Les récepteurs aux imidazolines dans le coeur : identification, distribution et fonction

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Mechanical effect of friction and stretching on endothelium denudation

Peer reviewed: NoNRC publication: Ye

Fabrication and surface modification of poly lactic acid (PLA) scaffolds with epidermal growth factor for neural tissue engineering

In an effort to design biomaterials that may promote repair of the central nervous system, 3-dimensional scaffolds made of electrospun poly lactic acid nanofibers with interconnected pores were fabricated. These scaffolds were functionalized with polyallylamine to introduce amine groups by wet chemistry. Experimental conditions of the amination protocol were thoroughly studied and selected to introduce a high amount of amine group while preserving the mechanical and structural properties of the scaffold. Subsequent covalent grafting of epidermal growth factor was then performed to further tailor these aminated structures. The scaffolds were then tested for their ability to support Neural Stem-Like Cells (NSLCs) culture. Of interest, NSLCs were able to proliferate on these EGF-grafted substrates and remained viable up to 14 d even in the absence of soluble growth factors in the medium

Mechanical effect of friction on endothelium denudation

Peer reviewed: NoNRC publication: Ye

Propri\ue9t\ue9s histologiques et biom\ue9caniques des r\ue9parations cartilagineuses

Peer reviewed: NoNRC publication: Ye

Constitutive Modelling of Endothelium Denudation for Finite Element Simulation of Angioplasty

This study aims at characterizing and modelling the effect of mechanical factors on endothelial denudation during angioplasty, such as normal force between balloon and artery, stretching of arterial walls, and relative displacement between contacting surfaces. Friction damage was applied to porcine aorta samples with different contact forces, relative displacements, and biplanar stretching conditions. After the tests, endothelium denudation was quantified by isolating and counting the remaining endothelial cells. Using multiple-regression analysis, a constitutive model is proposed for integration in finite element software. This model will help optimize balloon and stent deployment conditions to minimize the amount of damage to the endothelium, and eventually to reduce the occurrence of restenosis.Peer reviewed: YesNRC publication: Ye

Physical and numerical simulation of 3D polymeric scaffolds for load-bearing tissue engineering and cell-based gene therapy

Peer reviewed: NoNRC publication: Ye

Design and Dynamic Culture of Macro/Microporous Scaffolds for Cartilage Tissue Engineering

Peer reviewed: NoNRC publication: Ye

Design and dynamic culture of 3D scaffolds for cartilage tissue engineering

Engineered scaffolds for tissue-engineering should be designed to match the stiffness and strength of healthy tissues while maintaining an interconnected pore network and a reasonable porosity. In this work, we have used 3D-ploting technique to produce poly-L-Lactide (PLLA) macroporous scaffolds with two different pore sizes. The ability of these macroporous scaffolds to support chondrocyte attachment and viability were compared under static and dynamic loading in vitro. Moreover, the 3D-plotting technique was combined with porogen-leaching, leading to micro/macroporous scaffolds, so as to examine the effect of microporosity on the level of cell attachment and viability under similar loading condition. Canine chondrocytes cells were seeded onto the scaffolds with different topologies, and the constructs were cultured for up to 2 weeks under static conditions or in a bioreactor under dynamic compressive strain of 10% strain, at a frequency of 1 Hz. The attachment and cell growth of chondrocytes were examined by scanning electron microscopy (SEM) and by MTT assay. A significant difference in cell attachment was observed in macroporous scaffolds with different pore sizes after one, 7, and 14 days. Cell viability in the scaffolds was enhanced with decreasing pore size and increasing microporosity level throughout the culture.Peer reviewed: YesNRC publication: Ye