Researchers have successfully replaced 20 per cent of a rat's oesophagus with an artificial organ grown in a lab.
Lab-grown replacement oesophagi are growing closer to clinical implementation: an international team of researchers, led by Professor Paolo Macchiarini at the Karolinska Institutet in Sweden, have managed to successfully grow a working oesophagus in a lab, then implant it in a rat.
To grow the section of oesophagus, the team took the oesophagus of a rat and stripped it of its cellular material, leaving behind a scaffolding of clean tissue. This was then tested for strength and function before being re-seeded with bone marrow mesenchymal stem cells -- stem cells that can grow into a variety of other cells -- harvested from the rats on which the final operation was to be performed. Using the host's own cells ensures a very low rate of rejection and eliminates the need for immunosuppressant drugs.
Within three weeks, the cells had attached to the scaffold and had started to show organ-specific characteristics. The researchers then removed 20 per cent of the healthy rat's oesophagus and replaced it with the lab-grown organ. The rats were then closely monitored for a period of two weeks. Although initially the rats were immobile, they recovered quickly and showed no signs of pain or impairment.
Tractography image of the decellularised oesophagus (left), showing fewer tracts than the native oesophagus (right).
Additionally, the new section of oesophagus started to show blood vessel and muscle tissue growth, and the rats gained weight quickly post-surgery.
"We believe that these very promising findings represent major advances towards the clinical translation of tissue engineered oesophagi," Professor Macchiarini said.
Although lab-grown organs have been used in a clinical setting before -- a urinary bladder, trachea and blood vessels -- oesophageal tissue has thus far proven difficult to replace. This research could prove a great boon to patients suffering oesophageal cancer, traumatic disorders, or birth defects, and provide a solution that could restore full digestive function.
The full study, "Experimental orthotopic transplantation of a tissue-engineered oesophagus in rats", can be read online in the journal Nature.