In vitro behaviour of osteoblast cells seeded into a COL/β-TCP composite scaffold

The purpose of the present study was to investigate the effect of a collagen/beta-tricalcium phosphate (COL/beta-TCP) composite on osteoblast growth and proliferation. The COL/beta-TCP composite was prepared by mixing COL type I with beta-TCP, in 1:1 (w/w) ratio and conditioned as sponge by freeze-drying. The osteoblast culture was obtained from rat calvaria bones by enzymatic digestion and cells were seeded in the COL/beta-TCP composite. The cell morphology and viability, alkaline phosphatase and osteocalcin, as markers of osteoblast proliferation were evaluated at 3, 7 and 25 days of culture. Histological sections revealed that cell colonization progressively increased inside the COL/beta-TCP scaffold, and osteoblasts had a random distribution throughout the scaffold. Cells cultured into the COL/beta-TCP scaffold presented osteoblast phenotype, intense staining of alkaline phosphatase and increased production of osteocalcin. Transmission electron micrographs revealed intimate contacts between osteoblasts and the scaffold. MTT test indicated that the viability of the cells cultivated in the presence of COL/beta-TCP scaffold was similar to that of the control. All these results show that our COL/beta-TCP composite act as a good substrate for rat osteoblast proliferation and migration and could be a promising substitute for bone repair.