A practical approach to increase the moderate antibacterial activity of the NiTi biomedical alloy: Surface modification by a HAp-Ta 2 O 5 composite layer

Bacterial infections are one of the main potential factors leading to implantation failure. The aim of this contribution is to improve the moderate antibacterial performance of the NiTi alloy through a surface finish by a hydroxyapatite (HAp)-Ta2O5 composite film. The influence of the Ta2O5 nanoparticles on surface chemistry, mechanical properties, and antibacterial properties was assessed using Fourier transform spectroscopy (FTIR), pull-off test, and plate-counting assay, respectively. The results illustrated successful codeposition of the Ta2O5 nanoparticles with the HAp matrix, which, in turn, improved the bonding strength of the HAp coating to the underlying substrate up to 9 MPa and antibacterial activity of the bare NiTi up to 74%. The HAp-1 g L−1 Ta2O5 composite electrodeposit rendered the most favourable mechanical and antibacterial performance and addressed the problem associated with the moderate antibacterial performance of the NiTi.