April 18, 2024
Ali Shanaghi

Ali Shanaghi

Academic rank: Associate Professor
Education: Ph.D in eng
Faculty: Technical Engineering


Title Enhanced corrosion resistance, antibacterial properties, and biocompatibility by hierarchical hydroxyapatite/ciprofloxacin-calcium phosphate coating on nitrided NiTi alloy
Type Article
Hierarchical coating, Hydroxyapatite coating, NiTi alloy, Ciprofloxacin, Corrosion resistance, Biocompatibility
Journal Materials Science and Engineering: C
Researchers Ali Shanaghi


Multi-functional hierarchical coatings are deposited on the nitrided NiTi alloy. The nitrided layer is first deposited by nitrogen plasma immersion ion implantation and a middle layer containing porous hydroxyapatite and ciprofloxacin (Cip) is produced before the top calcium phosphate coating is deposited by the sol-gel method. The thicknesses of the coating and nitrided intermediate layer are about 1.54 μm and 160 nm, respectively and Cip penetrates to a depth of about 530 nm. Calcium phosphate reduces surface defects resulting in a surface roughness of 17 ± 2 nm compared to 34 ± 5 nm of the porous hydroxyapatite coating. The corrosion resistance is improved due to reduced defects and localized corrosion as manifested by the decrease in the Ni2+ release rate by 11.6% from 0.0198 to 0.0175 mg L−1 cm−2. The bacterial resistance against E. coli is also improved by about 88 times on account of Cip release and good biocompatibility is confirmed by proliferation of MC3T3 cells. This multi-functional hierarchical coating has large potential in orthopedic and dental applications.