title: The osteogenic properties of CaP/silk composite scaffolds.
abstract: The rationale for the present study was to develop porous CaP/silk composite scaffolds with a CaP-phase distribution and pore architecture better suited to facilitate osteogenic properties of human bone mesenchymal stromal cells (BMSCs) and in vivo bone formation abilities. This was achieved by first preparing CaP/silk hybrid powders which were then incorporated into silk to obtain uniform CaP/silk composite scaffolds, by means of a freeze-drying method. The composition, microstructure and mechanical properties of the CaP/silk composite scaffolds were ascertained by X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM) and a universal mechanical testing machine. BMSCs were cultured in these scaffolds and cell proliferation analyzed by confocal microscopy and MTS assay. Alkaline phosphatase (ALP) activity and osteogenic gene expression were assayed to determine if osteogenic differentiation had taken place. A calvarial defect model in SCID mice was used to determine the in vivo bone forming ability of the hybrid CaP/silk scaffolds. Our results showed that incorporating the hybrid CaP/silk powders into silk scaffolds improved both pore structure architecture and distribution of CaP powders in the composite scaffolds. By incorporating the CaP phase into silk scaffolds in vitro osteogenic differentiation of BMSCs was enhanced and there was increased in vivo cancellous bone formation. Here we report a method with which to prepare Ca/P composite scaffolds with a pore structure and Ca/P distribution better suited to facilitate BMSC differentiation and bone formation.
authors.affiliation: Ministry Education Key Laboratory for Oral Biomedical Engineering, School of Stomatology, Wuhan University, Wuhan 430079, PR China. zyf@whu.edu.cn
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Chengtie
authors.initials: C
authors.lastname: Wu
authors.forename: Thor
authors.initials: T
authors.lastname: Friis
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002130:Calcium Phosphates / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D019245:Compressive Strength / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000187:drug effects*; D016062:Porosity / Q000187:drug effects; D011208:Powders; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D047011:Silk / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D054457:Tissue Scaffolds / Q000737:chemistry*; D014961:X-Ray Diffraction; D055114:X-Ray Microtomography
chemical_list: D002130:Calcium Phosphates; D011208:Powders; D012333:RNA, Messenger; D047011:Silk; C020243:calcium phosphate; D000469:Alkaline Phosphatase