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See detailInnovative high-performance liquid chromatography method development for the screening of 19 antimalarial drugs based on a generic approach, using design of experiments, independent component analysis and design space
Debrus, Benjamin ULg; Lebrun, Pierre ULg; Mbinze Kindenge, Jérémie et al

in Journal of Chromatography. A (2011), 1218

An innovative methodology based on design of experiments (DoE), independent component analysis (ICA) and design space (DS) was developed in previous works and was tested out with a mixture of 19 ... [more ▼]

An innovative methodology based on design of experiments (DoE), independent component analysis (ICA) and design space (DS) was developed in previous works and was tested out with a mixture of 19 antimalarial drugs. This global LC method development methodology (i.e. DoE–ICA–DS) was used to optimize the separation of 19 antimalarial drugs to obtain a screening method. DoE–ICA–DS methodology is fully compliant with the current trend of quality by design. DoE was used to define the set of experiments to model the retention times at the beginning, the apex and the end of each peak. Furthermore, ICA was used to numerically separate coeluting peaks and estimate their unbiased retention times. Gradient time, temperature and pH were selected as the factors of a full factorial design. These retention times were modelled by stepwise multiple linear regressions. A recently introduced critical quality attribute, namely the separation criterion (S), was also used to assess the quality of separations rather than using the resolution. Furthermore, the resulting mathematical models were also studied from a chromatographic point of view to understand and investigate the chromatographic behaviour of each compound. Good adequacies were found between the mathematical models and the expected chromatographic behaviours predicted by chromatographic theory. Finally, focusing at quality risk management, the DS was computed as the multidimensional subspace where the probability for the separation criterion to lie in acceptance limits was higher than a defined quality level. The DS was computed propagating the prediction error from the modelled responses to the quality criterion using Monte Carlo simulations. DoE–ICA–DS allowed encountering optimal operating conditions to obtain a robust screening method for the 19 considered antimalarial drugs in the framework of the fight against counterfeit medicines. Moreover and only on the basis of the same data set, a dedicated method for the determination of three antimalarial compounds in a pharmaceutical formulation was optimized to demonstrate both the efficiency and flexibility of the methodology proposed in the present study. [less ▲]

Detailed reference viewed: 139 (40 ULg)
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See detailINNOVATIVE INJECTABLE LIPOSOME AND DRUG-IN-CYCLODEXTRIN-IN LIPOSOME SYSTEMS ENCAPSULATING ESTETROL FOR THE TREATMENT OF ISCHEMIA DISEASES IN PREMATURE BABIES
Palazzo, Claudio ULg; Laloy, Julie; Delvigne, Anne-Sophie et al

Conference (2016, September 28)

Purpose: In 2010, almost 15 million of babies in the world are prematurely borned, 11.1 % of the total amount of alive children. Despite the better neonatology techniques, the number of preterm babies ... [more ▼]

Purpose: In 2010, almost 15 million of babies in the world are prematurely borned, 11.1 % of the total amount of alive children. Despite the better neonatology techniques, the number of preterm babies with motor, vision, hearing or mental deficiencies is still constant along the last twenty years. Moreover, no efficacy treatment is available to the present day. The estetrol (E4) has an important role in the brain development and protection. The aim of this study is to develop new injectable liposome and drug-in-cyclodextrin-in-liposome (DCL) formulations, encapsulating E4 in order to enhance its crossing through the blood-brain barrier (BBB). Methods: Hydroxypropyl-β-cyclodextrins (degrees of substitution 0.87 and 0.63) (HPβCD 0.87 and HPβCD 0.63) were used to increase E4 aqueous solubility. Liposome and DCL (E4-HPβCD 0.63 complex) formulations were prepared by thin-film hydration technique. The formulations were physicochemical characterized and stability in foetal bovine serum (FBS) was evaluated. LDH and MTS tests on endothelial, neuronal and BBB model cells were performed in vitro on the liposome formulation. Hemocompatibility of the formulations was evaluated on red blood cells, platelet aggregation and coagulation. BBB passage tests were performed using human BBB cell line (hCMEC/D3). Results: E4-HPβCD complexes proportionally increased the solubility of the hormone. Due to the lower solubility obtained with HPβCD ds 0.87, only HPβCD ds 0.63 was retained for future tests. Liposomes and DCL encapsulating E4 were prepared. All the formulations had average particle size below 150 nm, polydispersity index below 0.10 and ζ potential around + 30 mV. The encapsulation efficacy for liposomes was between 3% and 10% while those of DCL are between 15% and 35%. Moreover, the formulations are capable to release 80 % (liposome) and 90 % (DCL) of encapsulated E4 after 3 h at 37°C. The formulations, incubated in FBS at 37°C under gentle stirring, keep the same size and do not form protein corona up to 6 h. The effect of liposome and DCL formulations on cell viability and integrity was evaluated. The results showed no toxic effects on all the tested cell lines. Hemocompatibility tests showed no hemolysis, platelet aggregation or effects on coagulation, confirming the possibility of the formulations to be intravenously administrated. Preliminary BBB passage tests highlighted the capability of the formulations to pass the BBB and reach the brain. Conclusions: New non-toxic, hemocompatible liposome and DCL formulations encapsulating E4 were prepared. The formulations are promising drug delivery system to target estrogens to the brain, due to their physiochemical characteristics. Aknowledgment : The authors thank Estetra SPRL for providing Estetrol. [less ▲]

Detailed reference viewed: 71 (9 ULg)
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See detailInnovative lactation stage specific prediction of CH4 from milk MIR spectra
Vanlierde, Amélie; Vanrobays, Marie-Laure ULg; Dehareng, Frédéric et al

in Book of abstracts of the 65th annual meeting of the European Federation of Animal Science (2014, August)

Detailed reference viewed: 29 (7 ULg)
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See detailInnovative lactation stage specific prediction of CH4 from milk MIR spectra
Vanlierde, Amélie; Vanrobays, Marie-Laure ULg; Dehareng, Frédéric et al

Conference (2014, August 28)

Detailed reference viewed: 84 (41 ULg)
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See detailInnovative Learning for Collaborative Design in Ergonomics
Folcher, Viviane; Zreik, Khaldoun; Ben Rajeb, Samia ULg et al

in Stouffs, Rudy; Sariyildiz, Sevil (Eds.) Computation and Performance (2013)

The proposed article deals with introducing collaborative architectural design into the training of ergonomists at the Master 2 level. The collaborative design workshop aims to confront ergonomists with ... [more ▼]

The proposed article deals with introducing collaborative architectural design into the training of ergonomists at the Master 2 level. The collaborative design workshop aims to confront ergonomists with the difficulties any design project involves, and which challenge architects, designers, engineers and so on: collaboration between people with different skills and different expertise; powerful time constraints; need for their work to converge; working together and/or at a distance; sharing documents; decision-making, etc. The article will present a short review of work carried out in the domains of architecture and design, and of the contribution of ergonomics within architectural projects. We shall then present the workshop’s educational aims, and give details of the way it functioned. Finally, observation results will be presented and discussed. [less ▲]

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See detailAn innovative lens surface functionalization to control Posterior Capsular Opacification
Huang, Yi-Shiang ULg

Poster (2014, May 26)

Cataract is the opacity of the lens, causing impairment of vision or even blindness and the surgery is still the only available treatment today. The intraocular lens (IOL) is a polymer implant designed to ... [more ▼]

Cataract is the opacity of the lens, causing impairment of vision or even blindness and the surgery is still the only available treatment today. The intraocular lens (IOL) is a polymer implant designed to replace the natural lens in the cataract surgery. However, the bio-inert materials could not satisfy the unmet need in the secondary cataract control. Posterior capsular opacification (PCO, or Secondary Cataract), characterized by a thick and cloudy layer of lens epithelial cells (LECs), is the most common postoperative complication. For the present study, a bioactive molecule is immobilized onto the conventional acrylic hydrophilic polymer pHEMA (Poly(2-hydroxyethyl methacrylate)) using oxygen plasma treatment followed by dip-coating deposition. The RGD peptide sequence, being well-known for its ability to promote cellular attachment by binding to integrin receptors, is designed to stimulate the adhesion of LECs on the IOL. The data have shown the peptide immobilized biomaterial not only exhibits similar optical and physical properties, but also reveals enhanced bio-logical properties in cell adhesion and cell morphology maintenance. By means of surface functionalization of IOL to stimulate LECs adhesion, the secondary cataract could be controlled. [less ▲]

Detailed reference viewed: 44 (0 ULg)
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See detailInnovative method for the detection of bovine blood products in feedingstuffs
Lecrenier, Marie-Caroline ULg; Marbaix, Hélène; Veys, Pascal et al

Poster (2014, October)

Detailed reference viewed: 12 (1 ULg)
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See detailInnovative Method for the Detection of Bovine Blood Proteins in Feedingstuffs
Lecrenier, Marie-Caroline ULg; Marbaix, Hélène; Veys, Pascal et al

Poster (2015, October)

Detailed reference viewed: 13 (1 ULg)
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See detailInnovative Methodology for the Definition of Design Spaces of Chromatographic Methods
Rozet, Eric ULg; Debrus, B; Lebrun, Pierre ULg et al

Conference (2013, June 06)

As defined by ICH [1] and FDA, Quality by Design (QbD) stands for “a systematic approach to development that begins with predefined objectives and emphasizes product and process understanding and process ... [more ▼]

As defined by ICH [1] and FDA, Quality by Design (QbD) stands for “a systematic approach to development that begins with predefined objectives and emphasizes product and process understanding and process control, based on sound science and quality risk management”. A risk–based QbD–compliant approach is proposed for the robust development of analytical methods. This methodology based on Design of Experiments (DoE) to study the experimental domain models the retention times at the beginning, the apex and the end of each peak corresponding to the compounds of a mixture and uses the separation criterion (S) rather than the resolution (RS) as a Critical Quality Attribute. Stepwise multiple linear regressions are used to create the models. The estimated error is propagated from the modelled responses to the separation criterion (S) using Monte Carlo simulations in order to estimate the predictive distribution of the separation criterion (S) over the whole experimental domain. This allows finding ranges of operating conditions that will guarantee a satisfactory quality of the method in its future use. These ranges define the Design Space (DS) of the method. In chromatographic terms, the chromatograms processed at operating conditions within the DS will assuredly show high quality, with well separated peaks and short run time, for instance. This Design Space can thus be defined as the subspace, necessarily encompassed in the experimental domain (i.e. the knowledge space), within which the probability for the criterion to be higher than an advisedly selected threshold is higher than a minimum quality level. Precisely, the DS is defined as “the multidimensional combination and interaction of input variables (e.g., material attributes) and process parameters that have been demonstrated to provide assurance of quality” [1]. Therefore, this DS defines a region of operating conditions that provide prediction of assurance of quality rather than only quality as obtained with traditional mean response surface optimisation strategies. For instance, in the liquid chromatography there is a great difference in e.g. predicting a resolution (RS) higher than 1.5 vs. predicting that the probability for RS to be higher than 1.5 (i.e. P(RS> 1.5)) is high. The presentation of this global methodology will be illustrated for the robust optimisation and DS definition of several liquid chromatographic methods dedicated to the separation of different mixtures: pharmaceutical formulations, API and impurities/degradation products, plant extracts, separation of enantiomers, … [less ▲]

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See detailInnovative methodology to transfer conventional GC-MS heroin profiling to UHPLC-MS/MS
Debrus, Benjamin ULg; Broséus, Julian; Guillarme, Davy et al

in Analytical and Bioanalytical Chemistry (2011), 399(8), 2719-2730

Nowadays, in forensic laboratories, heroin profiling is frequently carried out by gas chromatography coupled with mass spectrometry (GC-MS). This analytical technique is well established, provides good ... [more ▼]

Nowadays, in forensic laboratories, heroin profiling is frequently carried out by gas chromatography coupled with mass spectrometry (GC-MS). This analytical technique is well established, provides good sensitivity and reproducibility, and allows the use of large databases. Despite those benefits, recently introduced analytical techniques, such as ultra-high-pressure liquid chromatography (UHPLC), could offer better chromatographic performance, which needs to be considered to increase the analysis throughput for heroin profiling. With the latter, chromatographic conditions were optimized through commercial modeling software and two atmospheric pressure ionization sources were evaluated. Data obtained from UHPLC–MS/MS were thus transferred, thanks to mathematical models to mimic GC-MS data. A calibration and a validation set of representative heroin samples were selected among the database to establish a transfer methodology and assess the models’ abilities to transfer using principal component analysis and hierarchical classification analysis. These abilities were evaluated by computing the frequency of successful classification of UHPLC–MS/MS data among GC-MS database. Seven mathematical models were tested to adjust UHPLC–MS/MS data to GC-MS data. A simplified mathematical model was finally selected and offered a frequency of successful transfer equal to 95%. [less ▲]

Detailed reference viewed: 161 (31 ULg)
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See detailInnovative methods for the determination of the taxonomic origin of processed animal proteins in feed.
Veys, Pascal; Ngo Njembe, M.; Lecrenier, Marie-Caroline ULg et al

Poster (2015, November)

The use of animal by-products in feed depends on their nature defined by the type of tissue or body parts and the species of origin. Currently, the detection of unauthorised processed animal proteins ... [more ▼]

The use of animal by-products in feed depends on their nature defined by the type of tissue or body parts and the species of origin. Currently, the detection of unauthorised processed animal proteins (PAPs) is based on light microscopy and PCR methods. Light microscopy identifies structures on the basis of their morphology and enables identification of particles (such as bones, cartilages, muscle fibres,…) while PCR is able to detect and identify the presence of specific animal DNA in feed. Nevertheless, for some scenarios, even combined, these methods do not succeed in determining the taxonomic origin of the PAPs. A typical example is that of an aquafeed containing authorised porcine PAP together with dairy products: the analysis will conclude of the potential presence of ruminant PAP. Therefore, there is a need for developing methods allowing a taxonomic characterisation of visual structures such as bones fragments and muscle fibres. For the characterisation of bones, NIRM has yet demonstrated its potential. However the limitation of NIRM is when the presence of bones is reduced or absent. This study investigated the potential of NIRM for the determination of the taxonomic origin of muscle fibres. The NIRM was experimented on 2 porcine PAPs vs. 6 ruminant PAPs and 7 fishmeals all of industrial origin. Results showed that NIRM allows differentiating muscle fibres from different taxonomic origins: fish, ruminant and pig. In addition to this taxonomic classification, results also reveal differences inside taxonomic clusters of PAPs (e.g among different ruminant PAPs and porcine PAPs). The results obtained on this type of meals are promising and offer new perspectives. Tests on adulterated feeds need to be performed by NIRM prior to validation. [less ▲]

Detailed reference viewed: 22 (4 ULg)
See detailInnovative multilayered nanofibers for wound dressing application
Croisier, Florence ULg; Detrembleur, Christophe ULg; Jérôme, Christine ULg

Poster (2012, April 18)

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This ... [more ▼]

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This polysaccharide has shown a great potential for biomedical and pharmaceutical applications, on account of its remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make chitosan an outstanding candidate for short- to medium-term applications. In this respect, nanometric fibers are highly interesting as their assembly mimics the skin extracellular matrix structure. Such nanofibrous materials can be prepared by electrospinning (ESP). This technique uses a high voltage to create an electrically charged jet of polymer solution or melt which leads to fibers formation. 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), polymer fibers ranging from nanometers to a few microns in diameter can be obtained and subsequently used as potential scaffolds, a.o. to form a temporary, artificial extracellular matrix. In the present study, electrospinning technique was combined with layer-by-layer deposition method (LBL) - a well-known method for surface coating, based on electrostatic interactions - in order to prepare multilayered chitosan-based nanofibers. The antibacterial properties of the obtained material were then assessed, and the presence of a multilayered deposit was confirmed by several techniques. (Future) possibilities for valorization: These multilayered chitosan-based nanofibers present great prospects for the preparation of new biomedical scaffolds - such as wound dressings that could improve skin regeneration. [less ▲]

Detailed reference viewed: 81 (5 ULg)
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See detailAn innovative non-animal chitosan hydrogel is able to restore the rheology of osteoarthritis synovial fluid ex vivo
Henrotin, Yves ULg; Rocasalbas, Guillem; Chausson, Mickaël et al

Poster (2016, September)

Detailed reference viewed: 36 (2 ULg)