Construction of tantalum/poly(ether imide) coatings on magnesium implants with both corrosion protection and osseointegration properties

• Main Authors: Kwang-Hee Cheon, Cheonil Park, Min-Ho Kang, In-Gu Kang, Min-Kyu Lee, Hyun Lee, Hyoun-Ee Kim, Hyun-Do Jung, Tae-Sik Jang
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2021-04-01
• Series: Bioactive Materials
• Subjects: Magnesium; Tantalum; Poly(ether imide); Bio-functionalized coating; Biodegradable orthopedic implants
• Online Access: http://www.sciencedirect.com/science/article/pii/S2452199X20302589

Poly(ether imide) (PEI) has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium (Mg), a potential candidate of biodegradable orthopedic implant material. However, its innate hydrophobic property causes insufficient osteoblast affinity and a lack of osseointegration. Herein, we modify the physical and chemical properties of a PEI-coated Mg implant. A plasma immersion ion implantation technique is combined with direct current (DC) magnetron sputtering to introduce biologically compatible tantalum (Ta) onto the surface of the PEI coating. The PEI-coating layer is not damaged during this process owing to the extremely short processing time (30 s), retaining its high corrosion protection property and adhesion stability. The Ta-implanted layer (roughly 10-nm-thick) on the topmost PEI surface generates long-term surface hydrophilicity and favorable surface conditions for pre-osteoblasts to adhere, proliferate, and differentiate. Furthermore, in a rabbit femur study, the Ta/PEI-coated Mg implant demonstrates significantly enhanced bone tissue affinity and osseointegration capability. These results indicate that Ta/PEI-coated Mg is promising for achieving early mechanical fixation and long-term success in biodegradable orthopedic implant applications.