Engineering Complex Synthetic Organs

At this time there is a substantial, and as yet unmet, demand for organs to replace nonfunctional tissues resulting from congenital defects, or to repair damaged or degenerated tissues. The field of regenerative medicine hopes to provide engineered replacement tissues in situations where our body’s regenerative capability or nonbiological mechanical devices cannot adequately replace lost physiological functions. This technology holds the promise to supply customized organs to overcome the severe shortages we currently face. Engineering synthetic organs is a complex process which necessitates careful (1) selection of cells or controlled proliferation of stem or progenitor cells to achieve appropriate numbers of cells for seeding onto biodegradable scaffolds to create cell-scaffold constructs, (2) design and selection of appropriate biodegradable or biomodifiable scaffold materials, and (3) design and construction of bioreactors to support generation of functional tissue replacements. To be successful, ongoing efforts to understand and engineer multicellular systems must continue, and new efforts to induce vascularization and integration of engineered tissues into the body will need to be developed. Current studies lead to improved understanding of how tissue systems can be integrated, as well as development of biomedical technologies not traditionally considered in tissue engineering, such as development of biohybrid organs or “bionic” devices.