Synopsis
We produced highly pressed nano-hydroxyapatite/collagen composites (P-nHAP/COL) by Newton press. The aim of this study was to investigate osteogenic differentiation profiles in osteoblastic SaOS-2 cells cultured on P-nHAP/COL and pressed collagen (P-COL) as control for 1, 2, 3 and 4 weeks. Total RNA were extracted from cultured cells, and expressions of osteogenic-differentiation related genes were evaluated with quantitative real-time (RT) PCR using primer sets of alkaline phosphatase (ALP), type 1 collagen (COL1), bone Sialo protein (BSP) and osteocalcin precursor (BGLAP) genes as well as β-actin gene. The cultured cells were also observed with scanning electron microscopy (SEM). RT-PCR analyses revealed that osteogenic differentiation was more accel-erated on P-nHAP/COL than on P-COL, especially revealed by up-regulation with time of BGLAP gene. In SEM images, SaOS-2 cells on P-COL were either cubic or fibroblastic up to 4 weeks, but those on P-nHAP/COL appeared as granular or highly stretched. The obtained results suggested that P-nHAP/COL could be employed as a new osteo-conductive bone substitute material.
Key words: Osteoblastic SaOS-2 cells, Nano-hydroxyapatite, Collagen composite, Newton press, Osteogenic differentiation
