References of "Aqil, Abdelhafid"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailEffect of non-ionic surfactant and acidity on chitosan nanofibers with different molecular weights
Ziani, Khalid; Henrist, Catherine ULg; Jerome, Christine et al

in Carbohydrate Polymers (2011), 83(2), 470-476

Detailed reference viewed: 62 (9 ULg)
Full Text
Peer Reviewed
See detailDevelopment of a Chitosan Nanofibrillar Scaffold for Skin Repair and Regeneration.
Tchemtchoua Tateu, Victor ULg; Atanasova, G.; Aqil, Abdelhafid ULg et al

in Biomacromolecules (2011), 12

The final goal of the present study was the development of a 3-D chitosan dressing that would shorten the healing time of skin wounds by stimulating migration, invasion, and proliferation of the relevant ... [more ▼]

The final goal of the present study was the development of a 3-D chitosan dressing that would shorten the healing time of skin wounds by stimulating migration, invasion, and proliferation of the relevant cutaneous resident cells. Three-dimensional chitosan nanofibrillar scaffolds produced by electrospinning were compared with evaporated films and freeze-dried sponges for their biological properties. The nanofibrillar structure strongly improved cell adhesion and proliferation in vitro. When implanted in mice, the nanofibrillar scaffold was colonized by mesenchymal cells and blood vessels. Accumulation of collagen fibrils was also observed. In contrast, sponges induced a foreign body granuloma. When used as a dressing covering full-thickness skin wounds in mice, chitosan nanofibrils induced a faster regeneration of both the epidermis and dermis compartments. Altogether our data illustrate the critical importance of the nanofibrillar structure of chitosan devices for their full biocompatibility and demonstrate the significant beneficial effect of chitosan as a wound-healing biomaterial. [less ▲]

Detailed reference viewed: 99 (31 ULg)
Full Text
Peer Reviewed
See detailNanostructured silica templated by double hydrophilic block copolymers with a comb-like architecture
Warnant, Jérôme ULg; Reboul, J.; Aqil, Abdelhafid ULg et al

in Powder Technology (2011), 208

An original way to synthesize nanostructured materials is the use of new structuring agents constituted of induced and reversible micelles of Double Hydrophilic Block Copolymers (DHBC). The present paper ... [more ▼]

An original way to synthesize nanostructured materials is the use of new structuring agents constituted of induced and reversible micelles of Double Hydrophilic Block Copolymers (DHBC). The present paper aims at showing that induced micelles can be obtained by complexation between a PAA-b-PAMPEO (DHBC) polymer containing a comb-type neutral block and a polyamine, that the micellization process is reversible as a function of the pH and finally, that the obtained polyion complex micelles can be successfully used in the preparation of well organized mesostructured silica materials. [less ▲]

Detailed reference viewed: 91 (19 ULg)
See detailElectrografting and LbL deposition for the elaboration of antimicrobial coatings
Aqil, Abdelhafid ULg; Cécius, Michaël; Jérôme, Christine ULg

Poster (2010, November 29)

Detailed reference viewed: 14 (1 ULg)
See detailChitosan nanofiber membranes for tissue engineering - synthesis, characterization and properties
Toncheva, Natalia ULg; Aqil, Abdelhafid ULg; Croisier, Florence ULg et al

Poster (2010, November 29)

This poster was presented by Natalia Toncheva

Detailed reference viewed: 53 (3 ULg)
See detailPreparation of cross-linked chitosan-based nanofibers as wound dressing
Aqil, Abdelhafid ULg; Ziani, K.; Tchemtchoua Tateu, Victor ULg et al

Poster (2009, November 18)

Detailed reference viewed: 52 (19 ULg)
Full Text
See detailDevelopment of multilayered chitosan-based nanofibers
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, June 14)

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method ... [more ▼]

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyelectrolytes including synthetic and natural materials, with designable layer structure, defined layer thickness and size. Electrospinning (ESP) allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fiber mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to prepare surface charged nanofibers. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the growth of a multilayered shell, obtaining hollow fibers. [less ▲]

Detailed reference viewed: 126 (32 ULg)
Full Text
See detailDevelopment of multilayered chitosan-based nanofibers for tissue engineering
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Conference (2009, June 13)

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method ... [more ▼]

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyelectrolytes including synthetic and natural materials, with designable layer structure, defined layer thickness and size. Electrospinning (ESP) allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fiber mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to prepare surface charged nanofibers. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the growth of a multilayered shell, obtaining hollow fibers. [less ▲]

Detailed reference viewed: 131 (21 ULg)
Full Text
See detailLayer-by-layer self-assembled chitosan coating on electrospun nanofibers
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, April)

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well-known method for surface ... [more ▼]

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyions including synthetic and natural materials, with designable layer structure, defined wall thickness and size. Electrospinning (ESP) technique allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fibers mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to obtain charges on fibers surface. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the existence of a multilayered shell, obtaining hollow fibers. [less ▲]

Detailed reference viewed: 275 (19 ULg)
Full Text
See detailPreparation of multilayered chitosan-based nanofibers by combination of electrospinning and layer-by-layer deposition techniques
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, March)

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well known method for surface ... [more ▼]

By combining electrospinning technique and layer-by-layer deposition, we produced a new material made of multilayered, chitosan-based nanofibers. Layer-by-layer (LBL) is a well known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyions including synthetic and natural materials, with designable layer structure, defined wall thickness and size. Electrospinning (ESP) technique allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate) (3). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fibers mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to obtain charges on fibers surface. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the existence of a multilayered shell, obtaining hollow fibers. [less ▲]

Detailed reference viewed: 130 (17 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 83 (13 ULg)
See detailDesign of thermoresponsive inorganic nanoparticles
Aqil, Abdelhafid ULg; Jérôme, Christine ULg

Conference (2008, November 28)

Detailed reference viewed: 24 (6 ULg)
See detailPolymer membrane by electrospinning
Aqil, Abdelhafid ULg; Grignard, Bruno ULg; Croisier, Florence ULg et al

Poster (2008, November 28)

Detailed reference viewed: 42 (9 ULg)
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)

Detailed reference viewed: 28 (4 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 154 (27 ULg)
See detailFunctional nanoobjects by means of polymers
Van Butsele, Kathy; Aqil, Abdelhafid ULg; Jérôme, Christine ULg

Conference (2008, September 08)

Detailed reference viewed: 6 (2 ULg)
Full Text
Peer Reviewed
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: 104 (19 ULg)