New bone formation induced by injection of native reindeer bone morphogenetic protein extract.
OBJECTIVE
Bone morphogenetic proteins (BMPs) are usually administered with a solid framing material during open surgery. In some instances, percutaneous administration of injectable BMP would be preferable. We tested the new bone-forming activity of injectable native reindeer BMP extract in the Balb/C mouse thigh muscle pouch model.


METHODS
The injectable implants contained 6 mg of native reindeer BMP extract and either physiological saline (NaCl/BMP) or collagen (Gel/BMP). Corresponding implants without BMP served as controls. New bone formation was evaluated based on incorporation of Ca45 and radiographically three weeks after the injection into the mouse thigh muscles.


RESULTS
None of the injections without BMP were able to induce new bone visible in radiographs, whereas the injections with BMP induced new bone effectively. There were no significant differences in the area of new bone (p = 0.247) and its density (p = 0.739) between the NaCl/BMP and Gel/BMP groups. Ca-45 incorporation was multifold in the NaCl/BMP and Gel/BMP groups compared to the controls (p = 0.000). No significant differences in Ca-45 incorporation (p = 0.739) between the NaCl/BMP and Gel/BMP groups were observed.


CONCLUSIONS
Our results suggest that BMP can be administered percutaneously, and that collagen and physiological saline are equally good carriers of injectable implants of native reindeer BMP.
Pekkarinen
T
T
Bone Transplantation Research Group, University of Oulu, Oulu, Finland.
Lindholm
T S
TS
Hietala
O
O
Jalovaara
P
P
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D007273:Injections, Intramuscular; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D010012:Osteogenesis / Q000187:drug effects*; D012053:Reindeer
D019485:Bone Morphogenetic Proteins