Compatibility with the biological host, cleanliness and intrinsic reliability are all crucially affected by the surface properties of materials used inside the body or in contact with skin surfaces for prostheses, implants or drug delivery. Low temperature plasma processing technologies, developed in association with Portal Medical, enable polymer surfaces to be modified in a controlled, clean and precise way to create biocompatible and anti-microbial environments and surfaces. Surfaces can be solid plastic, sheet or fibre. All can be enhanced to change lubricity, adhesion, permeability, biocompatibility and wetting without substrate heating, surface damage or undesirable secondary oxidation. Full traceability and compliance with cGMP standardsis included in the operating process.
Plasma surface modification processing opens up new opportunities for bioengineering, with plastics and other materials that melt at low temperatures or cannot withstand autoclaving, the aggressive environments of ethylene oxide or gamma irradiation. It can also be applied to ceramic and metal components for etching, super finishing, cleaning and other surface modifications designed to aid lubricity, adhesion or other aspects of biocompatibility and chemical processes, such as polymerisation and cross-linking.
Plasma processing applications for medical devices
■ Polymer and composite surfaces used in prostheses such as knee and hip joints.
■ Delicate fabrics such as wicks to draw blood or other body fluids into sensors, for example, blood glucose sensors.
■ Wound-care materials such as polyurethane film and foams and medical gauze.
■ Drug-delivery systems such as inhalers and other items such as stents for cardiac care and fabric stents used to repair aneurysms can be made more biocompatible or safely enhanced to meet desired performance levels.
Tecvac offers a complete range of thermal processing services including heat treatment for advanced metallics, and vacuum brazing for assembly of complex metal components . These processes are backed by a full suite of analytical services including electron microscopy and X-ray surface and composition analysis. These services help customers achieve wear resistance, biocompatibility improvements, drug delivery enhancements, extended implant life and performance, friction reduction, controlled surface adhesion or bonding, sterilisation and infection control.
Surface modification & thermal processing
Project BERTI; (Biomedical implant with Exceptional Resistance to Tribo-bio-corrosion and with Inherent antimicrobial properties) is expected to lead to new designs of knee and hip implants and substantially reduce the number of costly revision surgeries for hip and knee replacement patients. Partners in the project include Corin Plc, Tecvac Ltd, Imperial College, University of London, Charing Cross Hospitals, Queen Mary College, University of London and the University of Sheffield.
SMART-HIP, a research project led by Cambridge coating specialist Tecvac Ltd and leading UK hip prosthesis manufacturer, Corin Ltd, has demonstrated the potential of new enhanced wear resistant coatings to increase implant longevity in Metal-on-Metal (MoM) hip prostheses and future potential applications to trunnions and tapers to prevent fretting and corrosion.
New PVD silver bearing coatings were developed which may protect against post-operative infection, and also provide a barrier to minimise metal ion release. Optimised coatings reduced the release of one important metal ion (Cobalt), implicated in chronic tissue inflammation, by 99%.
£500,000 EPSRC project at the University of Sheffield
Tecvac Ltd has designed and built a unique, world class surface engineering research machine for The University of Sheffield as part of a £500,000 EPSRC project.