How are PEEK materials shaping the future of medical devices?

Wissem Chambazi, global communications officer at Solvay, discusses different PEEK materials, their benefits and what they are used for.

The medical and healthcare market has been growing significantly in the last decades. New products and innovations are being generated almost on a daily basis, and to satisfy the new demands, the selection of appropriate materials have become more and more crucial to deliver desired performances. Requirements such as high mechanical properties, enhanced biocompatibility, resistance to repeated sterilisation and chemical resistance to disinfectants. All of these are often combined with complex part design, special colour requirements and high aesthetics. Within this space, plastic materials became very popular and started replacing metal in many applications. However, only a few plastics are eligible for applications that require higher performance than those delivered by commodity materials such as PP, PVC, PE, etc. PolyEtherEtherKetone (PEEK) is one of these high-performance plastics that is suitable for use in the medical and healthcare sector.  

KetaSpire PEEK 

KetaSpire polyetheretherketone is widely considered one of the highest performing, semi-crystalline thermoplastics available on the market today. Its chemistry offers a combination of exceptional properties that allow KetaSpire PEEK to withstand the harshest conditions and effectively replace metal in some of the most severe end-use environments such as those employed in the medical sector during sterilisation and disinfection procedures.  

Solvay offers KetaSpire PEEK in multiple versions, which include unreinforced, glass-reinforced, carbon-reinforced and lubricated grades. The versatility of the material makes it suitable for multiple processing techniques such as extrusion, injection moulding and coating. Most grades are also biocompatible and can be therefore put in direct contact with bodily fluids for less than 24 hours. It is compatible with a variety of sterilisation methods, including EtO sterilisation, gamma irradiation, hydrogen peroxide and steam sterilisation. In particular, 1000+ steam sterilisation cycles can be applied to components made of KetaSpire PEEK without any significant alteration in performance.  

Chemical resistance, high mechanical strength, fatigue resistance, low moisture absorption, high purity and resistance to hydrolysis make KetaSpire PEEK a front-line option for a variety of applications within the healthcare market.  

Typical healthcare applications of KetaSpire PEEK are: 

• Reusable medical devices: in this domain, KetaSpire PEEK is mainly used as a metal replacement alternative to stainless steel. By taking advantage of its extreme resistance to steam sterilisation (1000+ autoclaving cycles), high mechanical resistance and design flexibility, KetaSpire PEEK can be used to manufacture surgical tools being significantly lighter than their metallic counterparts. Moreover, harsh disinfectants such as bleach, IPA 70% and many others are not posing any issues to KetaSpire PEEK. Examples are external fixation devices, orthopedic surgical tools, microtubes and microneedle patches used for drug delivery. 

• Surgical robots: surgical robots are becoming more and more common and are nowadays utilised by several hospital facilities. It is an industry trend based on the advantages of surgical robots such as reduced post-surgery pain, fewer and smaller scars, increased accuracy, shorter hospitalisations and lower risk of infections. KetaSpire PEEK proves very valuable for this type of applications: multiple components of surgical robots are required to resist repeated sterilisation by autoclaving, high mechanical loads and high speed rotations.  
• Single use biopharma equipment: Single-use biopharma technologies continue to replace reusable ones. This is a strong industry trend observed in the latest decades, and this is driven by an increasing need of cost reduction, elimination of cross-contamination risks and enhanced production flexibility, which single-use productions can help achieve with lower effort and cost. In this scenario, KetaSpire PEEK can greatly contribute to the manufacturers’ strategic objectives. With its compatibility with gamma sterilisation, extremely low leaching in biopharma chemicals, high purity and USP Class VI compliance, KetaSpire PEEK is successfully being used in many different single use biopharma components such as connectors, flow-meters, sensor housing and in all those parts where mechanical loads are significant such as in clamping parts.  

Another important market for PEEK materials is that of implantable plastic components. In this field, having a plastic implant carries multiple advantages vs metals, such as increased biocompatibility, lower weight and radio transparency. For these reasons, the industry started moving towards these solutions almost a decade ago with the overall aim of easing the life of patients carrying implantable devices. This, combined with the organic growth of this market and the ever-coming innovations, made this sector a significant outlet market for PEEK materials. 

Zeniva PEEK 

As an implantable solution, Solvay offers Zeniva PEEK. Zeniva PEEK is a high-performance specialty polymer with high strength and advanced stiffness that offers extreme toughness and reliability for use in structural, load-bearing implantable medical devices.  

Solvay manufactures Zeniva PEEK in a facility registered to the ISO 13485 quality standard and in compliance with relevant current Good Manufacturing Practices (cGMP) and ensures that it meets ASTM F2026-17 requirements as a PEEK polymer for surgical implant applications. Zeniva PEEK is compatible with a full range of sterilisation methods including steam, ethylene oxide gas, vaporised hydrogen peroxide and high-energy gamma radiation. Moreover, it is capable of resisting prolonged contact with bodily fluids without any performance alteration. 

As material for implantable devices, Zeniva PEEK provides several advantages over metals and other plastics. This material is easily moulded or machined in complex shapes maintaining tight tolerances. It is also radiolucent and MRI compatible, allowing surgeons and their equipment to see through parts made of this material without any obstructions of the image, leading to easier procedures and enhanced effectiveness of surgery being performed. On top of this, its lower density vs metals allows to manufacture lighter implants that can prove for the patient to bear.  

All of these properties make Zeniva PEEK ideal for applications such as dental implants, knee implants, trauma plates and spinal cages.