AIM
The short lifespan of orthopaedic implants is a major clinical problem, where failure often occurs within a few months as a result of infection or within 10–15 years due to loosening. Most orthopaedic implants use titanium alloys (Ti-6Al-4V), which often cannot achieve sufficient integration with bone, and currently used hydroxyapatite (HAp) coatings are prone to delamination and fragmentation. This focused project aims to develop a family of ceramic coatings for orthopaedic implants featuring osteogenic and antimicrobial properties coupled with high bonding strength to prevent premature implant failure.
GOALS
This project will examine existing implant technologies and biomaterials research, then design novel coatings to evaluate the possibility for these newly discovered materials to be used as a coating for orthopaedic implants. The plasma spraying procedure is used to create coatings, which are then tested to determine their suitability for usage in orthopaedic implants. Three patented ceramics would be used as the materials in the project would be Baghdadite_Ca3ZrSi2O9 (US patent 9,005,647), Strontium-Hardystonite (Sr-HT)_Sr-Ca2ZnSi2O7 (US patent 8,765,163), and Strontium-Hardystonite-Gahnite (Sr-HT-Gahnite)_Sr-Ca2ZnSi2O7-ZnAl2O4 (US patent 9,220,806) with the optimization of plasma spraying technology for coating. The new coatings of these new bioceramics using plasma spray as a technique for deposition are expected to provide excellent performance to enhance the longevity of the implants. The evaluations of the project’s delivery were investigated to achieve the following objectives:
- To process the raw powder of the bioceramics to get them sprayable using plasma spray coating. Key focuses were improving the powder flowability and maintaining the acceptable particle sizes to fit in the requirement of feedstocks for plasma spray coating. Next, produce coatings from the processed powders using plasma spray coating techniques, including investigating and optimizing process parameters to achieve the desirable coatings. In addition, coatings were produced on the actual knee replacement prostheses.
- To perform coating characterizations, including the physical, chemical, and micromechanical properties of the new bioceramic coatings. These results would be compared with the properties of the commercial HAp coating as the control.
- To study the biological properties of the new bioceramic coatings regarding cell performance and antibacterial properties. These works collaborated with the University of Sydney and RMIT University. These results would also be evaluated against the commercial HAp coating to determine the effectiveness of the new coatings.