title: Effects of dextran on proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells.
abstract: BACKGROUND
  Bioreactors have been used extensively to construct tissue-engineered bone. However, mass transport and flow shear stress, the two main factors contributing to the construction of tissue-engineered bone, cannot be studied separately when changing the perfusing rate. A tackifier needs to be added into the medium to separate the two factors. This study investigated the feasibility of using dextran as a tackifier in the study of individual effects of mass transport and flow shear stress on the construction of tissue-engineered bone.
  
  
  METHODS
  Human bone marrow-derived mesenchymal stromal cells (hBMSC) were isolated and cultured in media containing 1%, 3%, 5%, 7% and 9% dextran [molecular weight (MW) 70000]. Cell proliferation and osteogenic differentiation were observed in vitro. hBMSC cultured without dextran provided a control group.
  
  
  RESULTS
  Cell proliferation was found to have no significant statistical difference (P>0.05) with a dextran concentration range of 1-7%. No significant difference in alkaline phosphatase (ALP) activity (P>0.05) was found among the different groups. Alizarin red staining showed no difference in mineralized extracellular matrix among the groups with a concentration of dextran less than 9%. Expression of collagen, ALP, osteopontin (OPN) and osteocalcin (OC) genes did not show any difference with a concentration range of 1-7%.
  
  
  CONCLUSIONS
  When using a bioreactor to construct tissue-engineered bone, it is feasible to add a 1-7% dextran (MW 70000) concentration into the medium in order to study the effects of mass transport and flow shear stress.
authors.affiliation: Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China.
authors.forename: D
authors.initials: D
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Dai
authors.forename: T
authors.initials: T
authors.lastname: Tang
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects*; D001842:Bone and Bones / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D003911:Dextrans / Q000494:pharmacology*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects; D023822:Tissue Engineering
chemical_list: D003911:Dextrans; D000469:Alkaline Phosphatase