The use of polymer based scaffolds in tissue-engineered heart valves☆

Abstract Using the basic principles of tissue engineering, promising alternatives to current replacement heart valves are being developed. Tissue engineering is a multidisciplinary science that applies engineering principles to the life sciences in an attempt to create neotissue that can be used to repair or replace native tissue that is either diseased, damaged or congenitally absent. One tissue engineering method uses a three-dimensional scaffold as a template for neotissue development. Cells can either be seeded onto the matrix in vitro or grown into the matrix from the surrounding native tissue in vivo. The scaffold provides space for cell attachment and neotissue growth and development. The scaffold can be rationally designed to modulate neotissue development to meet the needs of a specific application. Tissue engineering methodology has been used to create neotissue that has been used to construct replacement heart valves. Tissue engineering scaffolds can generally be characterized into two types: natural matrices (scaffolds constructed from naturally occurring substances such as collagen or decellularized heart valve tissue) and polymer based matrices (scaffolds constructed from synthetic materials such as polyglycolic acid). Each type of scaffold has particular advantages and disadvantages. This review will provide a brief overview describing the difference between a natural and a synthetic matrix. We will then expand upon the synthetic polymer based scaffold for heart valve tissue engineering—including the different types of polymers used, and scaffold design. Finally, a broader overview of all the basic elements of a tissue-engineered heart valve will be described.