An international team under the direction of Prof. Paolo Macchiarini from the Karolinska University Hospital developed a special artificial trachea consisting of the patient’s own stem cells derived from bone marrow. The tissue engineering was performed in collaboration with the University College of London, where scientists from Alexander Seifalian’s team studied the patient’s X-ray scans. Based on these scans they first constructed a glass trachea in order to perfectly reproduce the dimensions and angles of the Y-shaped organ, then constructed a scaffold around the glass structure using a special nano-plastic. The wafer-thin trachea scaffold was then stabilised with salt and the glass removed. A living organ was grown on the scaffold in a bioreactor using adult stem cells from the patient´s bone marrow together with growth factors. In a fourteen hour operation at the Karolinska Hospital in Stockholm, Prof. Macchiarini replaced the old trachea with the implant. In the patient´s body the cells continue to grow and finish shaping the trachea.

Tracheas created using tissue engineering have been transplanted earlier, for instance in 2008 in Barcelona. However, the international research team from Barcelona, Bristol, Padua and Milan was still reliant on donor organs. This involved cutting the donor organ to the desired length, removing the donor cells and keeping just the scaffold. Chondrocytes and epithelial cells were grown in a bioreactor using adult stem cells from the recipient. These were then later successfully used to colonise the exterior and interior of the natural scaffold.

Sources: http://www.welt.de/print/die_welt/wissen/article13488162/Die-erste-kuenstliche-Luftroehre.html
http://www.sciencedaily.com/releases/2008/11/081119092939.htm