title: Topographical analyses of proliferation and differentiation of osteoblasts in micro- and macropores of apatite-fiber scaffold.
abstract: A variety of calcium phosphates have been used for bone tissue-engineering applications. We developed porous hydroxyapatite (HAp) ceramics by firing green compacts consisting of spherical carbon beads and HAp fiber. The apatite-fiber scaffold (AFS) forms a three-dimensional network of fibers with two different pore sizes (micro- and macropores). In this study, we investigated cell distribution and fine cell structure in AFS by confocal laser scanning microscopy. Osteoblastic cells were permeated homogenously throughout the scaffold under static culture conditions and grew three-dimensionally in macropores of AFS. Cells penetrated into micropores when they were capable of cell-cell formations. Cell proliferation and differentiation were also evaluated by biochemical and molecular biological approaches. The expression levels of early-phase osteogenic genes in AFS increased immediately, and those of middle-phase genes were maintained during the 2-week study period. Furthermore, the expression of late-phase markers increased gradually during the incubation period. These data indicate that macropores provide sufficient space for cell growth and proliferation and that micropores facilitate cell differentiation via cell-cell networks. This study provides evidence for the effectiveness of three-dimensional culture systems comprising AFS, which mimics the microenvironment of bone cells.
authors: Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo, Japan.
authors: Michiyo
authors: M
authors: Honda
authors: Takahiko J
authors: TJ
authors: Fujimi
authors: Shigeki
authors: S
authors: Izumi
authors: Kouji
authors: K
authors: Izawa
authors: Mamoru
authors: M
authors: Aizawa
authors: Hikaru
authors: H
authors: Morisue
authors: Takahide
authors: T
authors: Tsuchiya
authors: Nobuyuki
authors: N
authors: Kanzawa
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D049109:Cell Proliferation; D017886:Durapatite / Q000737:chemistry* / Q000378:metabolism; D008422:Materials Testing; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D016062:Porosity; D023822:Tissue Engineering / Q000379:methods
chemical_list: D017886:Durapatite