Carlos Solis
Researchers from Sungkyunkwan University and Harvard have modified a standard glue gun to extrude a bone-like material. This device could allow surgeons to repair fractures during operations by printing custom grafts directly onto the injury.
The team tested the device on rabbits and says it could be especially useful for fixing irregularly shaped fractures during surgery.
“As far as I know, there are no known examples in science of using such technology for replacing bone tissue during surgery. This technology is unique,” said biomedical engineer Chung Sin Lee, the lead author of the study, in an interview with Live Science.
Typically, large fractures or other bone defects require bone grafting and metal fixation, such as a rod or plate, to support the broken bone. However, the shape of prefabricated implants often doesn’t match a patient’s specific fracture, which can lead to poor healing and reduced bone stability.
Previous studies have shown that it’s possible to create custom bone grafts using 3D printing for individual patients. But those grafts took significant time and effort to produce and couldn’t be made during surgery.
What do we know about the new technology?
In a study published in the journal Device, Lee and his colleagues detailed a method for 3D printing a bone substitute directly onto a fracture using a glue gun. They successfully tested the technology on rabbits with limb fractures.
In traditional 3D printing, flexible plastic filament is typically heated and shaped layer by layer. Lee and his colleagues made a filament from two materials: polycaprolactone, which has been used before to create biodegradable bone scaffolds, and hydroxyapatite, a calcium mineral that gives bone its structure. The researchers also added two antibiotics to the material to prevent infection; the drugs are released slowly over several weeks.
Using a glue gun modified for low-temperature extrusion of this filament, the researchers first created small shapes that cooled to body temperature within 40 seconds. They then printed 3D bone grafts directly onto fractures and defects during surgeries on New Zealand white rabbits (Oryctolagus cuniculus). The team stabilized the fractures with metal plates and screws, then filled the bone defects with either the specialized bone-like filament or traditional bone cement.
After 12 weeks of monitoring the rabbits’ recovery, the researchers observed better outcomes from the new method. The animals treated with the printed grafts showed greater bone formation and growth than those treated with traditional bone cement.
Chung Sin Lee noted, “Further research on larger animals is necessary before the technology can be tested on humans. We believe this approach could find widespread application in the future of trauma surgery.”
Photo: Unsplash
