Topic: Multifunctional Coatings for Biomedical Mg Alloys
Magnesium (Mg) and its alloys are emerging materials for biomedical applications owing to their desirable mechanical and biological features. However, their clinical applications are significantly restricted by the rapid and uncontrollable degradation progress, which gives rise to hydrogen gas evolution, deterioration of mechanical strength and dramatic changes in local pH in chloride-rich physiological environments, such as human body fluid. Furthermore, a feasible coating strategy is required to yield biomedical Mg implants in vivo with satisfactory biocompatibility and controlled biodegradation. In addition, it is of great significance to tackle device-associated infections caused by dwelling of pathogen colonies on the surface of biomedical implants. Existing research explores either protective coatings with reduced degradation rate or techniques to suppress pathogenic infection issues of Mg-based implants. It is a pressing requirement to discover a sound and efficient solution to these two key issues at the same time as clinical implementation of biomedical Mg alloys.
This project aims to develop gallium phosphate (GaPO4)-based multifunctional coatings, which not only suppress the initial degradation kinetics of Mg alloys but also reduce the risk of implant-associated infections through sustainable release of antibacterial agents (i.e. Ga3+ ions) from coatings into the surrounding tissue during the degradation process. Though Ga3+ ions are a well-recognised broad-spectrum antibacterial element, their use in the formation of protective coatings for Mg alloys is yet to be assessed. In this study, protective coatings containing Ga3+ ions as germ-killer will be prepared through several techniques including cost-effective chemical conversion methods and RF magnetron sputtering deposition to yield a variety of microstructures, chemical compositions and thus dissolution rates. Physical, chemical, electrochemical and antibacterial features will be characterised by SEM-EDX, FIB-TEM, XRD, XPS, potentio-dynamic and static polarisation curves, EIS, SECM and in vitro cell and bacteria cultures. It is anticipated that this new series of coatings will open up new possibilities for the clinical application of degradable Mg alloys with desired functionality in terms of both corrosion and bacterial resistance.
- 05/2014 - 03/2015: The national key research development plan (State Project’973’) - Modification research for key parts of the nuclear main pump in the Surface Engineering Laboratory, Dalian University of Technology.
- 05/2013 - 09/2013: Project atmospheric-induced corrosion of cold worked grade 2205 duplex stainless steel in Corrosion and Protection Centre (CPC) & Materials Performance Centre (MPC), School of Materials, University of Manchester, UK
- M.-S. Song et al., "Recent advances in biodegradation controls over Mg alloys for bone fracture management: A review," Journal of Materials Science & Technology, IN PRESS, 2018.
Best ECR Session Oral Presentation, International Symposium on Advanced Materials & Sustainable Technologies 2018 (AM&ST18), Brisbane (Australia), 22-25 July 2018.
- Senior Supervisor: Dr Xiao-Bo Chen (RMIT University)
- Associate Supervisor: Prof Ivan Cole (RMIT University)