A handheld machine can apply artificial bone grafts straight on the web site of a defect or damage with out the necessity for prior imaging or fabrication.
Researchers demonstrated the expertise by modifying a sizzling glue gun to 3-D print the fabric straight onto bone fractures in rabbits. As a substitute of utilizing an everyday glue stick, they employed a specifically made “bioink,” the workforce studies September 5 in Gadget.
The thought was to design a printing system that may very well be simply geared up and utilized in scientific settings, says biomedical engineer Jung Seung Lee of Sungkyunkwan College in Seoul, South Korea.
“We will save time, value and complicated procedures [compared with those] required in standard 3-D printing–primarily based bone graft fabrication,” Lee says. Often, scans and measurements of accidents are wanted to construct bonelike implants to precise specs, a course of that may take days and delay surgical procedures.
The bioink consists of two compounds generally used for 3-D printing implants: hydroxyapatite, which helps bone formation pathways and enhances tissue regeneration, and a biocompatible plastic known as polycaprolactone, or PCL, which turns into the scaffold for bone progress.
“PCL is [approved by the U.S. Food and Drug Administration] and progressively degrades in our physique over months,” Lee says. “This permits the gradual substitution of the graft with the newly grown bone tissue.” The proportions of the 2 compounds could be adjusted to optimize the fabric’s energy, stiffness and biochemical properties for every use. The researchers additionally included antibiotics into the bioink to stop postoperative infections.
The bioink is just loaded into the printing machine and utilized the place wanted. As a result of standard sizzling glue weapons function at temperatures far too excessive for residing tissues, the researchers modified their prototype to limit its warmth. In addition they adjusted the tip for higher management. Because of the low melting level of PCL, the bioink could be utilized at about 60 levels Celsius, cooling to physique temperature inside 40 seconds. The path, angle and depth of the machine could be tuned throughout printing, and the entire course of takes just some minutes.
Lee and his colleagues examined the glue gun and bioink on femoral bone fractures in rabbits. Evaluating outcomes from rabbits receiving the remedy with a management group receiving common bone cement, the workforce discovered that the previous group had higher therapeutic and regeneration of bone tissue. The animals additionally confirmed no indicators of an infection throughout the 12 weeks following surgical procedure.
Lee goals to develop this right into a multifunctional printing system, one which has further substances resembling progress elements, antibiotics and different medicine, to be used in orthopedic surgical procedures on people. At this level, he cautions, that is nonetheless a proof of idea. Standardized manufacturing processes, sterilization protocols and additional animal research are all vital earlier than the expertise could make its strategy to working rooms.
Deborah Mason, a molecular and cell biologist at Cardiff College in Wales who wasn’t concerned within the examine, finds the elevated temperature to be a limitation. “The excessive temperature of the extruded materials is prone to stress or kill the cells,” she says.
The researchers are working to change the tip of the machine to make the fabric’s temperature fall sooner proper after extrusion.
Nieves Cubo-Mateo, a biomaterials engineer at Nebrija College in Madrid, says that this machine has the potential to evolve right into a “bone printer pen” for surgeons. However there’s a lengthy strategy to go for that to occur, she says. For instance, Lee’s printer should be appropriate with imaging applied sciences and robotic help used throughout surgical procedures. That will make this machine “not only a defect-filler however a real regenerative software adaptable to completely different surgical specialties.”
