Tissue engineering using synthetic extracellular matrices

transplantation is limited by a shortage of donor tissue suitable for transplantation. Synthetic prostheses typically do not replace all functions of a lost tissue or organ, and are incapable of adapting to the body's changing needs over time. These limitations have spurred interest in engineering tissues that could be used to replace lost or failing tissues using cells and synthetic extracellular matrices. Tissue engineering integrates the advantages of tissue/organ transplantation and purely synthetic prostheses by combining cells, the functional units of tissues, with synthetic extracellular matrices that can be synthesized reproducibly on a large scale. This field has been formally defined as a "combination of the principles and methods of the life sciences with those of engineering to elucidate fundamental understanding of structure-function relationships in normal and diseased tissues, to develop materials and methods to repair dam~ aged or diseased tissue, and to create entire tissue replacements'". Three basic strategies have evolved over the past 15