Production et effet catabolique du 4-hydroxynonénal dans les tissus articulaires arthrosiques : un nouveau facteur impliqué dans la dégradation du cartilage

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Identification des petits protéoglycanes riches en leucine comme nouveaux substrats de la MMP-13 dans le cartilage humain et caractérisation de leur site de clivage

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Caractérisation et évaluation in vitro de la section osseuse de treillis 3D polymériques ostéochondraux pour le remplacement de cartilage articulaire par génie tissulaire

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The Weapons of Mass Destruction and the Global Security Strategy of the EU

The proliferation of weapons of mass destruction (WMD), nuclear, biological and chemical (NBC) is one of the main security challenges facing the international community today. However the new Global Security Strategy of 2016 raises the question of non-proliferation of WMD only as an incidental matter, not addressing directly the threat, a fundamental threat in the regional and global security. This is a clear step backwards for the European common security.

Designing Creative Destruction

This research aims to make a contribution in the context of design thinking at a global cultural scale and specifically how design methods are a feature of the homogenising and heterogenising forces of globalisation via creative destruction. Since Schumpeter’s description of economic innovation destroying the old and creating the new, a number of other interpretations of creative destruction have developed including those driving cultural evolution. However a design model showing the impact of different types of design method on cultural evolution can develop an understanding on a more systemic level from the medium to longer term impact of new designs that homogenise or increase the differences between various cultures. This research explores the theoretical terrain between creative destruction, design thinking and cybernetics in the context of exchanging cultural influences for collaborative creativity and concludes with an experiment that proposes a feedback loop between ubiquitising and differentiating design methods mediating cultural variety in creative ecosystems.

Designing Creative Destruction

This research aims to make a contribution in the context of design thinking at a global cultural scale and specifically how design methods are a feature of the homogenising and heterogenising forces of globalisation via creative destruction. Since Schumpeter’s description of economic innovation destroying the old and creating the new, a number of other interpretations of creative destruction have developed including those driving cultural evolution. However a design model showing the impact of different types of design method on cultural evolution can develop an understanding on a more systemic level from the medium to longer term impact of new designs that homogenise or increase the differences between various cultures. This research explores the theoretical terrain between creative destruction, design thinking and cybernetics in the context of exchanging cultural influences for collaborative creativity and concludes with an experiment that proposes a feedback loop between ubiquitising and differentiating design methods mediating cultural variety in creative ecosystems.

Co-creation and co-destruction: : A practice-theory based study of interactive value formation

Drawing on an empirical study of public transport, this paper studies interactive value formation at the provider—customer interface, from a practice—theory perspective. In contrast to the bulk of previous research, it argues that interactive value formation is not only associated with value co-creation but also with value co-destruction. In addition, the paper also identifies five interaction value practices — informing, greeting, delivering, charging, and helping — and theorizes how interactive value formation takes place as well as how value is intersubjectively assessed by actors at the provider—customer interface. Furthermore, the paper also distinguishes between four types of interactive value formation praxis corresponding with four subject positions which practitioners step into when engaging in interactive value formation.

Chitosan fibrous scaffolds for cartilage tissue engineering

The biocompatibility of chitosan and its similarity with glycosaminoglycans make it attractive for cartilage engineering despite its limited cell adhesion properties. Structural and chemical characteristics of chitosan scaffolds may be improved for cartilage engineering application. We planned to evaluate chitosan meshes produced by a novel technique and the effect of chitosan structure on mesenchymal stem cells (MSCs) chondrogenesis. Another objective was to improve cell adhesion and chondrogenesis on chitosan by modifying the chemical composition of the scaffold (reacetylation, collagen II, or hyaluronic acid (HA) coating). A replica molding technique was developed to produce chitosan meshes of different fiber-width. A polyglycolic acid (PGA) mesh served as a reference. Constructs were analyzed at two and 21 days after seeding chondrocytes with confocal microscopy, scanning electron microscopy, histology, and quantitative analysis (weights, DNA, glycosaminoglycans, collagen II). Chondrocytes maintained their phenotypic appearance and a high viability but attached preferentially to PGA. Matrix production per chondrocyte was superior on chitosan. Chitosan meshes and sponges were analyzed after seeding and culture of MSCs under chondrogenic condition for 21 days. The cellularity was similar between groups but matrix production was greater on meshes. Chitosan and reacetylated-chitosan scaffolds were coated with collagen II or HA. Scaffolds were characterized prior to seeding MSCs. Chitosan meshes were then coated with collagen at two densities. PGA served as a reference. Constructs were evaluated after seeding or culture of MSCs for 21 days in chondrogenic medium. MSCs adhered less to reacetylated-chitosan despite collagen coating. HA did not affect cell adhesion. The cell attachment on chitosan correlated with collagen density. The cell number and matrix production were improved after culture in collagen coated meshes. The differences between PGA and chitosan are likely to result from the chemical composition. Chondrogenesis is superior on chitosan meshes compared to sponges. Collagen II coating is an efficient way to overcome poor cell adhesion on chitosan. These findings encourage the use of chitosan meshes coated with collagen II and confirm the importance of biomimetic scaffolds for tissue engineering. The decreased cell adhesion on reacetylated chitosan and the poor mechanical stability of PGA limit their use for tissue engineering.

Scaffolds for controlled release of cartilage growth factors

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