At the forefront of new synthetic endeavors, such as drug discovery or natural product synthesis, large quantities of material are rarely available and timelines are tight. A miniaturized automation ...platform enabling high-throughput experimentation for synthetic route scouting to identify conditions for preparative reaction scale-up would be a transformative advance. Because automated, miniaturized chemistry is difficult to carry out in the presence of solids or volatile organic solvents, most of the synthetic "toolkit" cannot be readily miniaturized. Using palladium-catalyzed cross-coupling reactions as a test case, we developed automation-friendly reactions to run in dimethyl sulfoxide at room temperature. This advance enabled us to couple the robotics used in biotechnology with emerging mass spectrometry–based high-throughput analysis techniques. More than 1500 chemistry experiments were carried out in less than a day, using as little as 0.02 milligrams of material per reaction.
Stability data of toxics or drugs in gel-based or mechanical separation blood collection tubes are lacking, especially for therapeutic drug monitoring and clinical toxicology procedures. According to ...ISO 15189 accreditation standard, laboratories need to master the entire preanalytical process including the stability of analytes in a specific tube. Here we explored the impact of BD PST™ II and Barricor™ separator tubes on the stability of 167 therapeutic compounds and common drugs of abuse in plasma samples using LC-MS/MS. Forty drugs were significantly affected by the use of PST™ II tubes, including antidepressants (11/26), neuroleptics (9/13), cardiovascular drugs (5/26), anxiolytics and hypnotics (4/25) and some drugs of abuse (5/26). Six compounds exhibited significant reduction by the mechanical Barricor™ tubes. Ten drugs exhibited low (<85%) but non-significant recoveries due to inter-assay variability. Besides, a logP > 3.3 was determined as a cut-off value to predict a potential lack of stability in PST™ II gel tubes with an 86.4% sensitivity and a 61.4% specificity. As a consequence, determination of drugs with a logP > 3.3 should be carried out with caution in plasma samples withdrawn on PST™ II. The study showed the Barricor™ and non-gel tubes cause less drug interference and are recommended for the drugs studied.
•Stability of drugs on separator gel blood collection tubes is concerning.•We assessed the impact of PSTII and Barricor tubes on the stability of 167 drugs.•LogP appears as a major contributor of drug stability in separator tubes.•Determination of drugs with a logP > 3.3 may be avoided in such collection tubes.
In vitro spermatogenesis appears to be a promising approach to restore the fertility of childhood cancer survivors. The rat model has proven to be challenging, since germ cell maturation is arrested ...in organotypic cultures. Here, we report that, despite a meiotic entry, abnormal synaptonemal complexes were found in spermatocytes, and in vitro matured rat prepubertal testicular tissues displayed an immature phenotype. RNA-sequencing analyses highlighted up to 600 differentially expressed genes between in vitro and in vivo conditions, including genes involved in blood-testis barrier (BTB) formation and steroidogenesis. BTB integrity, the expression of two steroidogenic enzymes, and androgen receptors were indeed altered in vitro. Moreover, most of the top 10 predicted upstream regulators of deregulated genes were involved in inflammatory processes or immune cell recruitment. However, none of the three anti-inflammatory molecules tested in this study promoted meiotic progression. By analysing for the first time in vitro matured rat prepubertal testicular tissues at the molecular level, we uncovered the deregulation of several genes and revealed that defective BTB function, altered steroidogenic pathway, and probably inflammation, could be at the origin of meiotic arrest.
The employment of ethylenediaminetetraacetic acid (EDTA) across several fields in chemistry and biology has required the creation of a high number of quantitative assays. Nonetheless, the ...determination of trace EDTA, especially in biologics and vaccines, remains challenging. Herein, we introduce an automated high-throughput approach based on EDTA esterification in 96-well plates using boron trifluoride-methanol combined with rapid analysis by ultra-high-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). Derivatization of EDTA to its methyl ester (Me-EDTA) serves to significantly improve chromatographic performance (retention, peak shape, and selectivity), while also delivering a tremendous enhancement of sensitivity in the positive ion mode electrospray ionization (ESI+). This procedure, in contrast to previous EDTA methods based on complexation with metal ions, is not affected by high concentration of other metals, buffers, and related salts abundantly present in biopharmaceutical processes (e.g., iron, copper, citrate, etc.). Validation of this assay for the determination of ng·mL
level EDTA in monoclonal antibody and vaccine products demonstrated excellent performance (repeatability, precision, and linear range) with high recovery from small sample volumes while also providing an advantageous automation-friendly workflow for high-throughput analysis.
Metabolic phenotyping is poised as a powerful and promising tool for biomarker discovery in inherited metabolic diseases. However, few studies applied this approach to mcopolysaccharidoses (MPS). ...Thus, this innovative functional approach may unveil comprehensive impairments in MPS biology. This study explores mcopolysaccharidosis VI (MPS VI) or Maroteaux⁻Lamy syndrome (OMIM #253200) which is an autosomal recessive lysosomal storage disease caused by the deficiency of arylsulfatase B enzyme. Urine samples were collected from 16 MPS VI patients and 66 healthy control individuals. Untargeted metabolomics analysis was applied using ultra-high-performance liquid chromatography combined with ion mobility and high-resolution mass spectrometry. Furthermore, dermatan sulfate, amino acids, carnitine, and acylcarnitine profiles were quantified using liquid chromatography coupled to tandem mass spectrometry. Univariate analysis and multivariate data modeling were used for integrative analysis and discriminant metabolites selection. Pathway analysis was done to unveil impaired metabolism. The study revealed significant differential biochemical patterns using multivariate data modeling. Pathway analysis revealed that several major amino acid pathways were dysregulated in MPS VI. Integrative analysis of targeted and untargeted metabolomics data with in silico results yielded arginine-proline, histidine, and glutathione metabolism being the most affected. This study is one of the first metabolic phenotyping studies of MPS VI. The findings might shed light on molecular understanding of MPS pathophysiology to develop further MPS studies to enhance diagnosis and treatments of this rare condition.
Nicardipine hydrochloride is an anti-hypertensive drug that is used off-label to treat hypertension in children. A previous oral formulation of nicardipine hydrochloride was developed using a ...commercial vehicle as an excipient. However, ready-to-use vehicles are prone to supply shortages, and their composition may undergo substantial modifications. The aim of this study was to propose a new oral formulation of nicardipine hydrochloride 2 mg/mL using simple excipients. The formulation included hydroxypropylmethylcellulose, simple syrup, polysorbate 80, sodium saccharin, citrate buffer, strawberry flavor and 0.2% potassium sorbate. The uniformity of content was maintained before and after agitation. Nicardipine hydrochloride concentration assessed by HPLC-MS/MS remained above 90% for 365 days before opening and for 28 days after opening. pH and osmolality were maintained throughout the study, and no microbial contamination was observed. The uniformity of mass of the delivered doses was evaluated using four different devices. A new oral formulation of nicardipine hydrochloride 2 mg/mL was developed using simple and safe excipients. Pharmacological and clinical parameters remain to be assessed and compared with those of the previous formulation.
Children undergoing cancer treatments are at risk for impaired fertility. Cryopreserved prepubertal testicular biopsies could theoretically be later matured
to produce spermatozoa for assisted ...reproductive technology. A complete
spermatogenesis has been obtained from mouse prepubertal testicular tissue, although with low efficiency. Steroid hormones are essential for the progression of spermatogenesis, the aim of this study was to investigate steroidogenesis and steroid signaling in organotypic cultures. Histological, RT-qPCR, western blot analyses, and steroid hormone measurements were performed on
cultured mouse prepubertal testicular tissues and age-matched
controls. Despite a conserved density of Leydig cells after 30 days of culture (D30), transcript levels of adult Leydig cells and steroidogenic markers were decreased. Increased amounts of progesterone and estradiol and reduced androstenedione levels were observed at D30, together with decreased transcript levels of steroid metabolizing genes and steroid target genes. hCG was insufficient to facilitate Leydig cell differentiation, restore steroidogenesis, and improve sperm yield. In conclusion, this study reports the failure of adult Leydig cell development and altered steroid production and signaling in tissue cultures. The organotypic culture system will need to be further improved before it can be translated into clinics for childhood cancer survivors.
Difficulties in isolating samples from complex biological matrices and sensitivity limitations have long stymied the utilization of heteronuclear 2D NMR for the characterization of drug metabolites. ...Small diameter cryogenic NMR probes have largely ameliorated sensitivity limitations and the recently reported pure shift HSQC 2D NMR pulse sequence offers a further and marked improvement in both resolution and sensitivity. Using a 7.4μg sample of the commercially available metabolite 3-hydroxy carbamazepine dissolved in 30μL of deuterated solvent and a 600MHz NMR equipped with a 1.7mm cryogenic NMR probe, it was possible to acquire high signal-to-noise pure shift HSQC data in just over 30min. A conventional HSQC spectrum acquired with identical parameters had approximately half the signal-to-noise of the pure shift HSQC spectrum. Collapsing the vicinal homonuclear couplings in the pure shift HSQC spectrum also significantly improves resolution. A practical, real world application of the technique is illustrated with the chromatographically isolated metabolite 3-hydroxy amiodarone from incubation with CYP2J2 recombinant enzyme. High quality pure shift HSQC data were recorded in slightly over 14h for a 3μg sample of the metabolite.
•A fully automated mass spectrometry method for determining steroids in serum was developed and validated.•The method includes protein precipitation, filtration and online 2D chromatography.•A ...biphenyl stationary phase demonstrated acceptable analytical performance for steroid separation.•Method comparison with immunoassay highlights improved performance of mass spectrometry.
Steroids play a key role in numerous physiological processes. Steroid determination is a useful tool to explore various endocrine diseases. Because of its specificity, mass spectrometry is considered to be a reference method for the determination of steroids in serum compared to radioimmunoassay. This technology could progress towards more automation for the optimal organization of clinical laboratories and ultimately for the benefit of patients.
A fully automated ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed and fully validated to determine five steroids in serum. Sample preparation was based on protein precipitation with filtration followed by online solid phase extraction. Chromatographic separation was performed using a biphenyl stationary phase.
The method was successfully validated according to European Medicine Agency guidelines. Coefficients of variation did not exceed, respectively, 8.4% and 8.1% for intra- and inter-assay precision. Method comparison with radioimmunoassay showed a proportional bias for all compounds, except for testosterone in men. Comparison with another LC-MS/MS method demonstrated acceptable concordance for all steroids, although a small bias was observed for androstenedione.
The novelty of this method is that it has been fully automated. Automation provides benefits in traceability and allows significant savings in cost and time.
Epoxyeicosatrienoic acids (EETs) are vasodilating lipid mediators metabolized into dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase. We aimed to develop a LC-MS/MS method to ...quantify EETs and DHETs in human plasma and monitored their levels during vascular endothelial stimulation. Plasma samples, collected from 14 healthy and five hypertensive subjects at baseline and during radial artery endothelium-dependent flow-mediated dilatation, were spiked with internal standards. Lipids were then extracted by a modified Bligh and Dyer method and saponified to release bound EETs and DHETs. Samples were purified by a second liquid–liquid extraction and analyzed by LC-MS/MS. The assay allowed identification of (±)8(9)-epoxy-5Z,11Z,14Z-eicosatrienoic acid (8,9-EET); (±)11(12)-epoxy-5Z,8Z,14Z-eicosatrienoic acid (11,12-EET); (±)14(15)-epoxy-5Z,8Z,11Z-eicosatrienoic acid (14,15-EET); (±)8,9-dihydroxy-5Z,11Z,14Z-eicosatrienoic acid (8,9-DHET); (±)11,12-dihydroxy-5Z,8Z,14Z-eicosatrienoic acid (11,12-DHET); and (±)14,15-dihydroxy-5Z,8Z,11Z-eicosatrienoic acid (14,15-DHET). (±)5(6)-epoxy-5Z,11Z,14Z-eicosatrienoic acid (5,6-EET) was virtually undetectable due to its chemical instability. The limits of quantification were 0.25 ng/mL for DHETs and 0.5 ng/mL for EETs. Intra- and inter-assay variations ranged from 1.6 to 13.2%. Heating induced a similar increase in 8,9-EET, 11,12-EET, and 14,15-EET levels and in corresponding DHET levels in healthy but not in hypertensive subjects. We validated a sensitive LC-MS/MS method for measuring simultaneously plasma EET and DHET regioisomers in human plasma and showed its interest for assessing endothelial function.
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