Researchers are making progress towards a methodology for growing intestinal tissues from a patient's cells. As is usually the case in this sort of work, the first results are not intended for use in therapies, but will instead provide raw materials that can help to speed further research:
Researchers have successfully transplanted "organoids" of functioning human intestinal tissue grown from pluripotent stem cells in a lab dish into mice. Through additional translational research the findings could eventually lead to bioengineering personalized human intestinal tissue to treat gastrointestinal diseases. "This provides a new way to study the many diseases and conditions that can cause intestinal failure, from genetic disorders appearing at birth to conditions that strike later in life, such as cancer and Crohn's disease. These studies also advance the longer-term goal of growing tissues that can replace damaged human intestine."
The scientists used induced pluripotent stem cells (iPSCs) - which can become any tissue type in the body - to generate the intestinal organoids. The team converted adult cells drawn from skin and blood samples into "blank" iPSCs, then placed the stem cells into a specific molecular cocktail so they would form intestinal organoids. The human organoids were then engrafted into the capsule of the kidney of a mouse, providing a necessary blood supply that allowed the organoid cells to grow into fully mature human intestinal tissue. The researchers noted that this step represents a major sign of progress for a line of regenerative medicine that scientists worldwide have been working for several years to develop.
Mice used in the study were genetically engineered so their immune systems would accept the introduction of human tissues. The grafting procedure required delicate surgery at a microscopic level, according to researchers. But once attached to a mouse's kidney, the study found that the cells grow and multiply on their own. Each mouse in the study produced significant amounts of fully functional, fully human intestine.