DCPD-to-HA coatings on laser-printed Mg scaffold for enhanced corrosion resistance and osteogenic performance

Laser powder bed fusion (LPBF) provides a promising approach for fabricating biodegradable magnesium (Mg) alloy implants with complex geometries, particularly porous scaffolds for bone defect repair. However, rapid degradation and insufficient bioactivity remain major challenges for their clinical application. In this study, a calcium phosphate-based coating strategy was developed on an LPBF-fabricated porous WE43 scaffold via dicalcium phosphate dihydrate (DCPD) deposition followed by alkaline conversion to hydroxyapatite (HA). The coating evolution, corrosion behavior, degradation characteristics, and biological performance were systematically investigated. The results demonstrate that the calcium phosphate-based coating​ strategy effectively regulates the surface and interfacial properties of the Mg alloy. Electrochemical measurements and immersion tests further confirm improved degradation control and the maintenance of structural integrity for the coated scaffolds. Furthermore, the HA-modified surface provides a favorable microenvironment for osteoblast adhesion, proliferation, and extracellular matrix formation. This study presents an effective surface modification strategy for balancing degradation regulation and bioactivity of LPBF-fabricated Mg alloys, highlighting their potential for biodegradable orthopedic applications.