Carbon nanotube bottles for incorporation, release and enhanced cytotoxic effect of cisplatin.

Carbon nanotubes (CNTs) have emerged as promising drug delivery systems particularly for cancer therapy, due to their abilities to overcome some of the challenges faced by cancer treatment, namely non-specificity, poor permeability into tumour tissues, and poor stability of anticancer drugs. Encapsulation of anticancer agents inside CNTs provides protection from external deactivating agents. However, the open ends of the CNTs leave the encapsulated drugs exposed to the environment and eventually their uncontrolled release before reaching the desired target.

Spatial memory training induces morphological changes detected by manganese-enhanced MRI in the hippocampal CA3 mossy fiber terminal zone.

Hippocampal mossy fibers (MFs) can show plasticity of their axon terminal arbor consequent to learning a spatial memory task. Such plasticity is seen as translaminar sprouting from the stratum lucidum (SL) of CA3 into the stratum pyramidale (SP) and the stratum oriens (SO). However, the functional role of this presynaptic remodeling is still obscure.

Graphene Multi-Walled Carbon Nanotubes for Electrochemical Glucose Biosensing.

A simple procedure was developed for the fabrication of electrochemical glucose biosensors using glucose oxidase (GOx), with graphene or multi-walled carbon nanotubes (MWCNTs). Graphene and MWCNTs were dispersed in 0.25% 3-aminopropyltriethoxysilane (APTES) and drop cast on 1% KOH-pre-treated glassy carbon electrodes (GCEs).

Structural basis for the interaction of unstructured neuron specific substrates neuromodulin and neurogranin with Calmodulin.

Neuromodulin (Nm) and neurogranin (Ng) are neuron-specific substrates of protein kinase C (PKC). Their interactions with Calmodulin (CaM) are crucial for learning and memory formation in neurons. Here, we report the structure of IQ peptides (24aa) of Nm/Ng complexed with CaM and their functional studies with full-length proteins.

Mediatorless amperometric glucose biosensing using 3-aminopropyltriethoxysilane-functionalized graphene.

A mediatorless glucose biosensor was developed by the immobilization of glucose oxidase (GOx) to graphene-functionalized glassy carbon electrode (GCE). The surface of GCE was functionalized with graphene by incubating it with graphene dispersed in 3-aminopropyltriethoxysilane (APTES), which acted both as a dispersion agent for graphene and as an amine surface modification agent for GCE and graphene. This was followed by the covalent binding of GOx to graphene-functionalized GCE using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) based crosslinking.

Quantitative analysis of zinc in rat hippocampal mossy fibers by nuclear microscopy.

Zinc (Zn) is involved in regulating mental and motor functions of the brain. Previous approaches have determined Zn content in the brain using semi-quantitative histological methods. We present here an alternative approach to map and quantify Zn levels in the synapses from mossy fibers to CA3 region of the hippocampus.

Rapid and simple preparation of a reagentless glucose electrochemical biosensor.

A rapid and simple procedure was developed for the preparation of a highly stable and leach-proof glucose oxidase (GOx)-bound glassy carbon electrode (GCE). Crosslinked GOx via glutaraldehyde was drop-cast on a KOH-pretreated GCE followed by drop-casting of 3-aminopropyltriethoxysilane (APTES) to form a stable bioactive layer. At -0.

Technology behind commercial devices for blood glucose monitoring in diabetes management: a review.

The blood glucose monitoring devices (BGMDs) are an integral part of diabetes management now-a-days. They have evolved tremendously within the last four decades in terms of miniaturization, rapid response, greater specificity, simplicity, minute sample requirement, painless sample uptake, sophisticated software and data management. This article aims to review the developments in the technologies behind commercial BGMD, especially those in the areas of chemistries, mediators and other components.

Sulfo-N-hydroxysuccinimide interferes with bicinchoninic acid protein assay.

This study revealed a major interference from sulfo-N-hydroxysuccinimide (sulfo-NHS) in the bicinchoninic acid (BCA) protein assay. Sulfo-NHS, a common reagent used in bioconjugation and analytical biochemistry, exhibited absorbance signals and absorbance peaks at 562 nm, comparable to bovine serum albumin (BSA). However, the combined absorbance of sulfo-NHS and BSA was not strictly additive.

Purification, functionalization, and bioconjugation of carbon nanotubes.

Bioconjugation of carbon nanotubes (CNTs) with biomolecules promises exciting applications such as biosensing, nanobiocomposite formulation, design of drug vector systems, and probing protein interactions. Pristine CNTs, however, are virtually water-insoluble and difficult to evenly disperse in a liquid matrix. Therefore, it is necessary to attach molecules or functional groups to their sidewalls to enable bioconjugation.

Advances in carbon nanotube based electrochemical sensors for bioanalytical applications.

Electrochemical (EC) sensing approaches have exploited the use of carbon nanotubes (CNTs) as electrode materials owing to their unique structures and properties to provide strong electrocatalytic activity with minimal surface fouling. Nanofabrication and device integration technologies have emerged along with significant advances in the synthesis, purification, conjugation and biofunctionalization of CNTs. Such combined efforts have contributed towards the rapid development of CNT-based sensors for a plethora of important analytes with improved detection sensitivity and selectivity.

Interfacing carbon nanotubes with living mammalian cells and cytotoxicity issues.

The unique structures and properties of carbon nanotubes (CNTs) have attracted extensive investigations for many applications, such as those in the field of biomedical materials and devices, biosensors, drug delivery, and tissue engineering. Anticipated large-scale productions for numerous diversified applications of CNTs might adversely affect the environment and human health. For successful applications in the biomedical field, the issue of interfacing between CNTs and mammalian cells in vitro needs to be addressed before in vivo studies can be carried out systematically.

Modification of carbon nanotubes with redox hydrogel: improvement of amperometric sensing sensitivity for redox enzymes.

This study demonstrated that redox hydrogel-modified carbon nanotube (CNT) electrodes can be developed as an amperometric sensor that are sensitive, specific and fast and do not require auxiliary enzymes. A redox polymer, poly(vinylimidazole) complexed with Os(4,4'-dimethylbpy)(2)Cl (PVI-dmeOs) was electrodeposited on Ta-supported multi-walled CNTs. The resulted PVI-dmeOs thin film did not change the surface morphology of the CNTs, but turned the CNT surface from hydrophobic to hydrophilic, as studied by scanning electron microscopy (SEM) and static water contact angle measurements.

Characterization and field emission performance of electrochemically synthesized FeOOH nanowalls.

We report a direct method for the synthesis of Iron(III) oxyhydroxide (FeOOH) nanowalls using an electrochemical technique at room temperature. The length of the nanowalls can be varied depending on the number of repetitive potentiostatic pulse cycles during the electrochemical process. The samples were characterized by ex-situ techniques such as SEM, XPS, FTIR, and TEM.

Selective and sensitive electrochemical detection of glucose in neutral solution using platinum-lead alloy nanoparticle/carbon nanotube nanocomposites.

Electrodeposition of Pt-Pb nanoparticles (PtPbNPs) to multi-walled carbon nanotubes (MWCNTs) resulted in a stable PtPbNP/MWCNT nanocomposite with high electrocatalytic activity to glucose oxidation in either neutral or alkaline medium. More importantly, the nanocomposite electrode with a slight modification exhibited high sensitivity, high selectivity, and low detection limit in amperometric glucose sensing at physiological neutral pH (poised at a negative potential). At +0.

Proteomics analysis of the expression of neurogranin in murine neuroblastoma (Neuro-2a) cells reveals its involvement for cell differentiation.

Neurogranin (Ng) is a neural-specific, calmodulin (CaM)-binding protein that is phosphorylated by protein kinase C (PKC). Although its biochemical property has been well characterized, the physiological function of Ng needs to be elucidated. In the present study, we performed proteomics analysis of the induced compositional changes due to the expression of Ng in murine neuroblastoma (Neuro-2a) cells using isotope coded affinity tags (ICAT) combined with 2-dimensional liquid chromatography/tandem mass spectrometry (2D-LC/MS/MS).

Frontal cortical alpha7 and alpha4beta2 nicotinic acetylcholine receptors in working and reference memory.

The alpha7 and alpha4beta2 nicotinic acetylcholine receptor (nAchR) subtypes have been shown to be involved in memory. It is also known that losses of frontal cortical nAchRs are correlated to declining memory function in Alzheimer's disease, but the subtype-specific role of frontal cortical nAchRs in memory has not been well characterized. Hence, we sought to understand the role of frontal cortical alpha7 and alpha4beta2 nAchR subtypes in both working and reference memory by observing the effects of subtype specific agonists and antagonists on radial arm maze performance.

Cell adhesion properties on photochemically functionalized diamond.

The biocompatibility of diamond was investigated with a view toward correlating surface chemistry and topography with cellular adhesion and growth. The adhesion properties of normal human dermal fibroblast (NHDF) cells on microcrystalline and ultrananocrystalline diamond (UNCD) surfaces were measured using atomic force microscopy. Cell adhesion forces increased by several times on the hydrogenated diamond surfaces after UV irradiation of the surfaces in air or after functionalization with undecylenic acid.

Tanshinone IIB, a primary active constituent from Salvia miltiorrhza, exhibits neuro-protective activity in experimentally stroked rats.

Tanshinone IIB (TSB) is a major active constituent of the root of Salvia miltiorrhiza (Danshen) used in the treatment of acute stroke. Danshen extracts and TSB have shown marked neuron-protective effects in mouse studies but there is a lack of clinical evidence for the neuron-protective effects of Danshen and its active ingredients. This study investigated the neuron-protective effects of TSB in experimentally stroked rats.

Characterization of transcriptional regulation of neurogranin by nitric oxide and the role of neurogranin in SNP-induced cell death: implication of neurogranin in an increased neuronal susceptibility to oxidative stress.

Neurogranin (Ng), a calmodulin (CaM)-binding protein kinase C (PKC) substrate, regulates the availability of Ca(2+)/CaM complex and modulates the homeostasis of intracellular calcium in neurons. Previous work showed Ng oxidation by NO donor induces increase in [Ca(2+)](i). The current study demonstrated that the gene transcription of Ng could be up-regulated by various nitric oxide (NO) donors via a NO-soluble guanylyl cyclase (sGC)-mediated pathway.

Role of P-glycoprotein in the intestinal absorption of glabridin, an active flavonoid from the root of Glycyrrhiza glabra.

Glabridin is a major constituent of the root of Glycyrrhiza glabra, which is commonly used in the treatment of cardiovascular and central nervous system diseases. This study aimed to investigate the role of P-glycoprotein (PgP/MDR1) in the intestinal absorption of glabridin. The systemic bioavailability of glabridin was approximately 7.

Preparation and characterization of aligned carbon nanotube-ruthenium oxide nanocomposites for supercapacitors.

A novel type of ruthenium oxide (RuO(2))-modified multi-walled carbon nanotube (MWNT) nanocomposite electrode (RuO(2)/MWNT) for supercapacitors has been prepared. The nanocomposites were formed by depositing Ru by magnetic-sputtering in an Ar/O(2) atmosphere onto MWNTs, which were synthesized on Ta plates by chemical vapor deposition. Cyclic voltammetry, chronopotentiometry, and electrochemical impedance measurements were applied to investigate the performance of the RuO(2)/MWNT nanocomposite electrodes.

St. John's wort attenuates irinotecan-induced diarrhea via down-regulation of intestinal pro-inflammatory cytokines and inhibition of intestinal epithelial apoptosis.

Diarrhea is a common dose-limiting toxicity associated with cancer chemotherapy, in particular for drugs such as irinotecan (CPT-11), 5-fluouracil, oxaliplatin, capecitabine and raltitrexed. St. John's wort (Hypericum perforatum, SJW) has anti-inflammatory activity, and our preliminary study in the rat and a pilot study in cancer patients found that treatment of SJW alleviated irinotecan-induced diarrhea.

Microelectrode array biochip: tool for in vitro drug screening based on the detection of a drug effect on dopamine release from PC12 cells.

Novel, yet simple detection techniques of drug effect, including the effect of a vesicular monoamine transporter inhibitor (reserpine), a dopamine precursor (L-dopa), and a dopamine transporter inhibitor (nomifensine), on dopamine release from dopaminergic PC12 cells were developed based on a microelectrode array (MEA) biochip. Upon multi-injections of KCl solution into the culture of PC12 cells attached on a MEA biochip, the K+-stimulated dopamine release was temporally and amperometrically recorded by biochip microelectrodes. Two parameters in the recorded amperometric spectra were defined in this study: the peak current of the first KCl injection (Max1), and the steady current after the fourth KCl injection (St4).