3D printing in vivo

Imagine 3D-printing a silicon band aid onto an unborn baby with spina bifida (open ruggetje in Dutch) inside its mother’s womb to prevent life-long handicaps. Is that idea open-minded and out-of-the-box enough? It can be no surprise that the jury of the annual Open Mind grant competition of Technology Foundation STW though so. They awarded the idea with 50.000 euro’s to take it a step further. Last week, Prof.dr. Dick Oepkes (LUMC), Dr. Alex Eggink (Erasmus MC) and Dr. John van den Dobbelsteen (TU Delft) happily accepted the award. “This project is a classic example of Medical Delta collaboration.”

– Medical Delta newsletter, November 2015.


Spina bifida is a birth defect resulting in an incomplete closing of the backbone and membranes around the spinal cord, leaving them very vulnerable to damage. Varying among countries, the condition affects 1 to as much as 19 per 10.000 births. Although the backbone can be surgically closed after birth, most of the damage is already done. The mother’s amniotic fluid damages the baby’s nervous system, especially in the second half of the pregnancy. As a result, children with spina bifida grow up to be severely handicapped in various ways. Oepkes: “We estimate that on average 80% of Dutch parents choose abortion when faced with the spina bifida diagnosis.”

Radically different

In Belgium, a procedure has been devised in which the unborn baby is operated on 5 or 6 months into the pregnancy. The procedure is extremely invasive for the mother, and often too late still to prevent a life of handicaps. “As spina bifida experts we were considering whether or not we needed to import this Belgian procedure to The Netherlands, when we sat down with our biomedical-engineering colleagues at TU Delft. Brainstorming, we discussed that we what we really wanted was something radically different. Something to shield the exposed nervous system of the baby throughout the pregnancy.”

3D printing

The team came up with a watertight silicon sheet temporarily covering the opening in the baby’s backbone. It is to be applied using a minimally invasive procedure. “We want to print it onto the unborn baby through a thin needle. It is well-known that if the diameter of such a needle is kept below 3 mm, the side effects can be minimized. For printing, 2 mm should be sufficient.” To firmly attach the cover onto the growing baby, the team is considering biomimetic approaches such as mussel-inspired surgical glue. Initial testing is to be done using a highly realistic simulation model, after which Oepkes hopes to be able to quickly move to the actual clinical practice.

Open mind

As an instrument to grant unusual research proposals, the STW Open Mind is a rare one. “In most funding schemes, there is a worrying trend to reject high-risk projects. This is an intrinsic consequence of the peer-review procedure. The STW Open Mind jury is much broader, looking at proposals from a different perspective. If we don’t take risks, there’s no innovation.”
So, is the project as risky as it is out-of-the-box? Oepkes: “I’m very confident the principle will work. The risk is in the time we need to get it right. Will our first approach be successful, or will we need to rethink the technical aspects and try again?” He adds: “In a year’s time, we will be able to present a working prototype.”