Why PEEK is becoming increasingly popular in the medical sector
John Devine, medical business director at Invibio Biomaterial Solutions, a subsidiary of Victrex, spoke with MPN to explain the accelerating role of both non-implantable and implantable grades of PolyEther Ether Ketone (PEEK) polymers.
What are the major trends you anticipate for drug-delivery devices within the future?
We see a key trend towards connected drug-delivery devices or e-devices, such as insulin pumps which are used in the treatment of diabetes. E-devices have smaller dimensions compared to non-e-devices and are miniaturised to precise tolerances, resulting in reduced weight and easier use. When complex electronic components must be embedded, they too are designed to be compact with the lowest possible wall thickness.
Is there a place for PEEK within the future of the medical sector?
Based on properties such as PEEK’s low moisture absorption and stability as a dielectric, PEEK has a long history of use in numerous applications. Polymer solutions provider, Victrex Group has acquired knowledge in design synergies and cross-applications, which allows us to address both the design and manufacturing challenges of these devices.
Can you expand on the properties of implantable PEEK and how these can benefit applications?
Invibio’s PEEK-OPTIMA is biocompatible, which is an absolute requirement for implantable applications. PEEK is inherently radiolucent, so medical imaging by X-ray, computerised tomography scan and magnetic resonance imaging, are artefact-free and therefore facilitate analysis and diagnosis with unobstructed views. Furthermore, it can be sterilised using standard processes such as gamma and e-beam radiation and steam sterilisation.
In terms of mechanics, given that the polymer can be processed by injection moulding or machining, very small parts with accurate dimensions and tight tolerances can be produced and assembled, making it a competitive option for drug-delivery applications. PEEK is also chemically inert, and this stability allows it to be in contact with aggressive chemicals or drugs without interactions, whether PEEK is present in the form of packaging or as a conduit. If mechanical strength is required, then PEEK parts can be designed to meet this key engineering requirement. Some companies are focused on subcutaneous drug delivery devices to make it easier for patients and this trend may require materials which are known to be safe for long-term implantation. (1)
What are the main benefits of using PEEK for non-implantable applications?
For non-implantable Victrex PEEK, the potential range of applications is quite broad and includes injection-pen/auto-injector and wearable segments. For these devices, the solutions must be reliable and safe as well as accurately dispense the right amount of drug at the right location at the right time. The requirement to be patient-friendly and low cost is important for these types of applications in order to address any treatment adherence challenges.
PEEK can play a key role thanks to its high mechanical strength, where it exhibits stiffness, along with impact and fatigue resistance, and a low frictional ratio. Additionally, it is chemically stable at both high and low temperatures, remaining non-leachable and non-extractable. In terms of processability, it can be machined and injected to precisely accurate dimensions and tolerances. One beneficial consequence could be the opportunity to reduce the number of parts and components that comprise the device.
Conclusion
PEEK has many attractive properties for the medical sector, and the choice of PEEK can help to reduce the number of parts by integrating functionality, reducing the size and weight of devices, and streamlining the manufacturing processes. As a result, PEEK has the potential to drive cost savings for the manufacturer.
References
- Sci Transl Med. 2017 Aug 30;9(405). pii: eaaf9166. doi: 10.1126/scitranslmed.aaf9166.Subcutaneous drug delivery: An evolving enterprise