Activating astrocytic α2A adrenoceptors in hippocampus reduces glutamate toxicity to attenuate sepsis-associated encephalopathy in mice.

BACKGROUND: Glutamate metabolism disorder is an important mechanism of sepsis-associated encephalopathy (SAE). Astrocytes regulate glutamate metabolism. In septic mice, α2A adrenoceptor (α2A-AR) activation in the central nervous system provides neuroprotection. α2A-ARs are expressed abundantly in hippocampal astrocytes. This study was performed to determine whether hippocampal astrocytic α2A-AR activation confers neuroprotection against SAE and whether this protective effect is astrocyte specific and achieved by the modulation of glutamate metabolism. METHODS: Male C57BL/6 mice with and without α2A-AR knockdown were subjected to cecal ligation and puncture (CLP). They were treated with intrahippocampal guanfacine (an α2A-AR agonist) or intraperitoneal dexmedetomidine in the presence or absence of dihydrokainic acid [DHK; a glutamate transporter 1 (GLT-1) antagonist] and/or UCPH-101 [a glutamate/aspartate transporter (GLAST) antagonist]. Hippocampal tissue was collected for the measurement of astrocyte reactivity, GLT-1 and GLAST expression, and glutamate receptor subunit 2B (GluN2B) phosphorylation. In vivo real-time extracellular glutamate concentrations in the hippocampus were measured by ultra-performance liquid chromatography tandem mass spectrometry combined with microdialysis, and in vivo real-time hippocampal glutamatergic neuron excitability was assessed by calcium imaging. The mice were subjected to the Barnes maze and fear conditioning tests to assess their learning and memory. Golgi staining was performed to assess changes in the hippocampal synaptic structure. In vitro, primary astrocytes with and without α2A-AR knockdown were stimulated with lipopolysaccharide (LPS) and treated with guanfacine or dexmedetomidine in the presence or absence of 8-bromo- cyclic adenosine monophosphate (8-Br-cAMP, a cAMP analog). LPS-treated primary and BV2 microglia were also treated with guanfacine or dexmedetomidine. Astrocyte reactivity, PKA catalytic subunit, GLT-1 an GLAST expression were determined in primary astrocytes. Interleukin-1ß, interleukin-6 and tumor necrosis factor-alpha in the medium of microglia culture were measured. RESULTS: CLP induced synaptic injury, impaired neurocognitive function, increased astrocyte reactivity and reduced GLT-1 and GLAST expression in the hippocampus of mice. The extracellular glutamate concentration, phosphorylation of GluN2B at Tyr-1472 and glutamatergic neuron excitability in the hippocampus were increased in the hippocampus of septic mice. Intraperitoneal dexmedetomidine or intrahippocampal guanfacine administration attenuated these effects. Hippocampal astrocytes expressed abundant α2A-ARs; expression was also detected in neurons but not microglia. Specific knockdown of α2A-ARs in hippocampal astrocytes and simultaneous intrahippocampal DHK and UCPH-101 administration blocked the neuroprotective effects of dexmedetomidine and guanfacine. Intrahippocampal administration of DHK or UCPH-101 alone had no such effect. In vitro, guanfacine or dexmedetomidine inhibited astrocyte reactivity, reduced PKA catalytic subunit expression, and increased GLT-1 and GLAST expression in primary astrocytes but not in primary astrocytes that received α2A-AR knockdown or were treated with 8-Br-cAMP. Guanfacine or dexmedetomidine inhibited microglial reactivity in BV2 but not primary microglia. CONCLUSIONS: Our results suggest that neurocognitive protection against SAE after hippocampal α2A-AR activation is astrocyte specific. This protection may involve the inhibition of astrocyte reactivity and alleviation of glutamate neurotoxicity, thereby reducing synaptic injury. The cAMP/protein kinase A (PKA) signaling pathway is a potential cellular mechanism by which activating α2A-AR modulates astrocytic function.

Chemical Constituent Analysis of Ranunculus sceleratus L. Using Ultra-High-Performance Liquid Chromatography Coupled with Quadrupole-Orbitrap High-Resolution Mass Spectrometry.

Ranunculus sceleratus L.(RS) has shown various pharmacological effects in traditional Chinese medicine. In our previous study, the positive therapeutic effect on α-naphthylisothiocyanate induced intrahepatic cholestasis in rats was obtained using TianJiu treatment with fresh RS. However, the chemical profile of RS has not been clearly clarified, which impedes the research progress on the therapeutic effect of RS. Herein, an ultra-high performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) method was developed to rapidly separate and identify multiple constituents in the 80% methanol extract of RS. A total of sixty-nine compounds (19 flavonoids, 22 organic acids, 6 coumarins, 4 lignans, 14 nitrogenous compounds, and 4 anthraquinones) were successfully characterized. A total of 12 of these compounds were unambiguously identified by standard samples. Their mass spectrometric fragmentation pathways were investigated. It is worth noting that flavonoids and lignans were identified for the first time in RS. In this study, we successfully provide the first comprehensive report on identifying major chemical constituents in RS by UHPLC-Q-Orbitrap HRMS. The obtained results enrich the RS chemical profile, paving the way for further phytochemical study, quality control, and pharmacological investigation of RS.

A New Ratiometric Fluorescent Probe for Specific Monitoring of hROS under Physiological Conditions Using Boric Acid-Protected l-DOPA Gold Nanoclusters.

The specific monitoring of physiological highly reactive oxygen species (hROS) using fluorescent gold nanoclusters (AuNCs) remains a challenge for scientists. Herein, SLB-AuNC was first synthesized via an ecofriendly one-pot method using starch as a template, l-3,4-dihydroxyphenylalanine (l-DOPA) as a reducing and a capping agent, and boric acid as a protecting agent for the catechol moiety of l-DOPA. The ingenious introduction of starch and boric acid enhanced the dispersibility, quantum yield, and photostability of fluorescent SLB-AuNCs. The obtained SLB-AuNCs possessed good monodispersity with an average diameter of 2.9 ± 0.8 nm and exhibited highly stable fluorescence with maximum emission at 480 nm under physiological conditions. A ratiometric fluorescent probe for hROS was developed through an oxidization-regulated Förster-resonance-energy-transfer process between SLB-AuNCs and 2,3-diaminophenazine (the oxidative product of hROS and o-phenylenediamine, with maximum fluorescence emission at 560 nm). With increasing amount of hROS, the outstanding fluorescence variation of the probe (I560 nm/I480 nm) enhanced about 300-fold, accompanied with a distinguishable color change from cyan to yellow. The detection limits of •OH, ClO-, and ONOO- were calculated as 0.11, 0.50, and 0.69 µM, respectively. High selectivity was achieved using o-phenylenediamine as a specific signal response for hROS to enable no interference reaction of other ROS toward SLB-AuNCs. The practicability of the proposed probe with super biocompatibility was evaluated by measuring exogenous and endogenous hROS levels in HeLa cells through fluorescence imaging. This work provides a novel strategy to design fluorescent AuNC probes for physiological hROS with great potential for the application of bioassay and bioimaging.

Increased minimum alveolar concentration-awake of Sevoflurane in women of breast surgery with sleep disorders.

BACKGROUND: Sleep disorders are commonly encountered in clinic. Evidences showed that sleep deprivation may modulate the effectiveness of general anesthetics in rats. However, this phenomenon has not been explored in humans. The study aimed to investigate whether the hypnotic potency of sevoflurane in patients with sleep disorders differ from patients with normal sleep habits. METHODS: We recruited 44 patients scheduled for elective breast surgery and eventually analyzed 38 patients, including 19 subjects with normal sleep habits and 19 subjects with sleep disorders. According to the Dixon 'up-and-down' design, patients received sevoflurane at preselected concentrations starting at 1.0 vol%. After a steady-state period, a verbal command for testing awakening was performed. Based on the negative or positive response to the verbal command, we decreased or increased the concentration of sevoflurane by 0.2 vol% in the next patient accordingly. Plasma orexin-A was also measured before observation. RESULTS: The MACawake of sevoflurane was 0.80% [95% confidence interval (CI), 0.683-0.926%] in the sleep disordered group vs 0.60% [95% CI, 0.493-0.689%] in the control group. The relative median potency between groups was 0.750 (95% CI, 0.236-0.969). Patients with sleep disorders had significantly higher orexin-A levels than control (72.17 ± 18.24 vs. 36.16 ± 14.18 pg/mL). A significant, positive relationship was detected between orexin-A level and probability of awakening (OR = 1.081, 95% CI is 1.020-1.146, P = 0.008). CONCLUSIONS: MACawake of sevoflurane is higher in mild-aged women of breast surgery with sleep disorders compared to those with normal sleep habits. The increased anesthetic requirement may be related to changes of orexin-A levels. These findings suggest that sleep may have a potential impact on clinical anesthesia, including changes of sensitivity to anesthetics or postoperative complications. Further research is needed to confirm this hypothesis. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR1800016022), date of registration 07 May 2018.

Sensitive determination of norepinephrine, epinephrine, dopamine and 5-hydroxytryptamine by coupling HPLC with [Ag(HIO6 )2 ](5-) -luminol chemiluminescence detection.

Based on the enhancing effects of norepinephrine (NE), epinephrine (EP), dopamine (DA) and 5-hydroxytryptamine (5-HT) on the chemiluminescence (CL) reaction between [Ag(HIO6 )2 ](5-) and luminol in alkaline solution, a high-performance liquid chromatography (HPLC) method with CL detection was explored for the sensitive determination of monoamine neurotransmitters for the first time. The UV-visible absorption spectra were recorded to study the enhancement mechanism of monoamine neurotransmitters on the CL of [Ag(HIO6 )2 ](5-) and luminol reaction. The HPLC separation of NE, EP, DA and 5-HT was achieved with isocratic elution using a mixture of aqueous 0.2% phosphoric acid and methanol (5:95, v/v) within 11.0 min. Under the optimized conditions, the detection limits of NE, EP, DA, and 5-HT were 4.8, 0.9, 1.9 and 2.3 ng/mL, respectively, corresponding to 17.6-96.0 pg for 20 µL sample injection. The recoveries of monoamine neurotransmitters in rat brain were >95.6% with the precisions expressed by RSD <5.0%. The validated HPLC-CL method was successfully applied for the quantification of NE, EP, DA and 5-HT in rat brain. This method has promising potential for some biological and clinical investigations focusing on the levels of monoamine neurotransmitters. Copyright © 2016 John Wiley & Sons, Ltd.

[Research progress on meridian-guiding theory of traditional Chinese medicine].

Ancient materia medica and medical formularies were consulted to illustrate the development history of meridian-guiding theory of traditional Chinese medicine (TCM). The influences of various meridian-guiding drugs (Achyranthis Bidentatae Radix, borneol, Bupleuri Radix, Platycodon Radix) on the pharmacokinetic and pharmacodynamic characteristics of other drugs were summarized. Meridian-guiding drugs can promote the absorption and targeted distribution of other drugs and enhance the efficacy of injured tissues. The possible mechanisms of meridian-guiding are related with changing the component of cell membrane, inhibiting the efflux of P-gp, opening physiological barriers, modulating the levels of biochemicals, promoting microcirculation and adjusting the pH of targeted tissues. The chemical components of meridian-guiding drugs are the substance basis of meridian-guiding. The aim of exploring meridian-guiding chemicals is to find a natural targeted delivery system. At the present time, some progress has been made in the research on meridian-guiding field. However, further studies are required for the meridian-guiding theory of TCM.

[Study on Appraising Storage Periods of Moutan Cortex and Its Quality by Means of Colorimeter].

Objective: To examine the correlation between storage periods and L*, a* and b* color of Moutan Cortex. Methods: A optical density meter was used for the measurement of reflected light from sieved powder and section samples using the CIE 1976 L~*,a~*,b~* color system. The content of paeonol were determined by HPLC. The correlation between storage periods,paeonol content and color indices of Moutan Cortex was analyzed. Results: The measured color was significantly correlated with storage periods. The color of Moutan Cortex shift toward the red with the increase of storage periods. The storage periods were correlated with paeonol content. The measured color was equably correlated with paeonol content. Conclusion: The correlation between the color of Moutan Cortex and storage periods was found in this study. Measurment of the color of Moutan Cortex can be used to appraise its storage periods and quality.

Rapid Fabrication of Gold Nanoflowers Tuned by pH: Insights Into the Growth Mechanism.

We reported a one-pot, no added seeding and green method to synthesize gold nanoflowers, in which HAuC4 and H2O2 were added one by one into the alkaline protocatechuic aldehyde solution at room temperature. Au(III) was partially reduced by protocatechuic aldehyde to produce primary Au nanocrystals, and then Au nanocrystals agglomerated into loose flower-like nanoparticles as seeds, which catalyzed H2O2 reduction of the residual Au(III), thus accelerating the formation of compact 3D gold nanoflowers. The key synthesis strategy was to use protocatechuic aldehyde as a structure-induced agent to influence the growth of gold nanoflowers. The pH value of growth solution could tune the size and/or morphology of gold nanoflowers through its influence on the adhesion force of protocatechuic aldehyde on gold surfaces and the species type of Au(III) complexes. When the pH value of growth solution was above 7.26 (the pKa of protocatechuic aldehyde), the flower-like of gold nanostructural architectures with different sizes could be fabricated. The obtained gold nanoflowers had a large dimension of 198 and 157 nm at the pH of 7.6 and 8, respectively. Size control of gold nanoflowers can be accomplished in the growth solutions of pH 9.4-12.0 with a similar diameter around 60 nm. The as-synthesized gold nanoflowers exhibited good stability and have the prospects for surface-enhanced Raman scattering enhancement.

Simultaneous quantification of catecholamines in rat brain by high-performance liquid chromatography with on-line gold nanoparticle-catalyzed luminol chemiluminescence detection.

A new method based on high-performance liquid chromatography (HPLC) coupled with on-line gold nanoparticle-catalyzed luminol chemiluminescence (CL) detection was developed for the simultaneous quantitation of catecholamines in rat brain. In the present CL system, gold nanoparticles were produced by the on-line reaction of H2 O2 , NaHCO3 -Na2 CO3 (buffer solution of luminol) and HAuCl4. Norepinephrine (NE), epinephrine (EP) and dopamine (DA) could strongly enhance the CL signal of the on-line gold nanoparticle-catalyzed luminol system. The UV-visible absorption spectra and transmission electron microscopy studies were carried out, and the CL enhancement mechanism was proposed. Catecholamines promoted the on-line formation of more gold nanoparticles, which better catalyzed the luminol-H2 O2 CL reaction. The good separation of NE, EP and DA was achieved with isocratic elution using a mixture of methanol and 0.2% aqueous phosphoric acid (5:95, v/v) within 8.5 min. Under the optimized conditions, the detection limits, defined as a signal-to-noise ratio of 3, were in the range of 1.32-1.90 ng/mL, corresponding to 26.4-38.0 pg for 20 µL sample injection. The recoveries of catecholamines added to rat brain sample were >94.6%, with the precisions <5.5%. The validated HPLC-CL method was successfully applied to determine NE and DA in rat brain without prior sample purification.

Phosphorylated VEGFR2 and hypertension: potential biomarkers to indicate VEGF-dependency of advanced breast cancer in anti-angiogenic therapy.

The efficacy of anti-VEGF agents probably lies on VEGF-dependency. Apatinib, a specific tyrosine kinase inhibitor that targets VEGF receptor 2, was assessed in patients with advanced breast cancer (ABC) (ClinicalTrials.gov NCT01176669 and NCT01653561). This substudy was to explore the potential biomarkers for VEGF-dependency in apatinib-treated breast cancer. Eighty pretreated patients received apatinib 750 or 500 mg/day orally in 4-week cycles. Circulating biomarkers were measured using a multiplex assay, and tissue biomarkers were identified with immunostaining. Baseline characteristics and adverse events (AEs) were included in the analysis. Statistical confirmation of independent predictive factors for anti-tumor efficacy was performed using Cox and Logistic regression models. Median progression-free survival (PFS) was 3.8 months, and overall survival (OS) was 10.6 months, with 17.5 % of objective response rate. Prominent AEs (≥60 %) were hypertension, hand-foot skin reaction (HFSR), and proteinuria. Higher tumor phosphorylated VEGFR2 (p-VEGFR2) expressions (P = 0.001), higher baseline serum soluble VEGFR2 (P = 0.031), hypertension (P = 0.011), and HFSR (P = 0.018) were significantly related to longer PFS, whereas hypertension (P = 0.002) and HFSR (P = 0.001) were also related to OS. Based on multivariate analysis, only p-VEGFR2 (adjusted HR, 0.40; P = 0.013) and hypertension (adjusted HR, 0.58; P = 0.038) were independent predictive factors for both PFS and clinical benefit rate. Apatinib had substantial antitumor activity in ABC and manageable toxicity. p-VEGFR2 and hypertension may be surrogate predictors of VEGF-dependency of breast cancer, which may identify an anti-angiogenesis sensitive population.

Two undescribed benzopyran derivatives from Ranunculus sceleratus L. with their in vitro anti-inflammatory activity in lipopolysaccharide-activated RAW 264.7 cells.

Previous studies on Ranunculus sceleratus L. have shown the existence of coumarins and their anti-inflammatory effect. Phytochemical work was conducted to investigate the bioactive compounds, leading to the isolation of two undescribed benzopyran derivatives, namely ranunsceleroside A (1) and B (3), together with two known coumarins (2, 4) from the whole plant of R. sceleratus L. All compounds were structurally identified by extensive spectroscopic analysis and then investigated for their inhibitory effect on nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) production induced by lipopolysaccharide (LPS) in RAW 264.7 murine macrophages, repectively. As a result, compound 1-4 presented inhibitory effects on the production of NO, TNF-α, IL-1ß, and IL-6 in a concentration-dependent manner, which provides a potential chemical basis for the traditional use of R. sceleratus L. as an anti-inflammatory plant.

Catalytic NIR chemiluminescence sensor with enhanced persistence and intensity for in vivo imaging.

Chemiluminescence (CL) is a self-illumination phenomenon that involves the emission of light from chemical reactions, and it provides favorable spatial and temporal information on biological processes. However, it is still a great challenge to construct effective CL sensors that equip strong CL intensity, long emission wavelength, and persistent luminescence for deep tissue imaging. Here, we report a liposome encapsulated polymer dots (Pdots)-based system using catalytic CL substrates (L-012) as energy donor and fluorescent polymers and dyes (NIR 695) as energy acceptors for efficient Near-infrared (NIR) CL in vivo imaging. Thanks to the modulation of paired donor and acceptor distance and the slow diffusion of biomarker by liposome, the Pdots show a NIR emission wavelength (λ em, max = 720 nm), long CL duration (>24 h), and a high chemiluminescence resonance energy transfer efficiency (46.5 %). Furthermore, the liposome encapsulated Pdots possess excellent biocompatibility, sensitive response to H2O2, and persistent whole-body NIR CL imaging in the drug-induced inflammation and the peritoneal metastatic tumor mouse model. In a word, this NIR-II CL nanoplatform with long-lasting emission and high spatial-temporal resolution will be a concise strategy in deep tissue imaging and clinical diagnostics.

(+)-Borneol Protects Dopaminergic Neuronal Loss in Methyl-4-phenyl-1,2,3,6-tetrahydropyridine-Induced Parkinson's Disease Mice: A Study of Dopamine Level using In Vivo Brain Microdialysis.

Considerable research efforts have been directed toward the symptom relief of Parkinson's disease (PD) by attenuating dopamine (DA) depletion. One common feature of these existing therapies is their unavailability of preventing the neurodegenerative process of dopaminergic neurons. (+)-Borneol, a natural highly lipid-soluble bicyclic monoterpene, has been reported to regulate the levels of monoamine neurotransmitters in the central nervous system and exhibit neuroprotective effects. However, the effect of (+)-borneol on the dopaminergic neuronal loss of methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice is not defined. Herein, we first report that 30 mg/kg (+)-borneol significantly attenuated the motor deficits of PD mice, which benefits from markedly increasing the level of DA and decreasing the metabolic rate of DA in the striatum of conscious and freely moving mouse detected by ultraperformance liquid chromatography tandem mass spectrometry online combined with in vivo brain microdialysis sampling. It is worth noting that the enhanced level of DA by (+)-borneol was enabled by the reduction in loss of tyrosine hydroxylase-immunoreactive dopaminergic neurons in the substantia nigra and striatum and promotion of reserpine- or nomifensine-induced DA release in PD mice. Interestingly, (+)-borneol evidently inhibited the decreased expression levels of DA transporter (DAT) and vesicular monoamine transporter 2 (VMAT2) on the MPTP mouse model of PD. Moreover, (+)-borneol suppressed the neuroinflammation by inhibiting the production of IL-1ß, IL-6, and TNF-α and attenuated oxidative stress by decreasing the level of MDA and increasing the activities of SOD and GSH-px in PD mice. These findings demonstrate that (+)-borneol protects DA neurons by inhibiting neuroinflammation and oxidative stress. Further research work for the neuroprotection mechanism of (+)-borneol will focus on reactive oxygen species-mediated apoptosis. Therefore, (+)-borneol is a potential therapeutic candidate for retarding the neurodegenerative process of PD.

[Simultaneous determination of eight active components in Chrysanthemum indicum by HPLC].

This study is aimed to establish a high-performance liquid chromatography (HPLC) method for simultaneous determination of chlorogenic acid, caffeic acid, 1,3-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, luteolin-7-O-beta-D-glucoside, 3,4-dicaffeoylquinic acid, linarin and luteolin in Chrysanthemum indicum. The separation was carried out on a Shim pack VP-ODS (4.6 mm x 250 mm, 5 microm) column eluting with mobile phases of methanol (A) and water containing 0.3% phosphoric acid (B) in gradient mode (0-9 min, 85% -80% B; 9-12 min, 80% -70% B; 12-15 min, 70% -65% B; 15-20 min, 65% -60% B; 20-23 min, 60% -55% B; 23-29 min, 55% -54.4% B; 29-32 min, 54.4% -45% B; 32-37 min, 45% -5% B; 37-45 min, 5% -85% B) at the flow rate of 1.0 mL x min(-1). The column temperature was 35 degrees C and the detection wavelength was set at 326 nm. The good separation of chlorogenic acid, caffeic acid, 1,3-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, luteolin-7-O-beta-D-glucoside, 3,4-dicaffeoylquinic acid, linarin and luteolin was achieved within 40 min. Calibration curves of the eight effective components showed good linear relationship (r > 0.999 5, n = 7). The average recoveries were within 97.03%-102.3% (RSD < 2.0%, n = 6). The method is simple, accurate and repeatable and can be used for the quality control of Ch. indicum.

Perceived Marriage Squeeze and Subjective Well-Being Among Unmarried Rural Men in China: The Mediating Role of Sense of Coherence.

The marriage-squeeze unmarried rural men perceive during their daily life is one of the main stressors severely affecting their subjective well-being under the universal marriage culture. The mechanism of this relationship is still unknown. Based on the Stress Process Model, using data from the "Survey on Rural Family Martial Status," this study examines the relationship between perceived marriage squeeze (PMS) and subjective well-being (SWB) and the mediating effect of sense of coherence (SOC). A sample of 417 Chinese unmarried rural men with an average age of 28.88 years was enrolled in this cross-sectional. Ordinary least square regressions and Bootstrap-mediated effect analysis methods were used to examine the association between PMS, SWB, and SOC. The results show that PMS has significant negative effects on both SWB and SOC of unmarried rural men, and SOC has a significant positive impact on SWB; the more perceived marriage squeeze they have, the lower SWB and SOC they have. The mediated analysis shows that SOC plays a mediating role in the influence of PMS on the SWB of unmarried rural men. This is to say, SOC can mitigate PMS's negative effects on the SWB of unmarried rural men. Our findings highlight the importance of SOC in protecting the SWB of unmarried rural men. Considering the propounding influence of the marriage squeeze, policies that enhance the level of SOC should be implemented to relieve the influence of PMS on vulnerable unmarried rural men's SWB.

An imidazole-derived polarity sensitive probe for lipid droplet target and in vivo tumor imaging.

Accurate differentiation of tumor cells from normal cells is a fundamental and critical challenge for the early diagnosis of cancer. The intrinsic low-polarity and increased numbers of lipid droplets can be utilized as potential biomarkers for tumor cells. Therefore, we synthesized and screened the polar fluorescent probe (PI-CHO), which exhibiting notable fluorescence color change and spectral shift in solvents of different polarities. PI-CHO has a high sensitivity to polarity changes in the linear range of ET(30) = 37.4-63.1, with a fluorescence enhancement of more than 474-folds. Intracellular imaging experiments showed that PI-CHO has low cytotoxicity, excellent lipid droplet-targeted performance and discernibility between tumor and normal cells. Ex vivo imaging of the tumors and major organs demonstrated the great reliability and sensitive responsiveness of PI-CHO towards tumors. Moreover, the proposed probe was successfully applied to detect tumors in living mice, exhibiting the potential to become a powerful tool in early cancer diagnosis.

Natural borneol serves as an adjuvant agent to promote the cellular uptake of piperlongumine for improving its antiglioma efficacy.

Piperlongumine (PL) can selectively inhibit the proliferation of various cancer cells by increasing reactive oxygen species (ROS) level to cause a redox imbalance in cancer cells rather than in normal cells. However, the clinical application of PL is limited by its poor cellular uptake. Natural borneol (NB) is extracted from the fresh branches and leaves of Cinnamomum camphora (L.) Presl. with the purity of (+)-borneol no less than 96.0%. NB has been often used as an adjuvant agent to promote the cellular uptake of other drugs. This study aims to investigate the effect of NB on the cellular uptake of PL for improving its antiglioma efficacy and underlying mechanism. NB obviously promoted the cellular uptake of PL with a 1.3-fold increase in the maximum peak concentration and an earlier peak time of 30 min in C6 glioma cells. The cellular uptake of PL was enhanced by NB through down-regulating the expression levels of P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2). The combination of NB and PL significantly induced higher levels of ROS, which increased apoptosis and enhanced G2/M cycle arrest of C6 glioma cells, compared to PL alone administration. NB-enhanced antiglioma efficacy of PL without side effects was confirmed in tumor-bearing mice, which was attributed to the improved cellular uptake of PL. The distribution of PL in the tumor tissue of combined group increased 2.39 times than that of PL-treated group. We firstly report NB as an adjuvant agent to improve the antiglioma efficacy of PL in a ROS-dependent manner, which is due to the enhanced cellular uptake of PL by NB though down-regulating the expression levels of ABCB1 and ABCG2. This work provides a new strategy to promote the cellular uptake of PL with great potential for the treatment of glioma.

EDTA-functionalized silica nanoparticles as a conditioning agent for dentin bonding using etch-and-rinse technique.

OBJECTIVE: This study investigated the possibility of using ethylenediaminetetraacetic acid functionalized silica nanoparticles (EDTA-SiO2) as a dentin-conditioning agent using etch-and-rinse technique to promote the durability of dentin bonding. METHODS: The SiO2-EDTA were synthesized by N- [(3- trimethoxysilyl) propyl] ethylenediamine triacetic acid (EDTA-TMS) and SiO2 (50 nm), then characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The capacity of SiO2-EDTA to chelate calcium ions from dentin was examined by inductively coupled plasma-optic emission spectrometry (ICP-OES). The dentin surfaces conditioned with SiO2-EDTA were detected by field emission scanning electron microscopy (SEM), TEM and microhardness testing. For dentin bonding, dentin surfaces were adopted wet- or dry-bonding technique and bonded with adhesive (AdperTM Single Bond2) and applied composite resin (Filtek Z350) on them. The durability of dentin bonding was evaluated by mircotensile bond strength test, in-situ zymography and nanoleakage testing. RESULTS: FTIR, TGA and XPS results showed that SiO2-EDTA contained N element and carboxyl groups. SEM, TEM and microhardness results indicated that SiO2-EDTA group created extrafibrillar demineralization and retained more intrafibrillar minerals within dentin surface. In the dentin bonding experiment, SiO2-EDTA group achieved acceptable bond strength, and reduced the activity of matrix metalloproteinase and nanoleakage along bonding interface. CONCLUSION: It was possible to generate a feasible dentin conditioning agent (SiO2-EDTA), which could create dentin extrafibrillar demineralization and improve dentin bond durability. CLINICAL SIGNIFICANCE: This study introduces a new dentin conditioning scheme based on SiO2-EDTA to create extrafibrillar demineralization for dentin bonding. This strategy has the potential to be used in clinic to promote the life of restoration bonding.

ROS-Responsive Fluorescent Sensor Array for Precise Diagnosis of Cancer via pH-Controlled Multicolor Gold Nanoclusters.

Intracellular reactive oxygen species (ROS) are closely associated with cancer cell types. Therefore, ROS-based pattern recognition is a promising strategy for precise diagnosis of cancer, but such a possibility has never been reported yet. Herein, we proposed an ROS-responsive fluorescent sensor array based on pH-controlled histidine-templated gold nanoclusters (AuNCs@His) to distinguish cancer cell types and their proliferation states. In this strategy, three types of AuNCs@His with diverse fluorescence profiles were first synthesized by only adjusting the pH value. Upon the addition of various ROS, fluorescence quenching of three types of AuNCs@His occurred with different degrees, thereby forming unique optical "fingerprints", which were well-clustered into several separated groups without overlap by principal component analysis (PCA). The sensing mechanism was attributable to the oxidation of AuNCs@His by ROS, as revealed by X-ray photoemission spectroscopy, Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and electrospray ionization mass spectrometry. Based on the ROS-responsive sensing pattern, cancer cell types were successfully differentiated via PCA with 100% accuracy. Additionally, the proposed sensor array exhibited excellent performance in distinguishing the proliferation states of cancer cells, which was supported by the results of the Ki-67 immunohistochemistry assay. Overall, the ROS-responsive fluorescent sensor array can serve as a promising tool for precise diagnosis of cancer, indicating great potential for clinical application.

Diazo probe-based chemical isotope labeling assisted liquid chromatography-tandem mass spectrometry analysis for sensitive determination of amino acids in biofluids.

Amino acids are important biomolecules and contribute to essential biological processes. Liquid chromatography tandem mass spectrometry (LC-MS) now is a powerful tool for the analysis of amino acid metabolites; however, the structural similarity and polarity of amino acids can lead to the poor chromatographic retention and low detection sensitivities. In this study, we used a pair of light and heavy isotopomers of diazo probes, d0/d5-2-(diazomethyl)-N-methyl-N-phenyl-benzamide (2-DMBA/d5 -2-DMBA) to label amino acids. The paired MS probes of 2-DMBA and d5 -2-DMBA carry diazo groups that can efficiently and specifically react with the carboxyl group on free amino acid metabolites under mild conditions. Benefiting from the transfer of the 2-DMBA/d5 -2-DMBA to carboxyl group on amino acids, the ionization efficiencies of amino acids presented great enhancement during LC-MS analysis. The results suggested that the detection sensitivities of 17 amino acids increased by 9-133-fold upon 2-DMBA labeling, and the obtained limits of detection (LODs) of amino acids on-column ranged from 0.011 fmol-0.057 fmol. With the application of the developed method, we successfully achieved the sensitive and accurate detection of the 17 amino acids in microliter level of serum sample. Moreover, the contents of most amino acids were different in the serum from normal and B16F10-tumour mice, demonstrating that endogenous amino acids may play important roles in the regulation of tumors development. This developed method of chemical labeling of amino acids with diazo probes assisted LC-MS analysis provides a potentially valuable tool to investigate the relationships between amino acids metabolism and diseases.