[The effect of HA mixed with adenovirus mediated rhBMP-2 transferred BMSCs of goats on distraction osteogenesis].
OBJECTIVE
To evaluate the effectiveness of HA mixed with adenovirus mediated rhBMP-2 gene (Adv-rhBMP-2) transferred BMSCs of goats on distraction osteogenesis.


METHODS
Nineteen adult goats were used for the experiment, no matter they were male or female, and the weight of the goats were 15-20 kg. The 10 mL marrow was obtained from the iliac crest of each goat. The BMSCs was expanded and passaged conventionally. The 3th BMSCs was infected by Adv-rhBMP-2 at 200 multiplicity of infection (MOI). The 1 x 10(8) infected BMSCs were digested by 0.25% trypsin and collected, then mixed with HA. The right tibia lengthening models were developed, and mixture with BMSCs was injected in the osteotomy position. The goats were divided randomly into 4 groups according to the material injected in operation, group A: Adv-rhBMP-2/BMSCs/HA (n = 6); group B: Adv-rhBMP-2/BMSCs (n = 5); group C: Adv-beta-gal/BMSCs/HA (n = 4); group D: sham without any injections (n = 4). After a seven-day latency period following ostectomy, distraction was carried out at a rate of 1 mm/day for 4 weeks. Roentgenography was practiced in 5, 8 and 12 weeks. After 12 weeks, the goats were sacrificed and dual-energy X-ray absorptiometry (DXA), biomechanical test and histology results were studied.


RESULTS
After five and eight weeks surgery, X-ray test showed the distraction callus was more in group A and B than group C and D, and the radiographic score was significantly higher in group A and B than in the other two groups (P < 0.05); after 12 weeks surgery, the continued callus was formed in the distraction defects in all groups. DXA showed the mean bone mineral content of distraction callus in group A, B, C, D was (4.175 +/- 1.921), (2.600 +/- 0.638), (2.425 +/- 0.826) and (1.175 +/- 0.574) g, and the mean bone mineral density was (0.612 +/- 0.196), (0.630 +/- 0.159), (0.450 +/- 0.166) and (0.266 +/- 0.113) g/cm2. The group A and B was significantly higher than group C and D (P < 0.05). Biomechanical test showed the maximum loading of group A, B, C, D was (490.20 +/- 155.08), (350.59 +/- 80.48), (221.95 +/- 68.79) and (150.65 +/- 92.29) N, and elastic modulus was (178.24 +/- 105.80), (105.88 +/- 27.09), (81.18 +/- 48.67) and (50.35 +/- 47.64) MPa. The group A was significantly higher than in group C and D (P < 0.05). Histology observation revealed abundant bone formation in the distraction defects in group A, and the bone trabecula was arranged longitudinal and netlike. Histomorphology analysis revealed the bone volume in group A, B, C, D was 72.35% +/- 5.68%, 67.58% +/- 7.42%, 49.63% +/- 4.87% and 38.87% +/- 2.35%, and the bone formation was significantly greater in group A compared with group D (P < 0.05).


CONCLUSIONS
HA mixed with rhBMP-2 modified BMSCs can accelerate distraction osteogenesis in goats.
Lin
Zaijun
Z
Department of Orthopaedics, Shanghai Ninth People's Hospital, Medical College of Shanghai Jiaotong University, Shanghai, 200011, P.R. China.
Zhu
Zhenan
Z
Tang
Tingting
T
Dai
Kerong
K
Lou
Jueren
J
Meng
Fanlin
F
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015519:Bone Density / Q000187:drug effects; D016026:Bone Marrow Transplantation / Q000379:methods*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics* / Q000494:pharmacology; D002478:Cells, Cultured; D005260:Female; D006041:Goats; D006820:Hyaluronic Acid; D008297:Male; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D019857:Osteogenesis, Distraction; D011994:Recombinant Proteins / Q000235:genetics* / Q000494:pharmacology; D033581:Stem Cell Transplantation / Q000379:methods*; D013977:Tibia / Q000293:injuries / Q000601:surgery; D023822:Tissue Engineering / Q000379:methods; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000494:pharmacology
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D006820:Hyaluronic Acid