Luminescent and Cytotoxic Characteristics of an Ellipsoidal and Microsized Europium (Eu)-doped Hydroxyapatite

doi:10.15541/jim20150662

Abstract

Abstract:

A novel europium (Eu³⁺)-doped hydroxyapatite microspheres (Eu-HApMs) was successfully prepared via the calcium carbonate template and ion exchange process. The physicochemical, luminescent and cytotoxic properties of the prepared Eu-HApMs powders were investigated by the Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Inductively Coupled Plasma (ICP), and MTT assays in vitro. Results showed that Eu-HApMs particles exhibited an ellipsoidal morphology with diameters of about 2.5 μm and lengths of about 7 μm with a hedgehog-like surface. Besides, the pure hexagonal phase of hydroxyapatite with high crystallinity of Eu-HApMs and successful doping of Eu³⁺ ions into HApMs were revealed. The present study showed that the Eu-HApMs powders actually displayed red fluorescence under ultraviolet (UV) irradiation. It was evident that the ⁵D₀→⁷F_1-4 transitions of Eu (III) ions played a key role in the photoluminescence (PL) activity. Finally, the MTT assay results revealed the continuous proliferation and no morphological change of MC3T3-E1 cells co-cultured with the extracts of Eu-HApMs powders and the calculated relative growth rate (RGR) indicating the cytotoxicity grade at level 1.

Key words: hydroxyapatite, biomaterials, europium-doped, ellipsoidal, fluorescence

CLC Number:

TQ174

MA Ming, LU Wei-Peng, CAO Xiao-Feng, MAO Ke-Ya, GUO Yan-Chuan. Luminescent and Cytotoxic Characteristics of an Ellipsoidal and Microsized Europium (Eu)-doped Hydroxyapatite[J]. Journal of Inorganic Materials, 2016, 31(8): 890-896.

Figures/Tables 8

Table 1 Correlation between RGR and grade of cytotoxicity

Relative growth rate/%	Grade of cytotoxicity	Cytotoxicity
≥100	0	No
75-99	1	No
50-74	2	Analyzed with the cell morphology
5-49	3	Yes
1-24	4	Yes
0	5	Yes

Fig. 1 SEM images of CCMs (a), HApMs (b) and EuHApMs (c: 1 h; d: 7 h)

Fig. 2 XRD patterns of CCMs (a), HApMs (b) and Eu- HApMs (c)

Fig. 3 XRD patterns of the transformation process of CCMs to HAPMs

Fig. 4 ICP results of the ion-doping process

Fig. 5 Emission (a) and exciation (b) spectra of the ions-doped HAPMs Inset is the corresponding photograph under ultraviolet (365 nm) irradiation

Table 2 Results of the cytotoxicity test

Date/d	OD ( ± s)	RGR/%	Grade
1	0.165±0.044	132.48	0
3	0.819±0.044	110.05	0
5	1.376±0.091	79.90	1
7	1.531±0.050	89.54	1

Fig. 6 (a) The MC3T3-E1 cells co-cultured with the extracts of Eu-HApMs powders for different culture time; (b) MTT results for tested Eu-HApMs for different culture time*P<0.05, **P<0.01

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