy to Generate Charged Droplets with Desired Polarities.

Water droplets are usually charged positively via either electrospray or contact electrification at the solid/liquid interface. Herein, we describe a facile two-step strategy to generate charged droplets with desired polarities. In particular, negatively charged droplets can be generated via electrostatic induction using a precharged superamphiphobic substrate as an electret. The interplay of repulsive and attractive interactions between like- and unlike-charged droplets or electret leads to rapid droplet transport and self-assembly of specific highly ordered arrays.

Synthesis of 'dual-key-and-lock' drug carriers for imaging and improved drug release.

In this work, a 'dual-key-and-lock' drug carrier was designed to respond to the tumor microenvironment (TME). A core-shell Fe-MOF@ZIF-8 was synthesized, with ZIF-8 as the shell (the first lock) to encapsulate catalase (CAT), and the Fe metal-organic framework (MOF) as the core (the second lock) to encapsulate the anticancer drug doxorubicin (DOX). Fe-MOF@ZIF-8 takes advantage of the TME-which includes a high concentration of H2O2, a weakly acidic environment and hypoxia-to achieve efficient cancer therapy. With the pH response, ZIF-8 and Fe-MOF are degraded in turn to release CAT and DOX, just like 'pH stimulation', as a key to open the two locks in turn. The released CAT reacts with the rich H2O2 in the tumor to produce O2 to regulate hypoxia, thereby improving the anticancer efficiency of the released DOX. The different cytotoxicity to L-02 cells and HeLa cells of Fe-MOF@ZIF-8 shows Fe-MOF@ZIF-8 is only harmful to cancer cells and is not harmful to normal cells. The reason is that the Fe2+/Fe3+ in Fe-MOF interact with the rich H2O2 in cancer cells to generate hydroxyl radicals (cOH), which is proved by the color of the solution of 3,3',5,5'-tetramethylbenzidine turning blue. After loading of the drug and CAT, Fe-MOF@ZIF-8 can release CAT, DOX and cOH in response to the TME, thus killing more HeLa cells. Therefore, synthesis of 'dual-key-and-lock' drug carriers responsive to the TME is a promising strategy for cancer treatment.

Acetaldehyde-modified-cystine functionalized Zr-MOFs for pH/GSH dual-responsive drug delivery and selective visualization of GSH in living cells.

In recent years, the construction of drug carriers that integrate diagnosis and treatment has become a new trend. In this article, a metal-organic framework (Zr-MOF) was synthesized and functionalized using acetaldehyde-modified-cystine (AMC) to form the functional drug carrier Zr-MOF/AMC which could be used to determine the concentration of glutathione (GSH) for cancer diagnosis, and to achieve pH/GSH dual-responsive release of methotrexate (MTX) for cancer therapy. The cleavage of the AMC disulfide bond by GSH generates two fluorescent molecules that produce strongly enhanced fluorescence, and the intensity is proportional to the GSH concentration. The green fluorescence of Zr-MOF/AMC in cancer cells proves that it can be applied in cell imaging to detect abnormal GSH concentrations for early diagnosis. In addition, MTX loaded on the Zr-MOF/AMC is released by the cleavage of the -S-S- and -C[double bond, length as m-dash]N- bonds at the high GSH concentration and low pH in cancer cells. This dual-responsive drug release helps to deliver drugs to cancer cells more precisely. All the experiments suggest that this novel type of pH/GSH dual-responsive Zr-MOF/AMC nanoparticle may serve as a new drug delivery system for cancer diagnosis and treatment.

DOX sensitized upconversion metal-organic frameworks for the pH responsive release and real-time detection of doxorubicin hydrochloride.

Drug resistance is a major obstacle in cancer treatment, and designing a material that monitors real-time drug release remains a top priority. In this study, metal-organic frameworks doped with lanthanum and thulium were synthesized and then coated with aminated silica to form La/Tm-MOF@d-SiO2 as a drug carrier. Doxorubicin hydrochloride (DOX) was selected as a drug model, and the drug loading and release were investigated. It was found that the release of DOX under acidic conditions reached an optimal level, indicating the pH-responsiveness of La/Tm-MOF@d-SiO2. Under acidic conditions (pH = 5.8), upconversion fluorescence was generated after loading DOX on La/Tm-MOF@d-SiO2. At pH = 5.8, the longer the drug released, the stronger the upconversion fluorescence. It was found that the upconversion fluorescence intensity is directly proportional to the amount of drug released; thus, the real-time monitoring of DOX release in tumor cells can be performed based on the upconversion fluorescence.

A multifunctional composite Fe3O4/MOF/l-cysteine for removal, magnetic solid phase extraction and fluorescence sensing of Cd(ii).

Fe3O4/MOF (metal organic framework)/l-cysteine was synthesized and applied for the removal of Cd(ii) from wastewater. The adsorption kinetics and isotherms were investigated, and the results indicated that the adsorption obeyed the pseudo-second-order kinetic model and Langmuir isotherm. The maximum adsorption capacity was calculated to be 248.24 mg g-1. Fe3O4/MOF/l-cysteine was further applied to determine trace amounts of Cd(ii) in real water samples using ICP-AES (inductively coupled plasma-atomic emission spectroscopy) based on magnetic solid-phase extraction (MSPE). The determination limit was 10.6 ng mL-1. Additionally, Fe3O4/MOF/l-cysteine can also be used as a fluorescent sensor for "turn-off" detection of Cd(ii), and the detection limit was 0.94 ng mL-1.

Controllable synthesis of a novel magnetic core-shell nanoparticle for dual-modal imaging and pH-responsive drug delivery.

In this study, novel magnetic core-shell nanoparticles Fe3O4@La-BTC/GO have been synthesized by the layer-by-layer self-assembly (LBL) method and further modified by attachment of amino-modified PEG chains. The nanoparticles were thoroughly characterized by x-ray diffraction, FTIR, scanning electron microscopy and transmission electron microscopy. The core-shell structure was shown to be controlled by the LBL method. The drug loading of doxorubicin (DOX) within the Fe3O4@La-BTC/GO-PEG nanoparticles with different numbers of deposited layers was investigated. It was found that DOX loading increased with increasing number of metal organic framework coating layers, indicating that the drug loading can be controlled through the controllable LBL method. Cytotoxicity assays indicated that the Fe3O4@La-BTC/GO-PEG nanoparticles were biocompatible. The DOX was released rapidly at pH 3.8 and pH 5.8, but at pH 7.4 the rate and extent of release was greatly attenuated. The nanoparticles therefore demonstrate an excellent pH-triggered drug release. In addition, the particles could be tracked by magnetic resonance imaging (MRI) and fluorescence optical imaging (FOI). A clear dose-dependent contrast enhancement in T 2-weighted MR images and fluorescence images indicate the potential of these nanoparticles as dual-mode MRI/FOI contrast agents.

Purple foliage coloration in tea (Camellia sinensis L.) arises from activation of the R2R3-MYB transcription factor CsAN1.

Purple foliage always appears in Camellia sinensis families; however, the transcriptional regulation of anthocyanin biosynthesis is unknown. The tea bud sport cultivar 'Zijuan' confers an abnormal pattern of anthocyanin accumulation, resulting in a mutant phenotype that has a striking purple color in young foliage and in the stem. In this study, we aimed to unravel the underlying molecular mechanism of anthocyanin biosynthetic regulation in C. sinensis. Our results revealed that activation of the R2R3-MYB transcription factor (TF) anthocyanin1 (CsAN1) specifically upregulated the bHLH TF CsGL3 and anthocyanin late biosynthetic genes (LBGs) to confer ectopic accumulation of pigment in purple tea. We found CsAN1 interacts with bHLH TFs (CsGL3 and CsEGL3) and recruits a WD-repeat protein CsTTG1 to form the MYB-bHLH-WDR (MBW) complex that regulates anthocyanin accumulation. We determined that the hypomethylation of a CpG island in the CsAN1 promoter is associated with the purple phenotype. Furthermore, we demonstrated that low temperature and long illumination induced CsAN1 promoter demethylation, resulting in upregulated expression to promote anthocyanin accumulation in the foliage. The successful isolation of CsAN1 provides important information on the regulatory control of anthocyanin biosynthesis in C. sinensis and offers a genetic resource for the development of new varieties with enhanced anthocyanin content.