Human Demineralized Bone Matrix as a Cell Transplant Scaffold for Bone Regenerative Cell Therapy

Aim This study examined the effectiveness of human demineralized bone matrix (DBM) as a scaffold material in bone regenerative medicine using cultured periosteal cells (CPCs). Methods A bone defect created in the parietal region of eight‐week‐old nude rats served as the graft bed. A polylactic acid resin dish shell was used as a covering material, and DBM (with (+) or without (−) CPC) was grafted at the site. Deproteinized bovine bone (DBB) was used in the control group. Four weeks later, the grafted site was sampled for micro‐computed tomography and histological observations. The osteoblastic induction effect of DBM was evaluated by co‐culturing with CPCs. Results The DBM‐CPC (+) group demonstrated a significantly larger new bone volume than the DBM‐CPC (−) group. New bone formation with a distinct lining of alkaline phosphatase (ALP)‐positive cells was observed in the DBM graft area, regardless of cell administration. However, the staining intensity and thickness tended to be higher in the DBM‐CPC (+) group. Cells positive for tartrate‐resistant acid phosphatase were more concentrated in areas close to the existing bone in the DBM‐CPC (−) group and throughout the newly formed bone area in the DBM‐CPC (+) group. Only slight bone conduction was observed adjacent to existing bone in the DBB graft group, with no new bone formation. The emergence of ALP‐positive cells was confirmed in CPC co‐cultured with DBM. Conclusions These findings demonstrate the bone inductive effect of DBM and indicate the effectiveness of DBM as a cell transplantation carrier in bone regeneration cell therapy.