Covalent organic frameworks-derived carbon nanospheres based nanoplatform for tumor specific synergistic therapy via oxidative stress amplification and calcium overload.

Combinational therapy in cancer treatment that integrates the merits of different therapies is an effective approach to improve therapeutic outcomes. Herein, a simple nanoplatform (N-CNS-CaO2-HA/Ce6 NCs) that synergized chemodynamic therapy (CDT), photodynamic therapy (PDT), photothermal therapy (PTT), and Ca2+ interference therapy (CIT) has been developed to combat hypoxic tumors. With high photothermal effect, excellent peroxidase-like activity, and inherent mesoporous structure, N-doped carbon nanospheres (N-CNSs) were prepared via in situ pyrolysis of an established nanoscale covalent organic frameworks (COFs) precursor. These N-CNSs acted as PTT/CDT agents and carriers for the photosensitizer chlorin e6 (Ce6), thereby yielding a minimally invasive PDT/PTT/CDT synergistic therapy. Hyaluronic acid (HA)-modified CaO2 nanoparticles (CaO2-HA NPs) coated on the surface of the nanoplatform endowed the nanoplatform with O2/H2O2 self-supply capability to respond to and modulate the tumor microenvironment (TME), which greatly facilitated the tumor-specific performance of CDT and PDT. Moreover, the reactive oxygen species (ROS) produced during PDT and CDT enhanced the Ca2+ overloading due to CaO2 decomposition, amplifying the intracellular oxidative stress and leading to mitochondrial dysfunction. Notably, the HA molecules not only increased the cancer-targeting efficiency but also prevented CaO2 degradation during blood circulation, providing double insurance of tumor-selective CIT. Such a nanotherapeutic system possessed boosted antitumor efficacy with minimized systemic toxicity and showed great potential for treating hypoxic tumors.

Ion channel-targeting near-infrared photothermal switch with synergistic effect for specific cancer therapy.

Despite significant achievement in chemotherapy, the off-target actions and low pharmaceutical selectivity of the therapeutic agents still limit their clinical efficacy. Herein, a multifunctional nanoplatform which integrates chemotherapy, chemodynamic therapy (CDT) and photoactivation of TRPV1 channels has been successfully established for specific cancer therapy. Polydopamine (PDA) coated hollow prussian blue nanocages (hPBNCs) are used as the photothermal switches and drug carriers for loading chemotherapeutic drug, doxorubicin (Dox). Conjugating with the TRPV1 antibodies enables the nanoplatform to bind specifically to TRPV1 channels on the plasma membrane of the TRPV1-positive cancer cells and then activate them by local heating upon NIR irradiation, leading to the over-influx of Ca2+. Critically, the laser irradiation can be carefully controlled to not only open the TRPV1 channels but also avoid burning of tumors by hyperthermia. Moreover, the exposed hPBNCs in the acidic tumor cells can decompose endogenous H2O2 into ˙OH by Fenton reaction to realize CDT, which further aggravates cancer cell apoptosis. Together with the chemotherapy caused by Dox, our nanoplatform displays an enhanced anticancer effect both in vitro and in vivo. Our work provides a powerful means for site-specific cancer synergetic therapy with high spatial and temporal resolution.

Mitochondria-targeting multifunctional nanoplatform for cascade phototherapy and hypoxia-activated chemotherapy.

Despite considerable progress has been achieved in hypoxia-associated anti-tumor therapy, the efficacy of utilizing hypoxia-activated prodrugs alone is not satisfied owing to the inadequate hypoxia within the tumor regions. In this work, a mitochondrial targeted nanoplatform integrating photodynamic therapy, photothermal therapy and hypoxia-activated chemotherapy has been developed to synergistically treat cancer and maximize the therapeutic window. Polydopamine coated hollow copper sulfide nanoparticles were used as the photothermal nanoagents and thermosensitive drug carriers for loading the hypoxia-activated prodrug, TH302, in our study. Chlorin e6 (Ce6) and triphenyl phosphonium (TPP) were conjugated onto the surface of the nanoplatform. Under the action of TPP, the obtained nanoplatform preferentially accumulated in mitochondria to restore the drug activity and avoid drug resistance. Using 660 nm laser to excite Ce6 can generate ROS and simultaneously exacerbate the cellular hypoxia. While under the irradiation of 808 nm laser, the nanoplatform produced local heat which can increase the release of TH302 in tumor cells, ablate cancer cells as well as intensify the tumor hypoxia levels. The aggravated tumor hypoxia then significantly boosted the anti-tumor efficiency of TH302. Both in vitro and in vivo studies demonstrated the greatly improved anti-cancer activity compared to conventional hypoxia-associated chemotherapy. This work highlights the potential of using a combination of hypoxia-activated prodrugs plus phototherapy for synergistic cancer treatment.

8-Hydroxyquinoline functionalized covalent organic framework as a pH sensitive carrier for drug delivery.

A porous 8-hydroxyquinoline functionalized organic covalent framework (named COF-HQ) was synthesized. The as-prepared COF-HQ showed stable crystal structure, suitable pore size, excellent dispersibility in physiological solution and pH sensitivity, which would be employed as a potential nanocarrier for drug transport and controlled release. The drug loading experiment with 5-Fluorouracil (5-FU) as the model molecule proved that the drug loading capacity of COF-HQ was significantly improved due to the introduction of quinoline groups. The drug release profiles of 5-FU from 5-FU loaded COF-HQ (termed 5-FU@COF-HQ) under different pH showed that its release was controlled by pH owing to the pH sensitivity of conjugated nitrogen atoms from quinoline groups and CN. The in vitro hemolysis and in vivo biocompatibility experiments further verified the good biocompatibility of COF-HQ. Importantly, 5-FU@COF-HQ-treated B16F10 cell-induced tumor models showed that 5-FU@COF-HQ displayed enhanced anti-tumor efficacy than other groups. These results suggested that the drug-loading COF-HQ delivery system showed the potential for effective cancer therapy with advantages of high drug loading, good biocompatibility and the pH-sensitive release of the tumor microenvironment. Overall, our research provided a new functionalized COF-HQ drug delivery system, which further expanded the application of COFs as carriers in the field of cancer treatment.

ATP induced alteration in the peroxidase-like properties of hollow Prussian blue nanocubes: a platform for alkaline phosphatase detection.

Breaking the pH limitation of the enzyme-like activity of nanomaterials is of great importance for extending their applications in environmental and biomedical fields. Herein, to mimic the role of histidine residues in horseradish peroxidase (HRP), adenosine 5'-triphosphate (ATP) is reported to improve the peroxidase-like activity of hollow Prussian blue nanocubes (hPBNCs). Due to the inherited porous structures, hPBNCs can expose all the binding sites as far as possible to ATP to significantly amplify their catalytic activity and broaden their applicable pH range up to pH 12. Introduction of ATP provides the possibility of realizing efficient catalytic reactions under alkaline conditions. Upon binding with hPBNCs, ATP can enhance the stability of hPBNCs, increase the affinities of the catalysts towards substrates and improve the conductivity of hPBNCs as well as change the decomposed product from H2O2. Moreover, on the basis of the different catalytic activities of hPBNCs towards ATP, adenosine 5'-diphosphate and adenosine 5'-monophosphate, hPBNCs-ATP is utilized to construct a novel colorimetric sensor for the detection of alkaline phosphatase (ALP) activity in biological fluids, which is significantly important for the clinical diagnosis of ALP-related diseases.

Expanded mesoporous silica-encapsulated ultrasmall Pt nanoclusters as artificial enzymes for tracking hydrogen peroxide secretion from live cells.

Design of synthetic structures that possess the similar functions to natural enzymes held great promise in environmental detection and biomedical application. Herein, a new concept for the fabrication of solid-supported catalysts as peroxidase mimic have been proposed to realize high-catalytic activity and stability by utilizing expanded mesoporous silica (EMSN)-encapsulated Pt nanoclusters. Compared with PtNCs, the introduction of amino group modified EMSN would enrich H2O2 on the surface of PtNCs and increase the catalytic sites for H2O2 decomposition, which gave rise to the higher catalytic activity of EMSN-PtNCs over a broad pH range, especially in weakly acidic and neural solutions. This would facilitate their applications for real-time monitoring the secretion of H2O2 from living cancer cells stimulated by various anticancer drugs. Our findings not only pave the way to use porous matrix as the structural component for the design of the biomimetic catalysts, but also provide a simple and reliable platform to monitor H2O2 released from living cells in real time, which holds great potential for elucidating the biological roles of H2O2 and underlying molecular mechanisms of drug cytotoxicity as well as drug therapeutic effects.

A nickel-cobalt bimetallic phosphide nanocage as an efficient electrocatalyst for nonenzymatic sensing of glucose.

The authors describe Ni-Co bimetal phosphide (NiCoP) nanocages that exhibit enhanced electrocatalytic performance toward glucose oxidation. The nanocages offer an appealing architecture, large specific area, and good accessibility for the analyte glucose. When placed on a glassy carbon electrode, the sensor exhibits attractive figures of merit for sensing glucose in 0.1 M NaOH solution including (a) a wide linear range (0.005-7 mM), (b) a low determination limit (0.36 µM), (c) high sensitivity (6115 µA•µM-1•cm-2), (d) a relatively low working potential (0.50 V vs. Ag/AgCl), and (e) good selectivity, reproducibility, and stability. The sensor is successfully applied to the determination of glucose in human serum samples. Graphical abstractSchematic representation of a glassy carbon electrode modified with Ni-Co bimetal phosphide (NiCoP) nanocage. NiCoP nanocage exhibits excellent electrocatalytic activity toward glucose oxidation. NiCoP nanocage is applied in a sensitive non-enzymatic glucose sensor.

[Neurotrophins up-express in peripheral blood of allergic rhinitis patients and related to Th2 hypothesis].

OBJECTIVE: To detect the expression of NGF, BDNF, NT-3 mRNA in the peripheral blood of patients with allergic rhinitis (AR). And to analyze the correlation between NGF, BDNF, NT-3 mRNA expression and the epidsode of rhinitis through Th-2 Hypothesis. METHOD: This study was a group controlled trial. The expression of NGF, BDNF and NT-3 mRNA were tested by real-time quantitative RT-PCR and the concentrations of IL-4, IL-6, IL-10 and INF-alpha were tested by ELISA. RESULT: The expression of NGF, BDNF and NT-3 mRNA in AR patients were 2.44, 4.46 and 1.78 times the amount of those in the healthy adults, respectively. The increased expression of NT-3 correlated positively with the scores of visual analog scale of AR. The concentrations of IL-4, IL-6 and IL-10, which were 2198 +/- 472 pg/mL, 9407 +/- 703 pg/mL and 3917 +/- 323 pg/mL respectively, were higher than those in the healthy adults. The concentration of INF-alpha was 2198 +/- 472 pg/mL and less than the healthy adults. The increased expressions of NGF, NT-3 were positively related to the increase of IL-4, IL-6 and IL-10. CONCLUSION: The expressions of NGF, BDNF and NT-3 mRNA in AR patients are higher than those in the healthy adults. NGF, BDNF and NT-3 may contribute to the pathogenesis of AR. Moreover, NGF and NT-3 may induce the episode of rhinitis through Th-2 Hypothesis.

[Increase expression of neurotrophins mRNA in peripheral blood of patients with allergic rhinitis].

OBJECTIVE: To assess the expression of NGF, BDNF, NT-3 mRNA in the peripheral blood of patients with allergic rhinitis (AR). Meanwhile, to analysis whether the expression of NGF, BDNF, NT-3 mRNA correlate with the severity of rhinitis. METHOD: This study is a group controlled trial, which takes the healthy adults as control group. The total RNA have been extracted from the peripheral blood of AR patients. The expression of NGF, BDNF and NT-3 mRNA have been tested by real-time quantitative RT-PCR. RESULT: Comparing with the healthy adults, the expression of NGF, BDNF and NT-3 mRNA as 2(-deltadeltaCt) are 2.436 8, 4.4588 and 1.781 8 respectively. The increasing expression of NT-3 correlated positively with the scores of visual analog scale. CONCLUSION: The expression of NGF, BDNF and NT-3 mRNA are as high as 2.4368, 4.4588 and 1.7818 times to healthy adults. We propose NGF, BDNF and NT-3 may contribute to the pathogenesis of AR. NT-3 could reflect the severity of rhinitis as a molecular biological index.

Cross-reactivity of anti-EV71 IgM and neutralizing antibody in series sera of patients infected with Enterovirus 71 and Coxsackievirus A 16.

OBJECTIVES: To evaluate the cross-reactivity of anti-EV71 IgM and neutralizing antibody in series sera of patients infected with EV71 and CA16. METHODS: Real-time RT-PCR, virus isolation, ELISA and neutralization test were used to detect enteroviruses from clinical specimens and series sera of 79 HFMD patients. RESULTS: 27 EV71, 37 CA16, and 11 other enterovirus-infected patients were identified by RT-PCR. Among EV71 infected patients, anti-EV71 IgM positive ratios were 87.5% during 1-3 days after onset and 100% over 4 days after onset. In CA16 infected patients, the positive ratios were 7.4%, 26.4%, and 62.5% during 1-3 days, 4-6 days, and over 6 days after onset, respectively. Meanwhile, the results of neutralization test showed 18.9% of CA16 infected patients and 11.1% of EV71 infected patients present high cross-neutralization antibody against each other. CONCLUSIONS: Cross-reactivity of anti-EV71 IgM in patients infected with EV71 and CA16 becomes stronger with the progress of disease. Moreover, high cross-neutralization antibody existing in part of patients suggests that the immune reactivity to EV71 infection can be recalled by CA16, and the immune reactivity to CA16 infection can be recalled by EV71. Therefore, identifying enteroviruses by neutralization test may not be an ideal selection.

[Construction and biological activity assessment of core mutants of hepatitis B virus adr subtype].

OBJECTIVE: To construct the core mutant (L97 and V60) plasmids of hepatitis B virus (HBV) and assess their biological activity. METHODS: Site-directed mutagenesis was performed to induce specific core point mutations in HBV adr suhtype 1.2 copy genome plasmid p3.8 II. The plasmids were transfected into HepG2 cells via liposome, and intracellular HBV DNA was analyzed by Southern hybridization, while extracellular HBV antigens (HBsAg and HBeAg) in the culture supernatant were assayed by enzyme-linked immunosorbent assay. RESULTS: Sequence analysis of the constructed mutant plasmids p3.8 L97 and p3.8 V60 demonstrated mutations at 2 189 A C and 2 086 C HBV adr subtype genome core mutant (L97 and V60) plasmids we have constructed possess biological activity.G respectively. These mutant plasmids exhibited HBV DNA replication activity and gene expression in host cells. CONCLUSION: HBV adr subtype genome core mutant (L97 and V60) plasmids we have constructed possess biological activity.

[Influence of mutation in HBV precore region on the expression of HLA-I in HepG2 cells].

OBJECTIVE: To study the influence of host cellular HLA-I molecules expression by HBV precore region mutants. METHODS: The plasmids of the wild type of HBV precore region and the mutants of A83 and A83/A86 were constructed, and then transected into HepG2 cells. The biological activity of HBV precore gene in the host cells was identified. The expression of HLA-I molecules was detected by flow cytometric analysis. RESULTS: DNA segments similar with HBV precore gene size and HBeAg were detected by PCR and ELISA, respectively. The fluorescence intensity of HLA-I on host cells was different: wild type being 1.3; A83, 17.6; and A83/A86, 7.3. CONCLUSIONS: HBV precore gene hot-spot mutants in vitro can increase the expression of HLA-I molecules on host cells.

Detection and significance of a G1862T variant of hepatitis B virus in Chinese patients with fulminant hepatitis.

The prevalence of a G1862T variant of hepatitis B virus (HBV) has been investigated in patients with fulminant hepatitis and chronic liver disease, using primer mismatch amplification, followed by restriction fragment length polymorphism analysis. This variant was five times more common in patients with fulminant hepatitis (13.7%, 7 of 52) than in chronic carriers (2.5%, 2 of 81). The G-->T substitution at position 1862 leads to an amino acid change in codon 17 of the precore protein of the virus, which is part of a signal peptidase recognition motif. Variants with this mutation were only seen in patients infected with genotype B. In vitro translation experiments showed that this variant has greatly reduced capacity to produce hepatitis B e antigen (HBeAg) from its precore protein precursor. Furthermore, 88.5% of patients with fulminant hepatitis had mutations that are known to be associated with abrogated or reduced production of HBeAg. This suggests that, following HBV infection, the absence or reduced amounts of HBeAg may be a contributing factor in fulminant disease.