A novel hydroxyapatite fiber mesh as a carrier for recombinant human bone morphogenetic protein-2 enhances bone union in rat posterolateral fusion model.
METHODS
An experimental study, in which spinal fusion in rats was conducted using a hydroxyapatite fiber mesh (HAM) as a carrier for recombinant human bone morphogenetic protein (rhBMP)-2.


OBJECTIVE
To study the usefulness of the HAM as a carrier and seek the possibility of clinical application in spinal fusion.


BACKGROUND
Several biomaterials have been used as a carrier for BMP to achieve spine fusion, however, to our knowledge, the most effective carrier has not been established.


METHODS
In experiment No. 1, HAMs and the controls (commercially available hydroxyapatite ceramic body), loaded with rhBMP-2, were immersed in phosphate-buffered saline to evaluate the time course of the release of rhBMP-2. In experiment No. 2, posterolateral fusion was conducted in rats using HAM and the control loaded with rhBMP-2. The fusion status was evaluated radiologically and histologically after surgery.


RESULTS
In experiment No. 1, HAMs released a larger amount of rhBMP-2 for up to 28 days than the controls (49.5% vs 7.8%). In experiment No. 2, the fusion rate was significantly higher in the HAM group (>80%) than in the control group (20%). Dense new bone formed close to the spine, and the HAMs were markedly absorbed compared with the controls.


CONCLUSIONS
HAM provided more solid fusion mass than the control, suggesting that HAM is an efficient carrier for BMP.
Morisue
Hikaru
H
Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Tokyo, Japan.
Matsumoto
Morio
M
Chiba
Kazuhiro
K
Matsumoto
Hideo
H
Toyama
Yoshiaki
Y
Aizawa
Mamoru
M
Kanzawa
Nobuyuki
N
Fujimi
Takahiro J
TJ
Uchida
Hiroshi
H
Okada
Isao
I