Back in March, BioNews Texas Science columnist Irlanda J. Espinosa published an article on how researchers at the University of Texas Medical Branch in Galveston had successfully grown viable lungs in laboratory. Now, researchers from the Texas Heart Institute have collaborated with a team of scientists at Karolinska Institutet in Sweden, led by Dr. Paolo Macchiarini, have managed to use tissue engineering to craft natural esophagi, which, along with bone marrow stem cells, has been successfully transplanted into rats. The new breakthrough could mean that the next frontier of being able to regenerate an esophagus has in fact been reached.
The landmark study, which was recently published in Nature Communications, revealed that not only was the generation of the esophagi, but also that the new organs, once transplanted, remained patent within the body, leading to a natural, healthy regeneration of muscles, nerves, blood vessels, and epithelial cells.
Thus far, in addition to the lung generation program at UTMB, researchers have managed to produce other organs in the lab as well, including trachea (perhaps the most successfully crafted tissue generation), a urinary bladder, and blood vessels, which have also been proven as viable clinically. However, replacing the esophagus has until this point remained elusive, given the dynamic nature of the organ.
Similar to the approach used in crafting lungs, researchers created scaffolds for the generation of the new esophagi by removing all of the cells from removed specimens. With only the mechanical and chemical properties of the organ preserved, researchers effectively reseeded the scaffolds with bone marrow cells. Because the bone marrow is known to have a low immunogenicity, they adhere well to the scaffold and minimize any risk of an immune reaction or graft rejection, all while eliminating any need for the prescription of immunosuppressive drugs after transplantation. In only three weeks, the bone marrow cells adhered to the scaffold and took on the organ-specific features of an esophagus.
The result of the study revealed that all of the rats who received the transplant had survived the procedure after two weeks, and that epithelium, blood vessels, muscle cells and nerves had all begun to regenerate around the new organ. Paolo Macchiarini, Director of Advanced center for translational regenerative medicine (ACTREM) at Karolinska Institutet, sees these early findings as truly promising: “We believe that these very promising findings represent major advances towards the clinical translation of tissue engineered esophagi.”
Current medical procedures that remove diseased esophagi leave patients with a compromised digestive system that effectively reduces quality of life and increases morbidity. If scientists are able to perform successful esophagus transplantations using lab-generated organs, however, the need for esophagectomy surgeries could be greatly reduced.