Rats receive lab-grown esophagi
Ordinarily, when patients require a total or partial replacement of their esophagus, tissue from their own stomach or intestine is used. This doesn't always result in a fully-functioning organ, plus it also involves the surgical removal of the needed material. Now, however, scientists have come a step closer to being able to grow a new esophagus from the patient's own stem cells, and in fact have already done so – with rats.
As part of an international collaboration, researchers at Sweden's Karolinska Institutet started by removing all of the cells from rat esophagi. This just left an empty scaffold of the organ, although one that retained the original's mechanical and chemical properties.
Mesenchymal stem cells were then harvested from the bone marrow of the recipient rats, and seeded into those scaffolds. After three weeks, those cells had adhered to the scaffolds, and were starting to spontaneously differentiate into various types of esophageal cells.
At this point, the scaffolds were implanted into the rats, replacing segments of their existing esophagi. All of the rats survived the procedure, and after two weeks it was noted that the implanted material had regenerated all the major cell and tissue components of the esophagus – these included epithelial cells (which cover the surfaces of bodily structures), muscle cells, blood vessels and nerves.
Because the stem cells that were used came from the recipients' own bodies (unlike the scaffolds), rejection by the immune system was not an issue. The scientists are additionally looking at applying the process to other organs, such as the heart.
Also participating in the study were scientists from the Texas Heart Institute, along with universities in Italy, Russia and Germany. A paper on the research was published today in the journal Nature Communications.