References of "Aqil, Abdelhafid"
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See detailDevelopment of a procedure to simultaneously isolate RNA, DNA, and proteins from characterizing cells invading or cultured on chitosan scaffolds.
Tchemtchoua Tateu, Victor ULg; Atanasova, Ganka; Aqil, Abdelhafid ULg et al

in Analytical Biochemistry (2009), 393(1), 145-7

For many years, chitosan and its derivatives have been considered to be promising biomaterials for tissue engineering and repair. However, information regarding their biological effect on cell phenotype ... [more ▼]

For many years, chitosan and its derivatives have been considered to be promising biomaterials for tissue engineering and repair. However, information regarding their biological effect on cell phenotype is usually limited to evaluation of cell proliferation and survival, overlooking proteomic and transcriptomic analysis. This is largely related to the lack of efficient and quantitative procedures for protein and nucleic acid purification from cells cultured on, or inside, chitosan scaffold. Here we describe an ultracentrifugation procedure enabling the simultaneous and quantitative recovery of high quality RNA, DNA and proteins from cells growing in close contact of biomaterial matrices containing chitosan. [less ▲]

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See detailDesign of thermoresponsive inorganic nanoparticles
Aqil, Abdelhafid ULg; Jérôme, Christine ULg

Conference (2008, November 28)

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See detailPolymer membrane by electrospinning
Aqil, Abdelhafid ULg; Grignard, Bruno ULg; Croisier, Florence ULg et al

Poster (2008, November 28)

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See detailPreparation and characterization of thermoresponsive iron nanoparticles for biomedical applications
Sibret, Pierre ULg; Aqil, Abdelhafid ULg; Gohy, Jean-François et al

Poster (2008, November 28)

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See detailPEO coated magnetic nanoparticles for biomedical application
Aqil, Abdelhafid ULg; Vasseur, S.; Duguet, E. et al

in European Polymer Journal (2008), 44(10), 3191-3199

This paper reports on the preparation, characterization and stealthiness of superparamagnetic nanoparticles (magnetite Fe3O4) with a 5 nm diameter and stabilized in water (pH 6.5) by a shell of water ... [more ▼]

This paper reports on the preparation, characterization and stealthiness of superparamagnetic nanoparticles (magnetite Fe3O4) with a 5 nm diameter and stabilized in water (pH 6.5) by a shell of water-soluble poly(ethylene oxide) (PEO) chains. Two types of diblock copolymers, i.e., poly(acrylic acid)-b-poly(ethylene oxide), PAA–PEO, and poly(acrylic acid)-b-poly(acrylate methoxy poly(ethyleneoxide)), PAA–PAMPEO, were prepared as stabilizers with different compositions and molecular weights. At pH 6.5, the negatively ionized PAA block interacts strongly with the positively-charged nanoparticles, thus playing the role of an anchoring block. Aggregates of coated nanoparticles were actually observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The hydrodynamic diameter was in the 50–100 nm range and the aggregation number (number of nanoparticles per aggregate) was lying between several tens and hundred. Moreover, the stealthiness of these aggregates was assessed “in vitro” by the hemolytic CH50 test. No response of the complement system was observed, such that biomedical applications can be envisioned for these magnetic nanoparticles. Preliminary experiments of magnetic heating (10 kA/m; 108 kHz) were performed and specific absorption rate varied from 2 to 13 W/g(Fe). [less ▲]

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See detailFunctional nanoobjects by means of polymers
Van Butsele, Kathy; Aqil, Abdelhafid ULg; Jérôme, Christine ULg

Conference (2008, September 08)

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See detailPreparation of stable suspensions of gold nanoparticles in water by sonoelectrochemistry
Aqil, Abdelhafid ULg; Serwas, Harry; Delplancke, J. L. et al

in Ultrasonics Sonochemistry (2008), 15(6), 1055-1061

Stable suspensions of gold nanoparticles in water were prepared with high yield by a novel one-step ultrasound assisted electrochemical process. Various strategies based on the addition of either tailor ... [more ▼]

Stable suspensions of gold nanoparticles in water were prepared with high yield by a novel one-step ultrasound assisted electrochemical process. Various strategies based on the addition of either tailor-made polymers or mixtures of commercially available polymers, in the electrochemical bath have been found successful to avoid nanoparticles aggregation commonly observed by sonoelectrochemistry. α-Methoxy-ω-mercapto-poly(ethylene oxide) or poly(vinyl pyrrolidone)/polyethylene oxide mixtures were able to build up a coalescence barrier around the gold nanoparticles. The results showed that the size of the gold nanoparticles could be easily tuned between 5 nm and 35 nm by simple control of the electrochemical parameters, i.e. the deposition time (TON) from 10 ms to 20 ms. The properties of as-prepared gold nanoparticles were compared to the ones of gold colloids prepared by the more conventional wet nanoprecipitation method using chemical reductive agents. [less ▲]

Detailed reference viewed: 87 (15 ULg)
See detailElectrospinning of biocompatible polymers for potential biomdical applications
Croisier, Florence ULg; Zalfen, Alina; Aqil, Abdelhafid ULg et al

Poster (2008, June 23)

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See detailCoating of gold nanoparticles by thermosensitive poly(N-isopropylacrylamide) end-capped by biotin
Aqil, Abdelhafid ULg; Qiu, Hongjin; Greisch, Jean-François ULg et al

in Polymer (2008), 49(5), 1145-1153

Gold nanoparticles (NPs) were prepared by reduction of HAuCl4 in aqueous solution and stabilized by poly(N-isopropylacrylamide) (PNIPAM). PNIPAM was prepared by two distinct routes: (i) conventional free ... [more ▼]

Gold nanoparticles (NPs) were prepared by reduction of HAuCl4 in aqueous solution and stabilized by poly(N-isopropylacrylamide) (PNIPAM). PNIPAM was prepared by two distinct routes: (i) conventional free-radical polymerization leading to polymer without any reactive end-group, and (ii) Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization with 2-dodecylsulfanylthiocarbonylsulfanyl-2-methyl propionic acid (DMP) as a RAFT agent. PNIPAM with low polydispersity was then end-capped by an α-carboxylic acid and an ω-trithiocarbonate that was converted into an ω-thiol upon hydrolysis. This hetero-telechelic polymer was analyzed by mass spectroscopy, size exclusion chromatography (SEC) and 1H NMR. Even without thiol end-group, known for chemisorption onto gold, PNIPAM was effective in stabilizing gold NPs (1–5 nm). The thermosensitivity of PNIPAM at the surface of gold NPs was, however, dependent on the molecular weight of the chains. Finally, the α-carboxyl end-group of PNIPAM was used to anchor biotin, which is indeed known for complexation with avidin, which is a possible strategy for the coated gold NPs to be involved as building blocks in supramolecular assemblies. TEM and UV–vis spectroscopy were used to characterize the gold nanoparticles. [less ▲]

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See detailSynthesis and stabilization of colloids for optical and magnetic detections
Aqil, Abdelhafid ULg

Doctoral thesis (2008)

The development of nano-sized particles is motivated by their optical, electronic and magnetic behavior related to quantum confinement resulting from the nanometric size. To prevent aggregation in ... [more ▼]

The development of nano-sized particles is motivated by their optical, electronic and magnetic behavior related to quantum confinement resulting from the nanometric size. To prevent aggregation in solution, the nanoparticles are covered with stabilizing molecules. The aim of this thesis is to develop a new generation of functional copolymers with different architectures to improve the stability of various synthesized NPs. Two types of nanoparticles are considered, gold NPs for the optical properties and iron oxide NPs for the magnetic properties. The copolymers considered in this study are synthesized following a controlled radical polymerization process, i.e. Reversible Addition - Fragmentation Chain Transfer (RAFT) and confer novel properties to the coated nanoparticles. Stealth NPs are obtained when they are covered by the poly(ethylene oxide), and thermosensitive NPs when they are stabilized by the poly (N-isopropyl acrylamide). These properties have been exploited in applications in the biomedical field. Another challenge in this work is the synthesis and functionalization of the surface of carbon NPs, and thus carbon nano-capsules were synthesized by graphitization of poly (acrylic acid)-poly (acrylonitrile) micelles and carbon nanotubes have been decorated by magnetite NPs allowing their orientation in a magnetic field. [less ▲]

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See detailMagnetic nanoparticles coated by temperature responsive copolymers for hyperthermia
Aqil, Abdelhafid ULg; Vasseur, Sébastien; Duguet, Etienne et al

in Journal of Materials Chemistry (2008), 18(28), 3352-3360

Various temperature-responsive N-isopropylacrylamide-based functional copolymers were prepared and used for the stabilization of iron oxide nanoparticles. The copolymers investigated are poly(acrylic acid ... [more ▼]

Various temperature-responsive N-isopropylacrylamide-based functional copolymers were prepared and used for the stabilization of iron oxide nanoparticles. The copolymers investigated are poly(acrylic acid)-b-poly(N-isopropylacrylamide) (PAA-PNIPAM) and poly(acrylic acid)-b-poly(N-isopropylacrylamide)-b-poly(acrylate methoxy poly(ethylene oxide)) (PAA-PNIPAM-PAMPEO), with different molecular weights. The coated nanoparticles were characterized in terms of size by a combination of dynamic light scattering (DLS) and transmission electron microscopy (TEM). A sharp temperature transition was confirmed by particle size measurements vs. temperature. In addition, the stealthiness of the coated nanoparticles has been assessed in vitro by the haemolytic CH50 test. These measurements evidenced the crucial role of the PEO segments on the stealthiness of the nanoparticles and thus that such copolymers are particularly suitable for biomedical applications. Preliminary experiments of alternating magnetic field induced heating were performed and specific absorption rates of the various samples were recorded. [less ▲]

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See detailControlled RAFT synthesis of polyacrylonitrile-b-poly(acrylic acid) diblocks as precursors of carbon nanocapsules with assistance of gold nanoparticles
Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg; Gilbert, Bernard ULg et al

in Chemistry of Materials (2007), 19(9), 2150-2154

A new strategy for the synthesis of carbon nanocapsules has been developed, based on the preparation of well-defined polyacrylonitrile-b-poly(acrylic acid) (PAN-b-PAA) block copolymers followed by their ... [more ▼]

A new strategy for the synthesis of carbon nanocapsules has been developed, based on the preparation of well-defined polyacrylonitrile-b-poly(acrylic acid) (PAN-b-PAA) block copolymers followed by their micellization in basic water to form spherical micelles with a PAN core and PAA shell. The PAN is then cross-linked by the use of gold nanoparticles. After pyrolysis, carbon nanocapsules are produced by graphitization of the PAN core and diffusion of the molten gold nanoparticles out of the nano-objects. [less ▲]

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See detailSurface modification of metallic cardiovascular stents by strongly adhering aliphatic polyester coatings
Jérôme, Christine ULg; Aqil, Abdelhafid ULg; Voccia, Samuel et al

in Journal of Biomedical Materials Research, Part A (2006), 76(3), 521-529

This article reports on a novel two-step strategy for the coating of cardiovascular stents by strongly adhering biocompatible and biodegradable aliphatic polyesters. First, a precoating of poly ... [more ▼]

This article reports on a novel two-step strategy for the coating of cardiovascular stents by strongly adhering biocompatible and biodegradable aliphatic polyesters. First, a precoating of poly(ethylacrylate) (PEA) was electrografted onto the metallic substrate by cathodic reduction of the parent monomer in dimethylformamide (DMF). The electrodeposition of PEA, in a good solvent of it, was confirmed by both Infra-red and Raman spectroscopies. The pendant ester groups of PEA were then chemically reduced into aluminum alkoxides, able to initiate the ring-opening polymerization (ROP) of either D,L-lactide (LA) or epsilon-caprolactone (CL). Growth of biodegradable PLA or PCL coatings from the adhering precoating was confirmed by both Infra-red and Raman spectroscopies, and directly observed by scanning electron microscopy (SEM). This type of coating can act as an anchoring layer for the subsequent casting of drug-loaded polyester films allowing the controlled release of antiproliferative agents for the treatment of in-stent restenosis. [less ▲]

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See detailAn easy and economically viable route for the decoration of carbon nanotubes by magnetite nanoparticles, and their orientation in a magnetic field
Stoffelbach, François; Aqil, Abdelhafid ULg; Jérôme, Christine ULg et al

in Chemical Communications (2005), (36), 4532-4533

A simple, cheap and tunable approach for the decoration of carbon nanotubes by magnetite nanoparticles and their orientation in a magnetic field is reported.

Detailed reference viewed: 22 (3 ULg)
See detailDesign of nanoobjects endowed with specific properties
Willet, Nicolas ULg; Qiu, Hongjin; Rieger, Jutta ULg et al

Conference (2004, March)

Detailed reference viewed: 5 (2 ULg)
See detailSurface modification of metallic stents by strongly adhering aliphatic polyesters
Aqil, Abdelhafid ULg; Voccia, Samuel; Labaye, David-Emmanuel et al

Poster (2003, May 16)

Detailed reference viewed: 15 (3 ULg)