An important problem that medical doctors have faced for decades is an acute shortage of tissue and organs that can be used to repair or replace damaged tissue in a patient. One of the principle reasons for this shortage is the lack of compatibility of the immune systems of the donor and recipient of tissue, which leads to rejection of implanted tissue that is recognized as a foreign invader. Tissue Engineering is an exciting research area that combines several disciplines, including material science, microfabrication, cell biology, fluid mechanics, - just to name a few – to generate tissue (such as skin, muscle, cartilage, liver, and kidney) that can be surgically implanted within a patient without eliciting an immune response. Development of artificial tissue typically involves the use of a “scaffold” that serves as a mechanical support construct that can be seeded with cells from the patient who needs new tissue. The seed cells are encouraged to proliferate within the scaffold, and while populating it with new material, to biodegrade (and replace) the scaffold material. Increasingly complex engineered tissue may be developed by incorporating vasculature within the scaffold, and development of mechanisms for incorporating a variety of cell types. “Self-assembly” of complex tissue structures is being investigated through the use of stem cells and surface-directed attachment of cells.
Prof. Cunningham first worked in the area of Tissue Engineering while in the MEMS Group at Draper Laboratory, where he had the opportunity to collaborate with Dr. Jay Vacanti at Massachusetts General Hospital, one of the pioneers in the field. Since that time, the Nano Sensors Group has collaborated with Dr. Dominique Griffon in the Veterinary Medicine Department at the University of Illinois on the development of engineered cartilage for hip and knee joint replacement.
Engineered chitosan fibers suspended in media (left) and SEM photo of chondrocyte cells attached to the chitosan scaffold (right)
- "Silicon Micromachining to Tissue Engineer Branched Vascular Channels for Liver Fabrication," S. Kaihara, J. Borenstein, R. Koka, S. Lalan, M. Ravens, H. Pien, B.T. Cunningham, and J. Vacanti, Tissue Engineering, 6(2):105-117, 2000.
- “A Replica Molding Technique for Producing Fibrous Chitosan Scaffolds for Cartilage Engineering," G.J. Slavik, G. Ragetly, N. Ganesh,a D.J. Griffon, and B.T. Cunningham, Journal of Materials Chemistry, Vol. 17, p. 4095 - 4101, 2007.
- "Cartilage tissue engineering on fibrous chitosan scaffolds produced by a replica molding technique," G. Ragetly, G. Slavik, B.T. Cunningham, D.J. Schaeffer, and D. Griffon, Journal of Biomedical Material Research Part A, In Print, September 2009.