The effect of blood supply in muscle and an elevated muscle flap on endogenous tissue-engineered bone by rhBMP-2 in the rat.
Metabolism and remodeling of bony tissue are maintained and controlled by blood supply. In this study, bony tissue osteoinduced heterotopically by recombinant human bone morphogenetic protein-2 (rhBMP-2) in rat muscles with different amounts of blood supply was investigated. The implant beds were in the latissimus dorsi muscle (LDM) and in the space wrapped with an elevated latissimus dorsi muscle flap (LDMF). The blood flow was preestimated at two muscle sites using a laser Doppler blood flowmeter. The flow value of the LDM was 2.23 +/- 0.17 ml/min/100 g (mean +/- standard deviation). The flow values of the LDMF were 1.71 +/- 0.22 ml/min/100 g 30 minutes after elevating the LDMF, 1.75 +/- 0.20 ml/min/100 g after 1 week, 1.83 +/- 0.19 ml/min/100 g after 2 weeks, and 1.99 +/- 0.18 ml/min/100 g after 3 weeks. Bony tissues induced heterotopically by rhBMP-2 were examined radiographically and histologically. On radiographs, radiopaque shadows in the LDM were almost as large as those in the LDMF. The radiopacity in the LDM was a little higher than that of the LDMF. The microscopic findings showed increased trabeculae and more hematopoietic marrow in the LDM than lamellalike bone in the LDMF. Mean bony area in the implant was 1.05 +/- 0.26 mm2 in the LDM, and was 0.70 +/- 0.11 mm2 in the LDMF. Bony proportions in the overall implant area were 18.3 +/- 3.46% in the LDF and 12.1 +/- 2.18% in the LDMF. The current study indicates that blood supply is an important factor for promoting heterotopic osteoinduction by rhBMP-2 to produce massive bony tissue as an endogenous method of tissue engineering.
Kusumoto
K
K
Department of Plastic and Reconstructive Surgery, Kansai Medical University, Moriguchi, Osaka, Japan.
Bessho
K
K
Fujimura
K
K
Akioka
J
J
Okubo
Y
Y
Ogawa
Y
Y
Iizuka
T
T
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins; D012212:Rheology; D013524:Surgical Flaps / Q000098:blood supply*; D016212:Transforming Growth Factor beta
C525718:BMP2 protein, human; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta