Biocompatibility and bioactivity enhancement of Ce stabilized ZrO2 doped HA coatings by controlled porosity change of Al2O3 substrates

Al2O3 substrates with controlled porosity were manufactured from nanosized powders obtained by plasma processing. It was observed that when increasing the sintering temperature the overall porosity was decreasing, but the pores got larger. In a second step, Ce stabilized ZrO2 doped hydroxyapatite coatings were pulsed laser deposited onto the Al2O3 substrates. It was shown that the surface morphology, consisting of aggregates and particulates in micrometric range, was altered by the substrate porosity and interface properties, respectively. TEM studies evidenced that Ce stabilized ZrO2 doped HA particulates ranged from 10 to 50 nm, strongly depending on the Al2O3 porosity. The coatings consisted of HA nanocrystals embedded in an amorphous matrix quite similar to the bone structure. These findings were congruent with the increased biocompatibility and bioactivity of these layers confirmed by enhanced growing and proliferation of human mesenchymal stem cells. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.