Chemical metrology tools to support the manufacture of advanced biomaterials in the medical device industry

Europe creates medical devices worth in excess of 200 billion euro annually, and is a major global supplier of millions of replacement hip joints, cardiovascular stents, and pacemakers, which can vastly improve the quality of life for patients. Ensuring devices are free from manufacturing contamination and optimising the complex drug coatings used to prevent infection or rejection are important for patient wellbeing. Implant manufacturers need improved analytical methods that are easy to use and have robust links to SI units to ensure the quality, efficacy, and safety of the devices they supply.

The EMRP project Chemical metrology tools to support the manufacture of advanced biomaterials in the medical device industry developed new high-vacuum analytical tools for accurately characterising thin films and surface implants coatings. The project also investigated optical techniques, such as vibrational spectroscopy, for potential application in surgical implant manufacturing environments.

The project:

• Developed reference materials simulating layers and coatings important for medical implants and characterised them using XPS and other well established analysis techniques that have robust traceability to SI units
• Used the characterised reference materials to calibrate high-vacuum measurement techniques, such as Time of Flight Secondary Ion Mass spectroscopy (ToF SIMS), for analysing medical implant materials and layers
• Validated technique performance by analysing accurately known ‘real world’ materials to demonstrate reliable chemical depth profiling of drug layers that are used to improve patient outcomes
• Investigated the feasibility of non-vacuum analysis techniques such Raman spectroscopy for near production line quality assurance, using contaminants on surfaces lining hip replacement joints
• Developed a guide to aid the selection of the most appropriate high-vacuum or ambient surface chemistry analysis techniques depending on specific measurement requirements. This provides users with the necessary advice to facilitate their analysis selection in a complex measurement area.

By providing a suite of advanced analytical techniques, validated using appropriate reference materials derived from real medicines, this project has had both an immediate and lasting impact on the global competitiveness of the European medical implant industry. The project’s analytical techniques have enabled the development of new medical devices, such as urinary catheters with novel coatings, prostheses with improved performance, and improved assessments of implant corrosion. Smith and Nephew, a global supplier of medical implants, used the project’s ToF SIMS methods to rapidly and categorically confirm a production batch was not contaminated; resulting in a swift resumption of production that avoided significant down-time costs. Another global supplier, B. Braun, is using the same technique to optimise drug implant coatings for the next generation of stents. Work continues to address the challenge of detecting low-level contamination on implants in the follow-on EMPIR project 15HLT01 Quantitative measurement and imaging of drug-uptake by bacteria with antimicrobial resistance (MetBadBugs).