Bone Formation In Segmental Defects Research Articles

Mesenchymal stem cells accelerate bone allograft incorporation in the presence of diabetes mellitus

Allograft (Allo) incorporation in the presence of a systemic disease like diabetes mellitus (DM) is becoming a major issue in the orthopedic community. Mesenchymal stem cells (MSC) are multipotent stem cells that may be derived from adult, whole bone marrow and have been shown to induce bone formation in segmental defects when combined with the appropriate carrier/scaffold. The objectives of this study were to analyze the effect of DM upon Allo incorporation in a segmental rat femoral defect and to also investigate MSC augmentation of Allo incorporation. Segmental (5 mm) femoral defects were created in non-DM and DM rats and treated with Allo containing demineralized bone matrix (DBM) or DBM with MSC augmentation. Histological scoring at 4 weeks demonstrated less mature bone in the DM/DBM group compared to its non-DM counterpart (p < 0.001). However, there was significantly more mature bone in the DM/MSC group when compared to the DM/DBM group at both 4 and 8 weeks (p < 0.001 and p = 0.004). Furthermore, significantly more bone formation was observed in the DM/MSC group compared to the DM/DBM group at the 4-week time point (p < 0.001). The results of this study suggest that MSC are a potential adjunct for bone regeneration when implanted in an orthotopic site in the presence of DM.

Repair of Segmental Defects with Nano-hydroxyapatite/Collagen/PLA Composite Combined with Mesenchymal Stem Cells

The aim of the present study was to investigate and compare the capacity of fresh-frozen allogeneic bone, nano-hydroxyapatite/collagen/PLA (nHAC/PLA) scaffold, and nHAC/PLA scaffold loaded with bone marrow mesenchymal stem cells (BMSCs) in inducing bone formation. A 10mm segmental rabbit radial defect was surgically created. The animals were divided into four groups in which the defect was either left untreated, or filled with the abovementioned three grafts. The animals were euthanized at 2, 4, 6, 8, 12, and 18 weeks. Radiographic and histologic analyses were performed on the harvested tissue. We show that nHAC/PLA composite combined with mesenchymal stem cells could enhance and accelerate bone formation in segmental defects of rabbits. nHAC/PLA composite is an ideal bone graft; implanting nHAC/PLA composite combined with mesenchymal stem cells is a potential method for surgical treatment of bone defects.

Use of cultivated osteoprogenitor cells to increase bone formation in segmental mandibular defects: an experimental pilot study in sheep

Abstract.The hypothesis of the present experimental pilot study was that autogeneous cultivated osteoprogenitor cells in porous calcium phosphate scaffolds can increase bone formation in segmental defects of the mandible. The autogenous osteoprogenitor cells of eight sheep were cultivated from bone biopsies from the iliac crest and seeded into cylindrical scaffolds of pyrolized bovine bone of an overall length of 35mm and 13mm in diameter. Segmental defects of 35mm length were created unilaterally in the mandibles of the animals. Reconstruction was performed using cylinders with cultivated osteoprogenitor cells in four animals and empty scaffolds in the remaining four sheep, which served as controls. After 5 months, the mandibles were retrieved and the reconstructed areas were analyzed by qualitative and quantitative histology in serial undecalcified thick-section specimens. There was significantly more bone formation in the group that had received scaffolds with cultivated bone cells (P=0.028). Bone formation was present in 34.4% of the evaluated cross-sectional units in the seeded scaffolds, while it was found in 10.4% in the control group. Although the spatial distribution of bone formation was significantly different across the scaffold in both groups, osteoprogenitor cells appeared to have increased bone formation, particularly in the centre of the defect when compared to the control group. It is concluded that the repair of segmental defects of the mandible can be enhanced by the transplantation of autogenous osteoprogenitor cells in a porous calcium phosphate scaffold.