Nanopowders of hydroxyapatite (HA), modified by magnesium (MgHA) and by silicon (SiHA) were obtained by liquid-phase microwave synthesis method. X-ray diffraction and IR spectroscopy results showed that Mg2+ and SiO44− ions were present in the synthesized products both as secondary phases and as part of the HA phase. Whitlockite was found in the magnesium-modified HA (MgHA) and larnite was found in the silicon-modified HA (SiHA); ion substitution for both materials resulted in solid solutions. In the synthesized samples of modified HA, the increase of particle size of powders was in the order HA < SiHA < MgHA, which was calculated through data specific surface area and measured pycnometric density of the powders. The Lewis acid sites (Ca2+, Mg2+, Si4+) were present using spectral probes on the surface of the samples of HA, MgHA, and SiHA, and the acidity of these sites decreased in the order SiHA > MgHA > HA. The rates of calcium phosphate layer deposition on the surface of these materials at 37 °C in the model simulated body fluid solution showed similar dependence.
The calcium
phosphate spherical material with a hierarchical structure has been
used as a bone implantation material. To improve the properties of
the implant material, the compositions of calcium phosphate, silicon,
and titanium are crucial. The presence of silicon on the surface of
the phosphate–calcium material accelerates the bonding of the
implant with the bone (osseointegration). The aim of this work was
to develop a sol–gel method to prepare spherical calcium-phosphate@TiO
2
–SiO
2
biomaterials for bone implantation.
The CaO@TiO
2
–SiO
2
biomaterial with a
core–shell structure was synthesized by the sol–gel
method. The biological properties of the materials were studied with
a simulated body fluid (SBF). The sample had a spherical shape. The
sample exhibited bioactive properties because an increase in the content
of calcium and phosphorus ions in the shell and the presence of precipitated
ions from the solution were detected on the surface. The TiO
2
–SiO
2
framework was uniformly fixed on the CaO
core. Heat treatment of the hybrid mesostructure led to the formation
of mesoporous materials with a specific regular structure in the nanometer
size in the shell, which is necessary for the fixation of biological
cells when the sample is introduced into the biological medium. The
formation of a calcium–phosphate layer on the materials and
the release of soluble silicon and calcium ions into the SBF are the
key factors for the rapid connection of these materials with tissue.
The results demonstrate that the CaO@TiO
2
–SiO
2
biomaterial with a core–shell structure is a good
candidate for bone implantation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.