Induction of new bone by basic FGF-loaded porous carbonate apatite implants in femur defects in rats.
OBJECTIVE
The aim of the present study was to investigate whether porous carbonate apatite (CA) containing basic FGF (bFGF) enhances bone augmentation as compared with porous CA alone.


METHODS
Thirty-six disc-shaped porous CA implants were inserted into femur defects in 36 Wister rats. Porous CA containing 0, 5, or 50 ng of bFGF was placed in the defect. Bone augmentation was evaluated radiographically using micro-CT and histologically by conventional staining at 2 and 12 weeks.


RESULTS
At 2 weeks postoperatively, new bone was evident in the defect sites with porous CA containing either 5 or 50 ng of bFGF. The area of regenerated bone, however, was significantly higher with porous CA containing 5 ng of bFGF than with porous CA containing 50 ng. At 12 weeks postoperatively, no differences in new bone formation were seen between porous CA containing 5 and 50 ng bFGF. Porous CA containing bFGF, however, markedly increased the amount of bone newly formed as compared with porous CA without bFGF. Regardless of the implantation period, TRAP-positive cells were visible around the material, indicating that osteoclast-like cells were resorbing porous CA. In accordance with the evidence, bioresorption of the material increased over time: 6.3-7.8% at 2 weeks to 9.1-11.5% at 12 weeks.


CONCLUSIONS
Porous CA is useful as a growth factor carrier and scaffold for bone augmentation.
Keiichi
Kanayama
K
Department of Periodontology, Division of Oral Infections and Health Science, Asahi University School of Dentistry, Gifu, Japan. k-k1@dent.asahi-u.ac.jp
Mitsunobu
Kitago
K
Masafumi
Shiraki
S
Yutaka
Doi
D
Toshiaki
Shibutani
S
D020341:Absorbable Implants; D000818:Animals; D001031:Apatites / Q000494:pharmacology*; D001672:Biocompatible Materials / Q000494:pharmacology; D018786:Bone Substitutes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers; D016503:Drug Delivery Systems; D005269:Femur / Q000502:physiology / Q000601:surgery / Q000648:ultrastructure; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage / Q000502:physiology*; D005500:Follow-Up Studies; D008297:Male; D016348:Osseointegration / Q000187:drug effects* / Q000502:physiology; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D016062:Porosity; D051381:Rats; D017208:Rats, Wistar; D054457:Tissue Scaffolds
D001031:Apatites; D001672:Biocompatible Materials; D018786:Bone Substitutes; D004337:Drug Carriers; D016222:Fibroblast Growth Factor 2; C030782:carboapatite