[Tissue engineering: artificial tissue replacement containing vital components].

Tissue engineering as a new field of research has gained increasing importance in recent years. The interdisciplinary field combines, biomaterials cell biology, and cell culture bio-engineering technology. The main focus of tissue engineering is the synthesis of artificial constructs or tissues based on vital cells or cell matrix. Biomaterials provide a three-dimensional structure to shape or guide tissue development. Isolated cartilage cells from a patient can form new tissues when suspended in non-woven resorbable polymers for reconstructive surgery. To achieve sufficient amounts of autologous cells for transplant formation, cells from biopsies have to be multiplied in monolayer culture. Dedifferentiated and undifferentiated mesenchymal cells may be used for bone and cartilage engineering. High cell densities in three-dimensional cultures require perfusion techniques to stabilize culture conditions. Morphogenetic factors such as BMP (bone morphogenetic protein) are thought to play a key role in inducing and controlling phenotypic tissue formation. In conclusion, modern in vitro approaches open new avenues for the development of vital tissue replacements for the clinic. Tissues can be repaired with the patient's own cells eventually leaving no residual artificial materials. Tissue engineering further provides new approaches for in vitro models of the extracellular matrix or diseases which mainly affect this matrix such as rheumatoid arthritis or osteoarthritis. This article describes recent developments in connective tissue engineering and discusses the potential for human tissue repair and reconstructive surgery.