Assessment of Magnesium Wire Coatings for Absorbable Medical Devices

Absorbable magnesiumMagnesium (Mg) wiresWire have the potential to replace many permanent medical devices. Permanent devices endure as an unnatural material in the body whereas eventual staples, stents, and sternal wires made from absorbableAbsorbable magnesium can enable complete tissue healing by elimination of most long-term foreign material. Due to magnesium’s relatively rapid degradationDegradation rate, thin devices may not provide adequate mechanical support during the entire healing phase without surface modificationsSurface modification or coatingsCoating to delay the onset of corrosionCorrosion. This study aimed to assess the feasibility and effectiveness of absorbable coatings which could be suitable for a range of Mg-based biomedical devices, spanning cardiovascular, orthopedic, and wound closure implants. Mg alloyMagnesium alloys (Mg alloys) LZ21 wire was drawn to 0.3 mm and annealed to impart high ductility. A portion of the wireWire was then anodized in an experimental electrolyte. Anodized wire was then coated with an absorbable polymer jacket of polycaprolactonePolycaprolactone (PCL) (PCL). Bare, anodized, and PCL-coated wire were then subjected to both in vitro and in vivo degradationDegradation testing to assess coatingCoating impact.