Titanium Modification by Calcium Ion Chelated Polydopamine and Its Cytocompatibility

doi:10.15541/jim20150097

Abstract

Abstract:

Calcium ions chelation platform was successfully obtained on a titanium surface by modification with polydopamine. The chelation mechanism of polydopamine with Ca²⁺ was studied. The in vitro bioactivity and cytocompatibility of Ca²⁺ chelation platform was assessed by incubation in simulated body fluids (SBF) and cultural osteoblast cells (MC3T3-E1), respectively. The results showed that the functional groups of polydopamine chelated Ca²⁺ were changed from phenolic hydroxyl to benzoquinone. The titanium surface modified by Ca²⁺-chelated polydopamine could induce nucleation and growth of hydroxyapatite in SBF. Meanwhile, Cell attachment and viability assay demonstrated that low concentration of Ca²⁺ chelation possessed good cytocompatibility.

Key words: polydopamine, chelation mechanism, calcium ion, bioactivity, cytocompatibility

CLC Number:

TB331

TAN Guo-Xin, OUYANG Kong-You, ZHOU Lei, LIU Yan, ZHANG Lan, NING Cheng-Yun. Titanium Modification by Calcium Ion Chelated Polydopamine and Its Cytocompatibility[J]. Journal of Inorganic Materials, 2015, 30(10): 1075-1080.

Figures/Tables 7

Fig. 1 XPS full spectra of samples

Table1 Chemical compositions of the surface layers of samples as analyzed by XPS

Samples	Element /at%					Ratio
Samples	C	O	N	Ti	Ca	N/C
Ti-OH	37.43	44.95	0.86	16.76	-	0.023
Ti-PDA	68.56	22.89	8.30	0.25	-	0.121
Ti-PDA-0.1M Ca²⁺	65.19	26.37	7.34	0.51	0.50	0.113
Ti-PDA-0.5M Ca²⁺	62.71	28.33	6.40	-	2.56	0.102

Fig. 2 Surface analysis by XPS showing that polydopamine binds to calcium ion, chelating Ca2+ in CaCl2 solution

Fig. 3 FE-SEM images(a-d) and mineralization mechanism diagram (e) of hydroxyapatite formation on polydopamine surface preloaded with Ca2+ in SBF at 37℃ for 0, 3 and 7 d

Fig. 4 FT-IR of the mineralized hydroxyapatite at 37℃ after 7 d being soaked in SBF

Fig. 5 Hydroxyapatite structural analysis of mineralization on Ti-PDA-0.5M Ca2+ after 7 d being soaked in SBF. (a) SEM, (b) XRD, (c) TEM and (d) SAED

Fig. 6 (a) SEM images of cells morphology and (b) fluorescence images of live/dead staining of osteoblasts (MC3T3-E1) after culturing for 24 h (the live cells are in green and dead cells in red)

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