Organoids – tie elements made in the laboratory – build self-contained in organs and open the stem cell therapy a promising path
Also in the Petri dishes follow stem cells of their destiny: they produce different cell types and create complex structures – so-called organoids, small functional units of body bodies. Attempts with moths have shown that these organoids integrate into living tie and repair damaged body organs. The effort for the production of organoids is low, and integration into the body points natural processes – good conditions for successful stem cell therapy.
A heart, completely newly created in the laboratory, contract rhythmically in a bioreactor – a fascinating picture. But if such a heart will ever beat in a person, stands in the stars. Because the effort is enormous: the technical implementation requires pumps, reactors and electrical impulses, and biology must contribute cell-free tie patterns, stem cellraphraparies, and accurately metered growth factors. Billions of cells must work perfectly together to guarantee the work ability of the heart muscle. Contracting movements alone are not enough to maintain a human being.
An alternative approach looks clearly unspectacular at first glance: small cell heaps on the floor of a Petri dish. But in this pile, the potential slumbers to build itself independently in living organs and renew the ties from scratch. Human Dazutun is limited to a minimum, timid technical apparatuses are not by notes.
The cell piles are created when pluripotent stem cells are exposed to the influence of suitable growth factors. Over time, all cell types from which a tie is developing. And more: the cells follow their natural development program and build tie typical structures. In miniature mabric, the functional units of body bodies are created – called organoids or organ buds by scientists.
Organoids continue their development even if they are transplanted into a living animal. Japanese scientists have done pioneering work (Yui et al., Nature Medicine, Marz 2012): They withdraws individual stem cells from the intestine, breeding out of the laboratory organoids and transplanted them in mause whose intestinal mucosa was faded. Within four weeks, the damage had been repaired, the new tie fell seamlessly and the mans went better again. Even after six months – half the life of a mouse – the transplanted cells were still active.
Recently, another Japanese researcher group has achieved similar success with liver organoids (Takebe et al., Nature, July 2013). However, the experimental set up was much more complicated: the researchers mixed reprogrammed stem cells, mesenchymal stem cells (which produces connective tie) and fabric from the umbilical cord – all of human origin. These cells also dominated the art of self-organization: Already after six days organoid structures resulting from researchers called liver buds.
These liver buds were transplanted into the head of mans, as they were observed there with the microscope and could document their growth exactly. The researchers then saw how the human gulf cells associated with the blood circulation of the mouse and see the liver buds within a few days. And this artificial organ was even functional: the transplanted mouse compensated a failure of the natural liver, which usually leads to death within a few days.
Various other self-organizing structures have already been created in the laboratory – pulmonary blades, eye mugs, shield drums and brain attacheDruse about. Even though not all of a therapy are suitable, the use of organoids for the healing of ill fabric remains a forward-looking approach – especially because the main part of the work is done by the stem cells itself.