tailieunhanh - Chapter 069. Tissue Engineering

The origins of tissue engineering date to the sixteenth century when complex skin flaps were used to replace the nose. Modern tissue engineering combines the disciplines of materials sciences and life sciences to replace a diseased or damaged organ with a living, functional substitute. The most common tissue engineering approach combines cells and matrices to produce a living structure (Fig. 69-1). These strategies also include the use of scaffolding, cells, and growth factors to shape new tissues. The term regenerative medicine has emerged as a concept inclusive of tissue engineering and stem cell therapy (Chap. 67). . | Chapter 069. Tissue Engineering The origins of tissue engineering date to the sixteenth century when complex skin flaps were used to replace the nose. Modern tissue engineering combines the disciplines of materials sciences and life sciences to replace a diseased or damaged organ with a living functional substitute. The most common tissue engineering approach combines cells and matrices to produce a living structure Fig. 69-1 . These strategies also include the use of scaffolding cells and growth factors to shape new tissues. The term regenerative medicine has emerged as a concept inclusive of tissue engineering and stem cell therapy Chap. 67 . Figure 69-1 Biodegradable potymer statfold Soum F ud A r K rp r-ĐL aríụnuíld I. St LoriflC PL. JtmtlOil JLj Loicitao Ji tAìĩtìứtá PríM ĩíi iff ỉĩiivmỉ MidUMi L7th Edition httpi 4Sỉnn di Cine coni Th Mí ãr i -Hll tompmuf. Inc Ali nflhti . Schematic of basic principles of tissue engineering. From Langer R Vacanti J Tissue engineering. Science 260 1993 Fig. 1 with permission. Cellular Components of Tissue Engineering The foundation of tissue engineering is the combination of a three-dimensional scaffold with live and functional cells. Cells used in tissue engineering should be easily accessible and capable of proliferation while maintaining their differentiated function. There are three possible sources for cells autologous allogenic and xenogenic. Autologous cells are isolated directly from the patient. They have the advantage of avoiding immune-mediated rejection. However a potential limitation is that they may not be available or able to proliferate to the required tissue mass. Allogenic cells are harvested from a donor other than the patient. They have the advantage of being more readily available but the immune system must be modulated to avoid rejection. Xenogenic cells or those from a different species may also be used but also risk immune rejection or transmission of animal pathogens.