Résumé
To investigate the feasibility of using poly-beta-hydroxybutyrate as scaffolds for bone tissue engineering. Marrow stromal cells were harvested from New Zealand rabbit′s iliac bone. After being cultured and multiplied in vitro,with the use of dexamethasone to promote the osteoblastic phenotype of the cells, the cells were seeded into poly-beta-hydroxybutyrate. The cells/ poly-beta-hydroxybutyrate construction was implanted subcutaneously in nude mice. In control animals, poly-beta-hydroxybutyrate alone was implanted. Osteogenesis was assessed by histological and roentgenographic analysis. Four weeks after implantation, osteoid tissue had been observed in the specimens of the composite; 8 weeks after implantation, large amount of new bone had been found, and lamellar bone had been observed also. In the control, only fibrous tissue had been found. It suggested that poly-beta-hydroxybutyrate can be used as a scaffold material for bone tissue engineering.
Résumé
The marrow stromal osteoblasts from New Zealand rabbits were seeded on coral treated with L-polylysine, fibronectin and culture medium only, then the cells/coral composites were cultured in vitro. The cells/coral composites were observed for the process of cells growth and matrix formation at 7, 14 and 21 days after culture. With the aid of electron microscope,it was demonstrated that on the surface of the coral holes,which was treated with fibronectin, there were more adhering osteoblasts and matrix formation than those treated with both L-polylysine and culture medium after 7 and 14 days.Cell count in coral blocks was determined by doing a fluorimetric DNA assay. Although the samples treated with L-polylysine demonstrated higher cell count than the coral treated with culture medium after 7 days, there was no statistically difference between the two after 14, 21 days. At each time point, the samples treated with fibronectin showed higher cell count and alkaline phosphatase activity than the orals otherwise treated, and the cell count also increased with culture time. The study suggests that fibronectin has a significant effect on promoting the adhesion and proliferation of osteoblasts on the surface of coral.