Biphasic calcium phosphate nano-composite scaffolds reinforced with bioglass provide a synthetic alternative to autografts in a canine tibiofibula defect model.
BACKGROUND
Bone grafting is commonly used to repair bone defects. As the porosity of the graft scaffold increases, bone formation increases, but the strength decreases. Early attempts to engineer materials were not able to resolve this problem. In recent years, nanomaterials have demonstrated the unique ability to improve the material strength and toughness while stimulating new bone formation. In our previous studies, we synthesized a nano-scale material by reinforcing a porous β-tricalcium phosphate (β-TCP) ceramic scaffold with Na2O-MgO-P2O5-CaO bioglass (β-TCP/BG). However, the in vivo effects of the β-TCP/BG scaffold on bone repair remain unknown.


METHODS
We investigated the efficacy of β-TCP/BG scaffolds compared to autografts in a canine tibiofibula defect model. The tibiofibula defects were created in the right legs of 12 dogs, which were randomly assigned to either the scaffold group or the autograft group (six dogs per group). Radiographic evaluation was performed at 0, 4, 8, and 12 weeks post-surgery. The involved tibias were extracted at 12 weeks and were tested to failure via a three-point bending. After the biomechanical analysis, specimens were subsequently processed for scanning electron microscopy analysis and histological evaluations.


RESULTS
Radiographic evaluation at 12 weeks post-operation revealed many newly formed osseous calluses and bony unions in both groups. Both the maximum force and break force in the scaffold group (n = 6) were comparable to those in the autograft group (n = 6, P > 0.05), suggesting that the tissue-engineered bone repair achieved similar biomechanical properties to autograft bone repair. At 12 weeks post-operation, obvious new bone and blood vessel formations were observed in the artificial bone of the experimental group.


CONCLUSIONS
The results demonstrated that new bone formation and high bone strength were achieved in the β-TCP/BG scaffold group, and suggested that the β-TCP/BG scaffold could be used as a synthetic alternative to autografts for the repair of bone defects.
Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
Dezhi
D
Tang
Shanghai Changzheng Hospital, Shanghai 200003, China. Email: xuguohuamail@126.com.
Guohua
G
Xu
Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
Zhou
Z
Yang
Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642, USA.
Jonathan
J
Holz
Shanghai Changzheng Hospital, Shanghai 200003, China.
Xiaojian
X
Ye
Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072, China.
Shu
S
Cai
Shanghai Changzheng Hospital, Shanghai 200003, China.
Wen
W
Yuan
Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
Yongjun
Y
Wang
D000818:Animals; D064592:Autografts; D018786:Bone Substitutes / Q000737:chemistry; D002516:Ceramics; D004285:Dogs; D005260:Female; D005360:Fibula / Q000293:injuries* / Q000601:surgery; D006882:Hydroxyapatites / Q000737:chemistry*; D013977:Tibia / Q000293:injuries* / Q000601:surgery; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
C022107:Bioglass; D018786:Bone Substitutes; D006882:Hydroxyapatites; C074950:hydroxyapatite-beta tricalcium phosphate