title: A new source for cardiovascular tissue engineering: human bone marrow stromal cells.
abstract: OBJECTIVE
  Vascular-derived cells represent an established cell source for tissue engineering of cardiovascular constructs. Previously, cell isolation was performed by harvesting of vascular structures prior to scaffold seeding. Marrow stromal cells (MSC) demonstrate the ability to differentiate into multiple mesenchymal cell lineages and would offer an alternative cell source for tissue engineering involving a less invasive harvesting technique. We studied the feasibility of using MSC as an alternative cell source for cardiovascular tissue engineering.
  
  
  METHODS
  Human MSC were isolated from bone marrow and expanded in culture. Subsequently MSC were seeded on bioabsorbable polymers and grown in vitro. Cultivated cells and seeded polymers were studied for cell characterization and tissue formation including extracellular matrix production. Applied methods comprised flow cytometry, histology, immunohistochemistry, transmission (TEM) and scanning electron microscopy (SEM), and biochemical assays.
  
  
  RESULTS
  Isolated MSC demonstrated fibroblast-like morphology. Phenotype analysis revealed positive signals for alpha-smooth muscle actin and vimentin. Histology and SEM of seeded polymers showed layered tissue formation. TEM demonstrated formation of extracellular matrix with deposition of collagen fibrils. Matrix protein analysis showed production of collagen I and III. In comparison to vascular-derived cell constructs quantitative analysis demonstrated comparable amounts of extracellular matrix proteins in the tissue engineered constructs.
  
  
  CONCLUSIONS
  Isolated MSC demonstrated myofibroblast-like characteristics. Tissue formation on bioabsorbable scaffolds was feasible with extracellular matrix production comparable to vascular-cell derived tissue engineered constructs. It appears that MSC represent a promising cell source for cardiovascular tissue engineering.
authors.affiliation: Clinic for Cardiovascular Surgery, University Hospital, Raemistrasse 100, CH 8091 Zurich, Switzerland. alexander.kadner@chi.usz.ch
authors.forename: Alexander
authors.initials: A
authors.lastname: Kadner
authors.forename: Simon P
authors.initials: SP
authors.lastname: Hoerstrup
authors.forename: Gregor
authors.initials: G
authors.lastname: Zund
authors.forename: Karim
authors.initials: K
authors.lastname: Eid
authors.forename: Christine
authors.initials: C
authors.lastname: Maurus
authors.forename: Serguei
authors.initials: S
authors.lastname: Melnitchouk
authors.forename: Jurg
authors.initials: J
authors.lastname: Grunenfelder
authors.forename: Marko I
authors.initials: MI
authors.lastname: Turina
mesh_terms: D000199:Actins / Q000032:analysis; D001854:Bone Marrow Cells / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure; D002319:Cardiovascular System; D002455:Cell Division; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D017154:Stromal Cells / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure; D023822:Tissue Engineering; D014746:Vimentin / Q000032:analysis
chemical_list: D000199:Actins; D014746:Vimentin