Novel Mg-Incorporated Micro-Arc Oxidation Coatings for Orthopedic Implants Application

Area of Science:

• Biomaterials Science
• Surface Engineering
• Materials Chemistry

Background:

• Titanium alloys like Ti-6Al-4V are widely used in orthopedic implants.
• Enhancing the surface properties and biocompatibility of titanium implants is crucial for successful osseointegration.
• Micro-arc oxidation (MAO) is a surface treatment technique that can improve the performance of metallic implants.

Purpose of the Study:

• To investigate the effect of magnesium (Mg) content on the surface characteristics and cytocompatibility of MAO coatings on Ti-6Al-4V alloy.
• To determine the optimal Mg concentration for enhancing the biological performance of MAO-treated titanium for orthopedic applications.

Main Methods:

• Ti-6Al-4V alloy samples were treated using micro-arc oxidation (MAO) in phytic acid electrolytes.
• Different concentrations of EDTA-MgNa2 (Na2MgY) and potassium hydroxide (KOH) were added to the electrolytes.
• Surface characterization (roughness, micropore size, composition) and cytocompatibility assays (cell viability, adhesion, proliferation, ALP activity, ECM mineralization, collagen secretion) were performed.

Main Results:

• MAO coatings formed in phytic acid are essential for coating formation.
• Increased Na2MgY and KOH concentrations led to higher surface roughness, larger micropores, and increased Mg content in the coatings.
• MAO coatings with approximately 2.97 at% Mg exhibited excellent cytocompatibility, while coatings with 6.82 at% Mg showed the worst performance due to excessive Mg.

Conclusions:

• MAO coatings with optimized magnesium content significantly enhance the cytocompatibility of Ti-6Al-4V alloys.
• The study highlights the potential of Mg-containing MAO coatings for orthopedic applications.
• Controlling Mg concentration is critical for achieving desired biological responses in MAO-treated titanium.