A handheld system can apply artificial bone grafts immediately on the website of a defect or harm with out the necessity for prior imaging or fabrication.
Researchers demonstrated the know-how by modifying a sizzling glue gun to 3-D print the fabric immediately onto bone fractures in rabbits. As a substitute of utilizing a daily glue stick, they employed a specifically made “bioink,” the crew stories September 5 in System.
The thought was to design a printing system that might be simply outfitted and utilized in medical settings, says biomedical engineer Jung Seung Lee of Sungkyunkwan College in Seoul, South Korea.
“We are able to save time, price and sophisticated procedures [compared with those] required in typical 3-D printing–based mostly bone graft fabrication,” Lee says. Normally, 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 development.
“PCL is [approved by the U.S. Food and Drug Administration] and steadily degrades in our physique over months,” Lee says. “This allows the gradual substitution of the graft with the newly grown bone tissue.” The proportions of the 2 compounds will be adjusted to optimize the fabric’s energy, stiffness and biochemical properties for every use. The researchers additionally integrated antibiotics into the bioink to stop postoperative infections.
The bioink is solely loaded into the printing system and utilized the place wanted. As a result of typical sizzling glue weapons function at temperatures far too excessive for residing tissues, the researchers modified their prototype to limit its warmth. Additionally they adjusted the tip for higher management. Due to the low melting level of PCL, the bioink will be utilized at about 60 levels Celsius, cooling to physique temperature inside 40 seconds. The route, angle and depth of the system will 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 crew 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 extra substances reminiscent of development components, antibiotics and different medication, 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 needed earlier than the know-how could make its method to working rooms.
Deborah Mason, a molecular and cell biologist at Cardiff College in Wales who wasn’t concerned within the research, finds the elevated temperature to be a limitation. “The excessive temperature of the extruded materials is more likely to stress or kill the cells,” she says.
The researchers are working to switch the tip of the system 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 system has the potential to evolve right into a “bone printer pen” for surgeons. However there’s a lengthy method to go for that to occur, she says. For instance, Lee’s printer have to be appropriate with imaging applied sciences and robotic help used throughout surgical procedures. That might make this system “not only a defect-filler however a real regenerative instrument adaptable to totally different surgical specialties.”
