[Repair of calvarial defects with human umbilical cord blood derived mesenchymal stem cells and demineralized bone matrix in athymic rats].
OBJECTIVE
To investigate the feasibility of using human umbilical cord blood derived mesenchymal stem cells (UCB-MSCs) and demineralized bone matrix (DBM) scaffolds to repair critical-sized calvarial defects in athymic rats.


METHODS
Human UCB-MSCs were isolated, expanded and osteogenically induced in vitro. Osteogenic differentiation of UCB-MSCs was evaluated by Alizarin Red staining and measurement of calcium content respectively, and then the cells were seeded onto DBM scaffolds. Bilateral full-thickness defects (5 mm in diameter) of parietal bone were created in an athymic rat model. The defects were either repaired with UCB-MSC/DBM constructs (experimental group) or with DBM scaffolds alone (control group). Animals were harvested at 6 and 12 weeks post-implantation respectively, and defect repair was evaluated with gross observation, micro-CT measurement and histological analysis.


RESULTS
Micro-CT showed that new bone was formed in the experimental group at 6 weeks post-implantation, while no sign of new bone formation was observed in the control group. At 12 weeks post-transplantation, scaffolds had been degraded almost completely in both sides. It was shown that an average of (78.19 +/- 6.45)% of each defect volume had been repaired in experimental side; while in the control side, only limited bone formed at the periphery of the defect. Histological examination revealed that the defect was repaired by trabecular bone tissue in experimental side at 12 weeks, while only fibrous connection was observed in the control group.


CONCLUSIONS
Tissue-engineered bone composed of osteogenically-induced human UCB-MSCs on DBM scaffolds could successfully repair the critical-sized calvarial defects in athymic rat models.
Liu
Guang-peng
GP
Key Laboratory of Tissue Engineering, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200011, China.
Li
Yu-lin
YL
Sun
Jian
J
Cui
Lei
L
Zhang
Wen-jie
WJ
Cao
Yi-lin
YL
D000818:Animals; D001861:Bone Regeneration; D018786:Bone Substitutes; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051381:Rats; D011923:Rats, Nude; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000293:injuries / Q000601:surgery*; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D014182:Transplantation, Autologous
D018786:Bone Substitutes