[Experimental study on repair of critical-sized cranial defect by tissue engineered bone].
OBJECTIVE
To evaluate repair of critical-sized cranial defect with tissue engineered bone fabricated by coral, bone mesenchymal stem cells (MSCs) and sustainedly released recombinant human bone morphogenetic protein 2 (rhBMP-2) by collagen.


METHODS
Three scaffolds of rhBMP-2 + coral, collagen + rhBMP-2 + coral and MSCs+collagen+rhBMP-2+coral were fabricated. Forty New Zealand rabbits were made the models of critical-sized defects and divided into 5 groups according to different implants: group I, auto-ilium; group II, coral; group III, rhBMP-2+coral; group IV, collagen+rhBMP-2+coral; and group V , MSCs+collagen+rhBMP-2+coral. Repair of bone defect was evaluated after 8 and 16 weeks of implantation by gross observation, X-ray, HE staining and Masson's trichrome staining.


RESULTS
Repair of bone defect in group V was similar to that in group I, and was better than that in group IV; and group III was worse. The gross appearance showed that defect region filled with bony tissue which had similar strength to adjacent bone and formed bone union with surrounding bone. The X-ray result displayed high radiopacity (80.45% +/- 2.52% in the 16th week). Histological observation showed new lamellar bone tissue and with few pore blank area. However, only transparent fibrous tissue filled the defect in group II.


CONCLUSIONS
Collagen may be a suitable sustained release system for rhBMP-2. And MSCs may have important effect on enhancing repair of bone defect. Tissue engineered bone fabricated by MSCs+collagen+rhBMP-2+coral may be a useful material for bone defect repair.
Hou
Rui
R
Department of Oral and Maxillofacial Surgery, Stomatological College, Fourth Military Medical University, Xi' an Shaanxi, 710032, PR China. denthr@sina.com
Mao
Tianqiu
T
Yang
Yaowu
Y
Gao
Zhan
Z
Cheng
Xiaobing
X
Chen
Shujun
S
Chen
Fulin
F
D000818:Animals; D037421:Anthozoa; D001854:Bone Marrow Cells; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D001861:Bone Regeneration; D018786:Bone Substitutes; D002478:Cells, Cultured; D003094:Collagen; D004195:Disease Models, Animal; D048091:Guided Tissue Regeneration; D006801:Humans; D059630:Mesenchymal Stem Cells; D011817:Rabbits; D011897:Random Allocation; D011994:Recombinant Proteins; D012886:Skull / Q000293:injuries* / Q000601:surgery; D023822:Tissue Engineering; D016212:Transforming Growth Factor beta
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen