Prof Elizabeth Tanner (University of Glasgow)
Location: NEW VENUE: King George VI Building, Lecture Theatre 4 (ground floor)
Time/Date: 20th February 2008, 11:00
As the population ages, the long term function we require from our bodies increases, additionally the mechanical demands we place on our bones and joints is increasing. Solve these twin problems by joint replacement is becoming more common, however we are demanding higher performance and longer life expectancies from replacement joints and other implants. The current generation of bone replacement and augmentation materials are metals, ceramics and polymers, all of which have different mechanical and biological properties to bone. This lack of biological and mechanical compatibility leads to limited and normally too low life expectancies for joint replacements. To solve these problems composites of ceramics in polymers are being used for bone augmentation.
Depending on the application either non-degradable composites can be produced for permanent implants or ones that will break down in the body are appropriate for fracture fixation and similar short term applications. For permanent implants micron scale hydroxyapatite particles in polyethylene can increase the stiffness of the polyethylene to the lower bonds of cortical bone, while the presence of the hydroxyapatite increases the bioactivity of the implant. Selective laser sintering can be used to manufacture porous custom built devices. For temporary implants the combination of either degradable tricalcium phosphate on non-degradable hydroxyapatite in polylactic acid can be further strengthened by the use of drawn fibres of polylactic acid gives tri-phasic composites with suitable mechanical properties for load bearing applications.
Professor Liz Tanner joined the Department of Mechanical Engineering at the University of Glasgow in August 2007. Her first degree was in Engineering Science at the University of Oxford followed by a DPhil when she was based in the Nuffield Orthopaedic Engineering Centre, Oxford. She then joined the Department of Materials at Queen Mary University of London, progressing from research assistant through to in 1998 being appointed Professor of Biomedical Materials. She was also Associate Director of the IRC in Biomedical Materials from 1998 to 2001 and Dean of Engineering from 1999 to 2000. She has been a Visiting Professor in the Department of Orthopaedics, Lund University since 1998. In 2006 she was elected Fellow of the Royal Academy of Engineering.
Her research interests are the development and use of bioactive materials for bone augmentation and replacement. This work has mainly concentrated on the development of composites of polymers filled with bioactive ceramics based on the mineral phase of bone. One such material is HAPEX™, used in patients since 1988 and currently marketed by ApaTech Ltd. In parallel she has been involved in projects on the mechanical properties of bone and the effects of pathology.
Published: 5th February 2008