Publications by authors named "Isabelle Chevalot"

Microbial cultures repurposing organic industrial residues for value-added metabolite production is pivotal for sustainable resource use. Highlighting polyunsaturated fatty acids (PUFAs), particularly gamma-linolenic acid (GLA), renowned for their nutritional and therapeutic value. Notably, Zygomycetes' filamentous fungi harbor abundant GLA-rich lipid content, furthering their relevance in this approach.

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The aim of the present work was to obtain microbial lipids (single-cell oils and SCOs) from oleaginous yeast cultivated on biodiesel-derived glycerol and subsequently proceed to the enzymatic synthesis of high-value biosurfactant-type molecules in an aqueous medium, with SCOs implicated as acyl donors (ADs). Indeed, the initial screening of five non-conventional oleaginous yeasts revealed that the most important lipid producer was the microorganism ATCC 20509. SCO production was optimised according to the nature of the nitrogen source and the initial concentration of glycerol (Glyc0) employed in the medium.

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The ferulic acid (FA)-oxidation by laccase was performed in phosphate buffer at 30 °C and pH 7.5 as an eco-friendly procedure. LC-MS analysis showed that oxidation products were four dehydrodimers (P1, P2, P3, P5) at MM = 386 g/mol, two dehydrotetramers (P6, P7) at MM = 770 g/mol and one decarboxylated dehydrodimer (P4) at MM = 340 g/mol.

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In the present study, innovative doxorubicin-loaded nanoparticles (NPs) made of a photosensitive poly(-nitrobenzyl acrylate) (PNBA) hydrophobic matrix and an hydrophilic dextran (Dex) shell were first formulated by the emulsion-solvent evaporation process. Doxorubicin (DOX), a very well-known anticancer drug, was herein chosen as the model. DOX-loaded NPs were successfully produced by covering the hydrophobic PNBA core with Dex chains either physically adsorbed or covalently linked by changing process parameters as the presence of a catalyst (CuBr or CuSO/ascorbic acid).

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As a clinical dose requires a minimum of 10 cells per kilogram of patients, it is, therefore, crucial to develop a scalable method of production of Wharton Jelly mesenchymal stem cells (WJ-MSCs) with maintained inner characteristics. Scalable expansion of WJ-MSCs on microcarriers usually found in cell culture, involves specific cell detachment using trypsin and could have harmful effects on cells. In this study, the performance of batch, fed-batch, and perfused-continuous mode of culture were compared.

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A new glyco-phenol was produced by the coupling between glucosamine (Glu) and ferulic acid (FA) using Myceliophthora thermophila laccase as biocatalyst in mild conditions (distilled water and 30°C) as an environmentally friendly process. Results indicated that the enzymatic reaction created a new derivative (FA-Glu), produced from coupling between Glu and FA by covalent bonds. By the high production of (FA-Glu) derivative and its stability, the optimal ratio of (FA:Glu) was of (1:1) at optimal time reaction of 6 h.

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N-acylated amino acids are widely used as surfactants and/or actives in cosmetics and household formulations. Their industrial production is based on the use of the Schotten-Baumann chemical and unselective reaction. Faced to the growing demand for greener production processes, selective enzymatic synthesis in more environment-friendly conditions starts to be considered as a potential alternative.

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The present study proposed to compare the impact of agitation mode (static, orbital, and mechanical) on the culture of mesenchymal stem cells extracted from the Wharton's jelly of umbilical cords (WJ-MSC), in a clinical grade culture medium, using human platelet lysate and different xeno-free microcarriers. Attachment, expansion, and detachment performances were characterized by a new dedicated tool of microscopic image posttreatment, allowing an in situ cell counting without detachment step. Results showed that performances in static mode were not necessarily representative of those obtained in dynamic mode.

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Data in this paper describes the catalytic performances, expressed in terms of conversion %, of geraniol and acetic acid to geranyl acetate, using the immobilized lipase B from in packed bed reactors (PBR) using supercritical CO as a solvent. Readers will find data related to different Figures or equations of the article as well as supplementary data that will help to make the difference between flowrates of CO in a liquid state and corresponding flowrates of supercritical CO for various CO pressure and temperature combinations.

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The presence of aminoacylase activities was investigated in a crude extract of ATCC23877. First activities catalyzing the hydrolysis of N-α or ε-acetyl-L-lysine were identified. Furthermore, the acylation of lysine and different peptides was studied and compared with results obtained with lipase B of (CALB).

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Multidrug resistance (MDR) of tumors to chemotherapeutics often leads to failure of cancer treatment. The aim of the study was to prepare novel MDR-overcoming chemotherapeutics based on doxorubicin (DOX) derivatives and to evaluate their efficacy in 2D and 3D in vitro models. To overcome MDR, we synthesized five DOX derivatives, and then obtained non-covalent complexes with human serum albumin (HSA).

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Hypothesis: For some years, smart nano-objects are one of the main focuses of current research. In the framework of polymeric nanomedicine, o-nitrobenzyl alcohol derivatives lead to light-responsive polymeric materials. At this day, nanomedicine based on polysaccharide/poly(o-nitrobenzyl acrylate) (PNBA) copolymers have never been reported.

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Objectives: To design novel 3D in vitro co-culture models based on the RGD-peptide-induced cell self-assembly technique.

Results: Multicellular spheroids from M-3 murine melanoma cells and L-929 murine fibroblasts were obtained directly from monolayer culture by addition of culture medium containing cyclic RGD-peptide. To reach reproducible architecture of co-culture spheroids, two novel 3D in vitro models with well pronounced core-shell structure from tumor spheroids and single mouse fibroblasts were developed based on this approach.

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Carnosine (CAR) dipeptide was functionalized with ferulic acid (FA) as substrate using laccase from Myceliophtora thermophila as biocatalyst. The enzymatic reaction was performed in aqueous medium under mild conditions (pH 7.5, 30°C) as an eco-friendly procedure.

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Mesenchymal stem cells (MSCs) are known to be an attractive cell source for tissue engineering and regenerative medicine. One of the main limiting steps for clinical use or biotechnological purposes is the expansion step. The research of compatible biomaterials for MSCs expansion is recently regarded as an attractive topic.

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The optimal conditions of supercritical carbon dioxide (SC-CO2) (160-220 bars, 40-80 °C) technology combined with co-solvent (ethanol), to recover oil, flavonolignans (silychristin, silydianin and silybinin) and fatty acids from milk thistle seeds, to be used as food additives and/or nutraceuticals, were studied. Moreover, the antioxidant and cytotoxic activities of the SC-CO2 oil seeds extracts were evaluated in Caco-2 carcinoma cells. Pressure and temperature had a significant effect on oil and flavonolignans recovery, although there was not observed a clear trend.

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Yeast extract (YE) is known to greatly enhance mammalian cell culture performances, but its undefined composition decreases process reliability. Accordingly, in the present study, the nature of YE compounds involved in the improvement of recombinant CHO cell growth and IgG production was investigated. First, the benefits of YE were verified, revealing that it increased maximal concentrations of viable cells and IgG up to 73 and 60%, respectively compared to a reference culture.

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Article Synopsis
  • Chitosan was modified by laccase-catalyzed oxidation of ferulic acid (FA) and ethyl ferulate (EF), resulting in derivatives with enhanced physico-chemical, antioxidant, and antibacterial properties.
  • The oxidation process produced FA-coloured and EF-colourless chitosan derivatives, with FA-products demonstrating better grafting efficiency and improved stability against chemical treatments.
  • The modified chitosan also showed increased molecular weight and viscosity, along with superior antioxidant properties, particularly the FA-chitosan derivative, while maintaining antibacterial activity even after thermal treatment.
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The extensive use of mesenchymal stem cells (MCS) in tissue engineering and cell therapy increases the necessity to improve their expansion. Among these, porcine MCS are valuable models for tissue engineering and are classically expanded in static T-flasks. In this work, different processes of stirred cultures were evaluated and compared.

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The enzymatic oxidation of ferulic acid (FA) and ethyl ferulate (EF) with Myceliophthora thermophila laccase, as biocatalyst, was performed in aqueous medium using an eco-friendly procedure to synthesize new active molecules. First, the commercial laccase was ultrafiltrated allowing for the elimination of phenolic contaminants and increasing the specific activity by a factor of 2. Then, kinetic parameters of this laccase were determined for both substrates (FA, EF), indicating a higher substrate affinity for ethyl ferulate.

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Many studies underlined the great benefits of hydrolysates used as additives in animal free media on cell culture performances. However, to precisely define hydrolysate supplementation strategies, a deeper understanding of their effect on cell growth and protein production is required. In the present study, the effect of addition of one yeast extract (YE) and two yeast peptones (named YP.

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Mesenchymal stem cells (MSC) are known to be a valuable cell source for tissue engineering and regenerative medicine. However, one of the main limiting steps in their clinical use is the amplification step. MSC expansion on microcarriers has emerged during the last few years, fulfilling the lack of classical T-flasks expansion.

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Chitosan particles were functionalized with ferulic acid (FA) and ethyl ferulate (EF) as substrates using laccase from Myceliophtora thermophyla as biocatalyst. The reactions were performed with chitosan particles under an eco-friendly procedure, in a heterogeneous system at 30°C, in phosphate buffer (50mM, pH 7.5).

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