微弧氧化镁表面钙磷生物涂层的制备及性能

To improve the bone implant performance of Mg alloys, composite coating with bio-activity was formed on pure Mg assisted by micro arc oxidation (MAO) and calcium phosphate coating (CaPh, fabricated by electro-deposition). Structure evolution, corrosion behavior, apatite formation ability and cell attachment of composite coating were investigated. Calcium hydrogen phosphate dihydrate (DCPD) is the main composition of the CaPh coating on MAO coated Mg. DCPD compounds prefer to nucleate at the through-holes and discharge channels of MAO layer, then grow and cover the MAO gradually, and seal the micro pores in return. The impedance modulus of the coated Mg at low frequency exceeds 10⁵ Ω•cm² in the initial immersion period, and maintains almost constant in 120 h. Corrosion current density decreases about 3 orders of magnitude compared to the pure Mg, indicating that the corrosion resistance is enhanced noticeably. The composite coating shows hydroxy-induced apatite deposition ability in simulated body fluid(SBF) and cell culture medium. Globular bone-like HA structure appears on coating surface after 14 days of immersion in cell culture medium. Live cells adhere almost at the whole coating surface, which shows excellent apatite formation ability and cell attachment in cell adhesion test.