Regenerative influence of nanostructured bredigite (Ca7MgSi4O16)/anodic spark coating on biodegradable AZ91 magnesium alloy implants for bone healing

• In vivo biocompatibility of magnesium alloy was improved by bredigite/ASD coating.
• Biodegradation of magnesium alloy decreased by bredigite/ASD coating.
• Bone regeneration of magnesium alloy was increased by bredigite/ASD coating.

Magnesium has been recently introduced as a novel biodegradable material for bone healing. However, the fast degradation of this material results in the fast release of hydrogen which limits its clinical applications. In view of that, in the present study, we attempt to overcome this drawback using a bredigite (Ca7MgSi4O16) coating. In our previous work, we have coated AZ91 magnesium implants with bredigite through the combination of anodic spark deposition (ASD) and electrophoretic deposition (EPD) techniques. As continuation to that work, in this paper, we have focused on the in vivo examination of the bredigite/ASD compared to the plain ASD coated and the uncoated AZ91 substrates. The results of the in vivo animal test in the greater trochanter of rabbits indicated improved regeneration of bone and less bone inflammation upon employing bredigite/ASD coated implants. In addition, an enhancement in in vivo biodegradation was observed by the reduction in magnesium ion released in the blood plasma. In summary, a surface treatment using bredigite on magnesium implants promotes their bone healing capabilities for future clinical applications.