Materials Frontier No.127
Title:Collagen-Based Scaffolds for Heart Valve Tissue Engineering
Speaker:Dr. Qi Chen, Department of Materials, University of Oxford, UK
Venue: Room.308, Material Building A
Inviter: Prof.Chaoying XIE
Dr. Qi Chen received his B.S. Degree in the Department of Materials Science and Engineering, Shanghai Jiao Tong University (SJTU), Shanghai, China, in 2009. Then he conducted his D.Phil study on biomaterials and tissue engineering in the Department of Materials, University of Oxford, UK, till December 2013, sponsored by the Chinese Ministry of Education-Oxford University Scholarship. He was also a visiting scholar in the Department of Bioengineering, University of Tokyo, from July to August 2013.
Tissue engineered heart valve (TEHV) is currently believed to be the most promising approach of a long-lasting and curative heart valve replacement. Collagen, glycosaminoglycans (GAGs) and elastin are the major components of the extracellular matrix of the heart valve. This work examined scaffolds made of collagen, collagen-elastin composite, and collagen-chondroitin sulfate (CS) composite. Scaffolds were prepared by freeze drying method, and had mean pore sizes ranging from 65.4µm to 201.5µm. Mechanical characterization (compression, tension and three-point bending) showed that the collagen scaffolds all behaved as elastomeric foams. By incorporating elastin or CS into the collagen scaffolds, the mechanical properties of the scaffolds were further adjusted. This work also developed a novel tri-layer structure that resembled the fibrosa-spongiosa-ventricularis structure of the native aortic valve, with each layer being collagen, collagen-CS, and collagen-elastin respectively. The different mechanical properties of each layer introduced a desirable bending anisotropy to the scaffold, which mimicked the characteristic behaviour of the native aortic valve that it is easier to bend towards the ventricularis side (with curvature) than towards the fibrosa side (against curvature). Cardiosphere-derived cells were investigated the in biological behaviours (attachment, proliferation, migration, etc) on the scaffolds, showing that the scaffolds had good biocompatibility. The findings of this work served as a framework for better designing a compositionally, mechanically and biologically qualified scaffold for heart valve tissue engineering.