Materials Frontier No.121
Title:New titanium alloys and scaffolds with ideal biocompatibility for biomedical applications
Speaker:Prof. Cuie Wen, Faculty of Engineering and Industrial Sciences,Swinburne University of Technology, John Street, Hawthorn Vic 3122 Australia
Venue: Room.308, Material Building A
Inviter: Prof.Deliang ZHANG
Prof. Cuie Wen received her PhD degree from Huazhong University of Science and Technology, China in 1992. After a postdoctoral fellowship at Beijing University of Aeronautics and Astronautics, she was employed as a researcher at National Institute of Advanced Industrial Science and Technology, Japan for 8 years. She worked at Deakin University for 7 years before she was appointed as professor at Swinburne University of Technology in 2010, Australia. Prof. Wen has won a number of national competitive research grants and her research has led to over 270 peer reviewed publications with citations over 1800 and an h index 20. Her research interest includes biocompatible titanium alloys and scaffolds; biodegradable magnesium alloy biomaterials; nanostructured metals, alloys, composites and nanolaminates, battery materials and shape memory metals and alloys.
Titanium (Ti) and titanium alloys are increasingly used as metallic biomaterial in load-bearing implants due to their relatively low elastic modulus, superior biocompatibility and excellent corrosion resistance, in comparison to other metals such as stainless steels and Co-Cr alloys. Pure titanium and some of its alloys such as Ti6Al4V and TiNi have found extensive applications in biomedical applications. However, studies have shown that the release of metal ions from the implant materials might have adverse biological effect or elicit allergy reaction, therefore, the composition of metal biomaterials should be carefully selected to avoid or minimise adverse reaction. In addition, most dense metallic implant materials used are much stiffer than natural bone, causing stress shielding and leading to implant loosening. The current study addressed the two challenges in the development of new implant titanium alloys. The first approach is to assess the cytotoxicity of titanium alloying elements and identify the ideal biocompatible alloying elements. A new class of completely biocompatible titanium alloys have been developed for implant applications. The second approach is to foam the titanium alloys into a porous structure with bone-mimicking properties. This porous structure provides not only new bone tissue ingrowth ability and vascularisation, but also low elastic modulus matching that of natural bone. The preferred alloying elements are selected from Nb, Zr and Ta; whilst Sn, Mo and Si are used with limited concentrations. The pore size of the scaffolds ranges from 200 to 800 µm and the porosity varies from 30 to 90%. In vitro and in vivo biocompatibility assessments demonstrated that the titanium alloy scaffolds showed excellent cell viability, proliferation and bone formation.