Evaluation of processed bovine cancellous bone matrix seeded with syngenic osteoblasts in a critical size calvarial defect rat model.
BACKGROUND
Biologic bone substitutes may offer alternatives to bone grafting procedures. The aim of this study was to evaluate a preformed bone substitute based on processed bovine cancellous bone (PBCB) with or without osteogenic cells in a critical size calvarial defect rat model.


METHODS
Discs of PBCB (Tutobone) were seeded with second passage fibrin gel-immobilized syngenic osteoblasts (group A, n = 40). Cell-free matrices (group B, n = 28) and untreated defects (group C; n=28) served as controls. Specimens were explanted between day 0 and 4 months after implantation and were subjected to histological and morphometric evaluation.


RESULTS
At 1 month, bone formation was limited to small peripheral areas. At 2 and 4 months, significant bone formation, matrix resorption as well as integration of the implants was evident in groups A and B. In group C no significant regeneration of the defects was observed. Morphometric analysis did not disclose differences in bone formation in matrices from groups A and B. Carboxyfluorescine-Diacetate-Succinimidylester (CFDA) labeling demonstrated low survival rates of transplanted cells.


CONCLUSIONS
Osteoblasts seeded into PBCB matrix display a differentiated phenotype following a 14 days cell culture period. Lack of initial vascularization may explain the absence of added osteogenicity in constructs from group A in comparison to group B. PBCB is well integrated and represents even without osteogenic cells a promising biomaterial for reconstruction of critical size calvarial bone defects.
Kneser
U
U
Department of Plastic and Hand Surgery, University of Erlangen Medical Center, Erlangen, Germany.
Stangenberg
L
L
Ohnolz
J
J
Buettner
O
O
Stern-Straeter
J
J
Möbest
D
D
Horch
R E
RE
Stark
G B
GB
Schaefer
D J
DJ
D000818:Animals; D001672:Biocompatible Materials; D018786:Bone Substitutes / Q000737:chemistry; D001842:Bone and Bones / Q000473:pathology*; D002417:Cattle; D017690:Cell Transplantation; D005456:Fluorescent Dyes / Q000494:pharmacology; D021621:Imaging, Three-Dimensional; D008297:Male; D015233:Models, Statistical; D016348:Osseointegration; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D023822:Tissue Engineering / Q000379:methods*
D001672:Biocompatible Materials; D018786:Bone Substitutes; D005456:Fluorescent Dyes