Bone regeneration following the implantation of osteoblasts from cell cultures

An animal model utilizing 26 inbred rats was aimed at the question if the regeneration of bone tissue is enhanced by implantation of osteoblasts previously cultured in vitro. Bone tissue was harvested from inbred rats (Lewis) and a cell line of rat osteoblasts was established. The osteoblasts were cultured in vitro and multiplied in three passages. Characterization of the cells was by various methods. Monocortical defects were created in the distal portion of the rat femurs by drilling; and the cells, embedded in 25% bone gelatine, were reimplanted into these defects. After observation periods of varying lengths, the femurs were examined radiographically and bone growth in the defect area was evaluated histologically. The results of this study indicated that there was an initial effect of the reimplanted cultured osteoblasts on the bone growth pattern. At a later point in time this effect could no longer be demonstrated in the young, healthy rats.