
Osteoconductive Filament Developed for 3D Printed Implants
“No other application field showcases more the classic advantages of 3D printing, such as individualization or design freedom, than medical technology,” says Marc Knebel, Head of Medical Systems at Evonik.
Evonik is a specialty chemical company developing biomaterials that serve as metal-free alternatives to traditional bone implants. Evonik’s VESTAKEEP product line includes an osteoconductive polyether ether ketone (PEEK) – a biostable polymer having similar mechanical properties to the human bone, which promotes osteointegration. According to Evonik, combining the PEEK material with the functional additive biphasic calcium phosphate (BCP) accelerates fusion at the bone-implant boundary, allowing bone cells to adhere to the implant more quickly. Unlike traditional titanium implants, Evonik claims that its PEEK-based polymer does not produce any unwanted artifacts in medical imaging processes such as X-ray or MRI. Further, Evonik indicates that the BCP additive provides a natural shadow allowing for accurate implant placement and observation of the fusion process.
Evonik is now set to add a new 3D-printable version of the osteoconductive PEEK material to their Fusion product line. The VESTAKEEP iC4800 3DF PEEK filament can be processed using the common extrusion-based 3D printing technology known as fused filament fabrication (FFF), in which a 3D printer releases a raw material out of a nozzle or orifice to build an object layer by layer. The PEEK filament, which has a diameter of 1.75 mm, is wound onto 250- or 500-gram spools suited for standard FFF 3D printers. Evonik reports that customer feedback and tests carried out on various 3D printers confirm the processability of the new filament.
Further, Evonik indicates that this osteoconductive filament is specially designed such that the functional additives are available directly on the surface of the 3D printed implant without film formation. This eliminates the need for additional post-processing steps, which Evonik touts as a novelty for osteo-integrative PEEK biomaterials.
The original VESTAKEEP Fusion product is available in granulate form and capable of being milled, compression molded, extruded and injection molded. The addition of this 3D printable filament expands the range of applications for osteoconductive implants even further, and allows for easier and improved customization of implants for patients.
Evonik plans to present the new product for the first time at the American Academy of Orthopaedic Surgeons (AAOS) trade show in Chicago later this month (March 2022).
FDA Provides Guidance on 3D-Printed Medical Device Products
The U.S. Food and Drug Administration released finalized guidance regarding 3D printing in medical devices. The guidance document, which issued on December 5, 2017, is based on the FDA’s review of more than 100 devices currently on the market that are manufactured using 3D printers. Importantly, many of these devices can be tailored to fit a specific patient’s anatomy. For example, the FDA has reviewed 3D-printed knee replacements and implants for facial reconstruction.
The new guidance gives the FDA’s recommendations regarding the content of FDA submissions, device testing, and manufacturing considerations for 3D printed devices.
In a press release announcing the new guidance, FDA Commissioner Scott Gottlieb stated:
[This guidance] will help manufacturers bring their innovations to market more efficiently by providing a transparent process for future submissions and making sure our regulatory approach is properly tailored to the unique opportunities and challenges posed by this promising new technology.
The new guidance comes on the heels of recent FDA approvals for several 3D-printed devices, including Medicrea’s 3D-printed titanium interbody device for spinal surgery. The FDA also recently approved a 3D-printed drug tablet, the epilepsy drug Spritam, marketed by Aprecia Pharmaceuticals.
Commissioner Gottlieb further opined that “3D printing is certain to alter the daily practice of medicine where patients will be treated with medical products manufactured specifically for them.” He noted that 3D printing could one day be used to treat burn patients by printing their own skin cells onto their wounds or used to grow replacement organs.
Commissioner Gottlieb noted, however, that the FDA’s new guidance is intended only “to provide the FDA’s initial thoughts on an emerging technology” and that the FDA’s recommendations likely will change as 3D-printing technology develops.