Tissue engineering

Definition

Tissue engineering is a field of science that combines the developments of both engineering and biology to create biological substitutes, usually for regenerative medicine to repair damaged tissue, or for use as models for in vitro research. Tissue substitutes can be produced by co-culture of various types of cells that are found in the native tissue, although scaffoldings made of biopolymers are frequently used to help proper organization of the cells and preserve desired shape of the tissue. The cells necessary for the production of such a substitute can be obtained from the patient who can be treated with autologous stem cells; alternatively, various types of stem cells can be isolated from tissues of an adult organism (such as mesenchymal stem cells), or induced pluripotent stem cells can be applied. Except of the cells and a scaffolding, the development of a tissue substitute also requires a specific microenvironment simulating that of a native tissue, which can be achieved by supplementing the cell culture with e.g. growth factors. The first products of tissue engineering were predominantly synthetic skin substitutes, used for treatment of large skin defects arising as a result of severe burns; nowadays, substitutes of bone, cartilage, bronchia or blood vessels are also used. However, despite significant advances made in the field over the past several years, the production of complex tissues (e.g. containing secretory glands), the proper vascularization of tissues, and – in the case of a tissue transplant – the full integration of the substitute with native tissue still remains a challenge for researchers and doctors involved in regenerative medicine.