title: Different types of scaffolds for reconstruction of the urinary tract by tissue engineering.
abstract: BACKGROUND
  Tissue engineering is an important and expanding field in reconstructive surgery. The ideal biomaterial for urologic tissue engineering should be biodegradable and support autologous cell growth. We examined different scaffolds to select the ideal material for the reconstruction of the bladder wall by tissue engineering.
  
  
  METHODS
  We seeded mouse fibroblasts and human keratinocytes in a co-culture model on 13 different scaffolds. The cell-seeded scaffolds were fixed and processed for electron microscopy, hematoxylin and eosin stain, and immunohistochemistry. Cell density and epithelial cell layers were evaluated utilizing a computer-assisted optical measurement system.
  
  
  RESULTS
  Depending on the growth pattern, scaffolds were classified into the following three distinct scaffold types: carrier-type scaffolds with very small pore sizes and no ingrowth of the cells. This scaffold type induces a well-differentiated epithelium. Fleece-type scaffolds with fibers and huge pores. We found cellular growth inside the scaffold but no epithelium on top of it. Sponge-type scaffolds with pores between 20 and 40 microm. Cellular growth was observed inside the scaffold and well-differentiated epithelium on top of it.
  
  
  CONCLUSIONS
  To our knowledge, this is the first time three distinct scaffold types have been reported. All types supported the cell growth. The structure of the scaffolds affects the pattern of cell growth.
authors.affiliation: Department of Urology, University Clinic Aachen, Aachen, Germany. Bernhard.Brehmer@post.rwth-aachen.de
authors.forename: Bernhard
authors.initials: B
authors.lastname: Brehmer
authors.forename: Dorothea
authors.initials: D
authors.lastname: Rohrmann
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker
authors.forename: Gunther
authors.initials: G
authors.lastname: Rau
authors.forename: Gerhard
authors.initials: G
authors.lastname: Jakse
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D002478:Cells, Cultured; D005347:Fibroblasts / Q000648:ultrastructure; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D019651:Plastic Surgery Procedures / Q000379:methods*; D023822:Tissue Engineering; D014551:Urinary Tract / Q000166:cytology / Q000601:surgery*