Quinone-rich polydopamine functionalization of yttria stabilized zirconia for apatite biomineralization: The effects of coating temperature

• Published in: Applied surface science 2015-08, Vol.346, p.317-328
• Main Authors: Zain, Norhidayu Muhamad, Hussain, Rafaqat, Abdul Kadir, Mohammed Rafiq
• Format: Article
• Language: English
• Subjects: Apatite; Apatite mineralization; Biomineralization; Chelation; Coating; Discs; Film thickness; Hydrophilicity; Polydopamine; Quinone-rich groups; Quinones; Yttria stabilized zirconia
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.04.007

•Synthesis of functionalized yttria stabilized zirconia using polydopamine.•The hydrophilicity (40.9±01.7°) was improved at coating temperature of 60°C.•More quinone groups were formed at optimum coating temperature of 50°C.•Ca2p percentage increased at 50°C due to the presence of abundant quinone groups.•Apatite layer with Ca/P ratio of 1.67 formed on the surface of the grafted samples. The use of yttria stabilized zirconia (YSZ) as biomedical implants is often offset by its bioinert nature that prevents its osseointegration to occur. Therefore, the functionalization of YSZ surface by polydopamine to facilitate the biomineralization of apatite layer on top of the coated film has incessantly been studied. In this study YSZ discs were first immersed in 2mg/mL of stirred dopamine solution at coating temperatures between 25 and 80°C. The specimens were then incubated for 7d in 1.5 SBF. The effect of coating temperature on the properties (chemical compositions and wettability) and the apatite mineralization on top of the generated films was investigated. It was found that at 50°C, the specimen displayed the highest intensity of Ca 2p peak (1.55±0.42 cps) with Ca/P ratio of 1.67 due to the presence of abundant quinone groups (CO). However, the hydrophilicity (40.9±01.7°) was greatly improved at 60°C accompanied by the highest film thickness of 306nm. Therefore, it was concluded that the presence of high intensity of quinone groups (CO) in polydopamine film at elevated temperature affects the chelation of Ca2+ ions and thus enhance the growth of apatite layer on top of the functionalized YSZ surface.