Effect of Initial Dissolution Behavior on Cellular Response in Uncoated and Calcium Phosphate-Coated Magnesium Alloy

However, the rapid dissolution that occurs during the early stages of immersion remains a critical challenge in their feasibility as a resorbable implant. In this work, RF magnetron-sputtered calcium phosphate (CaP) coatings of ∼0.5 μm and ∼1 μm thickness corresponding to 15- and 30-hour deposition times, respectively, were applied to a WE22 alloy.

The effect on initial dissolution behavior, ion release, and cellular responses was evaluated when immersed for 1, 7, and 24 h. Uncoated WE22 exhibited rapid dissolution with substantial Mg²⁺ release (∼18 mg/L at 24 h) and raised pH levels from ∼7 to ∼8.8. While ∼0.5 μm CaP coatings reduced these effects, they showed greater mass gain and protein adhesion, suggesting potential coating inhomogeneity or nano-defects trapping corrosion constituents.