A few years ago, researchers at Northeastern University invented a new way of 3-D printing strong, flexible materials in industrial quantities. Now, federal health officials are asking them to shrink the process down small enough to make custom medical devices for newborns.
The technology was developed in the lab of Randall Erb, an engineering professor at Northeastern. Erb and graduate student Joshua Martin figured out how to combine composite materials made of plastics and ceramics with a special magnetic coating.
That coating allowed the researchers to zap the liquid composite with a magnetic field, ensuring that individual fibers in the composite were in the strongest arrangement possible — and making the composites strong enough for industrial use.
“In general, they’re very strong and very lightweight. We’re replacing a lot of our planes and trains, and cars with them,” Erb said of the composite materials. “But if we don’t orient [the fibers], they go from strong to weak.”
Once the composite is in the proper alignment, the researchers are able to use a laser beam to harden it, layer by layer, into a solid form with a 3-D printer.
At first, Erb used the process to make strong, flexible composites in large sheets for industrial construction. Now, with a $225,000 grant from the National Institutes of Health, he is trying to use the system to print much smaller objects: custom catheters for newborns who need surgery or other lifesaving medical help.
Standard medical catheters are typically fine for use on adults, Erb said, simply because their veins are larger and more robust. But a newborn’s small, delicate body is more susceptible to damage from a catheter that is too large or too long, he said.
The hope is that doctors could scan the vein of a neonatal patient to determine its size and shape, and use the data and a 3-D printer to create a special catheter that would precisely fit the diameter of the tiny vein and be just long enough to work properly without causing damage.
The catheters, Erb said, are “very small and delicate systems, but they also have to be very durable and strong.”
This is just one of many ways researchers are trying to adapt 3-D printing for medical purposes. Boston Children’s Hospital has embraced the technology as a way to allow doctors to study structures in patients’ bodies before surgery, giving them extremely accurate mockups.
The Food and Drug Administration has already approved some 3-D printed medical devices, including pills that carry liquid medication and prosthetic plates for repairing damaged skulls.
Michael Leinauer, a lawyer who specializes in medical devices at the firm IceMiller, said that so far, the FDA’s review of 3-D printed devices, and the way they are made, has not created extra hurdles.
“There really isn’t any extra consideration,” said Leinauer. “They’re just running the same tests and asking the same questions that they would for any other medical device, and there are a handful of medical devices that have been approved.”