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Mark Ware, Gopi Shankar, Patrick Breslin, Tong-Yuan Yang
No abstract text is available yet for this article.
March 21, 2018: Bioanalysis
Aimin Tan, John C Fanaras
LC-MS/MS has been the dominant analytical technology for quantitative bioanalysis of drugs and metabolites for more than two decades. Despite this, a very fundamental question like how much separation is required for LC-MS/MS quantitative bioanalysis of drugs and metabolites has not been adequately addressed. Some think that no or only very limited separation is necessary thanks to the unparalleled selectivity offered by tandem mass spectrometry. Others think that the more separation, the better, because of the potential detrimental impact of matrix effect (ion suppression or enhancement)...
March 14, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Flávia N S Fachel, Marina C Nemitz, Bruna Medeiros-Neves, Kleyton S Veras, Valquíria L Bassani, Letícia S Koester, Amelia T Henriques, Helder F Teixeira
Currently, there is an increasing interest on the development of topical formulations containing rosmarinic acid (RA) due to its well-documented antioxidant activity. This study aimed to develop and validate a stability-indicating ultra-fast liquid chromatography (UFLC) method for the determination of RA in nanoemulsions, porcine skin and nasal mucosa intended to be applied in permeation/retention studies and for development of topical nanoemulsions. Chromatographic separation was carried out using a C18 column packed with 2...
March 12, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Beatriz Díez-Buitrago, Nerea Briz, Luis M Liz-Marzán, Valeri Pavlov
Enzymes are pivotal elements in bioanalysis due to their specificity and extremely high catalytic activity. The sensitivity of bioanalytical assays depends mainly on the capacity of an observer to detect the product(s) of a biocatalytic reaction. Both natural and artificial compounds have been traditionally used to evaluate enzymatic activities. The drawbacks of chromogenic and fluorogenic organic enzymatic substrates are their high cost and low stability, resulting in high background signals. We review here state of the art assays in the detection of enzymatic activities using recent advances in nanoscience...
March 19, 2018: Analyst
Claudia Spatari, Wenlong Li, Alfred H Schinkel, Gaetano Ragno, Jan H M Schellens, Jos H Beijnen, Rolf W Sparidans
A bio-analytical assay for the first third generation ALK inhibitor lorlatinib in mouse plasma was developed and validated. Ten-μl plasma samples were prepared by adding rucaparib as the internal standard and precipitation of the plasma proteins. For LC-MS/MS analysis, compounds were eluted at 0.5 mL/min and separated on a 3-μm particle-size, polar embedded octadecyl silica column by gradient elution using 0.1% of formic acid (in water) and methanol. Compounds were monitored with positive electrospray ionization using a triple quadrupole mass spectrometer in selected reaction monitoring mode...
March 9, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Louise Wogelred, Fredrik Höök, Björn Agnarsson, Peter Sjövall
Accurate detection and quantification of individual molecules is important for the development of improved diagnostic methods as well as biochemical characterization of disease progression and treatments. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a surface analysis technique capable of imaging the distribution of specific molecules on surfaces with a high spatial resolution (<1 μm) and high sensitivity. ToF-SIMS is particularly suitable for detection of molecules up to ∼2 kDa, including lipids, whereas larger molecules, such as peptides and proteins, are fragmented during analysis, which makes them difficult to identify...
March 15, 2018: Biointerphases
Juanmin Li, Huipeng Zhou, Yunyi Zhang, Sohail Anjum Shahzad, Meiding Yang, Zhenzhen Hu, Cong Yu
Silver nanoparticles (Ag NPs) enhanced perylene probe excimer emission is reported for the first time. It was observed that strong interactions between the perylene probe and the Ag NPs induced co-aggregation. As a result, a new in situ generated plasmonic absportion band of the Ag NPs at longer wavelength emerged. The monomer emission of the perylene probe was efficiently quenched, and dramatically enhanced probe excimer emission was observed. A remarkable emission enhancement of over 1000 fold was obtained compared to anionic polymers and other nanoparticles...
August 3, 2018: Analytica Chimica Acta
Bo Zhang, Mouzhe Xie, Lei Bruschweiler-Li, Rafael Brüschweiler
Understanding and harnessing the interactions between nanoparticles and biological molecules is at the forefront of applications of nanotechnology to modern biology. Metabolomics has emerged as a prominent player in systems biology as a complement to genomics, transcriptomics and proteomics. Its focus is the systematic study of metabolite identities and concentration changes in living systems. Despite significant progress over the recent past, important challenges in metabolomics remain, such as the deconvolution of the spectra of complex mixtures with strong overlaps, the sensitive detection of metabolites at low abundance, unambiguous identification of known metabolites, structure determination of unknown metabolites and standardized sample preparation for quantitative comparisons...
March 13, 2018: Metabolites
Atul Bhatnagar, Matthew J McKay, Megan Crumbaker, Ketan Ahire, Peter Karuso, Howard Gurney, Mark P Molloy
Abiraterone acetate is administered as a prodrug to patients with metastatic, castration-resistant prostate cancer (mCRPC) and is readily metabolized into the potent 17a-hydroxylase/17,20-lyase (CYP17) enzyme inhibitor and androgen receptor inhibitor abiraterone and Δ(4)-abiraterone (D4A), respectively. To investigate pharmacokinetic variability in abiraterone acetate metabolism we developed highly sensitive liquid chromatography/mass spectrometry (LC/MS) assays for the simultaneous quantitation of abiraterone and D4A in human plasma using high-resolution mass spectrometry (HRMS) on an Orbitrap mass spectrometer...
March 6, 2018: Journal of Pharmaceutical and Biomedical Analysis
Dajana Vuckovic
No abstract text is available yet for this article.
March 1, 2018: Bioanalysis
Jiří Novák, Branislav Vrana, Tatsiana Rusina, Krzysztof Okonski, Roman Grabic, Peta A Neale, Beate I Escher, Miroslava Macová, Selim Ait-Aissa, Nicolas Creusot, Ian Allan, Klára Hilscherová
Many aquatic pollutants can be present at low concentrations, but their mixtures can still affect health or behavior of exposed organisms. In this study, toxicological and chemical analyses were combined for spatial contamination profiling using an innovative passive sampling approach. A novel Dynamic Passive Sampler (DPS) was employed as a mobile sampler from a ship cruising along 2130km of the Danube river during the Joint Danube Survey 3 (JDS3). The sampling was performed in eight subsequent river stretches with two types of complementary passive samplers: silicone rubber sheets (SR) used for non-polar chemicals and SDB-RPS Empore™ disks (ED) for more hydrophilic compounds...
March 9, 2018: Science of the Total Environment
Xiao-Mei Shi, Li-Ping Mei, Qian Wang, Wei-Wei Zhao, Jing-Juan Xu, Hong-Yuan Chen
We report herein the energy transfer (ET) between semiconducting polymer dots (Pdots) and gold nanoparticles (Au NPs) in a photoelectrochemical (PEC) system and its feasibility for cathodic bioanalysis application. Specifically, COOH-capped Pdots were first fabricated and then assembled onto the indium-tin oxide (ITO) surface, followed by the modification of single-strand (ss) DNA probe (pDNA). After the DNA hybridization with the Au NP-tethered complementary ssDNA (Au NP-tDNA), the Au NPs were brought into the close proximity of Pdots...
March 13, 2018: Analytical Chemistry
Mohamed A Korany, Hoda Mahgoub, Rim S Haggag, Marwa A A Ragab, Osama A Elmallah
A direct, eco-friendly, stability-indicating GC method was developed for the determination of Lacosamide (LCM) in tablet dosage forms in presence of its degradation products as well as in human urine in presence of the co-administered drug Zonisamide (ZON). The assay method in tablets was validated according to the ICH guidelines, while the method for determination of LCM in urine was validated according to FDA; Bioanalytical Method Validation guidance. Linear response (r = 0.9998) was observed over the range of 20-280 μg/mL of LCM, with detection and quantitation limits of 5...
March 7, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Thi Thuy Nguyen, Fayna Mammeri, Souad Ammar
Iron oxide and gold-based magneto-plasmonic nanostructures exhibit remarkable optical and superparamagnetic properties originating from their two different components. As a consequence, they have improved and broadened the application potential of nanomaterials in medicine. They can be used as multifunctional nanoprobes for magneto-plasmonic heating as well as for magnetic and optical imaging. They can also be used for magnetically assisted optical biosensing, to detect extreme traces of targeted bioanalytes...
March 7, 2018: Nanomaterials
Hanumanth Srikanth Cheruvu, Navneet K Yadav, Guru R Valicherla, Rakesh K Arya, Zakir Hussain, Chetan Sharma, Kamal R Arya, Rama K Singh, Dipak Datta, Jiaur R Gayen
Eclipta alba (Bhringraj) in ayurveda has been widely used as a traditional medicine for its multi-therapeutic properties for ages. Luteolin (LTL), wedelolactone (WDL) and apigenin (APG) are the three main bioactive phytochemicals present in Eclipta alba extract. However there was a lack of sensitive bioanalytical method for the pharmacokinetics of these free compounds in plasma which majorly contributes for their activities after oral administration of Eclipta alba. The present study aims to develop a sensitive, rapid and reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous estimation of mice plasma concentrations of LTL, WDL and APG using quercetin as an internal standard for the pharmacokinetic analysis...
January 31, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Juan C Domínguez-Romero, Bienvenida Gilbert-López, Miriam Beneito-Cambra, Antonio Molina-Díaz
In this work, the implementation of Bead Injection with multicommutation-based flow systems is reported. A surface renewable chemiluminescence (CL) flow sensor is presented based on the use of CL reaction of luminol with H2 O2 . Dowex 1 × 8 beads with immobilized luminol onto them were injected in the flow system by means of a six-port rotary valve and were accommodated into a 1 mm optical glass flow cell placed just in front of the rectangular photosensor window with the same size than the cell wall. Automatic computer-controlled manipulation of both reagents and sample solutions was undertaken using a multicommutated flow system which comprises five three-way solenoid valves, a home-made electronic interface and a Java-written software...
May 15, 2018: Talanta
Patrick Neiens, Angela De Simone, Anna Ramershoven, Georg Höfner, Lars Allmendinger, Klaus T Wanner
MS Binding Assays represent a label free alternative to radioligand binding assays. In this study, we present an LC-ESI-MS/MS method for the quantification of (R,R)-4-(2-benzhydryloxyethyl)-1-(4-fluorobenzyl)piperidin-3-ol ((R,R)-D-84, (R,R)-1), (S,S)-reboxetine ((S,S)-2), and (S)-citalopram ((S)-3) employed as highly selective nonlabelled reporter ligands in MS Binding Assays addressing the dopamine (DAT, (R,R)-D-84), the norepinephrine (NET, (S,S)-reboxetine), and the serotonin transporter (SERT, (S)-citalopram), respectively...
March 3, 2018: Biomedical Chromatography: BMC
Hanlu Wang, Yibang Zhang, Haiping Yang, Meng Qin, Xinxin Ding, Rihe Liu, Yongping Jiang
Aptamers are widely used in numerous biochemical, bioanalytical, and biological studies. Most aptamers are developed through an in vitro selection process called SELEX against either purified targets or living cells expressing targets of interest. We report here an in vivo SELEX in mice using a PEGylated RNA library for the identification of a 2'-F RNA aptamer (RA16) that specifically binds to NCI-H460 non-small-cell lung cancer cells with an affinity (KD ) of 9 ± 2 nM. Interestingly, RA16 potently inhibited cancer cell proliferation in a dose-dependent manner with an IC50 of 116...
March 2, 2018: Molecular Therapy. Nucleic Acids
Rolf Altenburger, Martin Scholze, Wibke Busch, Beate I Escher, Gianina Jakobs, Martin Krauss, Janet Krüger, Peta A Neale, Selim Ait-Aissa, Ana Catarina Almeida, Thomas-Benjamin Seiler, François Brion, Klára Hilscherová, Henner Hollert, Jiří Novák, Rita Schlichting, Hélène Serra, Ying Shao, Andrew Tindall, Knut-Erik Tolefsen, Gisela Umbuzeiro, Tim D Williams, Andreas Kortenkamp
Chemicals in the environment occur in mixtures rather than as individual entities. Environmental quality monitoring thus faces the challenge to comprehensively assess a multitude of contaminants and potential adverse effects. Effect-based methods have been suggested as complements to chemical analytical characterisation of complex pollution patterns. The regularly observed discrepancy between chemical and biological assessments of adverse effects due to contaminants in the field may be either due to unidentified contaminants or result from interactions of compounds in mixtures...
February 27, 2018: Environment International
Olivier Mortelé, Philippe Vervliet, Celine Gys, Maarten Degreef, Matthias Cuykx, Kristof Maudens, Adrian Covaci, Alexander L N van Nuijs, Foon Yin Lai
Designer benzodiazepines have recently emerged as a class of new psychoactive substances. These substances are used in recreational settings and as alternatives to prescription benzodiazepines as self-medication for patients suffering from anxiety or other mental disorders. Due to the limited information available on the metabolic fate of these new substances, it is challenging to reliably detect their usage in bioanalytical (e.g. clinical and forensic) settings. The objective of this study was to investigate the in vitro Phase I and Phase II metabolism of the new designer benzodiazepine cloniprazepam and identify potential biomarkers for its detection in human biological fluids...
February 21, 2018: Journal of Pharmaceutical and Biomedical Analysis
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