title: Bioengineered three-dimensional physiological model of colonic longitudinal smooth muscle in vitro.
abstract: BACKGROUND
  The objective of this study was to develop a physiological model of longitudinal smooth muscle tissue from isolated longitudinal smooth muscle cells arranged in the longitudinal axis.
  
  
  METHODS
  Longitudinal smooth muscle cells from rabbit sigmoid colon were isolated and expanded in culture. Cells were seeded at high densities onto laminin-coated Sylgard surfaces with defined wavy microtopographies. A highly aligned cell sheet was formed, to which addition of fibrin resulted in delamination.
  
  
  RESULTS
  (1) Acetylcholine (ACh) induced a dose-dependent, rapid, and sustained force generation. (2) Absence of extracellular calcium attenuated the magnitude and sustainability of ACh-induced force by 50% and 60%, respectively. (3) Vasoactive intestinal peptide also attenuated the magnitude and sustainability of ACh-induced force by 40% and 60%, respectively. These data were similar to force generated by longitudinal tissue. (4) Bioengineered constructs also maintained smooth muscle phenotype and calcium-dependence characteristics.
  
  
  CONCLUSIONS
  This is a novel physiologically relevant in vitro three-dimensional model of colonic longitudinal smooth muscle tissue. Bioengineered three-dimensional longitudinal smooth muscle presents the ability to generate force, and respond to contractile agonists and relaxant peptides similar to native longitudinal tissue. This model has potential applications to investigate the underlying pathophysiology of dysfunctional colonic motility. It also presents as a readily implantable band-aid colonic longitudinal muscle tissue.
authors.affiliation: Department of Pediatrics-Gastroenterology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0658, USA.
authors.forename: Shreya
authors.initials: S
authors.lastname: Raghavan
authors.forename: Mai T
authors.initials: MT
authors.lastname: Lam
authors.forename: Lesley L
authors.initials: LL
authors.lastname: Foster
authors.forename: Robert R
authors.initials: RR
authors.lastname: Gilmont
authors.forename: Sita
authors.initials: S
authors.lastname: Somara
authors.forename: Shuichi
authors.initials: S
authors.lastname: Takayama
authors.forename: Khalil N
authors.initials: KN
authors.lastname: Bitar
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003106:Colon / Q000166:cytology / Q000502:physiology*; D003470:Culture Media; D005455:Fluorescent Antibody Technique; D009130:Muscle, Smooth / Q000166:cytology / Q000502:physiology*; D011817:Rabbits; D023822:Tissue Engineering
chemical_list: D003470:Culture Media; D002118:Calcium