title: Chondrogenesis and hypertrophy in response to aggregate behaviors of human mesenchymal stem cells on a dendrimer-immobilized surface.
abstract: OBJECTIVE
  To investigate the behaviors of aggregates of human mesenchymal stem cells (hMSCs) on chondrogenesis and chondrocyte hypertrophy using spatiotemporal expression patterns of chondrogenic (type II collagen) and hypertrophic (type X collagen) markers during chondrogenesis.
  
  
  RESULTS
  hMSCs were cultured on either a polystyrene surface or polyamidoamine dendrimer surface with a fifth generation (G5) dendron structure in chondrogenic medium and growth medium. At day 7, cell aggregates without stress fibers formed on the G5 surface and triggered differentiation of hMSCs toward the chondrogenic fate, as indicated by type II collagen being observed while type X collagen was undetectable. In contrast, immunostaining of hMSCs cultured on polystyrene, which exhibited abundant stress fibers and did not form aggregates, revealed no evidence of either type II and or type X collagen. At day 21, the morphological changes of the cell aggregates formed on the G5 surface were suppressed as a result of stress fiber formation. Type II collagen was observed throughout the aggregates whereas type X collagen was detected only at the basal side of the aggregates. Change of cell aggregate behaviors derived from G5 surface alone regulated chondrogenesis and hypotrophy, and this was enhanced by chondrogenic medium.
  
  
  CONCLUSIONS
  Incubation of hMSCs affects the expression of type II and X collagens via effects on cell aggregate behavior and stress fiber formation.
authors.affiliation: Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand.
authors.forename: Sopita
authors.initials: S
authors.lastname: Wongin
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Ogawa
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Mee-Hae
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand.|Department of Chemical Engineering, of Engineering, Faculty King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand.
authors.forename: Kwanchanok
authors.initials: K
authors.lastname: Viravaidya-Pasuwat
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan. kino-oka@bio.eng.osaka-u.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kino-Oka
mesh_terms: D002449:Cell Aggregation / Q000187:drug effects / Q000502:physiology; D020219:Chondrogenesis / Q000187:drug effects / Q000502:physiology; D024043:Collagen Type II / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D024121:Collagen Type X / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D050091:Dendrimers / Q000494:pharmacology*; D006801:Humans; D006984:Hypertrophy; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000502:physiology; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D011137:Polystyrenes; D013499:Surface Properties
chemical_list: D024043:Collagen Type II; D024121:Collagen Type X; D050091:Dendrimers; C104700:PAMAM Starburst; D011137:Polystyrenes
keywords: Aggregate formation; Chondrogenic phenotype; Dendrimer surface; Human mesenchymal stem cell; Hypertrophic phenotype