title: [Angiogenesis investigations in tissue engineering. The cylinder model on the chorioallantois membrane].
abstract: BACKGROUND
  Tissue engineering (TE) applications include the isolation, culture, and seeding of cells into a suitable matrix or scaffold prior to in vivo transplantation. After transplantation, vascularization of the scaffold is a principal factor limiting cell viability for the first 6-8 days post transplantation. A model has been developed for systematic analysis of this process.
  
  
  METHODS
  Fertilized white Leghorn eggs were incubated and opened at day 3 of incubation. Preadipocyte-seeded fibrin constructs were implanted in a specially designed plastic cylinder and placed through the opening onto the surface of the chorioallantoic membrane (CAM) at day 8 of incubation. Vascularization of the constructs by chorioallantoic blood vessels was assessed for up to 8 days post transplantation.
  
  
  RESULTS
  The survival rate for embryos receiving constructs was about 90%. Histology confirmed transplant cell viability at day 4 post transplantation, and vascularization of the constructs by avian endothelial cells progressively increased thereafter.
  
  
  CONCLUSIONS
  A new in vivo model to study the effect of angiogenesis in TE constructs including assessments of viability, proliferation, and differentiation of transplanted cells and biomaterial properties is presented. Advantages include easy access to the CAM vascular network, lack of immunocompetence, low cost, and avoidance of animal experiments.
authors.affiliation: Abteilung für Plastische und Handchirurgie, Chirurgische Universitätsklinik Freiburg. borges@ch11.ukl.uni-freiburg.de
authors.forename: J
authors.initials: J
authors.lastname: Borges
authors.forename: F T
authors.initials: FT
authors.lastname: Tegtmeier
authors.forename: N
authors.initials: N
authors.lastname: Torio-Padron
authors.forename: M C
authors.initials: MC
authors.lastname: Mueller
authors.forename: G B
authors.initials: GB
authors.lastname: Stark
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000637:transplantation; D000482:Allantois / Q000098:blood supply*; D000818:Animals; D002196:Capillaries / Q000166:cytology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002642:Chick Embryo; D002823:Chorion / Q000098:blood supply*; D004730:Endothelium, Vascular / Q000166:cytology; D006801:Humans; D018919:Neovascularization, Physiologic / Q000502:physiology*; D033581:Stem Cell Transplantation; D023822:Tissue Engineering / Q000379:methods*; D014183:Transplantation, Heterologous