An Exciting Time for Regenerative Medicine

Previous transplants of tissue-engineered tracheas have been performed, but the tracheas used on those occasions were taken from organ donors and then reseeded with the patients’ own stem cells. In 2011, my colleagues and I performed an operation that gave a 36-year old male patient a new trachea made from a synthetic scaffold seeded with his own stem cells. The patient had been suffering from late-stage tracheal cancer. Despite maximum treatment with radiation therapy, the tumor had reached approximately 6 cm in length and was extending to the main bronchus. It was progressing and almost completely blocked the trachea. No suitable donor windpipe was available, so transplantation of a synthetic tissue-engineered trachea was performed as the last possible option for the patient. The patient made a full recovery and was discharged from the hospital following the operation. Synthetic Tissue-Engineered Trachea The international team that completed the procedure also involved Prof. Alexander Seifalian, PhD, from University College London, who designed and built the nanocomposite tracheal scaffold, and Harvard Bioscience, which produced a specifically designed, shoebox-sized bioreactor that was used to seed the scaffold with the patient’s own stem cells. The cells were grown on the scaffold inside the bioreactor for about 2 days. The scaffold was rotated while its surface was soaked with stem cells obtained from a bone marrow biopsy from the patient’s hip. The patient’s stem cells settled into the pores within the scaffold and began to grow into each other, slowly transforming from individual cells into genuine tissue. A few days after implantation of the new trachea, the patient’s own blood vessels actually started to grow into...