title: Ex vivo method to visualize and quantify vascular networks in native and tissue engineered skin.
abstract: OBJECTIVE
  Neovascularization plays a pivotal role in tissue engineering and tissue regeneration. However, reliable technologies to visualize and quantify blood vessel networks in target tissue areas are still pending. In this work, we introduce a new method which allows comparing vascularization levels in normal and tissue-engineered skin.
  
  
  METHODS
  Normal skin was isolated, and vascular dermal regeneration was analyzed based on tissue transillumination and computerized digital segmentation. For tissue-engineered skin, a bilateral full skin defect was created in a nude mouse model and then covered with a commercially available scaffold for dermal regeneration. After 3 weeks, the whole skin (including scaffold for dermal regeneration) was harvested, and vascularization levels were analyzed.
  
  
  RESULTS
  The blood vessel network in the skin was better visualized by transillumination than by radio-angiographic studies, the gold standard for angiographies. After visualization, the whole vascular network was digitally segmented showing an excellent overlapping with the original pictures. Quantification over the digitally segmented picture was performed, and an index of vascularization area (VAI) and length (VLI) of the vessel network was obtained in target tissues. VAI/VLI ratio was calculated to obtain the vessel size index.
  
  
  CONCLUSIONS
  We present a new technique which has several advantages compared to others, as animals do not require intravascular perfusions, total areas of interest can be quantitatively analyzed at once, and the same target tissue can be processed for further experimental analysis.
authors.affiliation: Department of Plastic Surgery and Hand Surgery, Burn Care Center, UKSH Campus Lubeck, University of Lubeck, Lubeck, Germany.
authors.forename: José Tomás
authors.initials: JT
authors.lastname: Egaña
authors.forename: Alexandru
authors.initials: A
authors.lastname: Condurache
authors.forename: Jörn Andreas
authors.initials: JA
authors.lastname: Lohmeyer
authors.forename: Mathias
authors.initials: M
authors.lastname: Kremer
authors.forename: Beate M
authors.initials: BM
authors.lastname: Stöckelhuber
authors.forename: Sergio
authors.initials: S
authors.lastname: Lavandero
authors.forename: Hans-Günther
authors.initials: HG
authors.lastname: Machens
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000033:anatomy & histology; D005260:Female; D007091:Image Processing, Computer-Assisted; D051379:Mice; D008819:Mice, Nude; D008833:Microcirculation / Q000502:physiology*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*; D012867:Skin / Q000098:blood supply*; D012984:Software; D023822:Tissue Engineering; D014172:Transillumination