title: Growth of bone marrow stromal cells on small intestinal submucosa: an alternative cell source for tissue engineered bladder.
abstract: OBJECTIVE
  To assess the potential use of bone marrow stromal cell (BMSC)-seeded biodegradable scaffold for bladder regeneration in a canine model, by characterizing BMSCs and comparing them to bladder smooth muscle cells (SMCs) by immunohistochemistry, growth capability, and contractility.
  
  
  METHODS
  Bone marrow was taken by direct needle aspiration from the femurs of five beagle dogs for the in vitro study. Mononuclear cells were isolated by Ficoll-Paque density gradient centrifugation and cultivated in medium 199 with 10% fetal bovine serum. BMSCs were characterized by cell proliferation, in vitro contractility, immunohistochemical analysis, and the growth pattern on small intestinal submucosa (SIS) scaffolds compared to bladder SMC cultures from the same dogs. Another six dogs had a hemicystectomy and bladder augmentation with BMSC-seeded (two), bladder cells including urothelial cells plus SMC-seeded SIS (two) and unseeded SIS scaffolds (two). The six dogs were followed for 10 weeks after augmentation.
  
  
  RESULTS
  In vitro BMSCs had a significant contractile response to calcium-ionophore, with a mean (sem) 36 (2)%, relative contraction (P < 0.01), which was similar to bladder SMCs but markedly different from fibroblasts. BMSCs also expressed alpha-smooth muscle actin by immunohistochemical staining and Western blotting, but did not express desmin or myosin. In vivo, both BMSC-seeded and bladder cell-seeded SIS grafts had solid smooth-muscle bundle formation throughout the graft.
  
  
  CONCLUSIONS
  BMSCs had a similar cell proliferation, histological appearance and contractile phenotype as primary cultured bladder SMCs. SIS supported three-dimensional growth of BMSCs in vitro, and BMSC-seeded SIS scaffold promoted bladder regeneration in a canine model. BMSCs may serve as an alternative cell source in urological tissue engineering.
authors.affiliation: Department of Urology, University of Oklahoma Health Sciences Center, 920 SL Young Boulevard, WP 3150, Oklahoma City, OK 73190, USA. yuanyuan-zhang@ouhsc.edu
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hsueh-Kung
authors.initials: HK
authors.lastname: Lin
authors.forename: Dominic
authors.initials: D
authors.lastname: Frimberger
authors.forename: Robert B
authors.initials: RB
authors.lastname: Epstein
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Kropp
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D000001:Calcimycin / Q000494:pharmacology; D049109:Cell Proliferation; D018920:Coculture Techniques; D004285:Dogs; D005260:Female; D005269:Femur; D007413:Intestinal Mucosa; D007421:Intestine, Small; D007476:Ionophores / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D032389:Myocytes, Smooth Muscle / Q000166:cytology; D012038:Regeneration; D017154:Stromal Cells / Q000166:cytology*; D023822:Tissue Engineering / Q000379:methods*; D001743:Urinary Bladder / Q000502:physiology* / Q000637:transplantation
chemical_list: D007476:Ionophores; D000001:Calcimycin