Can Porosity Influence the Osteoconductive Properties of Synthetic Hydroxyapatite?

摘要

The adhesion, proliferation and differentiation of human osteoblast-like cells have been assessed on HA disks with 3 different porosity groups: group A (35 percent), B (35-55 percent), and C (55 percent), using plastic culture disks as control. The aim of the work was to study if the porosity of HA can influence its osteoconductive properties. Human osteoblast-like cells were isolated and characterized. Cells were plated in multi-wells on hydroxyapatite disks. The proliferation was determined by the MTT colorimetric method at 1, 3, 7, 15, 21, 28 days. Alkaline phosphatase (ALP) activity was measured by a spettrophotometric method at 1, 3, 7, 15, 21, 28 days and type-I collagen and osteonectin production demonstrated with fluorescence microscopy. Osteoblast adhesion was studied by SEM analysis. The cell growth on HA is 3 to 6 fold lower than on controls. In particular, at 28 days GroupC allowed the growth of 2141 (+/-350) cells/well and the differences with the control group, 12184 (+/-3038) cells/well, were highly significant (p <0,005). The ALP production was 2-3 fold lower on HA than on plastic. The Group C showed a mean ALP activity of 2,95 (+/-0.07) UI/well after 28 days, the higher compared to the other groups. The ALP activity/cell demonstrated a major synthesis of ALP on HA samples.