Scientists created the first practical bioresorbable 3D-printed airway stent

Various injuries and diseases cause the main bronchi or the trachea to narrow, which then makes breathing very difficult and people may suffer from the lack of oxygen. Surgical methods can bring quick relief, but metal or silicone stents usually require other surgeries. New study showed that 3D printable bioresorbable airway stents could be the answer in these situations.

These stents are 3D printed using a new light-activated resin. They disappear in the body in 6-7 weeks. Image credit: ETH Zurich

Metal airway stents have to be surgically removed, which is another invasive surgery, while silicone ones sometimes move away from the implant site, which also requires a surgery to fix. Scientists at the ETH Zurich revealed that digital light processing 3D printing technology using light-​sensitive resins allows making bioresorbable airway stents which can be left alone in the patient’s body. In some time these implants are simply absorbed by a person’s body and disappear entirely without the need of new surgeries.

Digital light processing is not new. However, up until now it could only produce very brittle and stiff  objects using biodegradable materials. Scientists had to develop a special new resin that would be elastic and bioresorbable for the new generation of implantable airway stents. This light-​sensitive resin is based on two different macromonomers that link together when exposed to UV light. This resin does have its disadvantages. At room temperature it happens to be too vicious, which means that scientists had to work it at temperatures of 70-90 degrees Celsius. Special instruments are also needed to implant this stent as it has to be folded but cannot have any kinks.

Researchers already performed some tests on rabbits to show that 3D printed stents are safe. They were able to show that these implants are biocompatible and only take 6-7 weeks to be reabsorbed by the body. Only 10 weeks after the surgery you couldn’t detect the stent using X-ray images. Jean-​Christophe Leroux, one of the authors of the study, said: “This promising development opens up prospects for the rapid production of customised medical implants and devices that need to be very precise, elastic and degradable in the body”.

There are some challenges left for this study. First of all, scientists need to figure out a way to make the insertion of the stents as gentle as possible. Secondly, they need to scale the manufacturing process up, because now these 3D printed stents can only be made in a laboratory setting. This means that we simply couldn’t make enough of them.

These challenges will definitely be overcome with time. The result will be a relatively inexpensive stent which does the job while also removing the need for one extra surgery. Furthermore, hopefully this study will lead to a wider use of these biodegradable resins for other kinds of implants.


Source: ETH Zurich

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