title: High-strength silk protein scaffolds for bone repair.
abstract: Biomaterials for bone tissue regeneration represent a major focus of orthopedic research. However, only a handful of polymeric biomaterials are utilized today because of their failure to address critical issues like compressive strength for load-bearing bone grafts. In this study development of a high compressive strength (~13 MPa hydrated state) polymeric bone composite materials is reported, based on silk protein-protein interfacial bonding. Micron-sized silk fibers (10-600 µm) obtained utilizing alkali hydrolysis were used as reinforcement in a compact fiber composite with tunable compressive strength, surface roughness, and porosity based on the fiber length included. A combination of surface roughness, porosity, and scaffold stiffness favored human bone marrow-derived mesenchymal stem cell differentiation toward bone-like tissue in vitro based on biochemical and gene expression for bone markers. Further, minimal in vivo immunomodulatory responses suggested compatibility of the fabricated silk-fiber-reinforced composite matrices for bone engineering applications.
authors.affiliation: Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
authors.forename: Biman B
authors.initials: BB
authors.lastname: Mandal
authors.forename: Ariela
authors.initials: A
authors.lastname: Grinberg
authors.forename: Eun Seok
authors.initials: ES
authors.lastname: Gil
authors.forename: Bruce
authors.initials: B
authors.lastname: Panilaitis
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001696:Biomechanical Phenomena; D012831:Bombyx / Q000737:chemistry*; D001861:Bone Regeneration / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D019245:Compressive Strength; D005260:Female; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D044968:Regenerative Medicine / Q000379:methods*; D047011:Silk / Q000737:chemistry*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D047011:Silk