Spina bifida surgery carried out in uterus using stem cells from placenta

Multipotent stem cells obtained from the placenta have been used to successfully treat spina bifida during fetal surgery.

Three babies have now been born after receiving this novel treatment, which uses the stem cells to grow a patch that goes over the spinal cord of the fetus, as part of pioneering research at the University of California, Davis. The trial launched in spring 2021 and is led by Professor Diana Farmer who aims to treat 35 patients in total.

'It's a four-day process to make the stem cell patch,' said Dr Priya Kumar, lead scientist to the team that creates the stem cell patches and delivers them to the operating room 'The time we pull out the cell, the time we seed on the scaffold, and the time we deliver, is all critical.'

Stem cell patches have been used previously to repair and restore pregnancy complications (see BioNews 626) and shown to repair and restore damaged tissue, beyond what surgery can accomplish alone (see BioNews 1123). Now this research team has gone further by using a stem cell patch method during the fetal surgery.

Preliminary work took place in lambs, and then English bulldogs. The research team proved that placenta-derived mesenchymal cells can be held in place with a biomaterial scaffold during prenatal surgery, which then helped the infant animals with spina bifida walk without noticeable disability.

Spina bifida occurs when spinal tissue fails to fuse properly during the early stages of pregnancy. Untreated, the birth defect can lead to range of lifelong issues, including problems with mobility such as leg paralysis. While surgery performed after birth can help reduce some of the effects, surgery before birth can prevent or lessen the severity of the fetus's spinal damage, which worsens over the course of pregnancy.

For the first human trial, fetal surgery was performed at 26 weeks gestation. Mesenchymal stem cells from placental tissue manufactured by the team were placed onto a material that mimics the spinal cord outer membrane and put directly over the exposed spinal cord of the fetus. At 36 weeks gestation a healthy baby girl was successfully delivered via c-section.

'It was very clear the minute she was born that she was kicking her legs… and wiggling her toes!' exclaimed Professor Farmer.

However, the team said that there is still a lot to be learned during this safety phase of the trial. The babies will be monitored until they are six years old, with a key check-up happening at 30 months to see if they are walking and potty training. Nevertheless, the success so far from this research may provide hope in the future for prenatal treatment of the thousands of children who are affected by spina bifida each year.