In:
Scientific Reports, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2019-11-08)
Abstract:
Taking advantage of the flexibility of the apatite structure, nano- and micro-particles of hydroxyapatite (HAp) were doped with different combinations of rare earth ions (RE 3+ = Gd, Eu, Yb, Tm) to achieve a synergy among their magnetic and optical properties and to enable their application in preventive medicine, particularly diagnostics based on multimodal imaging. All powders were synthesized through hydrothermal processing at T ≤ 200 °C. An X-ray powder diffraction analysis showed that all powders crystallized in P 6 3 / m space group of the hexagonal crystal structure. The refined unit-cell parameters reflected a decrease in the unit cell volume as a result of the partial substitution of Ca 2+ with smaller RE 3+ ions at both cation positions. The FTIR analysis additionally suggested that a synergy may exist solely in the triply doped system, where the lattice symmetry and vibration modes become more coherent than in the singly or doubly doped systems. HAp:RE 3+ optical characterization revealed a change in the energy band gap and the appearance of a weak blue luminescence (λ ex = 370 nm) due to an increased concentration of defects. The “up”- and the “down”-conversion spectra of HAp:Gd/Yb/Tm and HAp:Gd/Eu powders showed characteristic transitions of Tm 3+ and Eu 3+ , respectively. Furthermore, in contrast to diamagnetic HAp, all HAp:RE 3+ powders exhibited paramagnetic behavior. Cell viability tests of HAp:Gd/Yb/Tm and HAp:Gd/Eu powders in human dental pulp stem cell cultures indicated their good biocompatibility.
Type of Medium:
Online Resource
ISSN:
2045-2322
DOI:
10.1038/s41598-019-52885-0
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2019
detail.hit.zdb_id:
2615211-3