Mechanical behavior of abdominal aorta aneurysm in rat model treated by cell therapy using mesenchymal stem cells

摘要

Regenerative medicine to substitute conventional surgery or an endovascular stent constitutes currently a challenge to treat abdominal aneurysm artery (AAA). The present paper addresses the following question: Can a cellular therapy from mesenchymal stem cells reestablish the mechanical properties of damaged abdominal aorta? For that, the xenograft rat model that mimics arterial dilatation due to aneurysmal disease is used to study the effects of the proposed cellular therapy. To investigate the changes in the mechanical behavior of the arterial wall, the artery is assumed to be made of a hyperelastic and incompressible material characterized by a strain energy function fitted to the average data set of uniaxial tests of AAA tissue samples. In order to compute the stresses in the artery by using an analytical approach, the aneurysm is represented as a "parabolic-exponential" thin membrane. Thus, when compared to healthy, untreated and treated arteries, the obtained results demonstrate that the cellular therapy stabilizes the geometry of AAAs, improves the stiffness of the tissue and decreases stress variations in the arterial wall.