Bone grafts cultured with bone marrow stromal cells for the repair of critical bone defects: an experimental study in mice.
Tissue engineering of autologous bone combined with osteoprogenitor cells is a suitable strategy for filling large bone defects. The aim of this study was to evaluate the osteogenicity of a xenogenic bone graft cultured with allogenic bone marrow stromal cells (BMSC) in a mouse critical size craniotomy. Bovine trabecular bone grafts were made free of bone marrow cells or debris and were delipidated. BMSC were harvested from C57BL/6-Tg(ACTbEGFP)1Osb/J mice (GFP+ cells) and were cultured 14 days on bone grafts in control or osteogenic medium. Engineered grafts were implanted in calvarial defect in C57BL/6 mice. Four groups were studied: graft with BMSC differentiated in osteoblasts (G-Ob), graft with BMSC (G-BMSC), graft without cells (G) and no graft. Calvariae were studied 2 and 8 weeks after implantation by radiographic and histomorphometric analyses. G group: the bone ingrowth was limited to the edges of the defect. The center of the graft was filled by a fibrovascular connective tissue. G-BMSC or G-Ob groups: bone formation occurred early in the center of the defect and did not increase between 2 and 8 weeks; the newly formed woven bone was partially replaced by lamellar bone. The preoperative osteoblastic differentiation of BMSC did not allow faster and better bone regeneration. After 2 weeks, GFP+ cells were observed around the grafted bone but no GFP+ osteocyte was present in the newly formed bone. No GFP+ cell was noted after 8 weeks. However, pre-implantation culture of the biomaterial with allogenic BMSC greatly enhanced the bone regeneration.
Dumas
Aline
A
INSERM, U922, LHEA, Faculté de Médecine, 49045 Angers Cedex, France.
Moreau
Marie-Françoise
MF
Ghérardi
Romain K
RK
Baslé
Michel F
MF
Chappard
Daniel
D
D000818:Animals; D001854:Bone Marrow Cells; D001861:Bone Regeneration; D016025:Bone Transplantation / Q000379:methods*; D002417:Cattle; D002454:Cell Differentiation; D018920:Coculture Techniques; D020007:Implants, Experimental; D051379:Mice; D008810:Mice, Inbred C57BL; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis; D017154:Stromal Cells / Q000166:cytology*; D023822:Tissue Engineering / Q000379:methods*; D014183:Transplantation, Heterologous