Printing a Future in 4D

Two decades ago, if someone had said that scientists would be able to use a printer to build human organs layer-by-layer, or to make 10 houses in one day, or to send a digital wrench to the International Space Station, you would have called them a crazy person. But as the limitations on our reality continue to waver and acquiesce to an astounding array of science fiction-worthy technologies, it seems that fewer and fewer fantasies lie beyond our grasp.

Now, a team of researchers from the University of Michigan has succeeded in taking the already-revolutionary process one step further by incorporating the fourth dimension: time.

One of the greatest medical implementations of 3D printing has been the creation of patient-specific devices such as hearing aids, prosthetic limbs, dental implants, and stents. These devices, however, are structurally rigid and incapable of adapting to suit a growing human body, precluding children from benefitting from 3D-printed implants.

The University of Michigan team, led by Dr. Glenn Green, implanted dynamic, biodegradable, 3D-printed airway splints in three infant boys who suffered from a life-threatening respiratory condition called tracheobronchomalacia (TBM). Over time, the splints will expand with the boys’ airways and eventually dissolve in the body, by which point they will no longer be necessary.

TBM causes the constant collapse of the windpipe and main airways into the lungs. One of the boys who received his implant suffered so severely that he could not keep food in his belly without lapsing into respiratory failure and cardiac arrest. The other boys’ conditions were equally grim.

“It is hard to convey how very sick these children were,” said Green. “All of these children had been in the intensive care unit for months. During that time to stay alive, they required heavy sedation narcotics and even paralytics. They all had tracheostomies where a breathing tube was placed through their necks and were on artificial ventilators.”

The team generated custom 3D models of the boys’ airways using images from CT scans. The cost of actually printing the splints was only $10.

Three years have passed since the boys received their implants. Today, each owes his life to the surgery.

“Before this procedure, babies with severe tracheobronchomalacia had little chance of surviving,” said Green. “Today, our first patient, Kaiba, is an active, healthy 3-year-old in preschool with a bright future. The device worked better than we could have ever imagined.”

The team is currently organizing a clinical trial with the FDA that would test 4D biomaterials for 30 children with less severe cases of TBM.

Feature photo courtesy of Wikimedia Commons.