Lipidomics by ultrahigh performance liquid chromatography-high resolution mass spectrometry and its application to complex biological samples

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B
Author(s): Alexander Triebl, Martin Trötzmüller, Jürgen Hartler, Tatjana Stojakovic, Harald C. Köfeler
An improved approach for selective and sensitive identification and quantitation of lipid molecular species using reversed phase chromatography coupled to high resolution mass spectrometry was developed. The method is applicable to a wide variety of biological matrices using a simple liquid-liquid extraction procedure.Together, this approach combines multiple selectivity criteria: Reversed phase chromatography separates lipids according to their acyl chain length and degree of unsaturation and is capable of resolving positional isomers of lysophospholipids, as well as structural isomers of diacyl phospholipids and glycerolipids. Orbitrap mass spectrometry delivers the elemental composition of both positive and negative ions with high mass accuracy. Finally, automatically generated tandem mass spectra provide structural insight into numerous glycerolipids, phospholipids, and sphingolipids within a single run.Calibration showed linearity ranges of more than four orders of magnitude, good values for accuracy and precision at biologically relevant concentration levels, and limits of quantitation of a few femtomoles on column.Hundreds of lipid molecular species were detected and quantified in three different biological matrices, which cover well the wide variety and complexity of various model organisms in lipidomic research. Together with a software package, this method is a prime choice for global lipidomic analysis of even the most complex biological samples.

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B

Author(s): Alexander Triebl, Martin Trötzmüller, Jürgen Hartler, Tatjana Stojakovic, Harald C. Köfeler

An improved approach for selective and sensitive identification and quantitation of lipid molecular species using reversed phase chromatography coupled to high resolution mass spectrometry was developed. The method is applicable to a wide variety of biological matrices using a simple liquid-liquid extraction procedure. Together, this approach combines multiple selectivity criteria: Reversed phase chromatography separates lipids according to their acyl chain length and degree of unsaturation and is capable of resolving positional isomers of lysophospholipids, as well as structural isomers of diacyl phospholipids and glycerolipids. Orbitrap mass spectrometry delivers the elemental composition of both positive and negative ions with high mass accuracy. Finally, automatically generated tandem mass spectra provide structural insight into numerous glycerolipids, phospholipids, and sphingolipids within a single run. Calibration showed linearity ranges of more than four orders of magnitude, good values for accuracy and precision at biologically relevant concentration levels, and limits of quantitation of a few femtomoles on column. Hundreds of lipid molecular species were detected and quantified in three different biological matrices, which cover well the wide variety and complexity of various model organisms in lipidomic research. Together with a software package, this method is a prime choice for global lipidomic analysis of even the most complex biological samples.





Use of LC-QqQ-MS for the detection of emodin metabolites in rat bile and urine

Emodin is the representative form of rhubarb, which is widely used in traditional Chinese medicine for the treatment of purgative, anti-inflammatory, antioxidative and antiviral, etc. Previous reports demonstrated that emodin glucuronide was the major metabolite in plasma. Due to the extensive conjugation reactions of polyphenols, the aim of this study was to identify the metabolites of emodin in rat bile and urine. Neutral loss and precursor ion scan methods of triple-quadrupole mass spectrometer revealed 13 conjugated metabolites in rat bile and 22 metabolites in rat urine, which including 4 phase I and 18 phase II metabolites. The major metabolites in rat bio-samples were emodin glucuronoconjugates. Moreover, rhein monoglucuronide, chrysophanol monoglucuronide and rhein sulfate were proposed for the first time after oral administration of emodin. Overall, liquid chromatography hybrid triple-quadrupole mass spectrometry (LC-QqQ-MS) analysis leads to the discovery of several novel emodin metabolites in rat bile and urine and underscores that conjugated with glucuronic acid is the main metabolic pathway.

Abstract

Emodin is the representative form of rhubarb, which is widely used in traditional Chinese medicine for the treatment of purgative, anti-inflammatory, antioxidative and antiviral, etc. Previous reports demonstrated that emodin glucuronide was the major metabolite in plasma. Due to the extensive conjugation reactions of polyphenols, the aim of this study was to identify the metabolites of emodin in rat bile and urine. Neutral loss and precursor ion scan methods of triple-quadrupole mass spectrometer revealed 13 conjugated metabolites in rat bile and 22 metabolites in rat urine, which including 4 phase I and 18 phase II metabolites. The major metabolites in rat bio-samples were emodin glucuronoconjugates. Moreover, rhein monoglucuronide, chrysophanol monoglucuronide and rhein sulfate were proposed for the first time after oral administration of emodin. Overall, liquid chromatography hybrid triple-quadrupole mass spectrometry (LC-QqQ-MS) analysis leads to the discovery of several novel emodin metabolites in rat bile and urine and underscores that conjugated with glucuronic acid is the main metabolic pathway.

Deciphering the influence of column chemistry and mass spectrometry settings for the analyses of geometrical isomers of L-chicoric acid

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B
Author(s): Keabetswe Masike, Fidele Tugizimana, Nombuso Ndlovu, Elize Smit, Louis du Preez, Ian Dubery, Edwin Madala
Resolving the chemo-diversity of plant extract samples is an essential step for in-depth analyses of natural products which often exhibit promising biological activities. One of the challenges in this endeavor has been the confident differentiation of geometrical isomers. In this study, we investigated these aspects in chromatography (column chemistry and mobile phase composition) and mass spectrometry settings with regards to better differentiation of geometrical isomers. A standard of a hydroxycinnamic acid (HCA) derivative, L-chicoric acid (L-CA) − a di-acylated caffeoyltartaric acid ester found in a number of plant families − was used. Geometrical isomers of L-CA were formed by exposing the compound to ultraviolet (UV) radiation, to mimic the natural environment. The high performance liquid chromatography photo-diode array (HPLC-PDA) and ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS) platforms were used to analyze the trans and cis geometrical isomers of L-CA. The HPLC-PDA results confirmed the generation of two cis geometrical isomers following UV exposure of the authentic trans-L-CA standard. Furthermore, the HPLC-PDA analyses demonstrated that the changes in both column chemistry (reverse-phase: C18, biphenyl, phenyl-hexyl and pentafluorophenyl propyl) and mobile phase composition (aqueous acetonitrile and aqueous methanol) affect the chromatographic elution profiles of the L-CA isomers. The MS results, on the other hand, revealed undisputed fragmentation differences between the geometrical isomers of L-CA. Thus, this study demonstrates that the identification of the L-CA isomers can be achieved more efficiently and confidently with good chromatography coupled to well-optimized mass spectrometry conditions, a requirement which has been proven impossible with other types of HCA derivatives. Moreover, differences in the binding modes of L-CA geometrical isomers to the HIV type 1 integrase enzyme were observed, suggesting a synergistic anti-HIV-1 activity of these isomers.

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B

Author(s): Keabetswe Masike, Fidele Tugizimana, Nombuso Ndlovu, Elize Smit, Louis du Preez, Ian Dubery, Edwin Madala

Resolving the chemo-diversity of plant extract samples is an essential step for in-depth analyses of natural products which often exhibit promising biological activities. One of the challenges in this endeavor has been the confident differentiation of geometrical isomers. In this study, we investigated these aspects in chromatography (column chemistry and mobile phase composition) and mass spectrometry settings with regards to better differentiation of geometrical isomers. A standard of a hydroxycinnamic acid (HCA) derivative, L-chicoric acid (L-CA) − a di-acylated caffeoyltartaric acid ester found in a number of plant families − was used. Geometrical isomers of L-CA were formed by exposing the compound to ultraviolet (UV) radiation, to mimic the natural environment. The high performance liquid chromatography photo-diode array (HPLC-PDA) and ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS) platforms were used to analyze the trans and cis geometrical isomers of L-CA. The HPLC-PDA results confirmed the generation of two cis geometrical isomers following UV exposure of the authentic trans-L-CA standard. Furthermore, the HPLC-PDA analyses demonstrated that the changes in both column chemistry (reverse-phase: C18, biphenyl, phenyl-hexyl and pentafluorophenyl propyl) and mobile phase composition (aqueous acetonitrile and aqueous methanol) affect the chromatographic elution profiles of the L-CA isomers. The MS results, on the other hand, revealed undisputed fragmentation differences between the geometrical isomers of L-CA. Thus, this study demonstrates that the identification of the L-CA isomers can be achieved more efficiently and confidently with good chromatography coupled to well-optimized mass spectrometry conditions, a requirement which has been proven impossible with other types of HCA derivatives. Moreover, differences in the binding modes of L-CA geometrical isomers to the HIV type 1 integrase enzyme were observed, suggesting a synergistic anti-HIV-1 activity of these isomers.





Impact of sample extraction on the accurate measurement of progesterone in human serum by liquid chromatography tandem mass spectrometry

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B
Author(s): Yuyong Ke, Renaud Gonthier, Fernand Labrie
In the present study, the impact of the extraction solvent on the accuracy of endogenous progesterone assay in human serum has been investigated using two selective reaction monitoring (SRM) transitions (315>97 & 315>109). Higher levels of noise and more interference were observed when more polar solvents were used for extraction, thus resulting in serious bias of the measured values of progesterone in serum. This is confirmed by monitoring the ion ratio of 315>97 to 315>109. This issue could not be easily resolved by changes in MS/MS transitions or chromatography conditions. More bias was observed with the SRM transition 315>09 for the polar solvent extraction. Hexane and 1-chlorobutane (polarity index of 0 and 1, respectively) did provide the cleanest samples with a lower noise level in the chromatograms. Moreover, the measured values of progesterone were not changed with different SRM transitions or longer retention time in search of an improved separation. Recovery tests of progesterone have been performed with 1-chlorobutane in matrices with phosphate buffered saline (PBS) 1x, PBS 1×3% bovine serum albumin (BSA), stripped serum/H2O (1:1) and unstripped serum. The recovery (70%∼80%) consistency is observed not only at different levels but also in different matrices. The equivalent recovery between PBS 1x, PBS 1×3% BSA and unstripped serum shows that the impact of progesterone binding to serum proteins on the measurement accuracy can be avoided with this sample preparation procedure. No significant matrix effect on the determination of progesterone was observed with 1-chlorobutane. Within the range of 12.5 – 2000pg/mL, a good linearity is observed with R>0.99 and weighting factor 1/X. Bias and covariance efficiency of QCs are within 10%. With 1-chlorobutane as the extraction solvent, the concentration of progesterone was measured where the range for postmenopausal serum is 5.74∼91.7 pg/mL, which is well below the reported concentrations of 314 pg/mL∼942pg/mL in postmenopausal serum by immunoassay-based techniques, while the range in premenopausal serum is 12.8 pg/mL∼18.6 ng/mL.

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B

Author(s): Yuyong Ke, Renaud Gonthier, Fernand Labrie

In the present study, the impact of the extraction solvent on the accuracy of endogenous progesterone assay in human serum has been investigated using two selective reaction monitoring (SRM) transitions (315>97 & 315>109). Higher levels of noise and more interference were observed when more polar solvents were used for extraction, thus resulting in serious bias of the measured values of progesterone in serum. This is confirmed by monitoring the ion ratio of 315>97 to 315>109. This issue could not be easily resolved by changes in MS/MS transitions or chromatography conditions. More bias was observed with the SRM transition 315>09 for the polar solvent extraction. Hexane and 1-chlorobutane (polarity index of 0 and 1, respectively) did provide the cleanest samples with a lower noise level in the chromatograms. Moreover, the measured values of progesterone were not changed with different SRM transitions or longer retention time in search of an improved separation. Recovery tests of progesterone have been performed with 1-chlorobutane in matrices with phosphate buffered saline (PBS) 1x, PBS 1×3% bovine serum albumin (BSA), stripped serum/H2O (1:1) and unstripped serum. The recovery (70%80%) consistency is observed not only at different levels but also in different matrices. The equivalent recovery between PBS 1x, PBS 1×3% BSA and unstripped serum shows that the impact of progesterone binding to serum proteins on the measurement accuracy can be avoided with this sample preparation procedure. No significant matrix effect on the determination of progesterone was observed with 1-chlorobutane. Within the range of 12.5 – 2000pg/mL, a good linearity is observed with R>0.99 and weighting factor 1/X. Bias and covariance efficiency of QCs are within 10%. With 1-chlorobutane as the extraction solvent, the concentration of progesterone was measured where the range for postmenopausal serum is 5.7491.7 pg/mL, which is well below the reported concentrations of 314 pg/mL942pg/mL in postmenopausal serum by immunoassay-based techniques, while the range in premenopausal serum is 12.8 pg/mL18.6 ng/mL.





Development, validation and different approaches for the measurement uncertainty of a multi-class veterinary drugs residues LC–MS method for feeds

Publication date: Available online 25 March 2017
Source:Journal of Chromatography B
Author(s): Andressa Camargo Valese, Luciano Molognoni, Naielly Coelho de Souza, Leandro Antunes de Sá Ploêncio, Ana Carolina Oliveira Costa, Fabiano Barreto, Heitor Daguer
A sensitive method for the simultaneous residues analysis of 62 veterinary drugs in feeds by liquid chromatography-tandem mass spectrometry has been developed and validated in accordance to Commission Decision 657/2002/EC. Additionally, limits of detection (LOD), limits of quantitation (LOQ), matrix effects and measurement uncertainty were also assessed. Extraction was performed for all analytes and respective internal standards in a single step and chromatographic separation was achieved in only 12min. LOQ were set to 0.63–5.00μgkg−1 (amphenicols), 0.63–30.00μgkg−1 (avermectins), 0.63μgkg−1 (benzimidazoles), 0.25–200.00μgkg−1 (coccidiostats), 0.63–200.00μgkg−1 (lincosamides and macrolides), 0.25–5.00μgkg−1 (nitrofurans), 0.63–20.00μgkg−1 (fluoroquinolones and quinolones), 15.00μgkg−1 (quinoxaline), 0.63–7.50μgkg−1 (sulfonamides), 0.63–20.00μgkg−1 (tetracyclines), 0.25μgkg−1 (β-agonists), and 30.00μgkg−1 (β-lactams). The top-down approach was adequate for the calculation of measurement uncertainty for all analytes, except the banned substances, which should be rather assessed by the bottom-up approach. Routine analysis of different types of feeds was then carried out. An interesting profile of residues of veterinary drugs among samples was revealed, enlightening the need for stricter control in producing animals. Among the total of 27 feed samples, 20 analytes could be detected/quantified, ranging from trace levels to very high concentrations. A high throughput screening/confirmatory method for the residue analysis of several veterinary drugs in feeds was proposed as a helpful control tool.

Publication date: Available online 25 March 2017
Source:Journal of Chromatography B

Author(s): Andressa Camargo Valese, Luciano Molognoni, Naielly Coelho de Souza, Leandro Antunes de Sá Ploêncio, Ana Carolina Oliveira Costa, Fabiano Barreto, Heitor Daguer

A sensitive method for the simultaneous residues analysis of 62 veterinary drugs in feeds by liquid chromatography-tandem mass spectrometry has been developed and validated in accordance to Commission Decision 657/2002/EC. Additionally, limits of detection (LOD), limits of quantitation (LOQ), matrix effects and measurement uncertainty were also assessed. Extraction was performed for all analytes and respective internal standards in a single step and chromatographic separation was achieved in only 12min. LOQ were set to 0.63–5.00μgkg−1 (amphenicols), 0.63–30.00μgkg−1 (avermectins), 0.63μgkg−1 (benzimidazoles), 0.25–200.00μgkg−1 (coccidiostats), 0.63–200.00μgkg−1 (lincosamides and macrolides), 0.25–5.00μgkg−1 (nitrofurans), 0.63–20.00μgkg−1 (fluoroquinolones and quinolones), 15.00μgkg−1 (quinoxaline), 0.63–7.50μgkg−1 (sulfonamides), 0.63–20.00μgkg−1 (tetracyclines), 0.25μgkg−1 (β-agonists), and 30.00μgkg−1 (β-lactams). The top-down approach was adequate for the calculation of measurement uncertainty for all analytes, except the banned substances, which should be rather assessed by the bottom-up approach. Routine analysis of different types of feeds was then carried out. An interesting profile of residues of veterinary drugs among samples was revealed, enlightening the need for stricter control in producing animals. Among the total of 27 feed samples, 20 analytes could be detected/quantified, ranging from trace levels to very high concentrations. A high throughput screening/confirmatory method for the residue analysis of several veterinary drugs in feeds was proposed as a helpful control tool.





Determination and quantification of intracellular fludarabine triphosphate, cladribine triphosphate and clofarabine triphosphate by LC–MS/MS in human cancer cells

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B
Author(s): Jean-Yves Puy, Lars Petter Jordheim, Emeline Cros-Perrial, Charles Dumontet, Suzanne Peyrottes, Isabelle Lefebvre-Tournier
Purine nucleoside analogues are widely used in the treatment of haematological malignancies, and their biological activity is dependent on the intracellular accumulation of their triphosphorylated metabolites. In this context, we developed and validated a liquid chromatography tandem mass spectrometry (LC–MS/MS) method to study the formation of 5′-triphosphorylated derivatives of cladribine, fludarabine, clofarabine and 2′-deoxyadenosine in human cancer cells. Br-ATP was used as internal standard. Separation was achieved on a hypercarb column. Analytes were eluted with a mixture of hexylamine (5 mM), DEA (0.4%, v/v, pH 10.5) and acetonitrile, in a gradient mode at a flow rate of 0.3mLmin−1. Multiple reactions monitoring (MRM) and electrospray ionization in negative mode (ESI-) were used for detection. The application of this method to the quantification of these phosphorylated cytotoxic compounds in a human follicular lymphoma cell line, showed that it was suitable for the study of relevant biological samples.

Publication date: Available online 24 March 2017
Source:Journal of Chromatography B

Author(s): Jean-Yves Puy, Lars Petter Jordheim, Emeline Cros-Perrial, Charles Dumontet, Suzanne Peyrottes, Isabelle Lefebvre-Tournier

Purine nucleoside analogues are widely used in the treatment of haematological malignancies, and their biological activity is dependent on the intracellular accumulation of their triphosphorylated metabolites. In this context, we developed and validated a liquid chromatography tandem mass spectrometry (LC–MS/MS) method to study the formation of 5′-triphosphorylated derivatives of cladribine, fludarabine, clofarabine and 2′-deoxyadenosine in human cancer cells. Br-ATP was used as internal standard. Separation was achieved on a hypercarb column. Analytes were eluted with a mixture of hexylamine (5 mM), DEA (0.4%, v/v, pH 10.5) and acetonitrile, in a gradient mode at a flow rate of 0.3mLmin−1. Multiple reactions monitoring (MRM) and electrospray ionization in negative mode (ESI-) were used for detection. The application of this method to the quantification of these phosphorylated cytotoxic compounds in a human follicular lymphoma cell line, showed that it was suitable for the study of relevant biological samples.





DEVELOPMENT AND VALIDATION OF A LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY METHOD FOR THE DETERMINATION OF CANNABINOIDS AND PHASE I AND II METABOLITES IN MECONIUM

Publication date: Available online 25 March 2017
Source:Journal of Chromatography A
Author(s): Pablo Prego-Meleiro, Elena Lendoiro, Marta Concheiro, Angelines Cruz, Manuel López-Rivadulla, Ana de Castro
A liquid chromatography–tandem mass spectrometry (LC–MSMS) method was developed and fully validated for the determination of Δ9-tetrahydrocannabinol (THC), 11-hydroxyTHC (OHTHC), 11-nor-9-carboxyTHC (THCCOOH), 8-β-11-dihydroxyTHC (diOHTHC), cannabinol, cannabidiol, and THC and THCCOOH glucuronides in 0.25±0.02g meconium. Samples were homogenized in methanol and subjected to cation exchange solid-phase extraction. Chromatographic separation was performed on a Kinetex C18 column (50 mm×2.1 mm, 2.6 μm) at 35°C, with a gradient of 0.1% formic acid in water and acetonitrile at a flow rate of 0.3 mL/min; total run time was 10min. Two transitions per analyte were monitored in MRM mode. The method was specific and sensitive; LOD was from 1 to 2ng/g, and LOQ from 4 to 10ng/g; linearity ranged from 4 to 400 ng/g for all the analytes, except for THC glucuronide (10 to 400 ng/g); intra-assay, inter-assay and total imprecision were <11.2%, <13.45% and <15.6%, respectively; accuracy ranged from 93.9% to 109.0% of the target concentration; matrix effect, extraction and process efficiency ranged from −26.4% to −71.4%, 49.9% to 69.5% and 14.3% to 45.0%, respectively. The inclusion of THC and THCCOOH glucuronides avoided the need for the hydrolysis process, thus facilitating sample pretreatment. Application of the method to 19 authentic meconium specimens from uncontrolled pregnancies or women suspicious of drug consumption revealed fetal cannabis exposure in 4 newborns. THCCOOH (24.1–288.8ng/g), diOHTHC (53.2–332.4ng/g), THC (4.2–7.7ng/g), CBN (30.7–93.3ng/g) and CBD (7.1–251.5ng/g) were detected in all cases; THCCOOH glucuronide (190.2–306.8ng/g) in 3 cases; and OHTHC (11.9ng/g) in the remaining one; however, THC glucuronide was not identified in any specimen.

Publication date: Available online 25 March 2017
Source:Journal of Chromatography A

Author(s): Pablo Prego-Meleiro, Elena Lendoiro, Marta Concheiro, Angelines Cruz, Manuel López-Rivadulla, Ana de Castro

A liquid chromatography–tandem mass spectrometry (LC–MSMS) method was developed and fully validated for the determination of Δ9-tetrahydrocannabinol (THC), 11-hydroxyTHC (OHTHC), 11-nor-9-carboxyTHC (THCCOOH), 8-β-11-dihydroxyTHC (diOHTHC), cannabinol, cannabidiol, and THC and THCCOOH glucuronides in 0.25±0.02g meconium. Samples were homogenized in methanol and subjected to cation exchange solid-phase extraction. Chromatographic separation was performed on a Kinetex C18 column (50 mm×2.1 mm, 2.6 μm) at 35°C, with a gradient of 0.1% formic acid in water and acetonitrile at a flow rate of 0.3 mL/min; total run time was 10min. Two transitions per analyte were monitored in MRM mode. The method was specific and sensitive; LOD was from 1 to 2ng/g, and LOQ from 4 to 10ng/g; linearity ranged from 4 to 400 ng/g for all the analytes, except for THC glucuronide (10 to 400 ng/g); intra-assay, inter-assay and total imprecision were <11.2%, <13.45% and <15.6%, respectively; accuracy ranged from 93.9% to 109.0% of the target concentration; matrix effect, extraction and process efficiency ranged from −26.4% to −71.4%, 49.9% to 69.5% and 14.3% to 45.0%, respectively. The inclusion of THC and THCCOOH glucuronides avoided the need for the hydrolysis process, thus facilitating sample pretreatment. Application of the method to 19 authentic meconium specimens from uncontrolled pregnancies or women suspicious of drug consumption revealed fetal cannabis exposure in 4 newborns. THCCOOH (24.1–288.8ng/g), diOHTHC (53.2–332.4ng/g), THC (4.2–7.7ng/g), CBN (30.7–93.3ng/g) and CBD (7.1–251.5ng/g) were detected in all cases; THCCOOH glucuronide (190.2–306.8ng/g) in 3 cases; and OHTHC (11.9ng/g) in the remaining one; however, THC glucuronide was not identified in any specimen.





Recognition-Mediated Particle Detection Under Microfluidic Flow with Waveguide-Coupled 2D Photonic Crystals: Towards Integrated Photonic Virus Detectors

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00221A, PaperJames Baker, Rashmi Sriram, Benjamin Locke MillerLabel-free biodetection schemes compatible with standard CMOS fabrication methods constitute an important goal, as these are enabling tool…

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC00221A, Paper
James Baker, Rashmi Sriram, Benjamin Locke Miller
Label-free biodetection schemes compatible with standard CMOS fabrication methods constitute an important goal, as these are enabling tools for the mass production of high-sensitivity biosensors. Two-dimensional slab photonic crystal (2D...
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In vitro nasal mucosa gland-like structure formation on a chip

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C6LC01564F, PaperKyuhawn Na, Mingyu Lee, Hyun-Woo Shin, Seok ChungThe emergence of microfluidic epithelial models using diverse types of cells within a physiologically relevant microenvironment has the po…

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C6LC01564F, Paper
Kyuhawn Na, Mingyu Lee, Hyun-Woo Shin, Seok Chung
The emergence of microfluidic epithelial models using diverse types of cells within a physiologically relevant microenvironment has the potential to be a powerful tool for preclinical drug screening and pathophysiologic...
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Directly embroidered micro-tubings for fluid transport in wearable applications

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00074J, PaperRahim Rahimi, Wuyang Yu, Manuel Ochoa, Babak ZiaieWe demonstrate, for the first time, a facile and low-cost approach for integrating highly flexible and stretchable microfluidic channels …

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC00074J, Paper
Rahim Rahimi, Wuyang Yu, Manuel Ochoa, Babak Ziaie
We demonstrate, for the first time, a facile and low-cost approach for integrating highly flexible and stretchable microfluidic channels into textile-based substrates. The integration of the microfluidics is accomplished by...
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Frequency tuning allows flow direction control in microfluidic network with passive features

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00058H, CommunicationRahil Jain, Barry R. LutzFrequency tuning has emerged as an attractive alternative to conventional pumping techniques in microfluidics. Oscillating (AC) flow driven through a pass…

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC00058H, Communication
Rahil Jain, Barry R. Lutz
Frequency tuning has emerged as an attractive alternative to conventional pumping techniques in microfluidics. Oscillating (AC) flow driven through a passive valve can be rectified to create steady (DC) flow,...
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Pharmacokinetic study of representative anti-oxidative compounds from Denshen-Chuanxiong-Honghua following oral administration in rats

Publication date: Available online 23 March 2017
Source:Journal of Chromatography B
Author(s): Xianhua Zhang, Wan Zheng, Huali Xu, Xi Huang, Ping Ren, Hui Zou, Guihua Liu, Jian Wang, Xinliang Ma
Almost no pharmacokinetic compounds to date have been precisely linked with the activity of their herbal or Traditional Chinese Medicine (TCM) formula. This creates challenges for pharmacokinetic significance and application of the TCM. In our study, a sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to quantitatively or qualitatively determine multiple-components (tanshinol, ferulic acid, protocatechuic acid, rosmarinic acid, salvianolic acid B, baicalin and 9′-methyl lithospermate B) in rat plasma following the oral administration of Denshen-Chuanxiong-Honghua (DCH) extract (20g/kg). Chromatographic separation was carried out on a 300SB-C18 column using a gradient elution with a mobile phase composed of acetonitrile-water (containing 0.1% formic acid) at a flow rate of 1.0mL/min. Determination by mass spectrometry (MS) was conducted in multiple reaction monitoring (MRM) mode with negative electrospray ionization. The validated method exhibited good linearity, with correlation coefficients greater than 0.9949 over a wide concentration range, and the lower limits of quantification were 2.09–12.2ng/ml for the 5 analytes. This assay was successfully applied to investigate the pharmacokinetics of 5 compounds in rat plasma after the oral administration of DCH extracts. In addition, the anti-oxidant capacities of the 5 active ingredients of DCH extract in vitro and the total absorbed DCH extract in vivo were investigated at different concentrations during pharmacokinetic studies.

Publication date: Available online 23 March 2017
Source:Journal of Chromatography B

Author(s): Xianhua Zhang, Wan Zheng, Huali Xu, Xi Huang, Ping Ren, Hui Zou, Guihua Liu, Jian Wang, Xinliang Ma

Almost no pharmacokinetic compounds to date have been precisely linked with the activity of their herbal or Traditional Chinese Medicine (TCM) formula. This creates challenges for pharmacokinetic significance and application of the TCM. In our study, a sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to quantitatively or qualitatively determine multiple-components (tanshinol, ferulic acid, protocatechuic acid, rosmarinic acid, salvianolic acid B, baicalin and 9′-methyl lithospermate B) in rat plasma following the oral administration of Denshen-Chuanxiong-Honghua (DCH) extract (20g/kg). Chromatographic separation was carried out on a 300SB-C18 column using a gradient elution with a mobile phase composed of acetonitrile-water (containing 0.1% formic acid) at a flow rate of 1.0mL/min. Determination by mass spectrometry (MS) was conducted in multiple reaction monitoring (MRM) mode with negative electrospray ionization. The validated method exhibited good linearity, with correlation coefficients greater than 0.9949 over a wide concentration range, and the lower limits of quantification were 2.09–12.2ng/ml for the 5 analytes. This assay was successfully applied to investigate the pharmacokinetics of 5 compounds in rat plasma after the oral administration of DCH extracts. In addition, the anti-oxidant capacities of the 5 active ingredients of DCH extract in vitro and the total absorbed DCH extract in vivo were investigated at different concentrations during pharmacokinetic studies.





Microfluidic magnetic fluidized beds

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00063D, PaperIago Pereiro, Sanae Tabnaoui, Marc Fermigier, Olivia du Roure, Stephanie Descroix, Jean-Louis Viovy, Laurent MalaquinFluidization, a process in which a granular solid phase behaves like a…

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC00063D, Paper
Iago Pereiro, Sanae Tabnaoui, Marc Fermigier, Olivia du Roure, Stephanie Descroix, Jean-Louis Viovy, Laurent Malaquin
Fluidization, a process in which a granular solid phase behaves like a fluid under the influence of an imposed upward fluid flow, is routinely used in many chemical and biological...
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Biophysical isolation and identification of circulating tumor cells

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00038C, PaperJames Che, Victor Yu, Edward B Garon, Jonathan Goldman, Dino Di CarloIsolation and enumeration of circulating tumor cells (CTCs) from blood is important for determining patient prognosis …

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC00038C, Paper
James Che, Victor Yu, Edward B Garon, Jonathan Goldman, Dino Di Carlo
Isolation and enumeration of circulating tumor cells (CTCs) from blood is important for determining patient prognosis and monitoring treatment. Methods based on affinity to cell surface markers have been applied...
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Preparation and application of epitope magnetic molecularly imprinted polymers for enrichment of sulfonamide antibiotics in water

Sulfonamides, which are widely used synthetic antibiotics, are hydrophilic and stable. They can easily migrate into the environment and aquatic animals, and increase the risk of cancer, drug resistance, and allergic symptoms if consumed by humans. Her…

Sulfonamides, which are widely used synthetic antibiotics, are hydrophilic and stable. They can easily migrate into the environment and aquatic animals, and increase the risk of cancer, drug resistance, and allergic symptoms if consumed by humans. Here, we developed an epitope magnetic imprinting approach to enrich multiple sulfonamide antibiotics from a water sample. Epitope magnetic molecularly imprinted polymers (EMMIPs) were prepared by free-radical polymerization using vinyl-functioned Fe3O4 as a core, sulfanilamide (SA) as a dummy template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker. The performance of the EMMIPs was first evaluated by rebinding SA, and then an adsorption experiment was conducted to assess the extraction of multiple sulfonamide antibiotics containing the SA group. The binding experiments showed that the EMMIPs reached adsorption equilibrium in only 5 min with adsorption of SA at 2040 μg/g, compared with just 462 μg/g for the epitope magnetic non-imprinted polymerss. EMMIPs were combined with HPLC for the detection of six sulfonamide antibiotics in surface water samples. The recoveries ranged from 79.3% to 92.4% and the relative standard deviations from 0.9% to 7.3%.

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Phosphorylated-tyrosine based pseudobioaffinity adsorbent for the purification of immunoglobulin G

Publication date: 1 May 2017
Source:Journal of Chromatography B, Volume 1052
Author(s): Gisele Luiza Pavan, Igor Tadeu Lazzarotto Bresolin, Angélica Grespan, Sonia Maria Alves Bueno
The present study evaluated the phosphorylated-tyrosine (P-Tyr) based pseudobioaffinity adsorbent for the purification of human immunoglobulin G (IgG). P-Tyr was selected as a ligand to mimic the natural interactions that occur between the immunoreceptor tyrosine-based activation motif and the IgG. The ligand was coupled to bisoxirane-activated agarose gel and the effect of buffer system, pH, and conductivity was performed to elucidate the nature of IgG-P-Tyr interactions. P-Tyr-agarose was able to purify IgG from human plasma solution in HEPES buffer at pH 7.0 exhibiting a purification factor of 9.1 with IgG purity of 91% (based on ELISA analysis of albumin, transferrin, and immunoglobulins A, G, and M). The evaluation of different functional groups of P-Tyr on the adsorption of human IgG indicated the predominance of electrostatic interactions with phosphate groups, although the contributions of aromatic and carboxylic groups also play a role. The thermodynamic parameters (ΔH°, ΔS°, ΔG°) for IgG adsorption onto P-Tyr-agarose were determined from the temperature dependence. The maximum IgG binding capacity at 20°C was 273.51±12.63mgg−1 and the dissociation constant value of the complex IgG-P-Tyr was in the order of 10−5molL−1 indicating low-affinity.

Publication date: 1 May 2017
Source:Journal of Chromatography B, Volume 1052

Author(s): Gisele Luiza Pavan, Igor Tadeu Lazzarotto Bresolin, Angélica Grespan, Sonia Maria Alves Bueno

The present study evaluated the phosphorylated-tyrosine (P-Tyr) based pseudobioaffinity adsorbent for the purification of human immunoglobulin G (IgG). P-Tyr was selected as a ligand to mimic the natural interactions that occur between the immunoreceptor tyrosine-based activation motif and the IgG. The ligand was coupled to bisoxirane-activated agarose gel and the effect of buffer system, pH, and conductivity was performed to elucidate the nature of IgG-P-Tyr interactions. P-Tyr-agarose was able to purify IgG from human plasma solution in HEPES buffer at pH 7.0 exhibiting a purification factor of 9.1 with IgG purity of 91% (based on ELISA analysis of albumin, transferrin, and immunoglobulins A, G, and M). The evaluation of different functional groups of P-Tyr on the adsorption of human IgG indicated the predominance of electrostatic interactions with phosphate groups, although the contributions of aromatic and carboxylic groups also play a role. The thermodynamic parameters (ΔH°, ΔS°, ΔG°) for IgG adsorption onto P-Tyr-agarose were determined from the temperature dependence. The maximum IgG binding capacity at 20°C was 273.51±12.63mgg−1 and the dissociation constant value of the complex IgG-P-Tyr was in the order of 10−5 molL−1 indicating low-affinity.