Improvement of chemo- and stereoselectivity for phosphorothioate oligonucleotides in capillary electrophoresis by addition of cyclodextrins.

Phosphorothioate (PS) modification is one of the most widely used oligonucleotide chemical alterations in the oligonucleotide backbone. It has proven to be crucial in the field of therapeutic oligonucleotides regarding the optimization of their physicochemical and biological properties. In this study, a capillary electrophoresis (CE) method with an acidic background electrolyte (BGE) containing a combination of β- and γ-cyclodextrins derivatives as chiral selectors is proposed for the diastereomeric separation of 5-mer oligonucleotides containing 0, 1, 2, or 3 phosphorothioate linkages (5´-TCGTG-3´).

Separation of phosphorothioated oligonucleotide diastereomers using multiplexed drift tube ion mobility mass spectrometry.

Hydrophilic interaction liquid chromatography (HILIC) coupled to drift tube ion mobility spectrometry (DTIMS) was used to separate diastereomers of five-unit oligonucleotides containing 0, 1, 2 or 3 phosphorothioate (PS) linkages. Multiplexed DTIMS (where ions are pulsed into the drift tube according to a pre-encoded sequence) and post-acquisition processing using an innovative demultiplexing tool were investigated. The electric field inside the drift tube was optimized to achieve the highest resolving power.

Analytical techniques currently used in the pharmaceutical industry for the quality control of RNA-based therapeutics and ongoing developments.

The number of RNA-based therapeutics has significantly grown in number on the market over the last 20 years. This number is expected to further increase in the coming years as many RNA therapeutics are being tested in late clinical trials stages. The first part of this paper considers the mechanism of action, the synthesis and the potential impurities resulting from synthesis as well as the strategies used to increase RNA-based therapeutics efficacy.

Novel Fast Chromatography-Tandem Mass Spectrometric Quantitative Approach for the Determination of Plant-Extracted Phytosterols and Tocopherols.

Phytosterols and tocopherols are commonly used in food and pharmaceutical industries for their health benefits. Current analysis methods rely on conventional liquid chromatography, using an analytical column, which can be tedious and time consuming. However, simple, and fast analytical methods can facilitate their qualitative and quantitative analysis.

Dibenzoylthiamine Has Powerful Antioxidant and Anti-Inflammatory Properties in Cultured Cells and in Mouse Models of Stress and Neurodegeneration.

Thiamine precursors, the most studied being benfotiamine (BFT), have protective effects in mouse models of neurodegenerative diseases. BFT decreased oxidative stress and inflammation, two major characteristics of neurodegenerative diseases, in a neuroblastoma cell line (Neuro2a) and an immortalized brain microglial cell line (BV2). Here, we tested the potential antioxidant and anti-inflammatory effects of the hitherto unexplored derivative O,S-dibenzoylthiamine (DBT) in these two cell lines.

Hyphenation of capillary zone electrophoresis with mass spectrometry for proteomic analysis: Optimization and comparison of two coupling interfaces.

Capillary electrophoresis tandem mass spectrometry (CE-MS/MS) is an interesting tool for proteomic analysis as the separation principle is orthogonal to liquid chromatography tandem mass spectrometry (LC-MS/MS). The combination of both techniques can bring complementary information to enlarge proteome coverage. In this study, sample preconcentration techniques were investigated in order to improve sample loading and therefore sensitivity.

Evaluation of hydrophilic interaction liquid chromatography, capillary zone electrophoresis and drift tube ion-mobility quadrupole time of flight mass spectrometry for the characterization of phosphodiester and phosphorothioate oligonucleotides.

Oligonucleotide-based medicines that can modulate gene expression have numerous potential applications in targeted therapies. Most of the commercialized therapeutic oligonucleotides are chemically modified to increase their in vivo lifetime. In this work, we studied poly-deoxy(thymidylic) acids (dT) and modified phosphorothioate oligonucleotides (PS).

Thiamine and benfotiamine protect neuroblastoma cells against paraquat and β-amyloid toxicity by a coenzyme-independent mechanism.

Background: Benfotiamine (BFT) is a synthetic thiamine precursor with high bioavailability. It is efficient in treating complications of type 2 diabetes and has beneficial effects in mouse models of neurodegenerative diseases. The mechanism of action of BFT remains unknown, though it is sometimes suggested that it may be linked to increased thiamine diphosphate (ThDP) coenzyme function.

Insulin aggregation assessment by capillary gel electrophoresis without sodium dodecyl sulfate: Comparison with size-exclusion chromatography.

Size-exclusion chromatography (SEC) is a method of choice for the analysis of protein aggregates in pharmaceuticals. The United States and European Pharmacopoeias currently use a SEC method with an acidic pH mobile phase to assess the content of aggregates in insulin formulations. In this article, we analyzed aggregated human insulin samples and demonstrated that both methods under neutral conditions, namely neutral pH SEC (nSEC) and capillary gel electrophoresis (CGE), yield to similar aggregate content contrary to SEC under acidic conditions (aSEC).

Separation and determination of alpha-synuclein monomeric and oligomeric species using two electrophoretic approaches.

Parkinson's disease (PD) is a frequent degenerative disorder that is diagnosed based on clinical symptoms. When the first symptoms appear, more than 70% of the dopaminergic cells are already lost. Therefore, it is of utmost importance to have reliable biomarkers to diagnose much earlier PD.

Analysis of protamine peptides in insulin pharmaceutical formulations by capillary electrophoresis.

Protamines are a group of highly basic peptides that are sometimes added to insulin formulations to prolong the pharmacological action. In this study, different methods were investigated to identify protamine in insulin formulations. Capillary electrophoresis in aqueous and non-aqueous media was tested to separate these peptides with very close amino acid sequences.

[Anatomic-clinical presentation. Testicular teratocarcinoma with thoracic-abdominal adenopathy].

This case report of a young man with a testicular germ cell-teratoma tumor illustrates the necessity of a multidisciplinary sequential approach to ensure chance of cure. The outcome of patients with advanced germ cell tumor depends on the optimal clinical management. Residual masses are frequent, and their histology can be different than the initial one (i.

[Recurrent urethral stenosis treated with a Urolome Plus stent implantation: intermediate multicenter follow-up].

We present the medium-term results of 33 patients treated with Urolume Plus urethral stent between August 1990 and June 1996 in 9 Belgian and Luxembourg centers. They all had previous treatments for bulbo-membranous urethral stricture, but without sustained benefit (dilatation, internal urethrotomy, or/and urethroplasty). The mean age of the stricture was 5.