Chitosan-based tissue engineered vascular grafts

Abstract

Cardiovascular diseases such as atherosclerosis, coronary artery and peripheral vascular diseases are the leading causes of death worldwide and often require surgical intervention to replace damaged blood vessels, restore blood flow and preserve functions of lesioned tissues. The materials currently available for this therapy are efficient only when used to replace blood vessels with diameter greater than six millimeters due to complications related to the immune response observed in smaller diameter devices. Tissue engineering is an alternative technique used to overcome the problems that give rise to these complications, comprising of the seeding of mesenchymal stem cells on biodegradable scaffolds for the development of vascular grafts. Natural polymers such as chitosan are widely used as scaffolds as they provide matrices which are able to facilitate cell growth. Various compounds, namely the polysaccharides alginate and pectin, as well as the silicone based polymers such as Silpuran®, are capable of forming complexes or blends with chitosan, and these combinations can contribute to the improvement of the biomaterials properties. In this context , the use of chitosan in combination or not with other compounds for obtaining dense or porous biocompatible matrices used for cell growth and applied as vascular grafts are the focus of this proposal. The vascular grafts produced will be evaluated according to their physicochemical, mechanical and biological properties and the performance of the seeded mesenchymal stem cells will be evaluated. In addition, the devices will be compared to each other to determine which formulation has the most appropriate characteristics to the desired application.