Design of Spatial pore structures in Micro-Arc oxidation coatings of Ti implant for nanoparticle drug delivery

• Drug-loaded nanoparticles were incorporated into porous micro-arc oxidation coatings, successfully developing a wear-resistant drug delivery platform on the surface of Ti-13Nb-13Zr implant material. • This study investigated the differences in the overall porous structure of micro-arc oxidation coatings prepared under varying voltages using micro-computed tomography technology. • This study further investigated that the pore connectivity within the micro-arc oxidation coating is a critical factor affecting its drug-loading capacity and drug-release performance. Medical titanium alloy implants, with insufficient antibacterial and wear-resistant properties, can lead to implant-associated infections (IAI), reducing their lifespan. Thus, developing surface coatings with both antibacterial and wear-resistant properties is crucial. In this study, MAO coatings were fabricated at different voltages, and their wear resistance was systematically evaluated. Drug-loaded mesoporous silica nanoparticles were integrated into the MAO coating structure to develop drug-loaded coatings, and the drug release behavior was investigated under both static and wear conditions. The results demonstrated that MAO coatings fabricated at higher voltages exhibited denser pore structures, increased thickness, and enhanced wear resistance. Notably, the coating prepared at 360 V showed superior pore interconnectivity, which facilitated efficient drug loading and sustained release during wear. These findings provide valuable insights for the design of wear-resistant and antibacterial coatings for titanium alloy implants.