title: [Effect of human adipose-derived stromal cells on osteogenesis in vivo].
abstract: OBJECTIVE
  To explore the effect of human adipose-derived stromal cells (hASCs) on the osteogenesis during the process of bone formation in vivo,  and to lay the foundation of further investigations on the mechanism of in vivo osteogenesis of hASCs.
  
  
  METHODS
  hASCs were isolated from adipose  tissue by the method of collagenase digestion, and were routinely proliferated and passaged. In the in vivo study 16 nude mice were used and 4 groups  were set and implanted subcutaneously into the back of nude mice: (1) blank; (2) β-tricalcium phosphate (β-TCP) scaffold only (scaffold control group);  (3) β-TCP scaffold with human fibroblasts (negative cell control group); (4) β-TCP scaffold with hASCs (test group). After 1 week, 2 weeks, 4 weeks and 6  weeks of implantation, samples from the 4 nude mice were collected at each time point. Scanning electron microscope (SEM) observation and histological  staining were performed to evaluate the in vivo osteogenesis of hASCs.
  
  
  RESULTS
  SEM images showed that large amount of extracellular matrix (ECM)  could be observed around hASCs in test group after 2 weeks of implantation. At the time point of 4 weeks, mineral deposit was found in ECM. At the time  point of 6 weeks, the mineral deposit was observed to increase significantly. HE staining showed that the ECM with eosinophilic staining could be  observed around hASCs after 2 weeks of implantation. At the time point of 4 weeks, newly-formed bone-like tissue could be found in ECM around the  scaffold materials. At the time point of 6 weeks, more bone-like tissues were observed in ECM with typical structure of bone tissue. In comparison, no  obvious mineralization and bone-like tissue were found in other groups.
  
  
  CONCLUSIONS
  hASCs play important roles in the process of osteogenesis in  vivo, including secretion of large amount of ECM, acceleration of the mineralization of ECM and guidance for the formation of bone-like tissues.
authors.affiliation: Department of Prosthodonties, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Yun-song
authors.initials: YS
authors.lastname: Liu
authors.forename: Long-wei
authors.initials: LW
authors.lastname: Lv
authors.forename: Yong-sheng
authors.initials: YS
authors.lastname: Zhou
authors.forename: Gui-e
authors.initials: GE
authors.lastname: Ma
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Cong
authors.initials: C
authors.lastname: Fan
authors.forename: Xiao
authors.initials: X
authors.lastname: Shao
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D039902:Multipotent Stem Cells / Q000166:cytology / Q000637:transplantation; D010012:Osteogenesis; D017154:Stromal Cells / Q000166:cytology / Q000637:transplantation*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014183:Transplantation, Heterologous