References of "Thomassin, Jean-Michel"
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See detailBio- and CO2-sourced polyhydroxyurethanes for hydrogels coatings, foams and high performance adhesives
Gennen, Sandro ULg; Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg et al

Poster (2017, June 09)

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and ... [more ▼]

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and industrial fields. Indeed, CO2 can be viewed as a cheap, non-toxic and renewable C1 building block precursor of sophisticated organic molecules and polymers. One representative example of CO2 transformation includes the synthesis of various (bis)cyclic carbonates via CO2/epoxide coupling.1-3 Bis-cyclic carbonates were then valorized as monomers for the synthesis of series of novel low carbon footprint poly(hydroxyurethane)s (PHUs). These polymers are now exploited to produce sustainable materials including foams for thermal insulation,4 hydrogels (for potential biomedical use)5 and high performance adhesives and glues (for metal, glass and wood). [less ▲]

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See detailDesign of new reprocessable shape-memory materials
Defize, Thomas ULg; Riva, Raphaël ULg; Thomassin, Jean-Michel ULg et al

Poster (2017, May 04)

Detailed reference viewed: 9 (2 ULg)
See detailPhoto-crosslinkable hydrogel for guided periodontal tissue regeneration
Chichiricco, Pauline Marie ULg; Riva, Raphaël ULg; Thomassin, Jean-Michel ULg et al

Poster (2017, May 04)

Periodontitis is an inflammatory disease resulting from the presence of oral bacteria biofilm in periodontal tissue, which destroys the tooth-supporting attachment apparatus. Untreated inflammation can ... [more ▼]

Periodontitis is an inflammatory disease resulting from the presence of oral bacteria biofilm in periodontal tissue, which destroys the tooth-supporting attachment apparatus. Untreated inflammation can spread to the gum tissue and lead, ultimately, to the loosening of the supporting tooth bone, with the risk that the tooth eventually falls. Guided Tissue Regeneration is a technique based on the application of a barrier membrane designed to prevent colonization of the wound space by epithelial cells from soft tissues. Indeed, these cells, characterized by a faster migration and proliferation rate compared to bone and periodontal ligament cells, could interfere with the regeneration process. In previously work Struillou et al. demonstrated the benefit effect of silated hydroxypropylmethylcellulose (Si HMPC)-based hydrogel can act as an efficient physical barrier in periodontal defect. Typically, this material is able to form a 3D network through the condensation of silanoate groups at physiological pH. However, a decrease of gelation time is necessary to assure the stability in peripheral part of the wound. In this project, we developed an injectable photo-crosslinkable membrane based on methacrylated carboxymethyl chitosan (CMCs) and Si HPMC that can be applied as a viscous solution and cured in situ in presence of a photoinitiator system made of riboflavin and triethanolamine. A visible light lamp (λ 420-480 nm), already used in dentistry, was preferred over a UV lamp. The addition of methacrylated polymer increase the stability of the material and increase the mass loss, in order to improve the bioresorption of the membrane. The chemical grafting of methacrylated carboxymethyl chitosan was characterized by 1H NMR and Infrared Spectroscopy. The gel point of the solution was determined by rheology and remained compatible with a clinical application. Moreover, the biocompatibility of this biomaterials was tested using murine cells using two assay: Neutral Red assay and MTT Cell Proliferation Assay. The in vitro tests validate the chemical synthesis in a biological point of view. The irradiation on cells and the direct contact with hydrogel doesn’t have an impact on cells viability. The capability of this material to act as a physical barrier was also evaluated using human gingival fibroblast. The cells were isolated from human gum explant before being put in contact with the hydrogel. After four days of contact no cells invasion was observed in the hydrogel using confocal microscopy. These preliminary results are quite promising for the development of novel injectable systems for Guided Periodontal Regeneration. In the future work, in vivo assays will be performed in Periodontal defect in a canine model. [less ▲]

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See detailSynthesis of hierarchical N-doped porous carbon structure/nanospheres Fe2O3 composites and its application in lithium-ion battery as lithium-ion anodes
Alkarmo, Walid ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2017, May 04)

Nitrogen-doped porous carbons are of special interest, because their unique physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, and ... [more ▼]

Nitrogen-doped porous carbons are of special interest, because their unique physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, and are thus very important for applications in the fields of catalysis, environment techniques and energy generation and storage. Moreover, nitrogen-doping can be further amplified in a porous structure that bears a high surface area to increases their materials performance in electrochemical devices, such as double layer capacitors and lithium-ion batteries. In addition, nitrogen-doping can enhance the lithium insertion, between the nitrogen-doped carbon material and lithium. And it can create a large number of defects in the porous configuration and offer more active sites for lithium insertion. Toward this goal, a hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. Integrated as a lithium ion battery anode, NDC@Fe2O3 exhibited high reversible capacity of 930 mA h/g over 200 cycles. The combination of Fe2O3 nanoparticles with nitrogen-doped porous carbons to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

Detailed reference viewed: 82 (9 ULg)
See detailReinforced poly(hydroxyurethane) coatings and high performance adhesive
Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the ... [more ▼]

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the environmental and REACH regulations, there is a need today to develop new greener and safer alternatives to produce PU. One of the most promising way relies on the synthesis of polyurethane by a non-isocyanate route (NIPU) by copolymerization between a bicyclic carbonate monomers and a diamine. This study reports on the synthesis of new sustainable NIPU coatings for Al anti-corrosion protection and for metal adhesion. In a first step, (bio- and) CO2-sourced cyclic carbonates will be synthesized by coupling of multifunctional epoxides with CO2 using a new efficient bicomponent organocatalyst. In a second step, various cyclic carbonates/amines formulations were developed and cured in presence of fillers to produce reinforced NIPUs thermosets which anti-corrosion and adhesive properties are evaluated and benchmarked with existing formulations. Some formulations present outstanding adhesions to various substrates. [less ▲]

Detailed reference viewed: 45 (5 ULg)
See detailHow to exploit bio- and CO2-based isocyanates-free polyurethanes for environmental and biomedical applications?
Gennen, Sandro ULg; Grignard, Bruno ULg; Alves, Margot et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors ... [more ▼]

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors. Classically, PU is produced by a step-growth polymerization between di- or polyols and di- or polyisocyanates. However, isocyanates are toxic and produced from even more toxic phosgene. To avoid the use of isocyanates, different synthetic alternatives for PUs have been developed. One of the most studied approaches relies on the step-growth polymerization between di- or polyamines and CO2-sourced di- or polycyclic carbonates, affording poly(β-hydroxyurethane)s (PHUs) that showed improved thermal, chemical and mechanical properties compared to conventional PUs. In this study, we would like to show how PHUs can be exploited to design (bio- and) CO2-based foams for thermal insulation as well as novel reinforced hydrogels for potential biomedical applications. First, we developed a highly efficient binary organocatalyst for the fast and selective synthesis of cyclic carbonates under very mild conditions from CO2 and various epoxides, including bio-based ones. Secondly, these cyclic carbonates were valorised as monomers for the preparation of foams and hydrogels based on PHUs. In this poster, we will describe the preparation and characterization of these PHU foams and hydrogels, and highlight their huge potential as thermal insulating materials (PHU foams) or as biomaterials for shock absorption properties (PHU hydrogels). [less ▲]

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See detailHot-Melt Extrusion as a Continuous Manufacturing Process to Form Ternary Cyclodextrin Inclusion Complexes
Thiry, Justine ULg; Krier, Fabrice; Ratwatte, Shenelka et al

in European Journal of Pharmaceutical Sciences (2017), 96

Detailed reference viewed: 57 (16 ULg)
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See detailReversible TAD chemistry as a convenient tool for the design of (re)processable PCL-based shape-memory materials
Defize, Thomas ULg; Riva, Raphaël ULg; Thomassin, Jean-Michel ULg et al

in Macromolecular Rapid Communications (2017), 38(1), 1600517

A chemically cross-linked but remarkably (re)processable shape-memory polymer (SMP) is designed by cross-linking poly(ε -caprolactone) (PCL) stars via the efficient triazolinedione click chemistry, based ... [more ▼]

A chemically cross-linked but remarkably (re)processable shape-memory polymer (SMP) is designed by cross-linking poly(ε -caprolactone) (PCL) stars via the efficient triazolinedione click chemistry, based on the very fast and reversible Alder– ene reaction of 1,2,4-triazoline-3,5-dione (TAD) with indole compounds. Typically, a six-arm star-shaped PCL function- alized by indole moieties at the chain ends is melt-blended with a bisfunctional TAD, directly resulting in a cross-linked PCL-based SMP without the need of post-curing treatment. As demonstrated by the stress relaxation measurement, the labile character of the TAD–indole adducts under stress allows for the solid-state plasticity reprocessing of the permanent shape at will by compression molding of the raw cross-linked material, while keeping excellent shape-memory properties. [less ▲]

Detailed reference viewed: 55 (24 ULg)
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See detailCurrent manufacturing processes of drug-eluting sutures
Champeau, Mathilde; Thomassin, Jean-Michel ULg; Tasaing, Thierry et al

in Expert Opinion on Drug Delivery (2017)

Introduction: Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These ... [more ▼]

Introduction: Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Two general approaches can be followed: (i) the ones that add the API into the material during the manufacturing process of the suture and (ii) the ones that load the API to an already manufactured suture. Areas covered: This review provides an overview of the current manufacturing processes for drug- eluting suture production and discusses their benefits and drawbacks depending on the type of drugs. The mechanical properties and the drug delivery profile of drug-eluting sutures are highlighted since these implants must fulfill both criteria. Expert opinion: For limited drug contents, melt extrusion and electrospinning are the emerging processes since the drug is added during the suture manufacture process. Advantageously, the drug release profile can be tuned by controlling the processing parameters specific to each process and the composition of the drug-containing polymer. If high drug content is targeted, the coating or grafting of a drug layer on a pre-manufactured suture allows for preservation of the tensile strength requirements of the suture. [less ▲]

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See detailIn vitro evaluation of biocompatibility of uncoated thermally reduced graphene and carbon nanotube-loaded PVDF membranes with adult neural stem cell-derived neurons and glia
Defteralı, Çağla; Verdejo, Raquel; Majeed, Shahid et al

in Frontiers in Bioengineering and Biotechnology (2016), 4(n° 64),

Graphene, graphene-based nanomaterials (GBNs), and carbon nanotubes (CNTs) are being investigated as potential substrates for the growth of neural cells. However, in most in vitro studies, the cells were ... [more ▼]

Graphene, graphene-based nanomaterials (GBNs), and carbon nanotubes (CNTs) are being investigated as potential substrates for the growth of neural cells. However, in most in vitro studies, the cells were seeded on these materials coated with various proteins implying that the observed effects on the cells could not solely be attributed to the GBN and CNT properties. Here, we studied the biocompatibility of uncoated thermally reduced graphene (TRG) and poly(vinylidene fluoride) (PVDF) membranes loaded with multi-walled CNTs (MWCNTs) using neural stem cells isolated from the adult mouse olfactory bulb (termed aOBSCs). When aOBSCs were induced to differentiate on coverslips treated with TRG or control materials (polyethyleneimine-PEI and polyornithine plus fibronectin- PLO/F) in a serum-free medium, neurons, astrocytes, and oligodendrocytes were generated in all conditions, indicating that TRG permits the multi-lineage differentiation of aOBSCs. However, the total number of cells was reduced on both PEI and TRG. In a serum-containing medium, aOBSC-derived neurons and oligodendrocytes grown on TRG were more numerous than in controls; the neurons developed synaptic boutons and oligodendrocytes were more branched. In contrast, neurons growing on PVDF membranes had reduced neurite branching, and on MWCNTs-loaded membranes oligodendrocytes were lower in numbers than in controls. Overall, these findings indicate that uncoated TRG may be biocompatible with the generation, differentiation, and maturation of aOBSC-derived neurons and glial cells, implying a potential use for TRG to study functional neuronal networks. [less ▲]

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Peer Reviewed
See detailHot-Melt Extrusion as a Continuous Manufacturing Process to Form Ternary Cyclodextrin Inclusion Complexes
Thiry, Justine ULg; Krier, Fabrice; Ratwatte, Shenelka et al

Poster (2016, November 16)

Detailed reference viewed: 22 (2 ULg)
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See detailPolyhydroxyurethane hydrogels: synthesis and characterizations
Gennen, Sandro ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

in European Polymer Journal (2016), 84

Hydrogels based on polyurethane (PU) are promising (bio-) materials because of their bio- compatibility, biodegradation and excellent mechanical properties. In this publication, polyurethane hydrogels ... [more ▼]

Hydrogels based on polyurethane (PU) are promising (bio-) materials because of their bio- compatibility, biodegradation and excellent mechanical properties. In this publication, polyurethane hydrogels were produced for the first time by a non-isocyanate route by solvent-free step-growth copolymerization between a CO2-sourced hydrophilic polyethy- lene glycol bi-cyclic carbonate with diamines in the presence of a cross-linker. Kinetic of poly(hydroxyurethane) (PHU) synthesis was monitored by ATR-IR and the chemical cross-linking was confirmed by rheology and gel contents measurements. Hydrogels were obtained by immersion of PHUs in water and the influence of the diamine/cross-linker ratio and the nature of diamine on the water swelling and compression properties (compression modulus, strain and stress at break) of PHU hydrogels was evaluated. Additionally, the compression properties of the hydrogels were improved by the addition of Montmorillonite as nanofiller in the PHU formulation. This work opens new application fields for CO2-sourced PHUs. [less ▲]

Detailed reference viewed: 69 (20 ULg)
See detailDesign and synthesis of Fe2O3 nanoparticles/N-doped porous carbon structures as high performance electrode for lithium ion battery
Alkarmo, Walid ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2016, October 13)

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous ... [more ▼]

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous frameworks have emerged as attractive materials for various electrochemical energy storage/conversion devices, including Li-ion batteries (LIBs), Li−S batteries, supercapacitors and fuel cells. In this context, a hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. The combination of Fe2O3 nanoparticles with porous carbon to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

Detailed reference viewed: 167 (15 ULg)
See detailNovel promising way to synthesize non-isocyanate polyurethanes (NIPUs) for innovative coating applications against corrosion protection of metal surfaces
Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2016, October 13)

Polyurethanes (PUs) are one of the most widely used polymeric materials with applications in automotive, as sealants, adhesives, decorative, aircraft topcoats, for coatings or as foams for thermal and/or ... [more ▼]

Polyurethanes (PUs) are one of the most widely used polymeric materials with applications in automotive, as sealants, adhesives, decorative, aircraft topcoats, for coatings or as foams for thermal and/or acoustic insulation. Industrially, PUs are produced by copolymerization between polyols and polyisocyanates. Because of the toxicity issues related to the use of isocyanates, there is a need to develop greener and safer route to produce such polymers. This study reports on the synthesis of new sustainable isocyanates-free PU (NIPU) coatings for aluminium anticorrosion. In a first step, bio- and CO2-sourced cyclic carbonates monomers were synthesized by coupling of epoxydized vegetable oils with CO2 using a new efficient bicomponent organocatalyst. In second step formulations including cyclic carbonates/amines/additives were optimized to produce highly adhesive cross-linked NIPU coatings that show good resistance against solvents and long-term barriers preventing the corrosion of the aluminiumsubstrate [less ▲]

Detailed reference viewed: 148 (3 ULg)
See detailSynthesis and characterization of non-isocyanate polyurethane (NIPU) hydrogels
Gennen, Sandro ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2016, October 13)

Due to its good biocompatibility, biodegradation and excellent mechanical properties, polyurethane (PU) is a material of choice for biomedical applications (gloves, tubing, artificial membranes…) and, as ... [more ▼]

Due to its good biocompatibility, biodegradation and excellent mechanical properties, polyurethane (PU) is a material of choice for biomedical applications (gloves, tubing, artificial membranes…) and, as hydrogels, it was used as wound dressing, soft contact lenses, drug delivery systems and scaffolds for tissue engineering. Classically, PU are synthesized by a step-growth polymerization between poly (di-)ols and poly (di-) isocyanates. Due to the toxicity of isocyanates, REACH regulations have changed and, today, there is a need to develop greener and safer route to produce isocyanate-free PUs. This contribution focus on the synthesis of NIPU hydrogels by copolymerizing a bifunctional CO2-sourced hydrophilic PEG bi-cyclic carbonate with diamines in presence of a cross- linker. The PEG bi-cyclic carbonates was prepared via a CO2/epoxide coupling reactions using a new efficient organocatalytic system based on the use of an ammonium salt (TBAI) in combination with a fluorinated alcohol. [less ▲]

Detailed reference viewed: 111 (7 ULg)