Tissue Engineering

Treating the loss of tissue and organ function has developed into one of the most challenging problems facing our health system. Unfortunately, many currently applied strategies are hindered by major limitations. Artificial prostheses, for example, often restore the function of the replaced tissue only to a limited extent and often do not sufficiently integrate into the host tissue. In many cases, the loss of organ function can only be compensated through transplantation; however, for many tissues and organs the tremendous and constantly growing demand greatly outpaces the availability of suitable donor tissues and organs.

Figure: (A) Cartilage tissue cultivated in three-dimensional cell culture (bovine chondrocytes). (B) Long-term culture of adipose tissue constructs.

Tissue engineering is a multidisciplinary approach to the generation of living tissue in vitro and in vivo that offers new solutions for the treatment of tissue and organ loss. Utilizing specific cell culture techniques, cells are stimulated to build up a new and functional tissue. A frequently applied strategy involves biodegradable polymeric scaffolds that function as cell carriers in which the tissue develops. Cells are isolated from a patient’s biopsy from healthy tissue and are propagated in vitro. The cells are then seeded onto the biodegradable three-dimensional scaffolds, which are manufactured in the shape and dimensions desired for the developing tissue. Under optimized culture conditions, a tissue develops over several weeks in vitro; it can subsequently be made available for implantation. Alternatively, strategies have been developed in which a short-term cultivation of the cell-polymer constructs is sufficient. In this case, the constructs integrate into the host tissue and develop further after implantation. At the end of the process, the polymeric scaffold is degraded and, ideally, an intact and fully functioning tissue is generated to replace the original tissue.