Preparation of Zn-doped β-tricalcium phosphate (β-Ca3(PO4)2) bioceramics

Pure β-tricalcium phosphate (β-TCP) and Zn-doped (600, 2900, 4100, 7000, 9300 and 10,100 ppm) β-TCP samples were prepared by using a wet chemical/coprecipitation synthesis technique, followed by calcination at 1000 °C in air. Precursor powders of the coprecipitation process were Ca-deficient nanoapatites (i.e., Ca/P molar ratio varying from 1.49 to 1.51) with needlelike but agglomerated particles of 30 nm thickness. In vitro culture tests performed by mouse osteoblast-like cells showed that the samples doped with 2900 to 4100 ppm Zn showed the highest cell viability (via Live/Dead counts), and with a further increase in the Zn-content towards 1 wt.% the number of dead cells in the well plates started to increase. Alkaline phosphatase (ALP) activity peaked for the β-TCP sample doped with 4100 pm Zn. The sample surface roughness, measured by non-contact profilometry, was also found to have an effect on the Live/Dead cell counts, and the highest cell viability encountered in this study corresponded to the surface with the least roughness.