Randall Erb and colleagues from Northeastern’s Department of Mechanical and Industrial Engineering have pioneered a new 3D printing method to make patient-specific medical devices.
The method, which appeared in the October 23rd issue of Nature Communications, uses magnetic fields to shape composite materials in a 3D printer. The printer mixes plastics and ceramics into patient-specific products, which could mean an end to ill-fitting medical equipment for infants.
A Prevalent Problem
In the United States alone, almost 500,000 babies are born premature every year. Many people are familiar with photos of premature infants as the struggle to grow and survive in the neonatal care units. Some of the tiny infants weigh hardly more than a pound, and are covered with plastic tubes and catheters that deliver the vital nutrients, fluid, oxygen and medications they need to survive.
Despite the large number of premature babies, modern catheters still only come in standard shapes and sizes, making them ill-suited for these tiny babies.
An Innovative Solution
“With neonatal care, each baby is a different size, each baby has a different set of problems,” Erb to Northeastern News. “If you can print a catheter whose geometry is specific to the individual patient, you can insert it up to a certain critical spot, you can avoid puncturing veins, and you can expedite delivery of the contents.”
The use of composite materials in 3D printing is not new, but this method is novel because it allows the researchers to take control of the arrangement of the ceramic fibers. This ability allows them to determine the mechanical properties of the material.
Such control is critically important when manufacturing materials with complicated architectures, which is definitely the case with small, custom biomedical devices. When crafting a patient-specific device, all components must be reinforced with ceramic fibers to ensure durability. The fibers must fill every corner, curve and hole in the device.
“I believe our research is opening a new frontier in materials-science research,” said Joshua Martin, a PhD student on the project.
A Lesson from Nature
“We are following nature’s lead,” said Martin, “by taking really simple building blocks but organizing them in a fashion that results in really impressive mechanical properties.”
The new method in many ways mimics the formation of other natural composites such as bones or trees. The human bone contains calcium phosphate fibers that appear around the holes for blood vessels, enabling the bone’s strength and durability.
“These are the sorts of architectures that we are now producing synthetically,” said Erb. “Another of our goals is to use calcium phosphate fibers and biocompatible plastics to design surgical implants.”
The research received one of the National Institutes of Health’s Small Business Technology Transfer grants to work on developing neonatal catheters.