3D Printing of Antibiotic Infused Implants – Patent Recently Published

Every year millions of people become ill, or even worse, die because of infections related to surgeries and implants. Antibiotics for years have been a saving grace within the medical community, however, oftentimes the proper dosage can not safely target the area which needs it the most. Orally ingesting antibiotics works in many cases, but sometimes the medication needs to be locally targeted to a particular area. For instance, certain infections require a direct injection of the medication within the infected area. They do this oftentimes for prostate infections, as well as other hard to manage localized infections, but it doesn’t always work as intended.

One company called Orthopaedic Innovation Center Inc, based in Winnipeg, Manitoba, Canada, has come up with a potential solution to this problem. Just recently a patent application was published (publication number WO2014075185 A1), which Orthopaedic Innovation Center Inc. applied for. The patent is for a process in which antimicrobial articles for implants are produced by additive manufacturing techniques.

One of the objectives of this patent is to 3D print implantable objects which have been infused with antibiotics or other antimicrobial drugs within the 3D printing process, as you can read in the abstract below:

“An antibiotic-eluting article for implantation into a mammalian subject, produced by an additive manufacturing process wherein a polymeric material is concurrently deposited with a selected antibiotic. The additive manufacturing process may be a fused deposition modeling process, a selective laser sintering process, a selective heat sintering process, a digital light processing process, or a stereolithography process. The antibiotic-eluting article may be temporary or permanent orthopaedic skeletal component, an orthopaedic articulating joint replacement component, and/or an external hard-shell casing for an implantable device.”

The patent covers several methods of additive manufacturing, including FDM and SLS technologies. One example of how such a process would work via an FDM (fused deposition modeling) technique would be as follows. Antibiotics could be mixed with PLA or PCL polymer pellets during the process of manufacturing filament for an FDM 3d printer. PLA and PCL are resorbable materials, meaning that over time they will break down in the mammalian body. Doctors would be able to choose the percentage of antibiotics by weight during the filament creation process. They would also have the option of adding in more than one antibiotic to the mixture. Once the filament is ready, an implant can be printed in any shape or size accordingly.

The second technique covered by this patent application is one in which ordinary PLA of PCL filament is used within a specialized FDM printer. As the printer melts and extruders the filament an antimicrobial powder or liquid could simultaneously be extruded from the print nozzle, infusing the melted plastic with the drugs.

The same basic techniques could be used with the other printing methods. For instance, researchers could use a selective laser sintering method, mixing powdered plastics, metals, ceramics, or glass material with antimicrobial agents within the the granular bed, as a laser melts the material together in a given form.  The implants could then be placed within the human body to eliminate or reduce the risk of infection following an injury or surgery of some kind.

The patent also covers the inclusion of bone growth material within each print, both with or without an anticirobial agent present. Such a process could allow for the simultaneous action of both infection fighting and bone growth within an implant, making such technology suitable for surgeries involving the skeleton. Such implants could also play vital roles in a slew of other medical applications, including that of chemotherapy, infusion pumps, pace makers and more, according to the following patent claim:

“The antibiotic-eluting article of claim 17, wherein the article is one of a cardiac pacemaker, a spinal cord stimulator, a neurostimulation system, an intrathecal drug pump for delivery of medicants into the spinal fluid, and infusion pump for delivery of chemotherapeutics and/or anti-spasmodics, an insulin pump, an osmotic pump, and a heparin pump. The antibiotic-eluting article of claim 1, wherein the article is an implantable dental prosthesis or a replacement tooth component. “

Without a doubt the medical community will see major changes thanks to additive manufacturing technologies. We are truly on the cusp of dozens of groundbreaking discoveries, which will save many lives in the years to come.  Whether this patent will be awarded or not doesn’t matter much, as such methodology will begin to take form either way.

Let us know what you think about this possible use of 3D printing for infection fighting in the 3D printed antimicrobial forum thread on 3DPB.com.