Hopes for bone implant coating to improve outcomes

The School of Aerospace, Mechanical and Mechatronic Engineering and the School of Civil Engineering at the University of Sydney have teamed up with several research partners to develop a an organic plasma coating for bone implants to reduce complications.
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Hopes for bone implant coating to improve outcomes

The School of Aerospace, Mechanical and Mechatronic Engineering and the School of Civil Engineering at the University of Sydney have teamed up with several research partners to develop a an organic plasma coating for bone implants to reduce complications.

Hip, knee and shoulder orthopaedic implants have higher than expected rates of revision, according to team, citing the 2013 annual report by the Australian Orthopaedic Association's National Joint Replacement Registry (AOANJRR).

To date, significant numbers of orthopaedic implants fail due to infection or poor integration with bone despite improvements in surgical techniques and post-operative care, the team said, and can lead to revision surgeries that are risky, invasive and costly.

The plasma coating study investigated the interaction of plasma-generated coatings with human-derived stem cells and found the new coating could improve functionality of bone-producing cells.

Lead author Dr Behnam Akhavan from the university's Faculty of Engineering whose research has focused on plasma technologies, said the study had shown "great promise" for the creation of a new class of robust, bio-active surfaces for orthopaedic implants.

“We have developed a highly robust plasma coating from a mixture of low-cost argon, nitrogen and acetylene gas that is placed on the implant," Dr Akhavan said.

"Bone-signalling molecules are then applied to encourage stem cells to produce bone. The mechanically-strong coating can remain on the implant surface for long durations, even if it is scratched during surgery.

The bioactive molecule coating effectively ‘hides’ the metallic implant from the body, so it is treated as a biological structure rather than an invasion.

“The implants have been surface-engineered using the plasma technology and will be overgrown with bone-producing cells once implanted in the body, allowing them to firmly attach to bone tissue," Dr Akhavan explained.

“Rapid implant integration reduces the chance of an implant loosening and failing, therefore eliminating the need for revision surgeries."

This research – Radical-functionalized plasma polymers: stable biomimetic interfaces for bone implant applications – has been published in Applied Materials Today. The study wasa collaboration between the University of Sydney’s School of Aerospace, Mechanic and Mechatronic Engineering, the School of Civil Engineering, and the School of Physics; the Heart Research Institute; and the University Medical Centre Utrecht, Netherlands.