title: Small intestinal submucosa seeded with intestinal smooth muscle cells in a rodent jejunal interposition model.
abstract: BACKGROUND
  Small intestinal submucosa (SIS) is a porcine-derived, acellular, collagen-based matrix that has been tested without seeded smooth muscle cells (SMCs) for intestinal tissue engineering. We examined the expression patterns of contractile proteins of SIS with SMCs implanted in an in vivo rodent model.
  
  
  METHODS
  Intestinal SMCs were isolated from Lewis rat pups. Four-ply tubular SMCs-seeded SIS or blank SIS scaffolds were implanted in an adult rat jejunal interposition model. Recipients were sacrificed at 2, 4, and 8 wk following the implantation. The retrieved specimens were examined using antibodies against contractile proteins of SMCs.
  
  
  RESULTS
  Cultured intestinal SMCs expressed α-smooth muscle actin (α-SMA), calponin, and less smooth muscle myosin heavy chain (SM-MHC) in vitro. Cell-seeded SIS scaffolds contracted significantly over 8 wk of implantation but were comparable to SIS scaffolds without cell seeding. Implanted cell-seeded SIS scaffolds at 2 wk expressed extensive α-SMA, some calponin, and minimal SM-MHC. At 4 wk, α-SMA-expressing cells decreased significantly, whereas calponin or SM-MHC expressing cells were rarely detected. A small number of α-SMA-expressing cells were present at 8 wk, whereas more calponin or SM-MHC expressing cells emerged in proximity with the anastomotic interface.
  
  
  CONCLUSIONS
  Cell-seeded SIS contracted significantly after implantation, but the expressions of contractile proteins were present at the site of SIS interposition. No organized smooth muscle was formed at the site of implantation. A better scaffold design is needed to produce structured smooth muscle.
authors.affiliation: Department of Surgery, University of California, Los Angeles, California, USA.
authors.forename: Harry H
authors.initials: HH
authors.lastname: Qin
authors.forename: James C Y
authors.initials: JC
authors.lastname: Dunn
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism / Q000637:transplantation; D005260:Female; D007413:Intestinal Mucosa / Q000601:surgery*; D007583:Jejunum / Q000601:surgery*; D008840:Microfilament Proteins / Q000378:metabolism; D023421:Models, Animal; D032389:Myocytes, Smooth Muscle / Q000378:metabolism / Q000637:transplantation*; D018995:Myosin Heavy Chains / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D011917:Rats, Inbred Lew; D012778:Short Bowel Syndrome / Q000601:surgery; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D020858:Tissue and Organ Harvesting / Q000379:methods; D000096985:Calponins
chemical_list: D000199:Actins; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D018995:Myosin Heavy Chains; D000096985:Calponins