Advances and Trends in Tissue Engineering of Heart Valves
Y. S. Morsi (Swinburne University of Technology, Australia), C. S. Wong (Swinburne University of Technology, Australia) and S. S. Patel (Swinburne University of Technology, Australia)
Copyright: © 2008
Improvements in health care and treatment of diseases have led to an increase in life expectancy in developed countries. However, this achievement has also inadvertently increased the prevalence of chronic illnesses such as cardiovascular disease, adding to the growing burden of health care cost globally. Unfortunately, this trend is expected to escalate in the foreseeable future. Cardiovascular disease remains one of the main problems in contemporary health care worldwide, accounting for approximately one third of the world’s total death (Poole-Wilson, 2005). This article focuses on a subgroup of cardiovascular disease known as valvular heart disease whereby abnormalities or malfunctions of the heart valves are detected. It is estimated that 93,000 valvular surgeries were conducted in the United States in 2002 (American Stroke Association & American Heart Association, 2005) and valve replacement surgeries accounted for 75% of the surgery performed for valvular defects in Australia and, of that, 56% were for aortic valves (Davies & Senes, 2003).
Key Terms in this Chapter
Computer Aided Design: Also known as CAD. A computer based software program which is commonly used to assist engineers and architects in designing detailed 3D models. CAD is also a useful tool for conceptualisation of designs and visualisation of models prior to production.
Cell Proliferation: An increase in the number of cells due to cell growth and cell division. In the area of tissue engineering, proliferation of cells would enable cells attached to the scaffold to gradually cover the surface area of interest, producing a layer of live cells.
Scaffold: A supporting structure for cells and tissue to grow on; a scaffold will provide the physical structure, which guides the cells to grow to the correct anatomical shape.
Biocompatible Polymer: Polymer that does not produce toxin or harmful products and stimulate an immune response in biological systems. This is essential so that during implantation, the material does not induce a rejection response.
Rapid Prototyping Technique: An advanced manufacturing technique that produces 3D models in an automated manner through sequential layering of the material. Models can be created in a time frame ranging from 3 to 72 hours, depending on size.
Biodegradable Polymer: Polymer that can be broken down into nontoxic by-products through biological processes. Biodegradation can occur physically or chemically via enzymes or bacteria. Examples of biodegradable polymers are polyglycolic acid and polycaprolactone.
Fused Deposition Modeling: Commonly known as FDM. A type of RP technique. FDM produces 3D scaffolds by heating the material in the extruder and depositing them in a horizontal and vertical direction (XYZ direction), which is controlled by CAD.