title: Customized Ca-P/PHBV nanocomposite scaffolds for bone tissue engineering: design, fabrication, surface modification and sustained release of growth factor.
abstract: Integrating an advanced manufacturing technique, nanocomposite material and controlled delivery of growth factor to form multifunctional tissue engineering scaffolds was investigated in this study. Based on calcium phosphate (Ca-P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposite microspheres, three-dimensional Ca-P/PHBV nanocomposite scaffolds with customized architecture, controlled porosity and totally interconnected porous structure were successfully fabricated using selective laser sintering (SLS), one of the rapid prototyping technologies. The cytocompatibility of sintered Ca-P/PHBV nanocomposite scaffolds, as well as PHBV polymer scaffolds, was studied. For surface modification of nanocomposite scaffolds, gelatin was firstly physically entrapped onto the scaffold surface and heparin was subsequently immobilized on entrapped gelatin. The surface-modification improved the wettability of scaffolds and provided specific binding site between conjugated heparin and the growth factor recombinant human bone morphogenetic protein-2 (rhBMP-2). The surface-modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 significantly enhanced the alkaline phosphatase activity and osteogenic differentiation markers in gene expression of C3H10T1/2 mesenchymal stem cells. Together with osteoconductive nanocomposite material and controlled growth factor delivery strategies, the use of SLS technique to form complex scaffolds will provide a promising route towards individualized bone tissue regeneration.
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong.
authors.forename: Bin
authors.initials: B
authors.lastname: Duan
authors.forename: Min
authors.initials: M
authors.lastname: Wang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000737:chemistry / Q000378:metabolism*; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000737:chemistry*; D002454:Cell Differentiation; D002460:Cell Line; D006493:Heparin / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D008863:Microspheres; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010012:Osteogenesis; D011091:Polyesters / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D000469:Alkaline Phosphatase; D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D002130:Calcium Phosphates; D006493:Heparin; D011091:Polyesters; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C499469:recombinant human bone morphogenetic protein-2; C020243:calcium phosphate