The goal of tissue engineering is to repair or replace tissues and organs by delivering implanted cells, scaffolds, DNA, proteins or protein fragments to areas where they are needed. Despite early success, tissue engineers have faced challenges in repairing or replacing injured or diseased tissues that serve a predominantly biomechanical function, such as bone and articular cartilage. An evolving discipline, “functional tissue engineering” seeks to address these challenges [Butler, et al, Functional Tissue Engineering: The Role of Biomechanics, Journal of Biomechanical Engineering, December 2000 122(6), pages 570-575].