1 research outputs found
Manipulation of Mg<sup>2+</sup>āCa<sup>2+</sup> Switch on the Development of Bone Mimetic Hydroxyapatite
Ionic
substitution can affect essential physicochemical properties leading
to a specific biological behavior upon implantation. Therefore, it
has been proposed as a tool to increase the biological efficiency
of calcium phosphate based materials. In the following study, we have
evaluated the contribution of an important cation in nature, Mg<sup>2+</sup>, into the structure of previously studied biocompatible
and biodegradable hydroxyapatite (HA) nanorods and its subsequent
effect on its chemical, morphology, and bone mimetic articulation.
Mg<sup>2+</sup>-substituted HA samples were synthesized by an aqueous
wet-chemical precipitation method, followed by an hydrothermal treatment
involving a Mg<sup>2+</sup> precursor that partially replace Ca<sup>2+</sup> ions into HA crystal lattice; Mg<sup>2+</sup> concentrations
were modulated to obtain a nominal composition similar to that exists
in calcified tissues. Hydrothermally synthesized Mg<sup>2+</sup>-substituted
HA nanoparticles were characterized by X-ray powder diffraction, FT-NIR
and EDX spectroscopies, field emission scanning and high resolution
transmission electron microscopies (FE-SEM, H-TEM). Molecular modeling
combining ab initio methods and power diffraction data were also performed.
Results showed that Mg<sup>2+</sup>-substitution promoted the formation
of calcium deficient HA (cdHA) where Mg<sup>2+</sup> replacement is
energetically favored at Ca(1) position in a limited and specific
amount directing the additional Mg<sup>2+</sup> toward the surface
of the crystal. The control of Mg<sup>2+</sup> incorporation into
HA nanorods gave rise to a tailored crystallinity degree, cell parameters,
morphology, surface hydration, solubility, and degradation properties
in a dose-replacement dependent manner. The obtained materials show
qualities that conjugated together to drive an optimal in vitro cellular
viability, spreading, and proliferation confirming their biocompatibility.
In addition, an improved adhesion of osteoblast was evidenced after
Mg<sup>2+</sup>āCa<sup>2+</sup> substitution