Bone and Periodontal Tissue Regeneration by the Secretomes from Bone Marrow Derived Mesenchymal Stem Cells - New Trends in Tissue Engineering and Regenerative Medicine - page 102

Images of micro-CT indicated that the newly regenerated bone was seen at an early stage of
bone regeneration and almost covered the defect at 4 weeks. (c) Percent bone regeneration by
area within defects as measured by micro-CT at 2 and 4 weeks. MSC-CM increased the bone
regeneration significantly compared with other groups at 2 and 4 weeks (*p<0.01, #p<0.05).
Furethermore, we performed the immunohistochemical staining against CD31 and CD105
antibody to confirm the endogeneous MSC migration and angiogenesis during the bone
regeneration by MSC-CM. In the MSC-CM group, numerous CD31-or CD105--positive cells
were seen the MSC-CM implanted area. In contrast, there were fewer CD31-or CD105-positive
cells in both the PBS and Defect groups (Fig 6). These results indicated MSC-CM enhanced the
endogeneous MSC migration and angiogenesis.
Newly regenerated bone in the defect, PBS and MSC-CM groups 2 or 4 weeks after implanta‐
tion was evaluated. In the defect group, majority of the defect was filled with connectivetissue
and the infiltrations of inflammatory cells were seen both at 2 and 4 weeks. In the MSC-CM
group, newly regenerated bone had begun to cover the defect at 2 weeks and ossification had
progressed gradually. In the PBS group, newly regenerated bone and partial connective tissue
had covered the defect at 4 weeks.
Figure 5. Histological analysis of newly regenerated bone.
Two weeks after implantation into carvalial defects, tissue specimens were analyzed using
immunohistostaining for: CD31 (RED), a marker for rat endothelial cells; CD105 (GREEN), a
marker for rat stem cells. Cell nuclei were labeled with DAPI (blue). In MSC-CM group, both
CD105 and CD31 positive cells were more prominent than those of the control PBS group.