Bone formation and degradation of a highly porous biphasic calcium phosphate ceramic in presence of BMP-7, VEGF and mesenchymal stem cells in an ectopic mouse model.
BACKGROUND
Angiogenesis and mesenchymal stem cells (MSCs) promote osteogenesis. The aim of the present study was to evaluate whether bone morphogenetic protein (BMP-7) promoted osteoinduction could be enhanced by combining it with vascular endothelial growth factor (VEGF) or MSCs in highly porous biphasic calcium phosphate (BCP) ceramics.


METHODS
BCP ceramic blocks were implanted in an ectopic site in 24 mice (BMP-7 vs. BMP-7/VEGF; BMP-7 vs. BMP-7/MSCs and BMP-7 vs. Control; each group n=8). Specimens were analysed 12 weeks after surgery by environmental scanning electron microscopy (ESEM) and Giemsa staining.


RESULTS
In all implanted scaffolds, newly formed bone was observed, even in the control site. No statistical differences in the amount of new bone were found in the presence of BMP-7 compared to BMP-7/VEGF (p=1.0) or BMP-7/MSCs (p=0.786). ESEM revealed a degradation of the scaffolds. A higher degradation was observed in areas where no bone-implant contact was present compared to areas where the ceramic was integrated in newly formed bone.


CONCLUSIONS
Neither VEGF nor MSCs enhanced BMP-7 induced bone formation under the selected conditions. The present ceramic seemed to be osteoinductive and degradable, making this material suitable for bone tissue engineering.
Roldán
J C
JC
Department of Cranio-Maxillofacial Surgery, University of Regensburg, Regensburg, Germany. roldan.schack@gmx.de
Detsch
R
R
Schaefer
S
S
Chang
E
E
Kelantan
M
M
Waiss
W
W
Reichert
T E
TE
Gurtner
G C
GC
Deisinger
U
U
D020341:Absorbable Implants; D000818:Animals; D055419:Bone Morphogenetic Protein 7 / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000737:chemistry*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D004338:Drug Combinations; D017886:Durapatite; D045164:Mesenchymal Stem Cell Transplantation; D051379:Mice; D008810:Mice, Inbred C57BL; D039902:Multipotent Stem Cells / Q000637:transplantation; D010012:Osteogenesis / Q000187:drug effects*; D054457:Tissue Scaffolds; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*
D055419:Bone Morphogenetic Protein 7; D002130:Calcium Phosphates; D004338:Drug Combinations; D042461:Vascular Endothelial Growth Factor A; C485817:beta-tricalcium phosphate; D017886:Durapatite