Gilles Subra

Gilles Subra

Gilles Subra
Professor, Faculty of Pharmacy of Montpellier

Gilles leads his researches in the Institute of Biomolécules Max Mousseron (IBMM) in the field of peptide science. His main research topics are at the interface of chemistry and biology and notably concern methodologies for solid phase and combinatorial chemistry, design of chemical tools to enhance detection and quantification by mass spectrometry in biological media. More recently, he is interested in the design of peptide-based materials and polymers. The main applications concern the conception of multi-ligand nanoparticles for cancer targeting, the functionalisation of silicone medical devices and dressings. His most recent research is related to the design of biomimetic peptide based hydrogel used for 3D biofabrication and cell-based therapies.

Gilles Subra founded the solid phase and automated synthesis platform (SynBio3) of the IBMM whose mission is to develop solid supported reagents, linkers and methodologies for the synthesis of biomolecules.

Contact:
gilles.subra@umontpellier.fr
+33 411 75 96 06

5 major publications :

Ciccione, J., Jia, T., Coll, J.-L., Parra, K., Amblard, M., Jebors, S., Martinez, J., Mehdi, A., and Subra, G. (2016). Unambiguous and Controlled One-Pot Synthesis of Multifunctional Silica Nanoparticles. Chem. Mater. 28, 885–889.

Echalier, C., Pinese, C., Garric, X., Van Den Berghe, H., Jumas Bilak, E., Martinez, J., Mehdi, A., and Subra, G. (2016). Easy Synthesis of Tunable Hybrid Bioactive Hydrogels. Chem. Mater. 28, 1261–1265.

Jebors, S., Ciccione, J., Al-Halifa, S., Nottelet, B., Enjalbal, C., M’Kadmi, C., Amblard, M., Mehdi, A., Martinez, J., and Subra, G. (2015). A New Way to Silicone-Based Peptide Polymers. Angew. Chem. Int. Ed. 54, 3778–3782.

Paramelle, D., Subra, G., Vezenkov, L.L., Maynadier, M., André, C., Enjalbal, C., Calmès, M., Garcia, M., Martinez, J., and Amblard, M. (2010). A Straightforward Approach for Cellular-Uptake Quantification. Angewandte Chemie International Edition 49, 8240–8243.

Paramelle, D., Enjalbal, C., Amblard, M., Forest, E., Heymann, M., Cantel, S., Geourjon, C., Martinez, J., and Subra, G. (2011). Solid-Phase Cross-Linking (SPCL): A new tool for protein structure studies. PROTEOMICS 11, 1277–1286.

Development of Amino Acids Functionalized SBA-15 for the Improvement of Protein Adsorption

Molecules 202126(19), 6085; https://doi.org/10.3390/molecules26196085

Abstract

Ordered mesoporous materials and their modification with multiple functional groups are of wide scientific interest for many applications involving interaction with biological systems and biomolecules (e.g., catalysis, separation, sensor design, nano-science or drug delivery). In particular, the immobilization of enzymes onto solid supports is highly attractive for industry and synthetic chemistry, as it allows the development of stable and cheap biocatalysts. In this context, we developed novel silylated amino acid derivatives (Si-AA-NH2) that have been immobilized onto SBA-15 materials in biocompatible conditions avoiding the use of toxic catalyst, solvents or reagents. The resulting amino acid-functionalized materials (SBA-15@AA) were characterized by XRD, TGA, EA, Zeta potential, nitrogen sorption and FT-IR. Differences of the physical properties (e.g., charges) were observed while the structural ones remained unchanged. The adsorption of the enzyme lysozyme (Lyz) onto the resulting functionalized SBA-15@AA materials was evaluated at different pHs. The presence of different functional groups compared with bare SBA-15 showed better adsorption results, for example, 79.6 nmol of Lyz adsorbed per m2 of SBA-15@Tyr compared with the 44.9 nmol/m2 of the bare SBA-15.

Hydrocarbon-Stapled Peptide Based-Nanoparticles for siRNA Delivery.

Nanomaterials (Basel). 2020 Nov 25;10(12):2334. doi: 10.3390/nano10122334

Simon M, Laroui N, Heyraud M, Laconde G, Ali LMA, Bourbiaux K, Subra G, Vezenkov LL, Legrand B, Amblard M, Bettache N.

 

Abstract

Small interfering RNAs (siRNAs) are promising molecules for developing new therapies based on gene silencing; however, their delivery into cells remains an issue. In this study, we took advantage of stapled peptide technology that has emerged as a valuable strategy to render natural peptides more structured, resistant to protease degradation and more bioavailable, to develop short carriers for siRNA delivery. From the pool of stapled peptides that we have designed and synthesized, we identified non-toxic vectors that were able to efficiently encapsulate siRNA, transport them into the cell and induce gene silencing. Remarkably, the most efficient stapled peptide (JMV6582), is composed of only eight amino-acids and contains only two cationic charges.

Nano-assemblies with core-forming hydrophobic polypeptide via polymerization-induced self-assembly (PISA)

Polym. Chem., 2021,12, 113-121 DOI: 10.1002/macp.202000311

Dao T, Vezenkov L, Subra G, Ladmiral V, Semsarilar M.

 

Abstract

The aim of this study is to produce self-assembled structures with hydrophobic polypeptide cores via Reversible Addition–Fragmentation chain Transfer (RAFT) – mediated Polymerisation-Induced Self-Assembly (PISA). Hydrophilic poly(glycerol monomethacrylate) macromolecular chain transfer agents (PGMA mCTAs) were used to polymerize the self-assembling peptide monomers, resulting in the formation of diblock copolymer nano objects. Methacrylamide derivatives containing self-assembling tripeptides MAm-GFF (MAm-Gly-Phe-Phe-NH2) and MAm-FGD (MAm-Phe-Gly-Asp-NH2) were used as hydrophobic monomers. The self-assembling behaviours of these monomers mainly derive from the interactions of the phenylalanine residues, however their difference in hydrophobicity required different polymerization conditions. MAm-GFF was polymerized in the presence of organic solvent (ethanol or acetonitrile), under either dispersion or emulsion polymerization, while MAm-FGD was polymerized under aqueous dispersion conditions. PGMA-b-P(MAm-FGD) obtained from aqueous PISA typically formed fibrous structures while a range of morphologies such as fibre-, flake-, and leaf-like or spherical vesicles were obtained for PGMA-b-P(MAm-GFF) depending on the copolymer composition and solvent used. In all cases the peptides self-assembling core had a crucial influence on the final morphologies.

Bottom-up strategies for the synthesis of peptide-based polymers

Progress in Polymer Science 115 (2021) 101377 https://doi.org/10.1016/j.progpolymsci.2021.101377

Martin J, Desfoux A, Martinez J, Amblard M, Mehdi A, Vezenkov L, Subra G

 

Abstract

Thanks to their wide range of biological activities, peptides have been extensively used to afford designed materials with tailored properties. Peptides can be associated to polymers combining the properties of various polymer backbones with those of bioactive peptide sequences. Such conjugates find promising applications in medical devices, tissue engineering, drug targeting and delivery. Improvement of existing polymers by post-modification peptide grafting is achieved through an extensive range of organic reactions, involving the prior preparation of functional polymers displaying suitable anchoring functions. Alternatively, peptides can be used as initiators of polymerization yielding a chimeric molecule bearing a single peptide at the end of macromolecular chains. Finally, novel polymer materials can be designed when the peptide itself is used as a macromonomer. In that case, the unmatched level of repetition of the peptide sequence or/and its self-assembly properties allow to access very high functionalization degree, original structures and bioactivities.

Sol-gel process – the inorganic approach in protein imprinting

J. Mater. Chem. B, 2021 Jan. https://doi.org/10.1016/j.xphs.2020.10.019

Abstract

Proteins play a central role for the signal transmission in living systems since they are able to recognize specific biomolecules acting as cellular receptors, antibodies or enzymes; or being themselves recognized by other proteins in protein/protein interactions, or displaying epitopes suitable for antibody binding. In this context, the specific recognition of a given protein, unlocks a range of interesting applications in diagnosis and in targeted therapies. Obviously, this role is already fulfilled with antibodies with unquestionable success. However, the design of synthetic artificial systems able to endorse this role is still challenging with a special interest to overcome limitations of antibodies, in particular their production and their stability. Molecular Imprinted Polymers (MIPs) are attractive recognition systems which could be an alternative for the specific capture of proteins in complex biological fluids. MIPs can be considered as biomimetic receptors or antibodies mimics displaying artificial paratopes. However, MIPs of proteins remains a challenge due to their large size and conformational flexibility, their complex chemical nature with multiple recognition sites and their low solubility in most organic solvents. Classical MIP synthesis conditions result in large polymeric cavities with and unspecific binding sites on the surface. In this review, the potentiality of sol-gel process as inorganic polymerization strategy to overcome the drawbacks of protein imprinting is highlighted. Thanks to the mild and biocompatible experimental conditions required and the use of water as solvent, the inorganic polymerization approach suits better to proteins than organic polymerization. Through numerous examples and applications of MIPs, we proposed a critical evaluation of the parameters that must be carefully controlled to achieve sol-gel protein imprinting (SGPI), including the choice of the monomers taking part in the polymerization.

Self-Assembling Peptide—Polymer Nano-Objects via Polymerization-Induced Self-Assembly

Macromolecules 2020, 53, 16, 7034–7043 https://doi.org/10.1021/acs.macromol.0c01260

Dao T,  Vezenkov L, Subra G, Amblard M, In M, Le Meins J-F, Aubrit F, Moradi M-A, Ladmiral A, Semsarilar M*

 

Abstract

Self-assembling peptides (SAPs) have been extensively studied for their ability to form nanoscale ordered structures driven by noncovalent molecular interactions. Meanwhile, polymerization-induced self-assembly (PISA) has been exploited as a facile and efficient way to produce various amphiphilic block copolymer nano-objects, whose self-assembly was governed predominantly by the interactions of the different blocks with the polymerization medium. In this work, we combined PISA with SAPs to prepare novel peptide–polymer hybrid nano-objects, thus harnessing the advantages of PISA and the self-assembling driving force of SAPs. A tripeptide methacrylamide derivative (MAm-Gly-Phe-Phe-NH2, denoted as MAm-GFF, where MAm means methacrylamide) was copolymerized with glycerol monomethacrylate (GMA) to produce a P(GMA65stat-(MAm-GFF)7) macro-chain transfer agent (macro-CTA) by reversible addition–fragmentation chain transfer polymerization in dimethylformamide. This peptide-based macro-CTA was then successfully chain-extended with poly(2-hydroxypropyl methacrylate) (PHPMA) by aqueous dispersion PISA, forming P(GMA65stat-(MAm-GFF)7)-b-PHPMA28 self-assembled objects. Fibrous structures were observed by transmission electron microscopy (TEM) and Cryo-TEM, in agreement with depolarized dynamic light scattering, static light scattering, and small-angle X-ray scattering experiments that also revealed long anisotropic morphologies. Such structures have not been reported previously for PISA-prepared nano-objects. This confirms the decisive influence of the GFF SAP on the self-assembly. In addition, annealing the PISA suspension at different temperatures led to a significant size decrease in the self-assembled objects and to a morphological transition caused by the thermosensitivity of both the core-forming PHPMA block and the stabilizing P(GMA-stat-(MAm-GFF)) block.

Turning peptides into bioactive nylons

European Polymer Journal 2020. doi: 10.1016/j.eurpolymj.2020.109886

Said Jebors, Coline Pinese, Titouan Montheil, Audrey Bethry, Simon Verquin, Louise Plais, Marie Moulin, Chloé Dupont, Xavier Garric, Ahmad Mehdi, Jean Martineza and Gilles Subra.

 

 

Abstract

New synthetic textiles with physical and/or biological properties are increasingly used in medical applications.While a simple textile coating is usually carried out to obtain biological properties, covalent grafting should be considered for long-term applications. Herein, we have developed a new hybrid bioactive nylon whose synthesis involves a peptide sequence with a diacyl derivative. Numerous types of peptide-nylons were prepared by varying the molar percentage (0.1 %, 1 % and 10%) and orientation of the peptide in the polymer backbone. Nylons incorporating antibacterial peptides significantly inhibited S. aureus proliferation whereas nylons functionalized with cell-adhesive peptide enhanced the proliferation of L929 fibroblast. These results show that the incorporation of the peptides directly into the nylon skeleton is efficient and provides biological properties that suggest new ways of functionalizing biomedical textiles

Inorganic Sol–Gel Polymerization for Hydrogel Bioprinting.

ACS Omega 2020, 5, 6, 2640-2647. doi: 10.1021/acsomega.9b03100.

Montheil T, Maumus M, Valot L, Lebrun A, Martinez J, Amblard M, Noël D, Mehdi A, Subra G.

 

 

Abstract

An inorganic sol–gel polymerization process was used as a cross-linking reaction during three-dimensional (3D) bioprinting of cell-containing hydrogel scaffolds. Hybrid hydroxypropyl methyl cellulose (HPMC), with a controlled ratio of silylation, was prepared and isolated as a 3D-network precursor. When dissolved in a biological buffer containing human mesenchymal stem cells, it yields a bioink that can be printed during polymerization by extrusion. It is worth noting that the sol–gel process proceeded at pH 7.4 using biocompatible mode of catalysis (NaF and glycine). The printing window was determined by rheology and viscosity measurements. The physicochemical properties of hydrogels were studied. Covalent functionalization of the network can be easily performed by adding a triethoxysilyl-containing molecule; a fluorescent hybrid molecule was used as a proof of concept.

Biocompatible Glycine-Assisted Catalysis of the Sol-Gel Process: Development of Cell-Embedded Hydrogels.

Chempluschem. 2019 Nov;84(11):1720-1729. doi: 10.1002/cplu.201900509.

Valot L, Maumus M, Montheil T, Martinez J, Noël D, Mehdi A, Subra G.

 

Abstract

The sol‐gel process can be used for hydrogel cross‐linking, thus opening an attractive route for the design of biocompatible hydrogels under soft conditions. The sol‐gel process can be catalysed at basic or acidic pH values, under neutral conditions with the addition of a nucleophile. Therefore, working around pH 7 unlocks the possibility of direct cell embedment and the preparation of bioinks. We aimed to propose a generic method for sol‐gel 3D bioprinting, and first screened different nucleophilic catalysts using bis‐silylated polyethylene glycol (PEG) as a model hydrogel. A synergistic effect of glycine and NaF, used in low concentrations to avoid any toxicity, was observed. Biocompatibility of the approach was demonstrated by embedding primary mouse mesenchymal stem cells. The measure of viscosity as a function of time showed the impact of reaction parameters, such as temperature, complexity of the medium, pH and cell addition, on the kinetics of the sol‐gel process, and allowed prediction of the gelation time.

Chemical cross-linking methods for cell encapsulation in hydrogels

Mater Today Comm., 2019, 20, 100536. doi: 10.1016/j.mtcomm.2019.05.012

Echalier C, Valot L, Martinez J, Mehdi A and Subra G.

 

Abstract

Cell-encapsulating hydrogels are of tremendous interest in regenerative medicine. Tissue engineering relies on biomaterials able to act as artificial extracellular matrices to guide cells towards the development of new tissues. Therefore, considerable efforts have been made to design biomaterials which mimic cells’ native environment, thus encouraging natural behavior. The choice of biomaterial in which cells are embedded is crucial for their survival, proliferation and differentiation. Being more stable, chemical hydrogels are preferred over physical hydrogels as cell-laden substrates. When designing chemical hydrogels, scientists must choose not only the nature of the network (synthetic and/or bio-polymers) but also the type of cross-link bridging hydrogel constituents. For that purpose, numerous chemistries have been used (i) to introduce reactive functions on the hydrogel precursors and (ii) to form covalent bonds in the presence of living cells. The review will discuss the advantages and limitations of each strategy.