Development of Large Engineered Cartilage Constructs from a Small Population of Cells Jillian M. Brenner Dept. of Chemical Engineering, Queen’s University, Kingston, Canada Human Mobility Research Centre, Kingston General Hospital and Queen’s University, Kingston, Canada Manuela Kunz Human Mobility Research Centre, Kingston General Hospital and Queen’s University, Kingston, Canada Man Yat Tse Dept. of Biomedical and Molecular Sciences, Queen’s University, Kingston, Canada Andrew Winterborn Anesthesiology and Perioperative Medicine, Queen’s University, Kingston, Canada Davide D. Bardana Human Mobility Research Centre, Kingston General Hospital and Queen’s University, Kingston, Canada Dept. of Surgery, Queen’s University, Kingston, Canada Stephen C. Pang Dept. of Biomedical and Molecular Sciences, Queen’s University, Kingston, Canada Stephen D. Waldman Dept. of Chemical Engineering, Queen’s University, Kingston, Canada Human Mobility Research Centre, Kingston General Hospital and Queen’s University, Kingston, Canada Dept. of Mechanical and Materials Engineering, Queen’s University, Kingston, Canada DOI 10.1002/btpr.1670 Published online January 17, 2013 in Wiley Online Library (wileyonlinelibrary.com). Confronted with articular cartilage’s limited capacity for self-repair, joint resurfacing techni- ques offer an attractive treatment for damaged or diseased tissue. Although tissue engineered cartilage constructs can be created, a substantial number of cells are required to generate suffi- cient quantities of tissue for the repair of large defects. As routine cell expansion methods tend to elicit negative effects on chondrocyte function, we have developed an approach to generate phenotypically stable, large-sized engineered constructs (3 cm 2 ) directly from a small amount of donor tissue or cells (as little as 20,000 cells to generate a 3 cm 2 tissue construct). Using rab- bit donor tissue, the bioreactor-cultivated constructs were hyaline-like in appearance and pos- sessed a biochemical composition similar to native articular cartilage. Longer bioreactor cultivation times resulted in increased matrix deposition and improved mechanical properties determined over a 4 week period. Additionally, as the anatomy of the joint will need to be taken in account to effectively resurface large affected areas, we have also explored the possibility of generating constructs matched to the shape and surface geometry of a defect site through the use of rapid-prototyped defect tissue culture molds. Similar hyaline-like tissue constructs were developed that also possessed a high degree of shape correlation to the original defect mold. Future studies will be aimed at determining the effectiveness of this approach to the repair of cartilage defects in an animal model and the creation of large-sized osteochondral constructs. V V C 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 213–221, 2013 Keywords: chondrocytes, extracellular matrix, cartilage, tissue engineering, bioreactors, continuous culture Introduction Osteoarthritis currently affects around 27 million Ameri- cans; a conservative estimate that will continue to rise with a progressively aging population. 1 This disease is characterized Correspondence concerning this article should be addressed to S. D. Waldman at waldman@me.queensu.ca. V V C 2013 American Institute of Chemical Engineers 213