References of "Lecomte, Philippe"
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See detailA novel strategy towards cyclic aliphatic (co)polyesters
Gao, Ch; Li, Y; Chi, J et al

in eXPRESS Polymer Letters (2013), 7(8), 690-702

This feature article focuses on a novel strategy towards macrocyclic (co)polyesters that combines controlled ring-opening polymerization of lactones initiated by a cyclic tin(IV) dialkoxide and ... [more ▼]

This feature article focuses on a novel strategy towards macrocyclic (co)polyesters that combines controlled ring-opening polymerization of lactones initiated by a cyclic tin(IV) dialkoxide and intramolecular cyclization by photocross- linking of pendant unsaturations next to the propagating sites. No linear species is ever involved in the polymerization and permanent cyclization steps, which allows higher molecular weight macrocycles to be prepared with high efficiency and no need for further purification. Moreover, this synthetic route is very flexible to the point where macrocyclic polyesters with more complex although well-defined architectures, such as tadpole-shaped and sun-shaped copolyesters, can be tailored. Synthesis of well-defined eight-shaped polyesters and twin tadpole-shaped copolymers has also been explored by using a spirocyclic tin(IV) alkoxides as an initiator. When functional lactones were introduced, the ‘click’ copper-mediated cycloaddition [3+2] reaction was utilized to make the eight-shaped and twin tadpole-shaped copolyesters amphiphilic. [less ▲]

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See detailBiomimetic polymers
Clement, Benoît ULg; Vanslambrouck, Stéphanie ULg; Koole, Leo H. et al

Poster (2013, July 08)

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See detailActivated anionic polymerization of ε-caprolactame: toward improved thermo-mechanical properties of polymaide-6
Tunc, Deniz; Lecomte, Philippe ULg; Desbois, Philippe et al

Poster (2013, June 16)

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See detailDesign and development of new polyamides by ring-opening polymerization for high performance composite materials
Tunc, Deniz; Carlotti, Stéphane; Lecomte, Philippe ULg et al

Poster (2013, May 16)

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See detailPolyphosphate-based copolymers for drug delivery applications
Lecomte, Philippe ULg

Conference (2013, April 09)

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See detailSynthesis and fabrication of polyesters as biomaterials
Lecomte, Philippe ULg; Jérôme, Christine ULg

in Popa, Valentin; Dumitriu, Daniela (Eds.) Polymeric biomaterials: structure and function, volume 1 (2013)

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See detailNovel functional degradable block copolymers for the building of reactive micelles
Cajot, Sébastien; Lecomte, Philippe ULg; Jérôme, Christine ULg et al

in Polymer Chemistry (2013), 4(4), 1025-1037

Amphiphilic biocompatible copolymers are promising materials for the elaboration of nanosystems for drug delivery applications. This paper aims at reporting on the synthesis of new functional amphiphilic ... [more ▼]

Amphiphilic biocompatible copolymers are promising materials for the elaboration of nanosystems for drug delivery applications. This paper aims at reporting on the synthesis of new functional amphiphilic copolymers based on biocompatible and bioeliminable blocks. Poly(ethylene oxide) was selected as the hydrophilic block, whereas an aliphatic polyester, i.e. poly(epsilon-caprolactone), or a polycarbonate, i.e. poly(trimethylene carbonate), were chosen as the degradable hydrophobic block. In order to allow a post-functionalization of the micelles core, azide groups were introduced on the hydrophobic segment to provide reactivity towards functional alkyne derivatives by the copper azide-alkyne cycloaddition (CuAAC). For this purpose, a functional lactone, i.e. alpha-chloro-epsilon-caprolactone was introduced during the polymerization of the hydrophobic block before being converted into azide on the preformed copolymer. Such reactivity of the block copolymers and their self-assemblies is of prime interest for drugs or fluorescent dyes grafting, so as for micelles cross-linking. The influence of the azides distribution along the degradable block on the micelles post-functionalization ability has been studied by using alkyne bearing fluorescent dyes as model for drugs. The hydrophilicity of the dye on the micelles post-functionalization efficiency has also been investigated. [less ▲]

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See detailRing-opening polymerization of cyclic phosphoesters
Vanslambrouck, Stéphanie ULg; Clement, Benoît ULg; Jérôme, Christine ULg et al

Poster (2012, November 16)

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See detailSynthesis of new biomimetic and biodegradable polymers for clinical use
Clement, Benoît ULg; Grignard, Bruno ULg; Koole, Leo et al

Conference (2012, November 15)

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See detailA review of dietary and non-dietary exposure to bisphenol-A.
Geens, Tinne; Aerts, Dominique; Berthot, Carl et al

in Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association (2012), 50(10), 3725-40

Due to the large number of applications of bisphenol-A (BPA), the human exposure routes are multiple. We aimed to review shortly the food and non-food sources of BPA, and to evaluate their contribution to ... [more ▼]

Due to the large number of applications of bisphenol-A (BPA), the human exposure routes are multiple. We aimed to review shortly the food and non-food sources of BPA, and to evaluate their contribution to the human exposure. Food sources discussed here include epoxy resins, polycarbonate and other applications, such as paperboard and polyvinylchloride materials. Among the non-food sources, exposures through dust, thermal paper, dental materials, and medical devices were summarized. Based on the available data for these exposure sources, it was concluded that the exposure to BPA from non-food sources is generally lower than that from exposure from food by at least one order of magnitude for most studied subgroups. The use of urinary concentrations from biomonitoring studies was evaluated and the back-calculation of BPA intake seems reliable for the overall exposure assessment. In general, the total exposure to BPA is several orders of magnitude lower than the current tolerable daily intake of 50 mug/kg bw/day. Finally, the paper concludes with some critical remarks and recommendations on future human exposure studies to BPA. [less ▲]

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See detailMetal-free strategies for the synthesis of functional and well-defined polyphosphoesters
Clement, Benoît ULg; Grignard, Bruno ULg; Koole, Leo et al

in Macromolecules (2012), 45(11), 4476-4486

We report here metal-free strategies using organocatalysis based on supramolecular recognition for the ring-opening polymerization (ROP) of several cyclic phosphate monomers (CPMs) by a variety of ... [more ▼]

We report here metal-free strategies using organocatalysis based on supramolecular recognition for the ring-opening polymerization (ROP) of several cyclic phosphate monomers (CPMs) by a variety of organocatalysts such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5,7-triazabicyclo[4.4.0]undec-5-ene (TBD), and a bicomponent thiourea−tertiary amine catalyst. Each of these catalysts is efficient to produce linear polyphosphoesters (PPEs) from CPMs but with different sensitivity toward transesterification side reactions. The strong basicity of DBU is sufficient to activate an alcohol initiating the polymerization in the absence of any other cocatalyst. Nevertheless, side chain transfer reactions leading to branched and/or cyclic polymeric structures are observed, especially for high monomer conversion. Unlike DBU, TBD is a dual catalyst activating both the alcohol and the monomer. This dual activation allows shorter polymerization time, but SEC analyses of polyphosphates reveal bimodal molecular weight distribution due to chains coupling. Finally, a mixture of DBU and thiourea (TU) appears by far the most efficient catalyst to carry out fast and controlled polymerization while minimizing transesterification reactions, even at near-complete conversion. Compared with polymerizations carried out with Sn(Oct)2 as a metal catalyst, the control of polymerization is much better so that it is possible to prepare polyphosphoesters (PPEs) with molecular weight close to 70 000 g mol−1 and polydispersity index below 1.10. Simultaneous activation by TU of both CPMs and the alcohol group of the initiator by DBU proves to be an effective and robust ROP catalytic system to synthesize polymers with predictable molecular weight and narrow polydispersity. The chain extension experiments through the use of hydroxy end- capped PPEs as macroinitiators confirm the controlled/living nature of the DBU/TU-catalyzed ROP of CPMs and pave the way to the synthesis of block copolymers based on polyphosphates. [less ▲]

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See detailEasy functionalization of amphiphilic poly(ethylene oxide)-b-poly(ε-caprolactone) copolymer micelles with unprotected sugar: synthesis and recognition by lectins
Freichels, Hélène; Auzély-Velty, Rachel; Lecomte, Philippe ULg et al

in Polymer Chemistry (2012), 3(6), 1436-1145

This paper aims at reporting the end-functionalization of a PEO block of an amphiphilic α-acetal-PEO-b-PCL copolymer. The acetal end-group, which is the fragment of the initiator used in the EO ... [more ▼]

This paper aims at reporting the end-functionalization of a PEO block of an amphiphilic α-acetal-PEO-b-PCL copolymer. The acetal end-group, which is the fragment of the initiator used in the EO polymerization, was first hydrolyzed into an aldehyde that was then reacted with an amine by reductive amination reaction in water. This two-step derivatization was carried out in one pot. In a preliminary study a model amine, i.e. fluorescein amine, was used and the impact of the composition, thus of the Hydrophilic–Lipophilic Balance (HLB) of the amphiphilic copolymer, was studied. The experimental conditions were extended to the coupling of an aminated mannose to the diblock copolymer. The frozen micelles formed by the mannosylated copolymer proved to form complexes with various lectins as shown by Surface Plasmon Resonance (SPR) and Isothermal Titration Calorimetry (ITC). [less ▲]

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See detailSynthesis of new biomimetic biodegradable materials for clinical use
Clement, Benoît ULg; Grignard, Bruno ULg; Lecomte, Philippe ULg et al

Poster (2012, May 10)

For recent decades, the most commonly biodegradable polymers used in clinical and therapeutic applications are aliphatic polyesters such as polyglycolide, polylactide, polycaprolactone and their ... [more ▼]

For recent decades, the most commonly biodegradable polymers used in clinical and therapeutic applications are aliphatic polyesters such as polyglycolide, polylactide, polycaprolactone and their copolymers, mainly due to their excellent biocompatibility and biodegradability properties. However, the lack of functional groups on the backbone of polyesters, which could otherwise be used for tuning physicochemical properties and for introducing bioactive units, limits their further biomedical applications. Polymers with repeating phosphoester bonds in the backbone are structurally versatile and biodegradable through hydrolysis and possibly enzymatic digestion of phosphates linkages under physiological conditions. An advantage of polyphosphoesters (PPEs) compared to aliphatic polyesters is the possible functionalization of side chains due to the patenvalency of the phosphorous atom, allowing the introduction of bioactive molecules and extensive modification of the physical and chemical properties of final material. The Ring-Opening Polymerization (ROP) of cyclic esters is a well-established process to provide linear polyesters with predictable molecular weight, narrow polydispersity and well-defined end-groups. Up to now, metallic compounds are particularly used as initiators or polymerization catalysts to synthetize these materials but metallic derivatives are cytotoxic and a lack of residual metal contaminants is strongly required in view of biomedical applications. To tackle these drawbacks, we developed synthetic approaches that are metal-free (i.e., organocatalytic) using organocatalysis based on supramolecular recognition. A variety of organocatalysts such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5,7-triazabicyclo[4.4.0]undec-5-ene (TBD) and a bicomponent thiourea-tertiary amine catalyst were studied. Each of these catalysts is efficient to produce linear polyphosphoesters (PPEs) from cyclic phosphate monomers (CPMs) but with different sensitivity towards transesterification side reactions. Compared with polymerizations carried out with Sn(Oct)2 as a metal catalyst, the control of polymerization is much better so that it is possible to prepare PPEs with molecular weight close to 70000 g.mol-1 and polydispersity index below 1.10. The chain extension experiments through the use of hydroxy end-capped PPEs as macro-initiators confirm the controlled/living nature of organo-catalyzed ROP of CPMs and pave the way to the synthesis of block copolymers based on polyphosphates. Finally, these polymerizations procedures are expected to facilitate the synthesis of well-defined PPEs with various architectures and free of potentially toxic metal remnants. The easy availability of catalysts, the mild conditions of polymerizations and the metal-free nature of the polymerizations makes these catalysts very attractive candidates for the synthesis of PPEs for biomedical applications such as drug and gene delivery, tissue engineering and dental applications. [less ▲]

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See detail"Click chemistry" to derived antimicrobial polymers
Lecomte, Philippe ULg; Riva, Raphaël ULg; Jérôme, Christine ULg

in Lagaron, José Maria; Ocio Zapata, Maria José; Lopez-Rubio, Amparo (Eds.) Antimicrobial polymers (2012)

Detailed reference viewed: 56 (12 ULg)