Researchers Develop Method for 3D Printing Antibiotic Beads on Desktop 3D Printer
Most of the medical stories we’ve covered involve hi-tech, expensive 3D printing equipment with accompanying bio-compatible materials. And, though laser sintering machines may be on the verge of dropping in price, they’re still nowhere near the low cost of the desktop 3D printers that have become popular in the past few years. As a result, 3D printed, patient-specific devices would have difficulty proliferating without a low-cost solution. Luckily, researchers at Louisiana Tech University have developed technique for utilizing a MakerBot Replicator 2 to produce custom medical implants embedded with antibacterial, chemotherapeutic medicines for smart drug delivery.
As it stands, antibiotic implants, called “beads”, are usually composted of bone cements, a type of Plexiglas, that are mixed by hand by surgeons during a surgical procedure. Because they cannot be absorbed by the body, surgeons have to perform further operations to remove the beads. A team of doctoral students and research faculty from the Louisiana Tech University’s biomedical engineering and nanosystems engineering program have designed their own filament extruding system, capable of manufacturing medical-grade 3D printing filaments that may one day make the traditional bead making process obsolete.
Jeffery Weisman, a doctoral student working in the lab of Dr. David K. Mills in the biological sciences and biomedical engineering program, teamed up with nanosystems engineering doctoral candidate Connor Nicholson to create their extruder and filament, in tandem with Dr. mills and Extrusionbot, LLC of Phoenix, Arizona. The team was able to create their own type of 3D printing filament made from a bioplastic that could be reabsorbed by the human body, without any further surgical procedures.
Dr. Mills describes how the project came about, saying, “We had been working on several applications of 3D printing. Several students in my lab including Jeff and Connor, who was a guest researcher from Dr. Wilson’s lab, had been working with colleagues for some time. I sent an email to them and asked them the question, ‘Do you think it would be possible to print antibiotic beads using some kind of PMMA or other absorbable material?’”
Weisman explains, “After identifying the usefulness of the 3D printers, we realized there was an opportunity for rapid prototyping using this fabrication method. Through the addition of nanoparticles and/or other additives, this technology becomes much more viable using a common 3D printing material that is already biocompatible. The material can be loaded with antibiotics or other medicinal compounds, and the implant can be naturally broken down by the body over time.”
By 3D printing beads with the material, the Louisiana Tech researchers can create antibiotic implants that are partially hollow, allowing for a greater control over the device’s drug deliver by increasing the beads surface area. At the same time, localized treatment with the beads can help prevent large doses of medication applied to the entire body, which can lead to harm to the liver and kidneys.
Dr. Mills goes on to explain how the team’s method for fabricating their material enables greater access to such technology, “Currently, embedding of additives in plastic requires industrial-scale facilities to ensure proper dispersion throughout the extruded plastic. Our method enables dispersion on a tabletop scale, allowing researchers to easily customize additives to the desired levels. There are not even any industrial processes for antibiotics or special drug delivery as injection molding currently focuses more on colorants and cosmetic properties.”
The new material developed by the team has the great benefit of being printable on low-cost 3D printers, with Weisman saying, “One of the greatest benefits of this technology is that it can be done using any consumer printer and can be used anywhere in the world.” He believes that, with their filament, hospital pharmacists and doctors will have a new technique for delivering medication.
As far as the team knows, no one else has developed such a way to fabricate antibiotic implants. Mills concludes, “It is truly novel and a worldwide first to be 3D printing custom devices with antibiotics and chemotherapeutics.”