The adjunctive effect of a binding peptide on bone morphogenetic protein enhanced bone healing in a rodent model of spinal fusion.
METHODS
A prospective 8-week interventional trial employing a rat model of spinal fusion to test the effect on bone morphogenetic protein binding peptide (BBP) on rhBMP-2 induced bone healing.


OBJECTIVE
To determine if the addition of BBP to the collagen sponges used as a carrier for rhBMP-2 reduces the amount of rhBMP-2 required to achieve a satisfactory clinical outcome.


BACKGROUND
Bone morphogenetic proteins (BMPs) although effective in promoting osseous growth and spinal fusion have limitations in their extensive use because of higher costs and possible adverse effects including ectopic bone formation and local inflammatory reaction, particularly in the cervical spine.


METHODS
Posterolateral intertransverse process spinal fusion at L4-L5 was performed in Lewis rats. Two doses of BBP (500 microg, and 1000 microg) were tested with or without "low dose" (1 microg) rhBMP-2 and the results were compared with the low dose (1 microg) rhBMP-2. Fusion was evaluated by radiology, histology, and manual palpation tests.


RESULTS
Radiology revealed significant earlier fusion with 1000 microg BBP + 1 microg BMP-2 combination when compared with low dose BMP-2 (1 microg) only (P < 0.05). Manual palpation and histology at eighth week revealed higher rate of fusion with the same combination with a nearly significant difference (P = 0.057).


CONCLUSIONS
Specific growth factor binding agents, such as BBP, can be compounded into carriers used in fusion procedures to decrease the dosage of BMP and possibly decrease the side effects which are most likely dose-related. This may also decrease costs and improve clinical outcomes.
Alanay
Ahmet
A
Department of Orthopaedics and Traumatology; Hacettepe University Faculty of Medicine, Ankara, Turkey.
Chen
Chihui
C
Lee
Sang
S
Murray
Samuel S
SS
Brochmann
Elsa J
EJ
Miyazaki
Masashi
M
Napoli
Antonia
A
Wang
Jeffrey C
JC
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D018786:Bone Substitutes / Q000008:administration & dosage; D016503:Drug Delivery Systems / Q000379:methods; D004357:Drug Synergism; D006801:Humans; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000601:surgery; D023421:Models, Animal; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000008:administration & dosage*; D013123:Spinal Fusion / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2