A role for the calcium-sensing receptor in the expression of inflammatory mediators in LPS-treated human dental pulp cells.

The aim of this study is to investigate the role of calcium-sensing receptor (CaSR) in the expression of inflammatory mediators of lipopolysaccharide (LPS)-treated human dental pulp cells (hDPCs). The expression profile of CaSR in LPS-simulated hDPCs was detected using immunofluorescence, real time quantitative PCR (RT-qPCR), and Western blot analyses. Then, its regulatory effects on the expression of specific inflammatory mediators such as interleukin (IL)-1ß, IL-6, cyclooxygenase 2 (COX2)-derived prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, and IL-10 were determined by RT-qPCR and enzyme-linked immunosorbent assay (ELISA). LPS significantly downregulated the gene expression of CaSR, but upregulated its protein expression level in hDPCs. Treatments by CaSR agonist R568 or its antagonist Calhex231, and their combinations with protein kinase B (AKT) inhibitor LY294002 showed obvious effects on the expression of selected inflammatory mediators in a time-dependent manner. Meanwhile, an opposite direction was found between the action of R568 and Calhex231, as well as the expression of the pro- (IL-1ß, IL-6, COX2-derived PGE2, and TNF-α) and anti-inflammatory (IL-10) mediators. The results provide the first evidence that CaSR-phosphatidylinositol-3 kinase (PI3K)-AKT-signaling pathway is involved in the release of inflammatory mediators in LPS-treated hDPCs, suggesting that the activation or blockade of CaSR may provide a novel therapeutic strategy for the treatment of pulp inflammatory diseases.

Molecularly imprinted ratiometric electrochemical sensor based on carbon nanotubes/cuprous oxide nanoparticles/titanium carbide MXene composite for diethylstilbestrol detection.

Conventional molecularly imprinted polymers (MIP)-based electrochemical sensors are generally susceptible to the changes of personal operation, electrode surface, and solution conditions. Herein, a ratiometric strategy was employed through introducing Cu2O nanoparticles (NPs) as inner reference probe to realize the reliable detection of diethylstilbestrol (DES). MIP film was prepared by electropolymerization of 1H-pyrrole-3-carboxylicacid in the presence of DES on carbon nanotubes/cuprous oxide/titanium carbide (CNT/Cu2O NPs/Ti3C2Tx) modified electrodes. The Ti3C2Tx with accordion-like structure not only possessed good electrical conductivity, but also facilitated the immobilization of Cu2O NPs, which contributed to stabilizing the signal. CNT was introduced to further improve the sensitivity of the sensor. Under optimum conditions, the MIP/CNT/Cu2O NPs/Ti3C2Tx electrochemical sensors showed a broad linear response range of 0.01 to 70 µM, and a low detection limit of 6 nM (S/N = 3). Moreover, the sensor was applied to detect DES in real samples including lake water, milk, and pork, and the recoveries for spiked standard were 88-112%. Thus, this work provides a new way for reliable DES detection.

A novel electrochemical sensor based on a Cu-coordinated molecularly imprinted polymer and MoS2 modified chitin-derived carbon for selective detection of dextromethorphan.

Dextromethorphan (DXM) is a widely utilized central antitussive agent, which is frequently abused by individuals seeking its recreational effect. But DXM overdose can cause some adverse effects, including brain damage, loss of consciousness, and cardiac arrhythmias, and hence its detection is significant. Herein, an electrochemical sensor based on a Cu-coordinated molecularly imprinted polymer (Cu-MIP) was fabricated for its detection. For constructing the sensor, nitrogen-doped carbon nanosheets (CCNs) were prepared through calcining chitin under an argon atmosphere, and molybdenum disulfide (MoS2) was allowed to grow on their surface. Subsequently, the obtained MoS2/CCNs composite was employed to modify a glassy carbon electrode (GCE), and the Cu-MIP was electrodeposited on the electrode in a Cu-1,10-phenanthroline (Cu-Phen) solution containing DXM, where Cu2+ played a role in facilitating electron transfer and binding DXM. Due to the large specific surface area, good electrocatalytic properties and recognition of the resulting composite, the resulting Cu-MIP/MoS2/CCNs/GCE showed high selectivity and sensitivity. Under optimized experimental conditions, the peak current of DXM and its concentration exhibited a good linear relationship over the concentration range of 0.1-100 µM, and the limit of detection (S/N = 3) was 0.02 µM. Furthermore, the electrochemical sensor presented good stability, and it was successfully used for the determination of DXM in pharmaceutical, human serum and urine samples.

Cupric ion coordination-mediated molecularly imprinted electrochemical sensor for the recognition and ratiometric detection of lidocaine.

Molecularly imprinted polymers (MIPs) have been widely used as artificial recognition elements in sensing applications. However, their electrochemical sensing performance is generally hampered by limited affinity and uncontrolled condition change. In this work, a novel MIP electrochemical sensor based on metal coordination interaction was prepared and used for the recognition and ratiometric detection of lidocaine (LC). The sensor was constructed by electrodepositing Cu-coordinated MIP on biomass carbon modified glassy carbon electrode. Herein, Cu2+ ions acted as anchor for the immobilization of LC during the synthesis process, enabling the orderly formation of molecular recognition sites. Reversely, the metal coordination between Cu2+ ions and LC molecules facilitated the recognition of LC. Moreover, the doped cupric ions in the polymer film could provide a reference signal for subsequent ratiometric strategy. Thus the resulting sensor exhibited high selectivity, sensitivity, satisfactory reproducibility, and anti-interference ability. Under the selected conditions, the peak current ratio of LC and cupric ion was linear to LC concentration in the range of 0.008-2.5 µmol L-1 (R2 = 0.9951), and the limit of detection was 1.9 nmol L-1 (S/N = 3). The practical feasibility of the sensor was evaluated by detecting human serum and pharmaceutical samples, and satisfactory outcomes were obtained.

A liposome encapsulated methylene blue-mediated electrochemical and UV-visible dual mode split-type immunoassay for the detection of 17ß-estradiol.

Herein, we fabricated an electrochemical (EC) and UV-visible absorption (UV-vis) dual mode split-type immunoassay for the detection of 17ß-estradiol (E2), which was mediated by liposome encapsulated methylene blue (MB@lip). MB molecule acted as the probe in the EC and UV-vis absorption dual mode detections, and its release was controlled by liposome. The competitive immune recognition was conducted between the E2 in the sample and E2 conjugated bovine serum protein (E2-BSA) adsorbed on the 96-wells plate in combining with E2 antibody labeled with MB@lip (E2-Ab/MB@lip). MB molecule could be released from the resulting immune composite of E2-BSA/E2-Ab/MB@lip in the presence of Triton X-100, and quantified by UV-vis and EC methods. The three-dimensional cross-linked reduced graphene oxide/Ti3C2 (3D-rGO/Ti3C2) aerogel was prepared through hydrothermal method, then complexed with the electroactive anthraquinone (AQ) and used as the electrode modified material. The AQ/3D-rGO/Ti3C2 composite had high surface area and provided abundant adsorption sites for MB, and the displacement/competitive behavior between AQ and MB could dexterously achieve the ratiometric EC detection of E2. In addition, the inherent blue color of MB allowed it to be analyzed by UV-vis absorption method. The proposed dual mode detection method exhibited broad linear ranges of 0.1 pg mL-1 to 50 ng mL-1 (by UV-vis) and 0.03 pg mL-1 to 50 ng mL-1 (by EC) for E2 detection, and the detection limits were 0.023 pg mL-1 (S/N = 3) and 8.0 fg mL-1 (S/N = 3), respectively. Moreover, the proposed immunoassay exhibited good practicability and was applied to monitor E2 in milk and serum successfully.

A ratiometric electrochemical sensing platform based on multifunctional molecularly imprinted polymer with catalytic activity for the detection of psychoactive substances.

Molecularly imprinted polymers (MIPs) are widely used as artificial recognition element in sensing field, but their electrochemical sensing performances are generally affected by their poor catalytic activity and unruly condition change. In this work, an MIP film with catalysis (Fe-DMMIP) is constructed by electrodeposition of Fe-coordinated aminophenanthroline and 3,4-ethylenedioxythiophene on N, S doped C material, using cannabinoid (CBD) as template molecule. Due to the presence of Fe-N active sites, the obtained Fe-DMMIP possesses enzyme-like catalytic activity besides conventional recognition capability. Accordingly, the sensor exhibits high electrocatalytic activity and selectivity. Moreover, the Fe-DMMIP can produce a stable and well-defined signal as an internal reference around 0 V (vs. Ag/AgCl) for ratiometric sensing. Under the optimal conditions, the ratiometric signal is linear to CBD concentration in the range of 0.004-0.8 µmol L-1 (R2 = 0.9946) with a detection limit of 2.9 nmol L-1. The ratiometric sensor shows high reproducibility, stability and applicability. In addition, through replacing the template molecule, the resulting biomimetic sensor also exhibits good performance in sensing other psychoactive substances such as melatonin and 5-hydroxytryptophan, with LODs of 19 nmol L-1 and 8 nmol L-1for them, respectively. Therefore, the developed sensing platform has good prospects, and this work provides a new way for developing ratiometric electrochemical sensors with high sensitivity, reproducibility and anti-interference ability.

Kill two birds with one stone: Selective and fast removal and sensitive determination of oxytetracycline using surface molecularly imprinted polymer based on ionic liquid and ATRP polymerization.

Oxytetracycline (OTC) residue in food and environment has potential threats to ecosystem and human health, thus its sensitive monitoring and effective elimination are very important. In this work, a new molecularly imprinted polymer (MIP) composite was prepared through atom transfer radical polymerization by using OTC as template, gold nanoparticles modified carbon nanospheres (Au-CNS) as supporter, ionic liquids (IL) as functional monomer and cross-linking agent. The obtained MIP-IL@Au-CNS composite was characterized by Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. It displayed high imprinting factor (5.50) and adsorption capacity (56.7 mg g-1), and could achieved the adsorption equilibrium in short time (about 15 min). Results also illustrated that the adsorption process basically conformed to the quasi-second-order kinetic model and Freundlich model, and MIP-IL@Au-CNS could be recycled at least 5 times. Furthermore, a sensitive OTC electrochemical sensor was developed by combining MIP-IL@Au-CNS with IL-modified carbon nanocomposites (IL@N-rGO-MWCNT). The resulting sensor demonstrated a linear response to OTC in the wide range of 0.02-20 µM, and the detection limit was down to 5 nM. It also had the advantages of high selectivity, fast elution/regeneration and simple construction procedure. The sensor had been applied to the detection of real samples, and acceptable recovery (96.4%-106%) and RSD (3.2%-6.2%) were obtained. This work expands the application of IL-based MIP in pollutant monitoring and enriching.

A novel ratiometric electrochemical sensor based on dual-monomer molecularly imprinted polymer and Pt/Co3O4 for sensitive detection of chlorpromazine hydrochloride.

In this work, a novel signal on/off ratiometric electrochemical sensor for the selective detection of chlorpromazine (CPZ) was developed. The sensor was constructed by electrodepositing dual-monomer molecularly imprinted polymer (DMMIP) film on the surface of Pt/Co3O4 nanoparticles modified glassy carbon electrode, using CPZ as template molecule, methylene blue and catechol as functional monomers. The copolymerization of two monomers increased the diversity of functional groups for binding template molecules, and enhanced stability. The quantitative detection of CPZ was performed by differential pulse voltammetry, using the peak current of poly (methylene blue) as reference signal and the peak current of CPZ as indicating signal. The results showed that the developed DMMIP sensor not only possessed high selectivity and sensitivity, but also exhibited satisfactory anti-interference ability. Under the optimum conditions, a linear detection range of 0.005-9 µmol L-1 (R2 = 0.9962) was obtained, and the limit of detection was 2.6 nmol L-1. Moreover, the sensor showed good reproducibility and stability toward CPZ detection. It was applied to detect CPZ in serum and pharmaceutical samples, and satisfactory recoveries (ranging from 95.3% to 108.0%) were achieved.

Antifouling ionic liquid doped molecularly imprinted polymer-based ratiometric electrochemical sensor for highly stable and selective detection of zearalenone.

Zearalenone (ZEN) is a nonsteroidal estrogenic mycotoxin, and its accurate detection in complex biological samples is still a challenge. Herein, an antifouling ratiometric electrochemical sensor has been developed for its detection. In this system, black phosphorus-graphene oxide is used as substrate to amplify the signal; ionic liquid doped molecularly imprinted polymer (MIP) endows the sensing surface not only high recognition ability but also high capability to resist nonspecific adsorption. During MIP preparation a magnetic field is introduced to regulate polymer structure for improving the recognition efficiency of the sensor. The signals of ZEN and poly methylene blue (MB) serve as response signal and internal reference signal, respectively. The peak current of ZEN increases with the increase of ZEN concentration, while the peak current of poly(MB) decreases simultaneously; their ratio changes with ZEN concentration variation. The obtained ratiometric sensor shows a wide linear response range of 0.05-13 µM and a low limit of detection of 12.7 nM (S/N = 3). Furthermore, it has high selectivity, stability and reproducibility, thanks to the advanced antifouling MIP and the built-in correction of poly(MB). The sensor has been successfully applied to determine ZEN in human serum.

A ratiometric electrochemical sensor based on Cu-coordinated molecularly imprinted polymer and porous carbon supported Ag nanoparticles for highly sensitive and selective detection of perphenazine.

In this work, a ratiometric electrochemical sensor was developed for the detection of perphenazine (PPZ). The sensor was constructed by electrodepositing Cu-coordinated molecularly imprinted polymer (Cu-MIP) on Ag nanoparticles (NPs) modified flexible porous carbon cloth. The Cu-MIP showed highly electrochemical response because of the enhanced adsorptive ability and electronic properties of Cu2+ chelation; Ag NPs could provide a stable and effective reference signal for ratiometric quantification. Thus the resulted sensor not only displayed high selectivity and sensitivity, but also exhibited satisfactory reproducibility and anti-interference ability. Under the optimum conditions, the quantitative detection of PPZ was performed with differential pulse voltammetry. It was found that the peak current ratio of PPZ and Ag NP was linear to the concentration of PPZ in the range of 1-700 nmol L-1 (R2 = 0.9968), and the limit of detection was 0.43 nmol L-1 (S/N = 3). The practicability of the sensor was examined by determining human serum and pharmaceutical samples, and satisfactory results and recoveries (ranging from 92.46% to 104.90%) were achieved.

Pharmacodynamics of cerebrospinal fluid asparagine after asparaginase.

PURPOSE: We evaluated effects of asparaginase dosage, schedule, and formulation on CSF asparagine in children with acute lymphoblastic leukemia (ALL). METHODS: We evaluated CSF asparagine (2114 samples) and serum asparaginase (5007 samples) in 482 children with ALL treated on the Total XVI study (NCT00549848). Patients received one or two 3000 IU/m2 IV pegaspargase doses during induction and were then randomized in continuation to receive 2500 IU/m2 or 3500 IU/m2 IV intermittently (four doses) on the low-risk (LR) or continuously (15 doses) on the standard/high risk (SHR) arms. A pharmacokinetic-pharmacodynamic model was used to estimate the duration of CSF asparagine depletion below 1 uM. RESULTS: During induction, CSF asparagine depletion after two doses of pegaspargase was twice as long as one dose (median 30.7 vs 15.3 days, p < 0.001). During continuation, the higher dose increased the CSF asparagine depletion duration by only 9% on the LR and 1% in the SHR arm, consistent with the nonlinear pharmacokinetics of serum asparaginase. Pegaspargase caused a longer CSF asparagine depletion duration (1.3-5.3-fold) compared to those who were switched to erwinase (p < 0.001). The median (quartile range) serum asparaginase activity needed to maintain CSF asparagine below 1 µM was 0.44 (0.20, 0.99) IU/mL. Although rare, CNS relapse was higher with decreased CSF asparagine depletion (p = 0.0486); there was no association with relapse at any site (p = 0.3). CONCLUSIONS: The number of pegaspargase doses has a stronger influence on CSF asparagine depletion than did dosage, pegaspargase depleted CSF asparagine longer than erwinase, and CSF asparagine depletion may prevent CNS relapses.

Class II Human Leukocyte Antigen Variants Associate With Risk of Pegaspargase Hypersensitivity.

We conducted the first human leukocyte antigen (HLA) allele and genome-wide association study to identify loci associated with hypersensitivity reactions exclusively to the PEGylated preparation of asparaginase (pegaspargase) in racially diverse cohorts of pediatric leukemia patients: St Jude Children's Research Hospital's Total XVI (TXVI, n = 598) and Children's Oncology Group AALL0232 (n = 2,472) and AALL0434 (n = 1,189). Germline DNA was genotyped using arrays. Genetic variants not genotyped directly were imputed. HLA alleles were imputed using SNP2HLA or inferred using BWAkit. Analyses between genetic variants and hypersensitivity were performed in each cohort first using cohort-specific covariates and then combined using meta-analyses. Nongenetic risk factors included fewer intrathecal injections (P = 2.7 × 10-5 in TXVI) and male sex (P = 0.025 in AALL0232). HLA alleles DQB1*02:02, DRB1*07:01, and DQA1*02:01 had the strongest associations with pegaspargase hypersensitivity (P < 5.0 × 10-5 ) in patients with primarily European ancestry (EA), with the three alleles associating in a single haplotype. The top allele HLA-DQB1*02:02 was tagged by HLA-DQB1 rs1694129 in EAs (r2  = 0.96) and less so in non-EAs. All single nucleotide polymorphisms associated with pegaspargase hypersensitivity reaching genome-wide significance in EAs were in class II HLA loci, and were partially replicated in non-EAs, as is true for other HLA associations. The rs9958628 variant, in ARHGAP28 (previously linked to immune response in children) had the strongest genetic association (P = 8.9 × 10-9 ) in non-EAs. The HLA-DQB1*02:02-DRB1*07:01-DQA1*02:01 associated with hypersensitivity reactions to pegaspargase is the same haplotype associated with reactions to non-PEGylated asparaginase, even though the antigens differ between the two preparations.

Ångstrom-scale silver particle-embedded carbomer gel promotes wound healing by inhibiting bacterial colonization and inflammation.

Poor wound healing after diabetes or extensive burn remains a challenging problem. Recently, we presented a physical approach to fabricate ultrasmall silver particles from Ångstrom scale to nanoscale and determined the antitumor efficacy of Ångstrom-scale silver particles (AgÅPs) in the smallest size range. Here we used the medium-sized AgÅPs (65.9 ± 31.6 Å) to prepare carbomer gel incorporated with these larger AgÅPs (L-AgÅPs-gel) and demonstrated the potent broad-spectrum antibacterial activity of L-AgÅPs-gel without obvious toxicity on wound healing-related cells. Induction of reactive oxygen species contributed to L-AgÅPs-gel-induced bacterial death. Topical application of L-AgÅPs-gel to mouse skin triggered much stronger effects than the commercial silver nanoparticles (AgNPs)-gel to prevent bacterial colonization, reduce inflammation, and accelerate diabetic and burn wound healing. L-AgÅPs were distributed locally in skin without inducing systemic toxicities. This study suggests that L-AgÅPs-gel represents an effective and safe antibacterial and anti-inflammatory material for wound therapy.

Immediate Hypersensitivity to Polyethylene Glycols and Polysorbates: More Common Than We Have Recognized.

BACKGROUND: The most common immediate hypersensitivity to macrogols is associated with polyethylene glycol (PEG) 3350; however, the epidemiology, mechanisms, and cross-reactivity are poorly understood. Thousands of medications contain either PEGs or structurally similar polysorbates. OBJECTIVE: Our objective was to better understand the mechanism, cross-reactivity, and scope of PEG hypersensitivity. METHODS: Two cases with a past history of immediate hypersensitivity to PEG-containing medications were used to study potential mechanisms and cross-reactivity of immediate reactions to PEG 3350. Skin testing and oral challenges with PEG and polysorbate-containing agents were employed to determine clinical reactivity and cross-reactivity between the 2 allergens. Enzyme-linked immunosorbent assay and electrochemiluminescent immunoassay were used to detect anti-PEG specific IgG and IgE, respectively, using PEGylated protein or PEG alone as antigens in 2 cases and 6 PEG 3350 tolerant controls. We searched US Food and Drug Administration (FDA) adverse event reports for immediate reactions to PEG 3350 to determine the potential scope of this problem in the United States. RESULTS: Skin and provocation testing demonstrated symptomatic reactivity in both cases to PEG 3350 and polysorbate 80. Plasma samples were positive for anti-PEG specific IgE and IgG antibodies only in cases and binding increased directly proportional to the molecular weight of PEG tested. FDA adverse event reports revealed 53 additional cases of possible PEG 3350 anaphylaxis. CONCLUSIONS: Immediate hypersensitivity to PEG 3350 with cross-reactive polysorbate 80 hypersensitivity may be underrecognized in clinical practice and can be detected with clinical skin testing. Our studies raise the possibility of an IgE-mediated type I hypersensitivity mechanism in some cases.

Antibodies Predict Pegaspargase Allergic Reactions and Failure of Rechallenge.

PURPOSE: Pegaspargase (PEG-ASP) has largely replaced native Escherichia coli asparaginase (L-ASP) in the treatment of acute lymphoblastic leukemia because of its longer half-life and lower immunogenicity. Risk factors for allergic reactions to PEG-ASP remain unclear. Here, we identify risk factors for reactions in a front-line acute lymphoblastic leukemia trial and assess the usefulness of serum antibodies for diagnosing allergy and predicting rechallenge outcome. PATIENTS AND METHODS: PEG-ASP was administered to 598 patients in St Jude's Total XVI study. Results were compared with Total XV study (ClinicalTrials.gov identifiers: NCT00549848 and NCT00137111), which used native L-ASP. Serum samples (n = 5,369) were analyzed for anti-PEG-ASP immunoglobulin G by enzyme-linked immunosorbent assay. Positive samples were tested for anti-polyethylene glycol (PEG) and anti-L-ASP. We analyzed potential risk factors for reactions and associations between antibodies and reactions, rechallenge outcomes, and PEG-ASP pharmacokinetics. RESULTS: Grade 2 to 4 reactions were less common in the Total XVI study with PEG-ASP (81 [13.5%] of 598) than in the Total XV study with L-ASP (169 [41.2%] of 410; P = 1.4 × 10-23). For Total XVI, anti-PEG, not anti-L-ASP, was the predominant component of anti-PEG-ASP antibodies (96%). In a multivariable analysis, more intrathecal therapy (IT) predicted fewer reactions (P = 2.4 × 10-5), which is consistent with an immunosuppressant contribution of IT. Anti-PEG-ASP was associated with accelerated drug clearance (P = 5.0 × 10-6). Failure of rechallenge after initial reactions was associated with anti-PEG-ASP (P = .0078) and was predicted by the occurrence of angioedema with first reaction (P = .01). CONCLUSION: Less IT therapy was the only independent clinical risk factor for reactions to PEG-ASP. PEG, and not L-ASP, is the major antigen that causes allergic reactions. Anti-PEG-ASP has utility in predicting and confirming clinical reactions to PEG-ASP as well as in identifying patients who are most likely to experience failure with rechallenge.