Scientists in Japan have developed a new method which could help to reduce the impact of myelomeningocele, the most severe form of spina bifida, by converting cells from the amniotic fluid into skin cells to make a personalised skin graft.
Myelomeningocele is a rare condition that occurs during the development of the foetus, where a structure called the neural tube fails to close properly. The neural tube eventually forms the spinal cord, the long bundle of nerves that carries messages from the brain to the body. The failure of the neural tube to close means the spinal cord protrudes outside the body, which can cause severe neurological problems, disability or even paralysis.
A recent trial has concluded that the most effective treatment for myelomeningocele is pre-natal surgery to the developing foetus in the uterus – however, the invasive nature of this surgery does carry significant risks for baby and mother.
Scientists led by Akihiro Umezawa, from the National Center for Child Health and Development in Tokyo, have developed a different approach: to create a miniature skin graft to patch up the exposed neural tube.
The researchers took cells that were floating in the amniotic fluid, and converted them into induced pluripotent stem cells (iPSCs) – reprogramming them so that they are able to theoretically make any cell type in the body. Using these iPSCs, the researchers were able to make a multi-layer skin patch.
To test the potential for the skin patch in treating myelomeningocele, pregnant rats were given chemicals so that the developing embryos had neural tube defects. Using the skin graft, the researchers were able to patch up the defects in 12 of the 20 rat embryos operated on. The researchers finally showed that the skin graft had integrated well in the rats two days after birth.
More research is needed to understand the effectiveness of the skin grafts in the long-term. Critically, longer studies in larger animals are needed to understand whether such a procedure can not only cover up a myelomeningocele but also halt or reverse the long-term neurological and physical disabilities it can cause. One option the researchers are exploring is that the graft could be improved to include nerve cells as well as skin, to help restore some of the function of the damage to the spinal cord.
However, the scientists are optimistic that this technique could become an effective treatment for myelomeningocele in the future. After diagnosing a neural tube defect, cells would be taken from the amniotic fluid, iPSCs generated from these, and then used to create a personalised skin patch that can be grafted onto the developing foetus with surgery in the uterus. Since the skin patch has been created from the child’s own cells, the risk that it will be rejected later by the immune system is low. The researchers estimate that the whole process, from collecting cells from the amniotic fluid to a skin patch ready for transfer onto an embryo, currently takes about 14 weeks, which is just within a reasonable timeframe to make it a feasible treatment for unborn babies.