Tissue Engineering allows organs to be grown from implantation (rather than transplantation) and hence free from imunological rejection. The starting point for any tissue-engineered organ is the harvesting of small amounts of tissue from the future recipient of the Tissue Engineered organ. This could be as small as a 2mm punch biopsy for some applications. Cells from the biopsy are cultured from explants or a collagenase digestion to create a "cell bank". These cells are then further cultured on collagenous substrates, under the correct physiological conditions, to form Tissue Engineered constructs for implantation. The process is carried out in a Tissue Culture facility to maintain a sterile environment.
Cellular biochemical and physical activity can be enhanced by the addition of growth factors or cytokines, also by the use of physical stimulation. The Tensioning-Culture Force Monitor applies minute physical loads to stimulate the resident cell population in the collagenous scaffold into bio-chemical and bio-physical activity normally associated with organogenesis and tissue repair. After further tissue culture under the correct conditions, the resident cells in the Tissue Engineered construct will dissolve the original collagen scaffold and secrete a new collagen rich neo-tissue, the construct can then be implanted back into the patient from whom the cells were originally removed.
Tissue engineering has significant market potential and financial investment continues apace. A 1997 survey of the field reported that in that year alone, R&D expenditure directly linked to corporate tissue engineering projects was about $0.5 billion, with a growth rate of about 22% per year. This demonstrates the sustained interest in this area, driven in part by positive results regarding specific products and processes in clinical settings. Technical advancements in the various components of the industry will contribute to market growth. One component is the availability of biomaterials that act as scaffolds for tissue repair and reconstruction, or for the deposition of engineered tissues and cells preceding implantation. An increasing amount of R&D is directed toward addressing the properties of these scaffolds with the goal of creating materials that have the desired functional profiles for various applications.