Wrapped omentum with periosteum concurrent with adipose derived adult stem cells for bone tissue engineering in dog model.

Adipose derived adult stem cells (ASCs) are multipotent cells that are able to differentiate into osteoblasts in presence of certain factors. The histological characteristics of periosteum makes it a specific tissue with a unique capacity to be engineered. Higher flexibility of the greater omentum is useful for reconstructive surgery. These criteria make it suitable for tissue engineering. The present study was designed to evaluate bone tissue engineering with periosteal free graft concurrent with ASCs and pedicle omentum in dog model. Twelve young female indigenous dogs were used in this experiment. In omental group (n = 4), end of omentum was wrapped by periosteum of the radial bone in abdomen of each dog. In omental-autogenously ASCs group (n = 4), 1 ml of ASCs was injected into the wrapped omentum with periosteum while in omental-allogenously ASCs group (n = 4), 1 ml of allogenous ASCs was injected. Lateral view radiographs were taken from the abdominal cavity postoperatively at the 2nd, 4th, 6th and 8th weeks post-surgery. Eight weeks after operation the dogs were re-anesthetized and the wrapped omenum by periosteum in all groups was found and removed for histopathological evaluation. Our results showed that omentum-periosteum, omental-periosteum-autogenous ASCs and omental-periosteum-allogenous ASCs groups demonstrated bone tissue formation in the abdominal cavity in dog model. The radiological, macroscopical and histological findings of the present study by the end of 8 weeks post-surgery indicate bone tissue engineering in all three groups in an equal level. The present study has shown that the wrapped omentum with periosteum concurrent with ASCs (autogenous or allogenous ASCs) lead to a favorable bone tissue formation. We suggested that it may be useful when pedicle graft omentum used concurrent with periosteum in the bone defect reconstruction, and this phenomenon should be studied in future.

Bone tissue engineering with periosteal-free graft and pedicle omentum.

BACKGROUND: The histological characteristics of periosteum make it a specific tissue with a unique capacity to be engineered. Higher flexibility of the greater omentum is useful for reconstructive surgery as it facilitates not only filling of the site of infections such as myelitis, but also is effective in filling complicated defects of the soft and hard tissues, and these criteria make it suitable for tissue engineering. The present study was designed to evaluate bone tissue engineering with periosteal-free graft concurrent with pedicle omentum and compare it with subcuticular periosteal grafting in a dog model. This is the first report in which periosteum-free graft has been used as bone tissue engineering. METHODS: Eight young female indigenous dogs were used in this experiment. In omental group (n = 4), end of omentum was wrapped by periosteum of the radial bone in the abdomen of each dog, while in the subcutaneous group (n = 4), the harvested periosteum was sutured on the subcutaneous layer. Lateral view radiographs were taken from the abdominal cavity post-operatively at 2, 4, 6 and 8 weeks post surgery. Eight weeks after operation, the dogs were re-anaesthetized and the omental or subcutical grafted periosteom was found and removed for histopathological evaluation. RESULTS AND DISCUSSION: Radiological, gross and histopathological evaluations revealed a superior bone formation in the wrapped omentum with periosteum compared with that of the subcuticular periosteal grafting. This is a novel and efficient technique in producing mature trabecular bone and could be used as a potential source of bone tissue engineering for autotransplantation.