Production of Hydroxyapatite Microspheres by Plasma Spray

CRISTIAN MARTINEZ; GUSTAVO LA GATTINA; LILIANA GARRIDO; ULISES GILABERT; ANDRES OZOLS,

Procedia Materials Science Journal

Elsevier

Lugar: Melbourne ; Año: 2015 vol. 8 p. 319 - 323

Hydroxyapatite is Ca5(PO4)3(OH) (HA) is a material used as a bone filler and dermal or therapeutic drug vehicles, due to theirbiocompatibility, bioactivity and relative reabsorption in hard or soft tissue. In particular, applications of facial fillers andcements formulated with HA require that this is available in the form of spheroidal particles, with size greater than 40 microns,with the purpose of reducing the in situ inflammation of connective tissue. Chemical synthesis techniques are limited to producesmaller particles, in micro or nanometric size. This paper proposes the reprocessing of the natural HA particles, obtained fromfresh bovine bone, which is subjected to chemical and thermal treatments (pyrolysis in an oxidizing atmosphere at 900 C for 2 h),grinding and sieving (particles less than 200 μm). These particles are atomized into plasma spray equipment that draws in a N2flow, and projects them in distilled water. This material is observed by electron microscopy, which revealed the formation ofspherical particles with smooth surfaces and with a size distribution of 20-70 μm. X-ray diffraction analysis revealed the partialdecomposition of the HA in other calcium phosphates: D-Ca3(PO4)2 and Ca4(PO4)2O, essential phases of the formulation ofbone cements, which accelerate the absorption of the biological particles in the biological medium, requirement searched infacial fillers. The process would increase the size of the spherical particles