Multiconfigurable logic gates based on fluorescence switching in adaptive coordination polymer nanoparticles

Fluorescence switching of guest molecules confined in coordination polymer nanoparticles (CPNs) generated from nucleotides and lanthanide ions are used to construct multiconfigurable logic gates. Moreover, the potential of the material as fluorescent probe with large Stokes shift is demonstrated for cellular imaging. In this work the logic gate is integrated into the therapeutic agent and this will be highly beneficial in future molecular computing.

Reduced graphene oxide upconversion nanoparticle hybrid for electrochemiluminescent sensing of a prognostic indicator in early-stage cancer

Upconversion nanoparticles (UCNPs) have been proposed as a promising new class of biological luminescent labels because of their weak auto-fluorescence background, strong penetration ability under near-infrared (NIR) radiation, resistance to photobleaching, and low toxicity. Although UCNPs hold great promise in nanotechnology and nanomedicine, their applications in ECL fields still remain unexplored. Herein, a label-free, ultra-sensitive and selective electrochemiluminescence (ECL) assay is developed for detection of cyclin A2 by using highly efficient ECL graphene-upconversion hybrid. Being an important member of the cyclin family, cyclin A2 is involved in the initiation of DNA replication, transcription and cell cycle reg-ulation through the association of cyclin-dependent kinases (CDK). Cyclin A2 is a prognostic indicator in early-stage cancers and a target for treatment of different types of cancers. However, the expression level of cyclin A2 is quite low, direct detection of cyclin A2 in crude cancer cell extracts is challenging and important for both clinical diagnosis of cancer in the early stage and the treatment. By chemically grafting cyclin A2 detection specific probe, a PEGlyted hexapeptide, to graphene-upconversion hybrid, the constructed ECL biosensor displays a superior performance for cyclin A2 , which can not only detect cyclin A2 directly in cancer cell extracts, but also discriminate between normal cells and cancer cells. More importantly, the ECL biosensor has different responses between clinical used anticancer drug-treated and non-treated cancer cells, which demonstrates that the sensor can be potentially used for drug screening, and for evaluation of therapeutic treatments in early-stage cancers.

One-step DNA-programmed growth of CpG conjugated silver nanoclusters: a potential platform for simultaneous enhanced immune response and cell imaging

We designed a one-pot synthesis that allows CpG-functionalized AgNCs to be prepared, combining attractive features of enhanced immune response and intracellular imaging.

G-Quadruplex binding enantiomers show chiral selective interactions with human telomere

Chiral recognition of DNA molecules is important because DNA chiral transition and its different conformations are involved in a series of important life events. Among them, polymorphic human telomere DNA has attracted great interests in recent years because of its important roles in chromosome structural integrity. In this report, we examine the short-term effect of chiral metallo-supramolecular complex enantiomers treatment on tumor cells, and find that a zinc-finger-like alpha helical chiral metallo-supramolecular complex, [Ni₂L₃]⁴⁺-P enantiomer (NiP), can selectively provoke the rapid telomere uncapping, trigger DNA damage responses at telomere and degradation of G-overhang and the delocalization of telomeric protein from telomeres. Further studies indicate that NiP can induce an acute cellular apoptosis and senescence in cancer cells rather than normal cells. These results are further evidenced by the upregulation of p21 and p16 proteins. Moreover, NiP can cause translocation of hTERT from nuclear to cytoplasm through Tyr 707 phosphorylation. While its enantiomer, [Ni₂L₃]⁴⁺-M (NiM), has no such mentioned effects, these results clearly demonstrate the compound’s chiral selectivity in cancer cells. Our work will shed light on design of chiral anticancer drugs targeting G-quadruplex DNA, and developing telomere and telomerase modulation agents.

One-step nucleotide-programmed growth of porous upconversion nanoparticles: application to cell labeling and drug delivery

A simple and "green" strategy has been reported for the first time to fabricate upconversion nanoparticles (UCNPs) by utilizing nucleotides as bio-templates. The influence of the functionalities present on the nucleotide on the production of nanoparticles was investigated in detail. Through the effects of nucleotides, the obtained nanoparticles possessed a porous structure. The use of the as-prepared UCNPs for cell imaging, drug delivery and versatile therapy applications were demonstrated. In view of the bright up-conversion luminescence as well as the excellent biocompatibility, and the good colloidal stability of the as-prepared UCNPs, we envision that our synthesis protocol might advance both the fields of UCNPs and biomolecule-based nanotechnology for future studies.

Polypyrrole nanoparticles as promising enzyme mimics for sensitive hydrogen peroxide detection

Polypyrrole nanoparticles possess intrinsic peroxidase-like activity, which can be employed to quantitatively monitor the H₂O₂ generated by macrophages.

Multifunctional upconverting nanoparticles for near-infrared triggered and synergistic antibacterial resistance therapy

A novel nanomaterial with CuS nanoparticles decorated onto the surface of NaYF₄:Mn/Yb/Er@photosensitizer doped SiO₂ was synthesized for synergistic multidrug-resistant bacteria therapy.

Towards intelligent bioreactor systems: triggering the release and mixing of compounds based on DNA-functionalized hybrid hydrogel

We have designed and synthesized an intelligent DNA-functionalized hydrogel bioreactor system that can be controlled by external stimuli.

Visual detection of telomerase activity with a tunable dynamic range by using a gold nanoparticle probe-based hybridization protection strategy

We developed a novel telomere complementary (TC) oligonucleotide modified AuNP probe (TC-AuNPs) for colorimetric analysis of telomerase activity. The mechanism of this method is that the telomerase reaction products (TRP), which can hybridize with the TC-AuNPs, are able to protect the AuNPs from the aggregation induced by salt. It is demonstrated that the colorimetric method enabled the analysis of the telomerase activity in 1000 HeLa cells with the naked eye, and down to 100 HeLa cells with the aid of UV-Vis spectroscopy. This strategy is not only convenient and sensitive, but also has a tunable dynamic range. The platform is also applicable for the initial screening of a telomerase inhibitor to discover new anticancer drugs.

Aptamer-directed synthesis of multifunctional lanthanide-doped porous nanoprobes for targeted imaging and drug delivery

Multifunctional lanthanide-doped porous nanoparticles are prepared via a facile one-step solvothermal route by employing aptamers as the biotemplate. The nanoparticles feature excellent aqueous dispersibility and biospecific properties and could work as effective nanoprobes for targeted imaging and drug delivery. With aptamer being in principle available for any kind of target, this synthetic strategy may open the door to a new generation of nanoprobes for bioapplications such as time-resolved biodetection, multimode bioimaging/biolabeling, and targeted cancer therapy.

3D graphene oxide-polymer hydrogel: near-infrared light-triggered active scaffold for reversible cell capture and on-demand release

An active cell scaffold based on a graphene-polymer hydrogel has been successfully fabricated. The macroporous hydrogel can efficiently capture cells not only through the bioadhesive ligand RGD but also through on-demand release of cells with an NIR light stimulus. The latter process shows better dynamic control over cells than traditional passive-hydrogel-based cell depots.

Nanoceria-triggered synergetic drug release based on CeO(2) -capped mesoporous silica host-guest interactions and switchable enzymatic activity and cellular effects of CeO(2)

Herein, a pH stimuli-responsive vehicle for intracellular drug delivery using CeO2 capped mesoporous silica nanoparticles (MSN) is reported. β-Cyclodextrin-modified CeO2 nanoparticles could cap onto ferrocene-functionalized mesoporous silica through host-guest interactions. After internalization into A549 cells by a lysosomal pathway, the ferrocenyl moieties are oxidized to ferrocenium ions by CeO2 lids, which could trigger the uncapping of the CeO2 and cause the drugs release. Because of the pH-dependent toxicity, the CeO2 here behaves as a multi-purpose entity that not only acts as a lid but also exhibits a synergistic antitumor effect on cancer cells. Meanwhile, the cell protective effect of CeO2 nanoparticles alone is demonstrated, which ensures that the dissolved CeO2 nanoparticles can be non-toxic to normal cells.

Repression of Farnesoid X receptor contributes to biliary injuries of liver grafts through disturbing cholangiocyte bile acid transport

Biliary epithelial damage is the critical point in the development of nonanastomotic strictures, a serious biliary complication after liver transplantation (LT). Current study focuses on the roles and mechanisms of unbalanced bile acid (BA) transporting of cholangiocytes in biliary epithelial damages following LT. Using rat LT models, we observed that biliary transit time (BTT) of BA was prolonged, and the degree and duration of BTT prolongation were related to the cold ischemia time of donor liver. Moreover, prolonged BTT was correlated with bile duct injury severity. The expression of Farnesoid X receptor (FXR) underwent a dramatic decrease after transplantation, and the decrease in FXR was related to cold ischemic time of donor liver. Negative correlation was observed between FXR expression and BTT. With in vitro cultured human biliary epithelial cells, it was observed that FXR expressions and DNA binding activities were repressed under hypoxic conditions. FXR repression by hypoxia mediated unparallel expressions of BA transporters and intracellular accumulation of BAs, which induced higher cell apoptosis rates and enhanced profibrotic factor expression in cholangiocytes. These findings indicated that FXR repression under ischemic/hypoxic conditions contributed to biliary epithelial damages by disturbing BA transporting of cholangiocytes after LT.

Increased expression of α5β1-integrin is a prognostic marker for patients with gastric cancer

OBJECTIVE

The study was to evaluate the association of expression level of α5β1-integrin with clinicopathologic features and prognosis in gastric cancer (GC).

METHODS

The expression of α5β1-integrin in normal gastric mucosa and GC tissue was detected with immunohistochemistry. The level of α5 and β1 mRNA in GC tissues and non-neoplastic tissues was evaluated in 48 paired cases by quantitative real-time polymerase chain reaction (qRT-PCR). Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance.

RESULTS

The α5β1-integrin expression was detected in 68.3 % (127/186) GC samples, and there was a significant difference on their positive expression rate between GC tissue and normal gastric mucosa (P < 0.001). The positive expression rate of α5β1-integrin in patients with poor histologic differentiation (P = 0.001), lymph node metastasis (P < 0.001), and recurrence (P < 0.001) group was heightened. Using Kaplan-Meier analysis, a comparison of survival curves of low versus high expresser of α5β1-integrin revealed a highly significant difference in human GC tissue (P = 0.002), which suggested that overexpression of α5β1-integrin is associated with a worse prognosis. Multivariate analyses showed that α5β1-integrin expression was independent risk factor predicting overall survival [Hazard ratio (HR) 1.594, 95 % confidence interval (CI) 1.236-2.408, P = 0.006] and disease-free survival [HR 3.952, 95 % CI 1.676-9.861, P = 0.003] in GC.

CONCLUSIONS

The α5β1-integrin promotes angiogenesis and associates with lymph node metastasis, vascular invasion and poor prognosis of GC. The current study shows that α5β1-integrin may be an independent prognostic factor for GC patients.

Self-assembled peptide-polyoxometalate hybrid nanospheres: two in one enhances targeted inhibition of amyloid β-peptide aggregation associated with Alzheimer's disease

Amyloid fibril formation is a critical step in Alzheimer's disease (AD) pathogenesis. Inhibition of Aβ aggregation has shown promising against AD and has been used in clinic trials. Here, a novel strategy is reported for the self-assembly of polyoxometalate-peptide (POM@P) hybrid particles as bifunctional Aβ inhibitors. The two-in-one bifunctional POM@P nanoparticles show an enhanced inhibition effect on amyloid aggregation in mice cerebrospinal fluid. Incorporating a clinically used Aβ fibril-staining dye, congo red (CR), into the hybrid colloidal spheres, the nanoparticles can also act as an effective fluorescent probe to monitor the inhibition process of POM@P via CR fluorescence change in real time. It is believed that such flexible organic-inorganic hybrid systems may prompt the design of new multifunctional materials for AD treatment.

Combination delivery of antigens and CpG by lanthanides-based core-shell nanoparticles for enhanced immune response and dual-mode imaging

Europium-doped GdPO4 hollow spheres/polymer core-shell nanoparticles are functionalized with ovalbumin (OVA) as a model antigen and an oligonucleotide (CpG) that stimulates the immune response. These functionalized core-shell nanoparticles are used as vaccines, where they enable efficient delivery of an antigen to target sites, tracking of the vaccines using non-invasive clinical imaging technology.

Development of exchange lists for Mediterranean and Healthy Eating diets: implementation in an intervention trial

BACKGROUND

There has been little research published on the adaptation of diabetic exchange list diet approaches for the design of intervention diets in health research despite their clinical utility. The exchange list approach can provide clear and precise guidance on multiple dietary changes simultaneously. The present study aimed to develop exchange list diets for Mediterranean and Healthy Eating, and to evaluate adherence, dietary intakes and markers of health risks with each counselling approach in 120 subjects at increased risk for developing colon cancer.

METHODS

A randomised clinical trial was implemented in the USA involving telephone counselling. The Mediterranean diet had 10 dietary goals targeting increases in mono-unsaturated fats, n-3 fats, whole grains and the amount and variety of fruits and vegetables. The Healthy Eating diet had five dietary goals that were based on the US Healthy People 2010 recommendations.

RESULTS

Dietary compliance was similar in both diet arms, with 82-88% of goals being met at 6 months, although subjects took more time to achieve the Mediterranean goals than the Healthy Eating goals. The relatively modest fruit and vegetable goals in the Healthy Eating arm were exceeded, resulting in fruit and vegetable intakes of approximately eight servings per day in each arm after 6 months. A significant (P < 0.05) weight loss and a decrease in serum C-reactive protein concentrations were observed in the overweight/obese subgroup of subjects in the Mediterranean arm in the absence of weight loss goals.

CONCLUSIONS

Counselling for the Mediterranean diet may be useful for both improving diet quality and for achieving a modest weight loss in overweight or obese individuals.

Lighting up silica nanotubes transcribed from the submicron structure of a metal-peptide hybrid

Fluorescent silica nanotubes are attracting increasing interest because of their versatile applicability in a range of diverse fields. By using sol-gel transcription of tetraethylorthosilicate (TEOS) from various soft templates, silica nanotubes can be conveniently prepared. Metal-peptide hybrids with well-defined nanostructures and outstanding functionalities are very interesting candidates to serve as templates. Herein, we demonstrate that glutathione (GSH) can act as a building block for a bioinspired structure with dimensions down to the nanoscale, based on specific interactions between metal ions and the peptide. Congo red is able to selectively stain the nanofibres obtained, and appears apple-green in colour, implying that Congo red is promising to serve as an effective and convenient probe for determining the self-assembly of GSH and copper ions. Furthermore, silica nanotubes are synthesized using the nanofibres as a template in a very simple way. The silica nanotubes can be lit up by biomolecule-templated metal nanoparticles or nanoclusters and emit bright fluorescence. This work will certainly open up new opportunities in fabricating a broad range of nanostructured materials with versatile functionalities.

Hydrophobic anticancer drug delivery by a 980 nm laser-driven photothermal vehicle for efficient synergistic therapy of cancer cells in vivo

A novel 980 nm laser-driven hydrophobic anticancer drug-delivery platform based on hollow CuS nanoparticles is constructed in this work. The excellent synergistic therapy combining drug treatment and photothermal ablation of cancer cells both in vitro and in vivo is demonstrated, which opens up new opportunities for biological and medical applications.