A number of research groups are working towards growing intestinal tissue, but this area of the field of tissue engineering is still at the exploratory stage, with no-one much past the level of creating small sections of usefully structured tissue. Getting the structure right is one of the challenging parts of tissue engineering; every organ is different and requires the development of its own particular recipe and methodology.
Tissue-engineered small intestine (TESI) grows from stem cells contained in the intestine and offers a promising treatment for short bowel syndrome (SBS), a major cause of intestinal failure. TESI may one day offer a therapeutic alternative to the current standard treatment, which is intestinal transplantation, and could potentially solve its largest challenges - donor shortage and the need for lifelong immunosuppression. Scientists had previously shown that TESI could be generated from human small intestine donor tissue implanted into immunocompromised mice. However, in those initial studies - published in 2011 - only basic components of the intestine were identified. For clinical relevance, it remained necessary to more fully investigate intact components of function such as the ability to form a healthy barrier while still absorbing nutrition or specific mechanisms of electrolyte exchange.
The new study determined that mouse TESI is highly similar to the TESI derived from human cells, and that both contain important building blocks such as the stem and progenitor cells that will continue to regenerate the intestine as a living tissue replacement. And these cells are found within the engineered tissue in specific locations and in close proximity to other specialized cells that are known to be necessary in healthy human intestine for a fully functioning organ. "We have shown that we can grow tissue-engineered small intestine that is more complex than other stem cell or progenitor cell models that are currently used to study intestinal regeneration and disease, and proven it to be fully functional as it develops from human cells. Demonstrating the functional capacity of this tissue-engineered intestine is a necessary milestone on our path toward one day helping patients with intestinal failure."