This paper studies the structural and photoluminescent properties of hydroxyapatite (HA) and europium-doped hydroxyapatite (HA:Eu) synthesised by the hydrothermal method and sintered by the spark plasma sintering (SPS) technique. HA and HA:Eu powders, synthesised at pH of 10, 11 and 12, were characterised by means of infrared spectroscopy, X-ray diffraction, scanning electron microscopy, Raman spectroscopy and luminescence spectroscopy. The HA and HA:Eu samples were sintered using the SPS technique at 900 and 1200 °C. It was determined that the HA and HA:Eu powders crystallised in the hexagonal phase, which is stable until 900 °C. The presence of Eu 3+ ions tended to stabilise the hexagonal phase of hydroxyapatite at 1200 °C. Undoped hydroxyapatite sintered at 1200 °C revealed a significant amount of tricalcium phosphate (β-TCP) as a result of its decomposition. By increasing the heat treatment temperature, different emission lines (

Hydroxyapatite (HAp) nanoparticles with a homogeneous rod morphology were successfully synthesized using the hydrothermal method. The powders were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The antibacterial and dermal irritation analyses of the samples were performed and discussed. The use of cationic and anionic surfactants, namely, cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), respectively, at a low concentration (2.5 mol%) modified the length/diameter (L/D) ratio of the HAp rods. Structural characterizations of hydroxyapatite synthesized without surfactant (HA), with 2.5 and 5 mol% of SDS (SDS− and SDS+, respectively), and with 2.5 and 5 mol% of CTAB (CTAB− and CTAB+, respectively) revealed well-crystallized samples in the hexagonal phase. The CTAB− sample presented antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Streptococcus anginosus, Staphylococcus aureus, Micrococcus luteus, and Klebsiella pneumoniae, suggesting that antimicrobial susceptibility was promoted by the bacterial nature and the use of the surfactant. Dermal irritation showed no clinical signs of disease in rabbits during the study, where there was neither erythema nor necrosis at the inoculation sites.

Hydroxyapatite (HA) nanoparticles with homogeneous rod morphology were successfully synthesized by the hydrothermal method. The use of cationic and anionic surfactants (cetyltrimethylammonium bromide, CTAB, and sodium dodecyl sulfate, SDS) does not change the morphology, but the length/diameter ratio of HA nanorods did. The structural characterizations revealed well-crystallized samples in the hexagonal phase. The HA samples with a smaller Ca/P ratio presented larger crystalline size. The CTAB- sample present antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Streptococcus anginosus, Staphylococcus aureus, Micrococcus luteus, and Klebsiella pneumoniae suggesting that the bacteria nature and surface charge of nanoparticles affect the susceptibility.