Enhancement of hydroxyapatite dissolution through structure modification by Krypton ion irradiation

Abstract

Hydroxyapatite (HA) synthesized by a wet chemical route was subjected to heavy ion irradiation, using 4 MeV Krypton ions (Kr 17+ ) with ion fluence ranging from 1×10 13 to 1×10 15 ions/cm 2 . Glancing incidence X-ray diffraction (GIXRD) results confirmed the phase purity of irradiated HA with a moderate contraction in lattice parameters, and further indicated irradiation-induced structural disorder, evident by a broadening of diffraction peaks. High-resolution transmission electron microscopy (HRTEM) observations indicated that the applied Kr irradiation induced significant damage in the hydroxyapatite lattice. Specifically, cavities were observed with their diameter and density varying with irradiation fluences while a radiationinduced crystalline-to-amorphous transition with increasing ion dose was identified. Raman and X-ray photoelectron spectroscopy (XPS) analysis further indicated the presence of irradiation-induced defects.Compositional analysis of pristine and irradiated materials following immersion in Tris (pH 7.4, 37℃) buffer showed that dissolution in vitro was enhanced by irradiation, reaching a peak for 0.1dpa. We examined the effects of irradiation on the early stages of the mouse osteoblast-like cells (MC3T3-E) response. A cell counting kit-8 assay (CCK-8 test) was carried out to investigate the cytotoxicity of samples, and viable cells can be observed on the irradiated materials.

Noble-metal-free hydroxyapatite activated by facile mechanochemical treatment towards highly-efficient catalytic oxidation of volatile organic compound

“…The relative composition of P–O decreases as the strengthened mechanical stress induces by larger ball in planetary ball-milling process, which exemplifies mechanochemical treatment selectively promotes surface defect generation on PO 4 3− site especially in part of asymmetric bonding of P–O. Moreover, the peak intensity at 531.99 eV increases in the case of HAp mechanochemically treated via 3 mm ball, whose phenomenon can be attributed to the generation of oxygen vacancy with the fact that corresponding characteristic peak will also emerge in such higher energy region 42 , 43 . In the case of P2p orbital in Fig.…”

Synthesis and visible-light photocatalytic degradation of Ag3PO4/AgBr/hydroxyapatite ternary nanocomposites prepared from oyster shells

“…The signal peaks at 530.7 eV and 531.9 eV in Fig. 4c are generated by O 1s of lattice oxygen and hydroxyl oxygen in the composite material, 25,26 respectively. The peak generated at 68.7 eV in Fig.…”

High performing additively manufactured bone scaffolds based on copper substituted diopside

“…However, the sintering of polycrystalline bioceramics at higher temperatures tends to produce a larger grain size, and thus slower degradation kinetics, thus posing a challenge in accommodating growing bone tissue. As improving the degradation rate of bioceramics is a key objective in much recent biomaterial research [51], there exists somewhat of a trade-off in achieving both good mechanical performance and bioresorpability. Nevertheless, for the materials fabricated here, toughness values in terms of K IC were higher than the previously reported data for akermanite (1.83 MPaÁm 1/2 ) [4], bredigite (1.57 MPaÁm 1/2 ) [5], wollastonite (<1 MPaÁm 1/2 ) [6],b-TCP (0.46 MPaÁm 1/2 ) and HAP (0.70 MPaÁm 1/2 ) [52].…”