[Experimental study of porous TCP to generate tissue-engineered long bone]

To study bone-forming of a new kind of porous beta-TCP as the scaffold for tissue-engineering, defects at the mid-portion of the left and right ulna were created in dog, the defects were repaired with beta-TCP cylinder coated with BMSCs, and beta-TCP cylinders alone as control. X-rays showed the defects were better bridged by the replant with obscure edge and new bone formed in the canal and at the interface in experimental group after three month of operation, whereas in control group, the replants were obviously deformed into dissociated granule with unequal density with only little new bone formed at the interface. After six month, the defects were bridged by new bone with osteodermatous cavum medullare ossium, but in control group, the defects were bridged by high density in radiography without osteodermatous cavum medullare ossium, the diameter of the ular was obviously less than experimental group. There were significant differences between both groups at month one and two in the development pattern through radionuclide observation. By gross, the diameter of ular was smaller in control group than in experimental at month three, and the replants in control group was difficult to detach from the fibroid tissue around it, but in experimental group, there was much more new bone formation, and the surface was rough for the compound of new bone and beta-TCP undegraded completely. The new bone in experiment had been obviously remodeled at month six, but at this moment, the new bone was of infirmity in volume and form. HE staining of three months demonstrated new bone adhered to the surface on the core of beta-TCP in experimental group, but in control group, at the same place, osteoid was observed with much megacayocytes and capillaries. At month six, beta-TCP disappeared completely with new bone formed in both groups, but the volume and structure of the bone was better in experimental group than in control group. From this study it is concluded that the porous beta-TCP can be combined with BMSCs, and the combination could generate new bone to repair long bone defect.