We describe the development of a highly stable and sensitive glucose biosensor based on the nanohybrid materials derived from gold nanoparticles (AuNPs) and multi-walled carbon nanotubes (MWCNT). The ...biosensing platform was developed by using layer-by-layer (LBL) self-assembly of the nanohybrid materials and the enzyme glucose oxidase (GOx). A high density of AuNPs and MWCNT nanocomposite materials were constructed by alternate self assembly of thiol functionalized MWCNTs and AuNPs, followed by chemisoption of GOx. The surface morphology of multilayered AuNPs/MWCNT structure was characterized by field emission-scanning electron microscope (FE-SEM), and the surface coverage of AuNPs was investigated by cyclic voltammetry (CV), showing that 5 layers of assembly achieves the maximum particle density on electrode. The immobilization of GOx was monitored by electrochemical impedance spectroscopy (EIS). CV and amperometry methods were used to study the electrochemical oxidation of glucose at physiological pH 7.4. The Au electrode modified with five layers of AuNPs/MWCNT composites and GOx exhibited an excellent electrocatalytic activity towards oxidation of glucose, which presents a wide liner range from 20
μM to 10
mM, with a sensitivity of 19.27
μA
mM
−1
cm
−2. The detection limit of present modified electrode was found to be 2.3
μM (S/N
=
3). In addition, the resulting biosensor showed a faster amperometric current response (within 3
s) and low apparent Michaelis–Menten constant
(
K
m
app
)
. Our present study shows that the high density of AuNPs decorated MWCNT is a promising nanohybrid material for the construction of enzyme based electrochemical biosensors.
A photothermal bacterium (PTB) is reported for tumor‐targeted photothermal therapy (PTT) by using facultative anaerobic bacterium Shewanella oneidensis MR‐1 (S. oneidensis MR‐1) to biomineralize ...palladium nanoparticles (Pd NPs) on its surface without affecting bacterial activity. It is found that PTB possesses superior photothermal property in near infrared (NIR) regions, as well as preferential tumor‐targeting capacity. Zeolitic imidazole frameworks‐90 (ZIF‐90) encapsulating photosensitizer methylene blue (MB) are hybridized on the surface of living PTB to further enhance PTT efficacy. MB‐encapsulated ZIF‐90 (ZIF‐90/MB) can selectively release MB at mitochondria and cause mitochondrial dysfunction by producing singlet oxygen (1O2) under light illumination. Mitochondrial dysfunction further contributes to adenosine triphosphate (ATP) synthesis inhibition and heat shock proteins (HSPs) down‐regulated expression. The PTB‐based therapeutic platform of PTB@ZIF‐90/MB demonstrated here will find great potential to overcome the challenges of tumor targeting and tumor heat tolerance in PTT.
A bacteria‐based photothermal therapeutic platform comprising PTB@ZIF‐90/MB is developed, which reveals great potential to augment photothermal therapy efficacy by tackling the challenges of tumor targeting and heat resistance.
Traditional phototherapies face the issue that the insufficient penetration of light means it is difficult to reach deep lesions, which greatly reduces the feasibility of cancer therapy. Here, an ...implantable nitric oxide (NO)‐release device is developed to achieve long‐term, long‐distance, remote‐controllable gas therapy for cancer. The device consists of a wirelessly powered light‐emitting diode (wLED) and S‐nitrosoglutathione encapsulated with poly(dimethylsiloxane) (PDMS), obtaining the NO‐release wLED (NO‐wLED). It is found that NO release from the NO‐wLED can be triggered by wireless charging and the concentration of produced NO reaches 0.43 × 10−6 m min−1, which can achieve a killing effect on cancer cells. In vivo anticancer experiments exhibit obvious inhibitory effect on the growth of orthotopic cancer when the implanted NO‐wLED is irradiated by wireless charging. In addition, recurrence of cancer can be prevented by NO produced from the NO‐wLED after surgery. By illumination in the body, this strategy overcomes the poor penetration and long‐wavelength dependence of traditional phototherapies, which also provides a promising approach for in vivo gas therapy remote‐controlled by wireless charging.
An implantable and wirelessly charged nitric oxide (NO)‐release device (NO‐wLED) capable of being remote‐controlled is constructed to overcome the issue in that it is difficult to treat deep cancer by phototherapy due to the insufficient penetration capability of light. With irradiation in the body and the good tissue penetration of NO, suppression of orthotopic and postsurgery cancers is achieved.
Yiqi Tongluo Granule (YQTL) is a kind of proprietary Chinese medicine, manufactured by China Shineway Pharmaceutical Group Ltd., under the authority of China Food and Drug Administration (CFDA) ...treating cardiovascular and cerebrovascular diseases such as ischemic stroke in China, however the underlying mechanism of YQTL on treating ischemic stroke has not been revealed. This study is aimed to evaluate the protective effect of YQTL on cerebral ischemia/reperfusion (I/R) injury and inquire into its underlying mechanisms. Cerebral I/R injury was induced by occluding the middle cerebral artery for 2 h followed by 24 h reperfusion. And regional cerebral flow was monitored by Laser Doppler flow during ischemia phase. The infarct volume was evaluated by Triphenyte-trazolium chloride staining. The protective effects of YQTL were assessed by a number of parameters, including neurological scores, regional cerebral blood flow, pathological changes of neuron in hippocampuses and hippocampus calcium level. The proteins of extracellular signal-regulated kinase (ERK), N-methyl D-aspartate receptor subtype 2B (GluN2B) and p-calcium-dependent protein kinaseII (CaMKII) response were assayed by Western blotting. I/R caused significant change in neurological deficit scores, regional cerebral flow and infarct volume. However results in YQTL groups and Nimodipine Tablets (NMDP) group were reversed. Subsequently YQTL reduced I/R-induced calcium influx. Results of hematoxylin–eosin staining manifested that YQTL significantly improved neuronal injury after I/R in rats. Meanwhile, microdialysis data demonstrated that extracellular glutamate was increased in the striatum during ischemia reperfusion, which was reduced by YQTL. YQTL and mitogen-activated protein extracellular kinase (MEK) inhibitor suppressed the I/R-mediated over-expression of GluN2B, p-ERK, ERK and p-CaMKII proteins expression. Putting these together, our results suggest that YQTL played a neuroprotective role in cerebral I/R injury, which might be exerted by inhibiting the excitotoxicity and expression of GluN2B, p-CaMKII and MEK/ERK signal pathway.
•A DNA walker-based electrochemical ratiometric platform was developed.•These dual signal ratiometric strategy overcome the changes of a variety of factors.•A detection limit of 0.31 fg/mL for ...ochratoxin A (OTA) was achieved.•The method was applied for determining OTA content in red wine samples.
Ochratoxin A (OTA) is a naturally occurring mycotoxin that poses serious threats, such as kidney damage, to human health. Therefore, we developed a DNA walker-based dual-signal electrochemical ratiometric platform for OTA detection, which could overlook the variations in environmental and instrumental factors and DNA load densities. Cobalt metal–organic frameworks (Co-MOFs) and toluidine blue were used as the electrochemical signal tag and internal reference probe, respectively. In the presence of OTA, this developed machine resulted in the DNA labelled-Co-MOFs far away from the electrode. Thus, Co-MOFs signal at −1.18 V decreased, while toluidine blue at −0.28 V increased. This proposed strategy has displayed superior sensitivity (limit of detection = 0.31 fg/mL, linear range = 1–50 ng/mL) and high reproducibility. The sensor was also applied for determining OTA content in red wine samples and the results were comparable to those of commercial enzyme-linked immunoassay kits with satisfactory results.
Epstein-Barr virus (EBV) is associated with a range of epithelial and B cell malignancies as well as autoimmune disorders, for which there are still no specific treatments or effective vaccines. ...Here, we isolate EBV gH/gL-specific antibodies from an EBV-infected individual. One antibody, 1D8, efficiently neutralizes EBV infection of two major target cell types, B cells and epithelial cells. In humanized mice, 1D8 provides protection against a high-dose EBV challenge by substantially reducing viral loads and associated tumor burden. Crystal structure analysis reveals that 1D8 binds to a key vulnerable interface between the D-I/D-II domains of the viral gH/gL protein, especially the D-II of the gH, thereby interfering with the gH/gL-mediated membrane fusion and binding to target cells. Overall, we identify a potent and protective neutralizing antibody capable of reducing the EBV load. The novel vulnerable site represents an attractive target that is potentially important for antibody and vaccine intervention against EBV infection.
Here, a highly cooperative liquid metal nanoparticle-enzyme (LM@GOX) was constructed for combinational starvation/photothermal therapy of tumor. It was found that the enzyme activity of glucose ...oxidase (GOX) could be strengthened along with the increased temperature within a given range and its optimal activity is around about 43–60 °C. Utilizing the photothermal conversion ability of liquid metal (LM), the GOX catalytic efficiency could be photo-controlled with improved starvation therapeutic efficiency. Furthermore, due to the accelerating blood flow during the photothermal therapy (PTT), the hypoxic situation in tumor tissues could also be relieved, which would contribute to conquering the hypoxia-suppressed GOX catalysis. In the meanwhile, the severe thermo-resistance of tumor cells during PTT process could be overcome by GOX induced decrease of adenosine triphosphate (ATP) and heat shock proteins (HSPs) level, eventually leading to an improved therapeutic effect of PTT. Both in vitro and in vivo studies proved that LM@GOX could significantly inhibit the growth of solid tumor under NIR illumination by a win-win cooperative starvation/photothermal therapy.
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Objective
To assess the association between dental anxiety and caries experience from late childhood through adolescence and into early adulthood (12, 15 and 18 years old, respectively).
Methods
A ...prospective cohort study was conducted among a population‐representative sample of Chinese in Hong Kong. A baseline survey was conducted at age 12 and follow‐up assessments were completed at ages 15 and 18. Caries experience was assessed as the number of decayed, missing and filled teeth (DMFT). Dental anxiety was assessed using the Modified Dental Anxiety Scale (MDAS). Participants’ socio‐economic status and oral health‐related behaviours were ascertained using a self‐complete questionnaire. Negative binomial regression was used to explore the association between dental anxiety and subsequent caries status, controlling for other factors.
Results
At baseline, 668 children participated; 279 (41.8%, comprising 57.0% females) completed all three phases of data collection. MDAS scores at age 18 were lower than at age 12. Caries experience increased as participants aged. At age 15 and 18, females had higher MDAS and DMFT scores than males. Reported frequency of snacking between meals was associated with MDAS scores at age 18. In regression analyses, dental anxiety at age 12 was not significantly associated with dental caries experience at age 15, controlling for socio‐demographic and oral‐health behaviour factors at age 12. Likewise, dental anxiety at age 15 was not significantly associated with dental caries experience at age 18, controlling for the same factors at age 15.
Conclusion
Dental anxiety assessed by MDAS in late childhood and adolescence appears not to predict dental caries experience later in life in this population.
Two-dimensional graphite-like carbon nitride nanosheets (g-C3N4 NSs) were hybridized with gold nanoparticles (Au NPs) to construct an electrochemiluminescence (ECL) immunosensor. The prepared Au ...NP-functionalized g-C3N4 NS nanohybrids (Au-g-C3N4 NHs) exhibit strong and stable cathodic ECL activity compared to g-C3N4 NSs due to the important roles of Au NPs in trapping and storing the electrons from the conduction band of g-C3N4 NSs, as well as preventing high energy electron-induced passivation of g-C3N4 NSs. On the basis of the improved ECL stability and ECL peak intensity of the Au-g-C3N4 NHs, a novel ECL immunosensor was developed to detect carcinoembryonic antigen (CEA) as a model target analyte. The ECL immunosensor has a sensitive response to CEA in a linear range of 0.02–80 ng mL–1 with a detection limit of 6.8 pg mL–1. Additionally, the proposed immunosensor shows high specificity, good reproducibility, and long-term stability.
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