OBJECTIVETo study the feasibility of ectopic bone formation for engineered bone constructs with bone marrow stromal cells (BMSCs).

METHODSBMSCs were obtained from 3-month female New-Zealand rabbits with weight of 3 kg, induced to osteogenitor cell, were expanded by culture and then seeded into the porous beta-tricalcium phosphate (beta-TCP) particles. Engineered bone constructs were implanted under the periostem of rabbit femur. Samples were retrieved and examed after 3 months. Blood vessels and osteoblast were examined through optical microscope.

RESULTSTwelve implanted engineered bone particles of 16 samples were fixed well under periosteum and rounded by periosteum. There were a lot of vessels and new bone in engineered bone. The structure of bone was disorder; the vessels arranged equally. Four cases found implanted bone freed outside of periosteum,lots of implanted material were absorbed,the volume of residual was less than osteogenesis, and lack of blood vessel. 80% engineered bone constructs attached to the femur under the periostem very well,osteogenesis was fine and vessels were growed into new bone.

CONCLUSIONEngineered bone can obtained good ectopic bone under the periostem.