Management and outcome of pediatric brainstem and cerebellar peduncular low-grade gliomas: a retrospective analysis of 62 cases.

PURPOSE: This study was designed to present our experience and recommendations regarding the management of pediatric brainstem and peduncular low-grade gliomas (LGGs). METHODS: Retrospective analysis was performed for pathologically proven brainstem or cerebellar peduncular LGGs in patients admitted between 2014 and 2019. These lesions were classified into the dorsal exophytic, focal brainstem, cervicomedullary, lower peduncular, and upper peduncular groups, and this classification was the basis for the surgical approach for the lesions. RESULTS: Sixty-two pediatric patients were included, and their distribution among the aforementioned groups were as follows: 12, 12, 3, 16, and 19 cases in the dorsal exophytic, focal brainstem, cervicomedullary, upper peduncular, and lower peduncular groups, respectively. Stereotactic biopsy was performed for all cases in the focal brainstem group, whereas other groups underwent open excision. Gross total resection (GTR) was achieved in 20 cases (40%), near-total resection (NTR) was achieved in 17 cases (34%), and subtotal resection (STR) was achieved in 13 cases (26%). The extent of GTR and NTR for the upper peduncular, lower peduncular, dorsal exophytic, and cervicomedullary groups were 81.2%, 68.4%,75%, and 66.6%, respectively. Then, 32 cases received chemotherapy. The 3- and 5-year progression-free survival rates were 95% (95% confidence interval (CI) 89.5-100%) and 90.3% (95% CI 79.9-100%), respectively. A significant difference in the 3-year progression-free survival rate was observed between the GTR and NTR groups (p = 0.06; 100% vs. 88.2% (95% CI 72.9-100%)). CONCLUSION: Surgery plays a definitive curative role in grossly resected cases. Additionally, the role of surgical debulking should be considered, even if GTR is impossible. Meanwhile, chemotherapy showed a beneficial role in patients with focal brainstem lesions and progressive lesions, those with STR, and some patients with NTR.

Cubically cage-shaped mesoporous ordered silica for simultaneous visual detection and removal of uranium ions from contaminated seawater.

A dual-function organic-inorganic mesoporous structure is reported for naked-eye detection and removal of uranyl ions from an aqueous environment. The mesoporous sensor/adsorbent is fabricated via direct template synthesis of highly ordered silica monolith (HOM) starting from a quaternary microemulsion liquid crystalline phase. The produced HOM is subjected to further modifications through growing an organic probe, omega chrome black blue G (OCBBG), in the cavities and on the outer surface of the silica structure. The spectral response for [HOM-OCBBG → U(VI)] complex shows a maximum reflectance at λmax = 548 nm within 1 min response time (tR); the LOD is close to 9.1 µg/L while the LOQ approaches 30.4 µg/L, and this corresponds to the range of concentration where the signal is linear against U(VI) concentration (i.e., 5-1000 µg/L) at pH 3.4 with standard deviation (SD) of 0.079 (RSD% = 11.7 at n = 10). Experiments and DFT calculations indicate the existence of strong binding energy between the organic probe and uranyl ions forming a complex with blue color that can be detected by naked eyes even at low uranium concentrations. With regard to the radioactive remediation, the new mesoporous sensor/captor is able to reach a maximum capacity of 95 mg/g within a few minutes of the sorption process. The synthesized material can be regenerated using simple leaching and re-used several times without a significant decrease in capacity.

In Situ Detection of Neurotransmitters from Stem Cell-Derived Neural Interface at the Single-Cell Level via Graphene-Hybrid SERS Nanobiosensing.

In situ quantitative measurements of neurotransmitter activities can provide useful insights into the underlying mechanisms of stem cell differentiation, the formation of neuronal networks, and neurodegenerative diseases. Currently, neurotransmitter detection methods suffer from poor spatial resolution, nonspecific detection, and a lack of in situ analysis. To address this challenge, herein, we first developed a graphene oxide (GO)-hybrid nanosurface-enhanced Raman scattering (SERS) array to detect dopamine (DA) in a selective and sensitive manner. Using the GO-hybrid nano-SERS array, we successfully measured a wide range of DA concentrations (10-4 to 10-9 M) rapidly and reliably. Moreover, the measurement of DA from differentiating neural stem cells applies to the characterization of neuronal differentiation. Given the challenges of in situ detection of neurotransmitters at the single-cell level, our developed SERS-based detection method can represent a unique tool for investigating single-cell signaling pathways associated with DA, or other neurotransmitters, and their roles in neurological processes.

Application of Conducting Polymer Nanostructures to Electrochemical Biosensors.

Over the past few decades, nanostructured conducting polymers have received great attention in several application fields, including biosensors, microelectronics, polymer batteries, actuators, energy conversion, and biological applications due to their excellent conductivity, stability, and ease of preparation. In the bioengineering application field, the conducting polymers were reported as excellent matrixes for the functionalization of various biological molecules and thus enhanced their performances as biosensors. In addition, combinations of metals or metal oxides nanostructures with conducting polymers result in enhancing the stability and sensitivity as the biosensing platform. Therefore, several methods have been reported for developing homogeneous metal/metal oxide nanostructures thin layer on the conducting polymer surfaces. This review will introduce the fabrications of different conducting polymers nanostructures and their composites with different shapes. We will exhibit the different techniques that can be used to develop conducting polymers nanostructures and to investigate their chemical, physical and topographical effects. Among the various biosensors, we will focus on conducting polymer-integrated electrochemical biosensors for monitoring important biological targets such as DNA, proteins, peptides, and other biological biomarkers, in addition to their applications as cell-based chips. Furthermore, the fabrication and applications of the molecularly imprinted polymer-based biosensors will be addressed in this review.

Carbon-dot wrapped ZnO nanoparticle-based photoelectrochemical sensor for selective monitoring of H2O2 released from cancer cells.

This study reports on a simple approach for the fabrication of an electrode modified with biocompatible C-dot wrapped ZnO nanoparticles for selective photoelectrochemical monitoring of H2O2 released from living cells. The biocompatibility of the ZnO nanoparticles was confirmed through in-vitro cellular testing using the MTT assay on Huh7 cell lines. The ZnO nanoparticles wrapped with dopamine-derived C-dots possess numerous catalytically active sites, excessive surface defects, good electrical conductivity, and efficient separation ability of photo-induced electrons and holes. These properties offer highly sensitive and selective non-enzymatic photo-electrochemical monitoring of H2O2 released from HeLa cells after stimulation with N-formylmethionyl-leucyl-phenylalanine. The sensor has a wide linear range (20-800 nM), low detection limit (2.4 nM), and reliable reproducibility, this implying its suitability for biological and biomedical applications. Graphical abstract Schematic of the fabrication of ZnO nanoparticles by using a plant extract as a reducing agent. Wrapping of ZnO with C-dots enhances the photoelectrocatalytic efficacy. Sensitive and selective photoelectrochemical monitoring of H2O2 released from cancer cells is demonstrated.

Silver Nanoparticle Modified Electrode Covered by Graphene Oxide for the Enhanced Electrochemical Detection of Dopamine.

Several neurological disorders such as Alzheimer's disease and Parkinson's disease have become a serious impediment to aging people nowadays. One of the efficient methods used to monitor these neurological disorders is the detection of neurotransmitters such as dopamine. Metal materials, such as gold and platinum, are widely used in this electrochemical detection method; however, low sensitivity and linearity at low dopamine concentrations limit the use of these materials. To overcome these limitations, a silver nanoparticle (SNP) modified electrode covered by graphene oxide for the detection of dopamine was newly developed in this study. For the first time, the surface of an indium tin oxide (ITO) electrode was modified using SNPs and graphene oxide sequentially through the electrochemical deposition method. The developed biosensor provided electrochemical signal enhancement at low dopamine concentrations in comparison with previous biosensors. Therefore, our newly developed SNP modified electrode covered by graphene oxide can be used to monitor neurological diseases through electrochemical signal enhancement at low dopamine concentrations.

Synthesis of copper/nickel nanoparticles using newly synthesized Schiff-base metals complexes and their cytotoxicity/catalytic activities.

Transition metal complexes compounds with Schiff bases ligand representing an important class of compounds that could be used to develop new metal-based anticancer agents and as precursors of metal NPs. Herein, 2,3-bis-[(3-ethoxy-2-hydroxybenzylidene)amino]but-2-enedinitrile Schiff base ligand and its corresponding copper/nickel complexes were synthesized. Also, we reported a facile and rapid method for synthesis nickel/copper nanoparticles based on thermal reduction of their complexes. Free ligand, its metal complexes and metals nanoparticles have been characterized based on elemental analysis, transmission electron microscopy, powder X-ray diffraction, magnetic measurements and by various spectroscopic (UV-vis, FT-IR, (1)H NMR, GC-MS) techniques. Additionally, the in vitro cytotoxic activity of free ligand and its complexes compounds were assessed against two cancer cell lines (HeLa and MCF-7 cells)and one healthy cell line (HEK293 cell). The copper complex was found to be active against these cancer cell lines at very low LD50 than the free ligand, while nickel complex did not show any anticancer activity against these cell lines. Also, the antibacterial activity of as-prepared copper nanoparticles were screened against Escherichia coli, which demonstrated minimum inhibitory concentration and minimum bactericidal concentration values lower than those values of the commercial Cu NPs as well as the previous reported values. Moreover, the synthesized nickel nanoparticles demonstrated remarkable catalytic performance toward hydrogenation of nitrobenzene that producing clean aniline with high selectivity (98%). This reactivity could be attributed to the high degree of dispersion of Ni nanoparticles.

Enzyme-free glucose sensor based on Au nanobouquet fabricated indium tin oxide electrode.

In this study, we demonstrated a simple, rapid and inexpensive fabrication method to develop a novel gold nanobouquet structure fabricated indium tin oxide (GNB/ITO) electrode based on electrochemical deposition of gold ions onto ITO substrate. The morphology of the fabricated electrode surface was characterized by scanning electron microscopy (SEM) to confirm the GNB formation. Enzyme-free detection of glucose using a GNB/ITO electrode was described with high sensitivity and selectivity based on cyclic voltammetry assay. The results demonstrate a linear relation within wide concentration range (500 nM to 10 mM) of glucose, with a correlation coefficient of 0.988. The interference effect of uric acid was effectively avoided for the detection of glucose (1 µM to 10 mM). Moreover, the developed sensor was applied to determine the concentration of glucose in the presence of human serum to indicate the ability of GNB/ITO electrodes in real samples. Hence, newly developed GNB/ITO electrode has potential application in enzyme-free glucose sensor with highly sensitivity and selectivity.

Inhibition of apoptosis and biofilm formation in Candida auris by click-synthesized triazole-bridged quinoline derivatives.

Candida auris, a recent addition to the Candida species, poses a significant threat with its association to numerous hospital outbreaks globally, particularly affecting immunocompromised individuals. Given its resistance to existing antifungal therapies, there is a pressing need for innovative treatments. In this study, novel triazole bridged quinoline derivatives were synthesized and evaluated for their antifungal activity against C. auris. The most promising compound, QT7, demonstrated exceptional efficacy with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 0.12 µg mL-1 and 0.24 µg mL-1, respectively. Additionally, QT7 effectively disrupted mature biofilms, inhibiting them by 81.98% ± 8.51 and 89.57 ± 5.47 at MFC and 2× MFC values, respectively. Furthermore, QT7 induced cellular apoptosis in a dose-dependent manner, supported by various apoptotic markers such as phosphatidylserine externalization, mitochondrial depolarization, and reduced cytochrome c and oxidase activity. Importantly, QT7 exhibited low hemolytic activity, highlighting its potential for further investigation. Additionally, the physicochemical properties of this compound suggest its potential as a lead drug candidate, warranting further exploration in drug discovery efforts against Candida auris infections.

ITO/gold nanoparticle/RGD peptide composites to enhance electrochemical signals and proliferation of human neural stem cells.

A cell chip composed of ITO, gold nanoparticles (GNP) and RGD-MAP-C peptide composites was fabricated to enhance the electrochemical signals and proliferation of undifferentiated human neural stem cells (HB1.F3). The structural characteristics of the fabricated surfaces were confirmed by both scanning electron microscopy and surface-enhanced Raman spectroscopy. HB1.F3 cells were allowed to attach to various composites electrodes in the cell chip and the material-dependent effects on electrochemical signals and cell proliferation were analyzed. The ITO/60 nm GNP/RGD-MAP-C composite electrode was found to be the best material in regards to enhancing the voltammetric signals of HB1.F3 cells when exposed to cyclic voltammetry, as well as for increasing cell proliferation. Differential pulse voltammetry was performed to evaluate the adverse effects of doxorubicin on HB1.F3 cells. In these experiments, negative correlations between cell viability and chemical concentrations were obseved, which were more sensitive than MTT viability assay especially at low concentrations (<0.1 µg/mL). FROM THE CLINICAL EDITOR: In this basic science study, a cell chip composed of ITO, gold nanoparticles and RGD-MAP-C peptide composites was fabricated to enhance electrochemical signals and proliferation of undifferentiated human neural stem cells (HB1.F3). The ITO/60 nm GNP/RGD-MAP-C composite electrode was found to best enhance the voltammetric signals of the studied cells.

Electrochemical Sensing of Dopamine Using Polypyrrole/Molybdenum Oxide Bilayer-Modified ITO Electrode.

The electrochemical sensing of biomarkers has attracted more and more attention due to the advantages of electrochemical biosensors, including their ease of use, excellent accuracy, and small analyte volumes. Thus, the electrochemical sensing of biomarkers has a potential application in early disease diagnosis diagnosis. Dopamine neurotransmitters have a vital role in the transmission of nerve impulses. Here, the fabrication of a polypyrrole/molybdenum dioxide nanoparticle (MoO3 NP)-modified ITO electrode based on a hydrothermal technique followed by electrochemical polymerization is reported. Several techniques were used to investigate the developed electrode's structure, morphology, and physical characteristics, including SEM, FTIR, EDX, N2 adsorption, and Raman spectroscopy. The results imply the formation of tiny MoO3 NPs with an average diameter of 29.01 nm. The developed electrode was used to determine low concentrations of dopamine neurotransmitters based on cyclic voltammetry and square wave voltammetry techniques. Furthermore, the developed electrode was used for monitoring dopamine in a human serum sample. The LOD for detecting dopamine by using MoO3 NPs/ITO electrodes based on the SWV technique was around 2.2 nmol L-1.

A photoluminescence sensor for in-situ monitoring of the dopamine neurotransmitters released from PC12 cells.

Constructing simple, stable, fast, and sensitive neurotransmitter-based sensors is a promising tool to diagnose neurological diseases. Dopamine (DA), "a catecholamine neurotransmitter" is important in transmitting nerve impulses. Therefore, great attention is taken to monitor DA concentrations received. The challenge in developing a DA-based sensor is to enhance its stability and sensitivity. Thus, we have used o-phthalaldehyde (OPA)/2-mercapto ethanol (2ME)/mesoporous silica instated of 2ME in solution. Here we have successfully developed a fluorescence DA neurotransmitters sensor. The sensor was used for detecting a wide range of concentrations of DA (5 nM to 5 µM). Effects of pH (4.3-11.4) and temperatures (25-70 °C) on the sensor efficiency were investigated. The detection limit was 1.35 × 10-11 mol/dm3, which is lower than the normal DA level in the central nervous system. The results indicated that using OPA/2ME/MSNPs has long-time stability over a year of its preparation. Moreover, the developed sensor showed high specificity towards DA in the presence of different interferences such as ascorbic acid or another catecholamine neurotransmitter such as γ-aminobutyric acid. Finally, the fabricated biosensor was used to monitor the DA neurotransmitter released from PC12 cells. Hence, it was successfully developed a simple and stable probe for accurate photoluminescence detection of DA neurotransmitters.

Cell chip based monitoring of toxic effects on dopaminergic cell.

Oxidative stress has been implicated in pesticide-induced neurotoxicity, base on its role in cascade of biochemical changes that lead to dopaminergic neuronal cell death. The present study examined the role of oxidative stress and the electrochemical detection by polychlorinated biphenyls (PCBs)-induced toxicant in SH-SY5Y cell. The cells were seed in the RED (Arg-Gly-Asp) nanopatterned coating gold substrate and treated with different concentration of PCBs for 24 h in culture, which induced the change of the cyclic voltammetry (CV) current peak. The CV results showed that PCB significantly decreased the current peaks in dose and time-dependent manner. After antioxidant treatment, the CV of the PCB-treated cell chip increased the current peak. Especially, gluthaione and catalase prevent PCB-induced decrease of CV current peak in the cell. The results demonstrated that the current peak decreased by the PCB and recovered by the antioxidant enzyme. In conclusion, results suggest that the electrochemical-based chip provide crucial information to improvement toward a cell chip system for drug screening application.

Nanoscale biofilm modification-method concerning a myoglobin/11-MUA bilayers for bioelectronic device.

We developed surface modification tools for the fabrication of a bioelectronic device which consists of a myoglobin monolayer self-assembled on an 11-MUA layer. To utilize a single protein as the active element, it was necessary to reduce protein aggregation on the protein layer in the nanobio electronic device, which was developed in our previous study and shown to display basic biomemory functions. Here, the reduction of myoglobin aggregation was accomplished by using 3-(3-cholamidopropyl) dimethylammonio-11-propanesulfonate (CHAPS) to fabricate a well-defined protein layer on the bioelectronic device. We investigated two different surface modification methods for making well oriented biofilm. The effects of CHAPS on the formation of a myoglobin layer self-assembled on an 11-MUA layer were examined by atomic force microscopy and Raman spectroscopy. The size of the myoglobin aggregates was reduced from 200-250 nm to 10-40 nm depending on treatment method. The sustaining redox property of the CHAPS treated myoglobin layer was examined using cyclic voltammetry. Using these techniques, we found that after surfactant CHAPS treatment, protein aggregation was dramatically reduced and the protein layer still maintained its inherent electrochemical properties.

Hydrothermal synthesis of Mn3O4 nanorods modified indium tin oxide electrode as an efficient nanocatalyst towards direct urea electrooxidation.

Control fabrication of metal-oxide nanocatalysts for electrochemical reactions has received considerable research attention. Here, manganese oxide (Mn3O4) nanorods modified indium tin oxide (ITO) electrodes were prepared based on the in-situ one-step hydrothermal methods. The nanorods were well characterized using field emission scanning electron microscopy, Fourier transform infrared, and X-ray diffraction spectroscopy. The results showed the formation of pure crystalline Mn3O4 nanorods with a length of approximately 1.4 µm and a thickness of approximately 100 ± 30 nm. The Mn3O4 nanorod-modified ITO electrodes were used for accelerating urea electrochemical oxidation at room temperature using cyclic and square wave voltammetry techniques. The results indicated that the modified electrode demonstrated excellent electrocatalytic performance toward urea electrooxidation in an alkaline medium over concentrations ranging from 0.2 to 4 mol/L. The modified electrode showed high durability, attaining more than 88% of its baseline performance after 150 cycles; furthermore, the chronoamperometry technique demonstrated high stability. Thus, the Mn3O4 nanorod-modified ITO electrode is a promising anode for direct urea fuel cell applications.

Synthesis of gold nanoparticles@reduced porous graphene-modified ITO electrode for spectroelectrochemical detection of SARS-CoV-2 spike protein.

Here, we reported the synthesis of reduced porous graphene oxide (rPGO) decorated with gold nanoparticles (Au NPs) to modify the ITO electrode. Then we used this highly uniform Au NPs@rPGO modified ITO electrode as a surface-enhanced Raman spectroscopy-active surface and a working electrode. The uses of the Au nanoparticles and porous graphene enhance the Raman signals and the electrochemical conductivity. COVID-19 protein-based biosensor was developed based on immobilization of anti-COVID-19 antibodies onto the modified electrode and its uses as a probe for capturing the COVID-19 protein. The developed biosensor showed the capability of monitoring the COVID-19 protein within a concentration range from 100 nmol/L to 1 pmol/L with a limit of detection (LOD) of 75 fmol/L. Furthermore, COVID-19 protein was detected based on electrochemical techniques within a concentration range from 100 nmol/L to 500 fmol/L that showed a LOD of 39.5 fmol/L. Finally, three concentrations of COVID-19 protein spiked in human serum were investigated. Thus, the present sensor showed high efficiency towards the detection of COVID-19.

Fabrication of Hollow Nanocones Membrane with an Extraordinary Surface Area as CO2 Sucker.

Recently, more and more attention has been paid to the development of eco-friendly solid sorbents that are cost-effective, noncorrosive, have a high gas capacity, and have low renewable energy for CO2 capture. Here, we claimed the fabrication of a three-dimensional (3D) film of hollow nanocones with a large surface area (949.5 m2/g), a large contact angle of 136.3°, and high surface energy. The synthetic technique is based on an electrochemical polymerization process followed by a novel and simple strategy for pulling off the formed layers as a membrane. Although the polymer-coated substrates were reported previously, the membrane formation has not been reported elsewhere. The detachable capability of the manufactured layer as a membrane braked the previous boundaries and allows the membrane's uses in a wide range of applications. This 3D hollow nanocones membrane offer advantages over conventional ones in that they combine a π-electron-rich (aromatic ring), hydrophobicity, a large surface area, multiple amino groups, and a large pore volume. These substantial features are vital for CO2 capturing and storage. Furthermore, the hydrophobicity characteristic and application of the formed polymer as a CO2 sucker were investigated. These results demonstrated the potential of the synthesized 3D hollow polymer to be used for CO2 capturing with a gas capacity of about 68 mg/g and regeneration ability without the need for heat up.

A stable naked-eye colorimetric sensor for monitoring release of extracellular gamma-aminobutyric acid (GABA) neurotransmitter from SH-SY5Y cells.

A novel optical γ-aminobutyric acid (GABA)-based sensor was developed on interacting thiol compounds and o-phthalaldehyde (OPA) to form thiacetal compounds. Then, the thiacetal interacts with the GABA molecule to form an isoindole compound. The effects of four thiol compounds on the stability of the resulting isoindole compound were assessed. The 2-mercaptoethanol, "one of the most used derivatizing agents," is unexpectedly the least stable; while, 16-mercaptohexadecanoic acid resulted in the most durable isoindole compound. The developed sensor showed the capability for detecting GABA within a wide concentration range spanning from 500 nmol L-1 to 100 µmol L-1. The detection limit was about 330 nmol L-1, which indicated the high sensitivity of the developed sensor compared with those previously reported. The findings illustrated the ability to detect GABA at the physiological pH (pH = 7.4) without adjusting the pH value, opening the door for real applications. Furthermore, the sensor could detect various GABA concentrations in human serum with good recovery percentages (98% to 101.4%). In addition, this assay was applied to monitor GABA release from the SH-SY5Y cell line to convert glutamate into GABA. This result indicates the capability of the proposed assay for visually monitoring the release of GABA neurotransmitters.

Design and synthesis of a combined meso-adsorbent/chemo-sensor for extraction and detection of silver ions.

We synthesized a new pH-dependent meso-captor/sensor for the visual monitoring and selective sequestering of Ag(I) ions from wastewater. The SBA-16 microspheres were successfully synthesized via a direct hydrothermal treatment through surfactant-assisted cooperative self-assembly. The meso-captor/sensor was designed via the direct immobilization of the chromogenic Acid Blue 90 (AB90) chelate into cubical large, open mesoporous SBA-16 carriers and investigate of its ability to detect and retain silver ions from aqueous solutions. Results show that the synthesized SBA-16 microspheres were retained after modification and the AB90 functional groups were immobilized hierarchically inside the mesopore channels. This was evidenced by the N2 adsorption, X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), High-Resolution Transmission Electron Microscope (HR-TEM), and elemental analyses. Batch adsorption experiments were carried out and the effects of various parameters on Ag(I) ions removal and detection were determined. The optimum adsorption/detection of Ag(I) ions were recorded at a pH of 6.2 within 30 min with color change from a brilliant blue to a pale blue-gray. The spectral response for [SBA-16@AB90 â†’ Ag(I)] complex showed a maximum reflectance at λmax = 385 nm within 2.5 min response time (tR); the LOD was close to 3.87 µg/L while the LOQ approached 12.83 µg/L, this was attributed to the concentration range at which a linear signal has been observed against Ag(I) analyte concentration (i.e., 5 to 1000 µg/L) at pH 6.2 with standard deviation (SD) of 0.077 (RSD% = 9.5 at n = 8).