title: Biomimetic collagen scaffolds for human bone cell growth and differentiation.
abstract: Type I collagen provides a structural framework for connective tissues and plays a central role in the temporal cascade of events leading to the formation of new bone from progenitors. The aim of this study was to examine the ability of the cell-binding domain of type I collagen (P-15 peptide) to promote human bone marrow stromal cell adhesion, proliferation, and differentiation on three-dimensional scaffolds. Human bone marrow stromal cells were selected, expanded, and cultured on particulate microporous ABM ("pure" hydroxyapatite) phase adsorbed with or without P-15 under basal or osteogenic conditions. Immobilized P-15 increased alkaline phosphatase activity and bone morphogenetic protein 2 (BMP-2) gene expression after 1 and 5 days as determined by real-time polymerase chain reaction. P-15 promoted human bone marrow stromal cell attachment, spreading, and alignment on ABM as well as alkaline phosphatase-specific activity in basal and osteogenic cultures. The presence of mineralized bone matrix, extensive cell ingrowth, and cellular bridging between three-dimensional matrices adsorbed with P-15 was confirmed by confocal microscopy, scanning electron microscopy, and alizarin red staining. Negligible cell growth was observed on ABM alone. In vivo diffusion chamber studies using MF1-nu/nu mice showed bone matrix formation and organized collagen formation after 6 weeks. These studies indicate the potential of P-15 to generate appropriate biomimetic microenvironments for osteoblasts and demonstrate the potential for the exploitation of extracellular matrix cues for osteogenesis and, ultimately, bone regeneration.
authors.affiliation: University Orthopaedics, University of Southampton, Southampton S016 6YD, UK.
authors.forename: Xuebin B
authors.initials: XB
authors.lastname: Yang
authors.forename: Rajendra S
authors.initials: RS
authors.lastname: Bhatnagar
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Richard O C
authors.initials: RO
authors.lastname: Oreffo
mesh_terms: D000327:Adsorption; D021522:Bioartificial Organs; D040761:Biomimetic Materials / Q000737:chemistry / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D001857:Bone Matrix / Q000502:physiology; D018786:Bone Substitutes; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D003094:Collagen / Q000737:chemistry; D024042:Collagen Type I / Q000737:chemistry / Q000494:pharmacology; D005109:Extracellular Matrix / Q000502:physiology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000737:chemistry; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods
chemical_list: D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D024042:Collagen Type I; D010446:Peptide Fragments; C407062:cell-binding peptide P-15; D003094:Collagen