Promoted bone healing at a rabbit skull gap between autologous bone fragment and the surrounding intact bone with biodegradable microspheres containing transforming growth factor-beta1.
This study is a trial to promote repairing of the rabbit skull bone gap between an autologous bone flap and the intact bone with biodegradable gelatin microspheres containing transforming growth factor-beta1 (TGF-beta1). A 10-mm diameter bone defect was prepared in rabbit skulls by drilling out a bone flap of 6 mm in diameter. After a surrounding gap defect of 2 mm was created and treated with 0.5 microg of free TGF-beta1 and gelatin microspheres containing 0.5 microg of free TGF-beta1, the circular autologous bone flap was placed in the center. Significant bone healing at the gap defect was observed 3 weeks after implantation of the TGF-beta1-containing gelatin microspheres. The bone mineral density (BMD) was significantly higher than that of other experimental groups. On the contrary, when applied with free TGF-beta1, a fibrous tissue initially infiltrated into the gap defect, resulting in impairing bone healing. The tissue response was similar to that at the defect implanted with empty gelatin microspheres and TGF-beta1-free phosphate-buffered saline solution alone. There was more space in the gap-filling bone in the 16-week view than the 3-week view. It is possible that this was an intermediate step along the way toward normal healing and formation of cancellous bone. We conclude that gelatin microspheres containing TGF-beta1 show promise as an agent to promote bone regeneration of subcritical size defects between surgically positioned autologous bone flaps and surrounding host bone.
Hong
L
L
Department of Neurosurgery, Medical School, Kyoto University, Kyoto, Japan.
Tabata
Y
Y
Miyamoto
S
S
Yamada
K
K
Aoyama
I
I
Tamura
M
M
Hashimoto
N
N
Ikada
Y
Y
D000818:Animals; D001672:Biocompatible Materials; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology*; D016025:Bone Transplantation / Q000502:physiology; D005780:Gelatin; D006801:Humans; D008863:Microspheres; D011817:Rabbits; D011994:Recombinant Proteins / Q000494:pharmacology; D012886:Skull / Q000166:cytology* / Q000502:physiology; D013524:Surgical Flaps; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D001672:Biocompatible Materials; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D005780:Gelatin