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Bruno Henrique Fumes, Mariane Aissa Andrade, Maraíssa Silva Franco, Fernando Mauro Lanças
The determination of residues and contaminants in complex matrices such as in the case of food, environmental and biological samples requires a combination of several steps to succeed in the aimed goal. At least three independent steps are integrated to provide the best available situation to deal with such matrices: (1) a sample preparation technique is employed to isolate the target compounds from the rest of the matrix; (2) a chromatographic (second) step further "purifies" the isolated compounds from the co-extracted matrix interferences; (3) a spectroscopy-based device acts as chromatographic detector (ideally containing a tandem high-resolution mass analyzer) for the qualitative and quantitative analysis...
October 19, 2016: Journal of Separation Science
Natalia Miękus, Ilona Olędzka, Alina Plenis, Piotr Kowalski, Ewa Bień, Aleksandra Miękus, Małgorzata Anna Krawczyk, Elżbieta Adamkiewicz-Drożyńska, Tomasz Bączek
The unbalanced secretion of biogenic amines (BAs) is considered to be a relevant biochemical biomarker in the screening for neuroendocrine tumors, such as: neuroblastoma and pheochromocytoma. However, there is still a need to improve the bioanalytical procedures for BA determination in biological samples due to their instability (photo- and thermosensitivity, easy oxidation) and low concentration in the body fluids. In this study, the primary analytical challenge was to optimize the method of extraction of seven compounds from among BAs and their precursors from urine samples...
October 11, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
M Herbrink, N de Vries, H Rosing, A D R Huitema, B Nuijen, J H M Schellens, J H Beijnen
BACKGROUND: A liquid chromatography/tandem mass spectrometry assay was developed to facilitate therapeutic drug monitoring (TDM) for 10 anticancer compounds (dasatinib, erlotinib, gefitinib, imatinib, lapatinib, nilotinib, pazopanib, sorafenib, sunitinib, and vemurafenib) and the active metabolite, N-desethyl-sunitinib. METHODS: The TDM assay is based on reversed-phase chromatography coupled with tandem mass spectrometry in the positive ion mode using multiple-reaction monitoring for analyte quantification...
October 5, 2016: Therapeutic Drug Monitoring
Wei-Wei Zhao, Xiao-Dong Yu, Jing-Juan Xu, Hong-Yuan Chen
Photoelectrochemical (PEC) bioanalysis is a newly developed technique for innovative biomolecular detection. Quantum dots (QDs) with unique photophysical properties are key components in realization of various exquisite PEC bioanalyses. Particularly, significant progress has been made in the QD-based PEC bioanalysis. In this work, we briefly summarize the most recent and important developments in the use of traditional and newly emerging QDs for novel PEC bioanalytical applications. The future prospects in this dynamic field are also highlighted...
October 14, 2016: Nanoscale
R Viter, K Jekabsons, Z Kalnina, N Poletaev, S H Hsu, U Riekstina
Using photoluminescent ZnO nanorods and carbohydrate marker SSEA-4, a novel cancer cell recognition system was developed. Immobilization of SSEA-4 antibodies (αSSEA-4) on ZnO nanorods was performed in buffer solution (pH = 7.1) over 2 h. The cancer cell line probes were fixed on the glass slide. One hundred microliters of ZnO-αSSEA-4 conjugates were deposited on the cell probe and exposed for 30 min. After washing photoluminescence spectra were recorded. Based on the developed methodology, ZnO-αSSEA-4 probes were tested on patient-derived breast and colorectal carcinoma cells...
October 12, 2016: Nanotechnology
Heather A Enright, Michael A Malfatti, Maike Zimmermann, Ted Ognibene, Paul Henderson, Kenneth W Turteltaub
Accelerator mass spectrometry (AMS) has been adopted as a powerful bioanalytical method for human studies in the areas of pharmacology and toxicology. The exquisite sensitivity (10(-18) mol) of AMS has facilitated studies of toxins and drugs at environmentally and physiologically relevant concentrations in humans. Such studies include risk assessment of environmental toxicants, drug candidate selection, absolute bioavailability determination, and more recently, assessment of drug-target binding as a biomarker of response to chemotherapy...
October 11, 2016: Chemical Research in Toxicology
Marcin Drozd, Mariusz Pietrzak, Paweł G Parzuchowski, Elżbieta Malinowska
Catalytic nanomaterials, widely used as substitutes of peroxidase, exhibit unique properties, which are unattainable for native enzymes. However, their activity is usually examined by means of substrates developed and methods standardized for horseradish peroxidase (HRP). The aim of the presented work was to determine the scope of usefulness of chromogenic substrates for gold nanoparticle (AuNP) activity studies under conditions which significantly extend beyond the activity range of a native HRP. The applicability of chromogens such as 3,3'5,5'-tetramethylbenzidine (TMB), o-phenylenediamine (OPD), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) beyond the typical range of pH, and for the samples of high concentration of hydrogen peroxide was examined...
October 8, 2016: Analytical and Bioanalytical Chemistry
Mohammad Mahdi Moein, Aziza El Beqqali, Mohamed Abdel-Rehim
Bioanalysis is an essential part in drug discovery and development. Bioanalysis is related to the analysis of analytes (drugs, metabolites, biomarkers) in biological samples and it involves several steps from sample collection to sample analysis and data reporting. The first step is sample collection from clinical or preclinical studies; then sending the samples to laboratory for analysis. Second step is sample clean-up (sample preparation) and it is very important step in bioanalysis. In order to reach reliable results, a robust and stable sample preparation method should be applied...
September 20, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Lu Yang, Takatoki Yamamoto
Viruses have drawn much attention in recent years due to increased recognition of their important roles in virology, immunology, clinical diagnosis, and therapy. Because the biological and physical properties of viruses significantly impact their applications, quantitative detection of individual virus particles has become a critical issue. However, due to various inherent limitations of conventional enumeration techniques such as infectious titer assays, immunological assays, and electron microscopic observation, this issue remains challenging...
2016: Frontiers in Microbiology
Eric Yang, Jan Welink, Stephanie Cape, Eric Woolf, Jens Sydor, Christopher James, Dina Goykhman, Mark Arnold, Neil Addock, Ronald Bauer, Michael Buonarati, Eugene Ciccimaro, Raj Dodda, Christopher Evans, Fabio Garofolo, Nicola Hughes, Rafiq Islam, Corey Nehls, Amanda Wilson, Chad Briscoe, Mark Bustard, Laura Coppola, Stephanie Croft, Dieter Drexler, Luca Ferrari, Daniela Fraier, Rand Jenkins, John Kadavil, Lloyd King, Wenkui Li, Gustavo Mendes Lima Santos, Adrien Musuku, Ragu Ramanathan, Yoshiro Saito, Natasha Savoie, Scott Summerfield, Rachel Sun, Nilufer Tampal, Steve Vinter, Jason Wakelin-Smith, Qin Yue
The 2016 10(th) Workshop on Recent Issues in Bioanalysis (10(th) WRIB) took place in Orlando, Florida with participation of close to 700 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations, and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - A Full Immersion Week of Bioanalysis including Biomarkers and Immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid LBA/LCMS, and LBA approaches, with the focus on biomarkers and immunogenicity...
October 7, 2016: Bioanalysis
T V Shishkanova, M Havlík, M Dendisová, P Matějka, V Král
The development of novel diagnostic tools is a primary goal in bioanalytical chemistry. Here we report the synthesis of Tröger's base functionalized with amino- and coumarin-units designed as a monomeric unit for the development of an electrochemical cancer sensor. The synthesized receptor was deposited onto a conducting support using electrochemical polymerization, characterized spectroscopically and tested potentiometrically towards metabolites used as tumor markers of neuroblastoma.
September 29, 2016: Chemical Communications: Chem Comm
Purva Thatai, Bharti Sapra
The human nail is one of the challenging membrane for the scientists to target and to improve the clinical efficacy of ungual formulations. The understanding of nail physiology, impact of hydration on its properties and presence of trace elements in nails as biomarkers has been explored by various researchers in clinical studies. Despite the importance of biophysical techniques for the assessment of structure and physiology of nail, minimum literature analyzes biophysical, biochemical and bioanalytical approaches...
October 6, 2016: International Journal of Cosmetic Science
Rajesh Krishna, Lilly East, Patrick Larson, Tara Siringhaus, Lisa Herpok, Crystal Bethel-Brown, Helen Manthos, John Brejda, Michael Gartner
Raltegravir is a human immunodeficiency virus (HIV)-1 integrase strand transfer inhibitor currently marketed at a dose of 400 mg twice daily (BID). Raltegravir for once daily regimen (QD) at a dose of 1200 mg (2 x 600 mg) is under development and offers a new treatment option for HIV-1 infected treatment-naive subjects. Since raltegravir is eliminated mainly by metabolism via an UDP-glucuronosyltransferase (UGT) 1A1-mediated glucuronidation pathway, co-administration of UGT1A1 inducers may alter plasma levels of raltegravir...
October 5, 2016: Biopharmaceutics & Drug Disposition
Sandra Ventura, Márcio Rodrigues, Sarah Pousinho, Amílcar Falcão, Gilberto Alves
A simple and rapid high-performance liquid chromatography method with diode-array detection (HPLC-DAD) using microextraction by packed sorbent (MEPS) during the sample preparation step was developed and validated to quantify lamotrigine (LTG) in rat plasma and brain samples. MEPS variables such as pH, number of draw-eject cycles, and washing and desorption conditions were optimized. The chromatographic resolution of LTG and chloramphenicol, used as internal standard (IS), was accomplished in less than 5min on a C18 column, at 35°C, using an isocratic elution with acetonitrile (13%), methanol (13%) and water-triethylamine (99...
November 1, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Shirin Hooshfar, Michael G Bartlett
Bioanalytical methods are employed for the quantitative determination of drugs and their metabolites in biological matrices, in all stages of the drug development process. However, because of the highly complex nature of these matrices there is a wide range of potential biological, chemical and physical hazards that can influence the quality of the data produced by these methods. The present review focuses on the evaluation of the most important and frequent errors that may be encountered during bioanalytical method development/validation and analysis of clinical or preclinical samples mainly using chromatography...
October 1, 2016: Biomedical Chromatography: BMC
Rajesh Krishna, Lilly East, Patrick Larson, Chandni Valiathan, Kathleen Deschamps, Julie Ann Luk, Crystal Bethel-Brown, Helen Manthos, John Brejda, Michael Gartner
Raltegravir is a human immunodeficiency virus (HIV)-1 integrase strand transfer inhibitor currently marketed at a dose of 400 mg twice-daily (BID). Raltegravir 1200 mg once-daily (QD) [investigational QD formulation of 2 x 600 mg tablets; QD RAL] was found to be generally well tolerated and non-inferior to the marketed 400 mg BID dose at 48 weeks in a Phase 3 trial. Since raltegravir is eliminated mainly by metabolism via a uridine diphosphate glucuronosyltransferase (UGT) 1A1-mediated glucuronidation pathway, coadministration of UGT1A1 inhibitors may increase plasma levels of QD RAL...
September 30, 2016: Biopharmaceutics & Drug Disposition
Seungmok Choi, Minsoo Kim, Changhee Kim, Jae-Kwan Hwang, Wonku Kang
Although xanthorrhizol, a sesquiterpenoid oil isolated from the rhizoma of Curcuma xanthorrhiza Roxb. known as Java turmeric, represents a variety of pharmacological activities, to date, there have been no validated determination methods of xanthorrhizol in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry for the determination of xanthorrhizol in rat plasma. After simple protein precipitation with acetonitrile including diclofenac (internal standard, IS), the analytes were chromatographed on a reversed-phased column with a mobile phase of 20mM ammonium acetate aqueous solution and acetonitrile (20:80, v/v)...
September 28, 2016: Journal of Pharmaceutical and Biomedical Analysis
Xiao Xia Han, Junbo Li, Ibrahim Halil Öner, Bing Zhao, Silke Leimkühler, Peter Hildebrandt, Inez M Weidinger
Practical use of many bioelectronic and bioanalytical devices is limited by the need of expensive materials and time consuming fabrication. Here we demonstrate the use of nickel electrodes as a simple and cheap solid support material for bioelectronic applications. The naturally nanostructured electrodes showed a surprisingly high electromagnetic surface enhancement upon light illumination such that immobilization and electron transfer reactions of the model redox proteins cytochrome b5 (Cyt b5) and cytochrome c (Cyt c) could be followed via surface enhanced resonance Raman spectroscopy...
October 19, 2016: Analytica Chimica Acta
Brian Rago, Tracey Clark, Lindsay King, Jenny Zhang, L Nathan Tumey, Fengping Li, Frank Barletta, Cong Wei, Mauricio Leal, Steve Hansel, Xiaogang Han
AIM: Complex nature of bioconjugates require multiple bioanalytical approaches to support PK and absorption, distribution, metabolism and excretion characterization. For antibody-drug conjugate (ADC) bioanalysis both LC-MS and ligand-binding assays (LBAs) are employed. RESULTS: A method consisting of immunocapture extraction of ADC from biomatrices followed by LC-MS analysis of light and heavy chain is described. Drug antibody ratio (DAR) profiles of ADC Tras-mcVC-PF06380101 dosed at 0...
November 2016: Bioanalysis
Philipp Holz, Benedikt Hauer, Albrecht Brandenburg, Simon Wadle, Steffen Zehnle, Mark Keller, Ronny Möller, Birgit Koger
No abstract text is available yet for this article.
September 1, 2016: Biomedizinische Technik. Biomedical Engineering
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