Improving osseointegration and antibacterial ability of Nb-doped micro arc oxidized coating with rod-like hydroxyapatite crystals on titanium surface

Abstract

A niobium (Nb)-doped micro arc oxidized coating (MAO) was fabricated on a titanium substrate, and microwave hydrothermal (MH) post-treatment was applied to regulate the microstructure of the coating, aiming to enhance bone-implant osseointegration and antibacterial performance. The experimental results showed that the as-prepared MAO coating was composed of nanocrystalline TiO₂ and a large amount of amorphous phase containing oxygen, Nb, calcium, phosphorus, and other bioactive elements. After MH treatment, short rod-like hydroxyapatite (HA) crystals were uniformly formed on the porous surface of the Nb-doped MAO coating, resulting in a well-ordered crystalline structure with tight interfacial bonding between the HA crystals and the MAO coating. The incorporation of Nb and MH post-treatment synergistically optimized the surface microtopography and chemical composition of the MAO coating, which markedly enhanced in vitro bioactivity, in vivo osseointegration, and antibacterial properties.

Keywords

Micro arc oxidation / Nb element / microwave hydrothermal treatment / osseointegration / antibacterial ability

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