Pulse electrodeposition and characterization of non-continuous, multi-element-doped hydroxyapatite bioceramic coatings

Multi-element-modified bioactive hydroxyapatite (mHAp) coatings were developed onto commercial titanium alloy material (Ti6Al4V) in clusters. The coatings were prepared by applying pulse current deposition technique. The pure HAp layer was doped and co-deposited with Ag+, Zn2+, Mg2+, and Sr2+ ions. Potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) were performed in simulated body fluid (SBF) using three-electrode open cell over a long time period to assess the corrosion properties of bioceramic coatings. The biocompatible characteristics of layers were investigated by seeding osteoblast-like MG-63 cells onto the samples' surface. The morphology and structure of coatings were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) while cross-sectional analyses were carried out by focused ion beam (FIB). The elemental composition of coatings was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The biocompatible measurements revealed enhanced bioactivity of modified HAp compared to uncoated implant materials and pure HAp bioceramic coating. The corrosion tests confirmed that the coatings were biodegradable.