Enhanced mineralization on electrically polarized hydroxyapatite ceramics in culture medium

Growth enhancement of the bone-like layer on electrically polarized hydroxyapatite was investigated. Dense hydroxyapatite ceramics were electrically polarized in a de held. For estimation of the bone-like grown layer on the polarized hydroxyapatite ceramic surfaces, polarized specimens were immersed not only in a simulated body fluid (SBF) with the inorganic ion-concentrations equal to those of human blood plasma, but also in minimum essential medium (MEM), and in MEM supplemented with 10% foetal bovine serum. After several days of immersion, the grown crystal layers were observed by scanning electron microscopy, and analyzed by X-ray diffraction and IR spectroscopy, As a result, the bone-like hydroxyapatite crystals grew rapidly on the negatively polarized surface, while the growth was restricted on the positively polarized surface both in SBF and MEM. The morphology of the grown layers on the polarized surface was different among the immersion fluids. The growth enhancement of the bone-like layer on the polarized HAp was demonstrated in multiple ions based on inorganic and organic groups. It was considered that the charged surfaces of the polarized HAp ceramics accelerated the growth of the bone-like layer on the negatively polarized surface, but was inhibited on the positively polarized surface.