Osteogenetic effect on cortical bone of cultured bone/ceramics implants

Hydroxyapatite(HA) has been reported to have a good affinity for cancellous bone with high osteoblastic activity, binding directly to such bone. However, little work has been done concerning the strength of binding to cortical bone with a low cellular activity. Bio-artificial bone with a high osteogenetic capacity can be produced by combining cultured bone tissue with an artificial bone material. We examined this bio-artificial bone for its osteogenetic capacity around the bone tissue to evaluate whether the bone is applicable to osteogenetic treatment. Bone marrow cells were collected from the femurs of 7-week-old male Fischer rats, placed into two T75 flasks, and incubated in standard medium. After 2 weeks in primary culture, the cells were seeded on a porous hydroxyapatite block, and incubated in an osteogenic medium prepared by adding 10 nM dexamethasone, ascorbic acid and b-glycerophosphate. to the standard medium. Two weeks later, cultured HA constructs were implanted onto the cortical bone of the femur. At four or eight weeks after implantation, the femur was removed and radiographically and histologically examined for osteogenesis. The bio-artificial bone of HA impregnated with cultured marrow cells bound firmly to the femoral cortex both radiographically and histologically, and calcification indicating new bone formation was observed around the HA. The use of this bio-artificial bone makes it possible to perforin osteogenetic treatment without damage to autogenous bone, avoiding pain at the site of bone collection and deformity of the pelvis, and reducing the burden on the patient.