title: Cell characterization of porcine aortic valve and decellularized leaflets repopulated with aortic valve interstitial cells: the VESALIO Project (Vitalitate Exornatum Succedaneum Aorticum Labore Ingenioso Obtenibitur).
abstract: BACKGROUND
  Heart valve bioprostheses for cardiac valve replacement are fabricated by xeno- or allograft tissues. Decellularization techniques and tissue engineering technologies applied to these tissues might contribute to the reduction in risk of calcification and immune response. Surprisingly, there are few data on the cell phenotypes obtained after cellularizing these naturally-derived biomaterials in comparison to those expressed in the intact valve.
  
  
  METHODS
  Aortic valve interstitial cells (VIC) were used to repopulate the corresponding valve leaflets after a novel decellularization procedure based on the use of ionic and nonionic detergents. VIC from leaflet microexplants at the third passage were utilized to repopulate the decellularized leaflets. Intact, decellularized and repopulated valve leaflets and cultured VIC were examined by immunocytochemical procedures with a panel of antibodies to smooth muscle and nonmuscle differentiation antigens. Intact and cellularized leaflets were also investigated with Western blotting and transmission electron microscopy, respectively.
  
  
  RESULTS
  Myofibroblasts and smooth muscle cells (SMC) were mostly localized to the ventricularis of the leaflet whereas fibroblasts were dispersed unevenly. Cultured VIC were comprised of myofibroblasts and fibroblasts with no evidence of endothelial cells and SMC. Two weeks after VIC seeding into decellularized leaflets, grafted cells were found penetrating the bioscaffold. The immunophenotypic and ultrastructural properties of the grafted cells indicated that a VIC heterogeneous mesenchymal cell population was present: fibroblasts, myofibroblasts, SMC, and endothelial cells.
  
  
  CONCLUSIONS
  VIC seeding on detergent-treated valve bioscaffolds has the cellular potential to reconstruct a viable aortic valve.
authors.affiliation: Department of Experimental and Clinical Medicine, University of Padua, Padua, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bertipaglia
authors.forename: Fulvia
authors.initials: F
authors.lastname: Ortolani
authors.forename: Lucia
authors.initials: L
authors.lastname: Petrelli
authors.forename: Gino
authors.initials: G
authors.lastname: Gerosa
authors.forename: Michele
authors.initials: M
authors.lastname: Spina
authors.forename: Paolo
authors.initials: P
authors.lastname: Pauletto
authors.forename: Dino
authors.initials: D
authors.lastname: Casarotto
authors.forename: Maurizio
authors.initials: M
authors.lastname: Marchini
authors.forename: Saverio
authors.initials: S
authors.lastname: Sartore
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000166:cytology*; D001705:Bioprosthesis; D015153:Blotting, Western; D003584:Cytological Techniques; D005347:Fibroblasts / Q000166:cytology; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009130:Muscle, Smooth / Q000166:cytology; D013552:Swine; D023822:Tissue Engineering; D014183:Transplantation, Heterologous; D014184:Transplantation, Homologous