Improvement of Antibacterial Activity Resistance of NiTi Alloy by Electrophoretic Deposition

Abstract

Biomedical NiTi shape memory alloys used in surgery suffer from post-surgery bacterial infection issues and it is importance to prevent bacteria adhesion and growth on the implants. In this paper Electrophoretic deposition (EPD) was used as a surface modification technique to improve the antibacterial activity of NiTi alloy by using organic inorganic coating Nanobiocomposite materials (Hydroxyapatite/Titania) were used as a thin deposition layer on NiTi substrate. EPD technique performed with different parameters used, (20-volt, 4 min, 2%C) for deposit layers of HA, (20 volt, 4 mint, 4%C) for TiO₂ layer and (60 volt, 4 min, 2%C) for composite (HA/TiO₂) layer. Chitosan was used as a binder and good antibacterial material with all coating. The antibacterial activity test performed diffusion methods.  Two types of bacteria, E. Coli, and Staphylococcus were investigated on the performance of coatings. The results showed that the coatings revealed good inhibition effect towards E. coli and S. aureus (Staphylococcus) within the incubation period than the substrate NiTi alloy.  The effect against Staphylococcus (gram positive) was more than the effect against the E. coli (gram negative).