Researchers create a continuous surface modification procedure for magnesium alloy wires that is scalable.

The first industrially scalable surface modification method for bioabsorbable magnesium alloy wires has been created by researchers from the IMDEA Materials Institute and the German company Meotec GmbH.

The results could significantly affect how such wires are used in biomedical applications in the future, according to two recent scientific papers published in the journal Biomaterials Advances.

Magnesium wires with surface modifications have a lot of potential in the biomedical field, including applications as polymer reinforcement in trauma fixation plates, wound closure, cardiovascular stents, nerve regeneration, and implants.

“There are presently no commercially authorized magnesium wire-based medical devices on the market because the high surface-to-volume ratio of magnesium wire results in its quick deterioration rate,”

 IMDEA Materials researcher and Marie Curie Fellow Syed Wahaaj Ali Rizvi.

The two recently published papers describe how scientists developed a novel method for plasma electrolytic oxidation (PEO)-based continuous surface modification of WE43 magnesium alloy wires.

Two of the biggest obstacles to using magnesium wires in biomedical implants—their rapid rate of degradation and the ensuing early loss of mechanical performance—can be removed by the new process, which increases the surface resistance to corrosion.

Since magnesium wire degrades quickly due to its high surface-to-volume ratio, there are currently no commercially approved magnesium wire-based medical devices on the market, according to IMDEA Materials researcher and Marie Curie Fellow Syed Wahaaj Ali Rizvi.

“However, by implementing these recent advances in surface modification, we were able to not only reduce that degradation rate but also to improve their mechanical and biological performance.”.

For instance, in a recent study, we demonstrated that wires dissolved in simulated bodily fluid at 37 degrees in an accelerated test environment without surface modification in less than 24 hours. They survived for seven days with our modifications. They were still displaying more than 100 MPa of strength, which is appropriate for a number of medical applications, even after four days.

Along with fellow IMDEA Materials scientists, Prof. Javier Llorca is a professor. Carlos González, Dr. Mónica Echeverry Rendón, Dr. Muzi Li, and Guillermo Dominguez The project also benefited from the contributions of Kerstin van Gaalen, another Marie Curie Fellow in the program, Dr. Alexander Kopp of Meotec, Leon Tillman, Tim Mayer, and others.

Dr. Kopp of Meotec expressed confidence that the research would increase industrial interest in the further advancement and application of surface-modified magnesium wires.

“We anticipate that our new continuous PEO process, or “C-PEO,” will have a significant impact on the industry,” he said. Since PEO is one of the most significant surface treatments to increase corrosion and surface resistance,

Because of the high surface fraction and aspect ratio of these wires, which are made of magnesium, which is prone to corrosion, it is crucial to apply a suitable surface treatment. By switching from a batch to a coil-to-coil process, such PEO treatment could now potentially be scaled up to high productivity lines.”.

The studies also demonstrate that a more uniform corrosion pattern of the wires as they disintegrated was produced by the novel surface modification technique. The survival of the cells needed for the growth of regenerative tissue was also improved by changing the superficial structure to make it more porous.

Additional clinical trials may be necessary to reach the next stage in the development of a new line of medical devices made of magnesium wire.

More information: Wahaaj Ali et al, Bioabsorbable WE43 Mg alloy wires modified by continuous plasma-electrolytic oxidation for implant applications. Part I: Processing, microstructure and mechanical properties, Biomaterials Advances (2023). DOI: 10.1016/j.bioadv.2023.213314

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