title: Osteogenic evaluation of calcium/magnesium-doped mesoporous silica scaffold with incorporation of rhBMP-2 by synchrotron radiation-based μCT.
abstract: The regenerative treatment of large osseous defects remains a formidable challenge in orthopedic surgery today. In the present study, we have synthesized biodegradable calcium/magnesium-doped silica-based scaffolds with hierarchically macro/mesoporous structure (CMMS), and incorporated recombinant human bone morphogenetic protein-2 (rhBMP-2) into the scaffolds to obtain a hybrid system for osteogenic factor delivery in the functional repair of bone defects. The developed CMMS/rhBMP-2 scaffolds presented interconnected porous network, macropores (200-500 μm) and mesopores (5.7 nm), as well as good bioactivity and biocompatibility and proper degradation rate. Combined with the capacity to deliver ions and growth factors, the CMMS/rhBMP-2 scaffolds significantly promoted the in vitro osteogenic differentiation of bone marrow stromal cells (bMSCs), as evidenced by the enhanced expression of Runx-2, osteopontin, osteocalcin and bone sialoprotein, and induced the ectopic bone formation in the thigh muscle pouches of mice. We further assessed the in vivo effects of CMMS/rhBMP-2 scaffolds in a rabbit femur cavity defect model by using synchrotron radiation-based μCT (SRμCT) imaging and histological analysis, indicating that the CMMS/rhBMP-2 scaffolds resulted in more bone regeneration compared to that observed with the CMMS scaffolds without rhBMP-2. Moreover, scaffolds with or without rhBMP-2 underwent gradual resorption and replacement with bone and almost disappeared at 12 weeks, while the dense CMMS/rhBMP-2 material showed slower degradation rate and promoted the least extensive neo-bone formation. This study suggested that the hybrid CMMS/rhBMP-2 scaffolds system demonstrates promise for bone regeneration in clinical case of large bone defects.
authors.affiliation: The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Dai
authors.forename: Han
authors.initials: H
authors.lastname: Guo
authors.forename: Jingxiong
authors.initials: J
authors.lastname: Lu
authors.forename: Jianlin
authors.initials: J
authors.lastname: Shi
authors.forename: Jie
authors.initials: J
authors.lastname: Wei
authors.forename: Changsheng
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001854:Bone Marrow Cells / Q000166:cytology; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D001842:Bone and Bones / Q000166:cytology; D002118:Calcium; D002454:Cell Differentiation; D049109:Cell Proliferation; D006801:Humans; D008274:Magnesium; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry; D012822:Silicon Dioxide; D017154:Stromal Cells / Q000166:cytology; D017356:Synchrotrons; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D012822:Silicon Dioxide; D008274:Magnesium; D002118:Calcium