Rabah Gahoual

Paris Descartes, CPSC | Paris 5 · Faculty of Pharmaceutical and Biological Sciences

Bothrops venoms are rich in enzymes acting on platelets and coagulation. This action is dependent on two major co-factors, i.e., calcium and phospholipids, while antivenoms variably neutralize venom-related coagulopathy effects. Our aims were (i) to describe the composition of B. atrox and B. lanceolatus venoms; (ii) to study their activity on the...

Despite reports indicating the potential impact of post-translational modifications on the activity of a monoclonal antibody, their prediction or monitoring post-administration remains a challenge. In addition, with the expiration of patents concerning the early generation of mAbs, the production of biosimilars is constantly increasing. Structural...

Monoclonal antibodies (mAbs) are demonstrating major success in various therapeutic areas such as oncology and the treatment of immune disorders. Over the past two decades, novel analytical methodologies allowed to address the challenges of mAbs characterization in the context of their production. However, after administration only their quantifica...

Monoclonal antibodies (mAbs) represent a dynamic class of biopharmaceutical products, as evidenced by an increasing number of market authorizations for mAb innovator and biosimilar products. Stability studies are commonly performed during product development, for instance, to exclude unstable molecules, optimize the formulation or determine the sto...

We report the formulation, characterization, colloidal stability, and in vitro efficiency of Fisetin nanocrystals stabilized by poloxamer P407. Such nanocrystals present a nanometer scale (148.6 ± 1.1 nm) and a high homogeneity (polydispersity index of 0.17 ± 0.01), with a production yield of 97.0 ± 2.5%. The engineered formulations of nanocrystals...

Among the biotherapeutic products, monoclonal antibodies (mAbs) are experiencing a remarkable success in different therapeutic fields like oncology and immunological disorders. This chapter details the implementation of capillary electrophoresis (CE) coupling with mass spectrometry (CE–MS) for the structural characterization of mAbs. It describes t...

Monoclonal antibodies (mAbs) represent a major category of biopharmaceutical products which due to their success as therapeutics have recently experienced the emergence of mAbs originating from different types of trafficking. We report the development of an analytical strategy which enables the structural identification of mAbs in addition to compr...

During pharmaceutical development, the stability of the product is assessed during long-term study. If any stability issues are discovered at this point of the process, it will result in re-formulation and important loss of time and cost. Therefore, important efforts are made in order to select the most stable product. Nevertheless, predicting the...

Objectifs Identification d’anticorps monoclonaux dans des échantillons saisis à l’aide de méthodes analytiques complémentaires permettant de démontrer sans ambiguïté l’identité de la protéine étudiée et de distinguer d’éventuelles traces de dégradations. Méthode Les anticorps monoclonaux (mAbs) connaissent un succès incontestable comme agents thér...

CE has been demonstrated to be a useful and powerful separation method for the characterization of charged and neutral molecules. Since the end of the 1980s and the development of the first commercialized CE device, the use of this separation method has continued to grow for academic and industrial research involving inexorably increasing of the nu...

Ascorbic acid is a powerful antioxidant compound involved in many biological functions, and a chronic deficiency is at the origin of scurvy disease. A simple, rapid and cost effective CE method was developed for the separation and simultaneous quantification of ascorbic acid and the major degradation products: dehydroascorbic acid, furfural and fur...

Protein conjugates such as antibody-drugs conjugates (ADCs) represents the next generation of therapeutic proteins. They allow to combine the biological properties of the protein format with the characteristics of the conjugated ligands. The reaction implemented to couple ligands to the peptide backbone represents a crucial aspect of the production...

Capillary electrophoresis-mass spectrometry (CE-MS) enables the characterization of the primary structure of ADCs. An analytical method based on a derived bottom-up proteomic workflow is designed to provide detailed information about the amino acid sequence, the glycosylation profiling, and the location on the peptide backbone of the conjugated dru...

In the last two decades the development of biomaterials has demonstrated an unprecedented progress which has been emphasized by the introduction of a significant number of innovative materials. As such, the advent of biomaterials represents a formidable opportunity for the implementation of therapeutic treatments, able to induce tissue or organ reg...

Synthetic peptides mimicking the binding site of fertilin β to its receptor, integrin α6β1, were shown to inhibit sperm−egg fusion when added to in vitro media. In contrast, the synthetic cyclic hexapeptide, cyclo(Cys 1-Ser 2-Phe 3-Glu 4-Glu 5-Cys 6), named as cFEE, proved to stimulate gamete fusion. Owing to its biological specificity, this hexape...

A 38-year-old man was admitted in the intensive care unit (ICU) after supposed ingestion of 504 sustained-release tablets of Theralithe™ corresponding ~200 g of lithium carbonate. At the admission, ~19.5 h after ingestion, the patient was conscious with trembling limbs, intense thirst, profuse sweats and vomiting and lithium serum concentration was...

The Fc-fusion protein atacicept is currently under clinical investigation for its biotherapeutic application in autoimmune diseases owing to its ability to bind the two cytokines B-Lymphocyte Stimulator (BLyS) and A PRoliferation-Inducing Ligand (APRIL). Like typical recombinant IgG-based therapeutics, atacicept is a glycoprotein whose glycosylatio...

Liposomes are nanocarriers composed of phospholipids, especially designed to potentially carry drugs. However, liposomes suffer in terms of leakage of small hydrophilic drugs. To control the release, a system with lipid shell and polymeric viscous core, namely Hybrid liposome/polymer inside (HLPin), has been designed. For this purpose, we setup a s...

Monoclonal antibodies (mAbs) and their related products as antibody-drug-conjugates (ADCs) or biosimilars represent a constantly growing class of molecules therapeutic proteins used as treatment against numerous diseases. These compounds can undergo several modifications which could alter the efficiency of treatments. In this context, several analy...

Lactosylated albumin is currently used as a radiopharmaceutical agent to image the liver asialoglycoprotein receptors and quantify hepatic liver function in various diseases. A lactosylated protein (LACTAL) conjugate showed excellent liver uptake compared to non-lactosylated protein and a high signal to noise ratio, based on the biodistribution in...

Introduction: The development and optimization of antibody drug conjugates (ADCs) rely on improving their analytical and bioanalytical characterization, by assessing critical quality attributes (CQAs). Among the CQAs, the glycoprofile, drug load distribution (DLD), the amount of unconjugated antibody (D0), the average drug-to-antibody ratio (DAR),...

Monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) are highly potent biopharmaceuticals designed for targeted cancer therapies. mAbs and ADCs can undergo modifications during production and storage which may affect binding to target receptors, potentially altering drug efficacy. In this work, liquid chromatography was coupled online t...

In the context of increasing liver diseases, no contrast agent is currently available in Europe and united states to directly assess the liver function. Sole, neolactosylated human serum albumin is being clinically used in Asia. In order to perform preclinical studies in the context of liver diseases, we conceived a fluorescent lactosylated albumin...

Capillary electrophoresis and mass spectrometry (CE‐MS) hyphenation remains a minor technique compared to liquid chromatography – mass spectrometry (LC‐MS), which represents nowadays the standard instrumentation, regardless of its introduction thirty years ago. However, from a theoretical point of view CE coupling should be quite favorable especial...

We report on the online coupling of FcRn affinity liquid chromatography (LC) with electrospray ionization mass spectrome-try (ESI-MS) in native conditions to study the influence of modifications on the interaction of recombinant mAbs with the immobilized FcRn receptor domain. The analysis conditions were designed to fit the requirements of both aff...

Out of all categories, monoclonal antibodies (mAbs), biosimilar, antibody-drug conjugates (ADCs) and Fc-fusion proteins attract the most interest due to their strong therapeutic potency and specificity. Because of their intrinsic complexity due to a large number of micro-heterogeneities, there is a crucial need of analytical methods to provide comp...

Amino acids residues are commonly submitted to various physicochemical modifications occurring at physiological pH and temperature. Post-translational modifications (PTMs) require comprehensive characterization because of their major influence on protein structure and involvement in numerous in vivo process or signaling. Mass spectrometry (MS) has...

In this work, we describe the characterization of a quantity-limited sample (100 ng) of yeast mitochondria by shotgun bottom-up proteomics. Sample characterization was carried out by sheathless capillary electrophoresis, equipped with a high sensitivity porous tip and coupled to tandem mass spectrometry (CESI-MS-MS) and concomitantly with a state-o...

Monoclonal antibody (mAb) therapeutics attract the largest concern due to their strong therapeutic potency and specificity. The Fc region of mAbs is common to many new biotherapeutics as biosimilar, antibody drug conjugate or fusion protein. Fc region has consequences for Fc-mediated effector functions that might be desirable for therapeutic applic...

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An innovative coupling of capillary electrophoresis and tandem mass spectrometry (CE–MS-MS) provides excellent results for the characterization of the primary structure of biologics. Using a single 200-fmol injection, it is possible to completely characterize the amino acid sequence and obtain information about the location, structure, and relative...

Mammalian cell culture is the starting point in many research studies focusing on biomedical applications. However, researchers have little control over the standardized cell microenvironment parameters. Here a modular ECM-mimicking surface coating for cell culture environment is designed. This substrate is a new and versatile thin film obtained by...

Monoclonal antibodies (mAbs) are highly complex glycoproteins that present a wide range of microheteroge-neities that requires multiple analytical methods for full structure assessment and quality control. Capillary zone electrophoresis-Mass spectrometry couplings (CZE-MS), especially by Electrospray (ESI), appear really attractive methods for the...

Monoclonal antibodies (mAbs) are highly complex glycoproteins that present a wide range of microheteroge-neities that requires multiple analytical methods for full structure assessment and quality control. Capillary zone electrophoresis-Mass spectrometry couplings (CZE-MS), especially by Electrospray (ESI), appear really attractive methods for the...

Out of all categories, monoclonal antibody (mAb) therapeutics attract the most interest due to their strong therapeutic potency and specificity. Six of the ten top-selling drugs are antibody-based therapeutics that will lose patent protection soon. The European Medicines Agency has pioneered the regulatory framework for approval of biosimilar produ...

Interfacings allowing the hyphenation of capillary electrophoresis (CE) to ESI mass spectrometry(MS) currently suffer from lack of robustness and sensitivity. This work describes the application of a new design of CE-ESl-MS coupling referred as the CESl-MS. Characterization of the ESI generated through the CESl-MS system showed the production of a...

Here we report the complete characterization of the primary structure of a multimeric glycoprotein in a single analysis by capillary electrophoresis (CE) coupled to mass spectrometry (MS). CE was coupled to electrospray ionization tandem MS by the mean of a sheathless interface. Transient isotachophoresis (t-ITP) was introduced in this work as an e...

Development of nano-electrospray (nanoESI) sources allowed to increase significantly the sensitivity which is often lacking when studying biological noncovalent assemblies. However, the flow rate used to infuse the sample into the mass spectrometer cannot be precisely controlled with nanoESI and the robustness of the system could represent an issue...

Monoclonal antibodies (mAbs) are highly complex proteins that display a wide range of microheterogeneity that requires multiple analytical methods for full structure assessment and quality control. As a consequence, the characterization of mAbs on different levels is particularly product-and time-consuming. This work presents the characterization o...

Monoclonal antibodies (mAbs) are highly complex proteins that display a wide range of microheterogeneity that requires multiple analytical methods for full structure assessment and quality control. As a consequence, the characterization of mAbs on different levels is particularly product - and time - consuming. This work presents the characterizati...