Clinical Transplantation of a Tissue-Engineered Airway

Due to demographic changes end-stage organ failure is currently one of the major challenges. In the majority of the cases the only so far curable therapeutic option is an allogenic organ transplantation. However, conventional transplantation is associated with a shortage of donor organs and a lifetime of immunosuppressant, which is a non-ideal solution. Regenerative medicine, including tissue engineering (TE), cell therapy and pharmaceutical intervention represents a very promising alternative in this context. During the recent years several attempts has been made to engineer various tissue/ organs and initial evidence exists about the clinical potential of this method. Despite early clinical applications for the trachea, bladder, skin or heart valves, more solid organs can probably never be transferred to the patient regarding their demanding and complicated engineering process. For complex organs, such as heart, lung or the liver, cell therapy and pharmaceutical intervention can be an optimum alternative. RM aims to replace and regenerate damaged tissue to restore organ function. It is very common that all three aspects of RM, such as TE, cell therapy and pharmaceutical intervention are combined at some level and should not be categorical separated from each other. The following components are necessary to be considered: a) a scaffold/ matrix seeded with b) different cell type(s) usingc) the body or a device as a native or artificial bioreactor, respectively, d) bioactive molecules/Signaling and e) cell/gene therapy. We already learned that each target tissue requires specific components, and  engineering processes need to be modified to distinctive needs. Early clinical application demonstrated the feasibility of using regenerative approaches to replace damaged tissue and organs with rather simple architecture. Preclinical findings suggest that even higher complex organs can be successfully partly engineered. However, due to the complexness of these solid organs cell therapy might be the more promising solution for the near clinical future. Notably, pharmaceutical strategies should be widely considered to increase endogenous regeneration and self-healing capacity of the recipient. The new field of RM rises novel ethical concerns and questions – these must be addressed and answered.