Effect of Strontium-Substituted Calcium Phosphate Coatings Prepared by One-Step Electrodeposition at Different Temperatures on Corrosion Resistance and Biocompatibility of AZ31 Magnesium Alloys

Abstract

As potential degradable biomaterials, magnesium (Mg) alloys have development prospects in the field of orthopedic load-bearing, whereas the clinical application has encountered a bottleneck due to a series of problems caused by its rapid corrosion. In this study, strontium-substituted calcium phosphate (CaP) coatings with different structures were prepared on the surface of the Mg matrix by a simple one-step electrodeposition method at different temperatures, which enhanced the poor corrosion resistance of the Mg matrix. The coated sample prepared at 65 °C reduced the corrosion current density by 3 orders of magnitude and increased the impedance by nearly 2 orders of magnitude compared with bare Mg alloy, thanks to its dense fibrous structure similar to that of natural bones. Although the coating composition varies with different preparation temperatures, CaP, as an inorganic component similar to natural bone, has good cytocompatibility. Doping the right amount of strontium, which is a trace element in human bones, is beneficial to stimulate osteoblast differentiation, inhibit the activity of osteoclasts, and induce the formation of bone tissues. This provides a new option for modifying the Mg alloy with CaP coatings as a base.

Evaluation of Corrosion Performance of AZ31 Mg Alloy in Physiological and Highly Corrosive Solutions

“…The electrochemical deposition method has the ability to produce coatings on the surface of samples with different shapes at relatively low temperatures. This technique can also produce coatings containing calcium and phosphate that are biocompatible and that may be bioactive . The morphology and composition of the coating can be controlled by adjusting the parameters of the electrochemical deposition, and this technique allows complex 3D surfaces to be coated. , …”

“…This technique can also produce coatings containing calcium and phosphate that are biocompatible and that may be bioactive. 41 The morphology and composition of the coating can be controlled by adjusting the parameters of the electrochemical deposition, and this technique allows complex 3D surfaces to be coated. 42 , 43 …”