title: Generation of functional human vascular network.
abstract: BACKGROUND
  One of the major obstacles in regenerating thick, complex tissues such as the liver is their need for vascularization, which is essential to maintain cell viability during tissue growth and to induce structural organization. Herein, we have described a method to engineer a functional human vascular network.
  
  
  METHODS
  Enhanced green fluorescence protein-labeled human umbilical vein endothelial cells (GFP-HUVECs) were cocultivated with kusabira orange-labeled human mesenchymal stem cells (KO-hMSCs) inside a collagen/fibronectin matrix. Premature vascular network formation was visualized by fluorescence microscopy imaging. Furthermore, constructs prevascularized in vitro were implanted into a transparency window in immunodeficient mice.
  
  
  RESULTS
  Following several days of cultivation, GFP-HUVECs formed vessel-like structures that were stabilized by pericytes differentiated from KO-hMSCs. After implantation in vivo, the patency of human vascular structures was proved by rhodamine dextran infusion. These functional vascular structures remained for over 2 months.
  
  
  CONCLUSIONS
  Vascularization is the key challenge to organ generation. We successfully generated human vascular networks inside a matrix. Integration of parenchymal cells using our engineering technique should facilitate future efforts to reconstitute vascularized human organ systems in vitro.
authors.affiliation: Department of Regenerative Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takebe
authors.forename: N
authors.initials: N
authors.lastname: Koike
authors.forename: K
authors.initials: K
authors.lastname: Sekine
authors.forename: M
authors.initials: M
authors.lastname: Enomura
authors.forename: Y
authors.initials: Y
authors.lastname: Chiba
authors.forename: Y
authors.initials: Y
authors.lastname: Ueno
authors.forename: Y-W
authors.initials: YW
authors.lastname: Zheng
authors.forename: H
authors.initials: H
authors.lastname: Taniguchi
mesh_terms: D000818:Animals; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation; D001808:Blood Vessels / Q000378:metabolism / Q000502:physiology*; D002450:Cell Communication; D002454:Cell Differentiation; D002478:Cells, Cultured; D018920:Coculture Techniques; D024042:Collagen Type I / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism / Q000502:physiology* / Q000637:transplantation; D006801:Humans; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008856:Microscopy, Fluorescence; D018919:Neovascularization, Physiologic; D020286:Pericytes / Q000502:physiology; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods; D014162:Transfection; D014654:Vascular Patency; D000097573:Red Fluorescent Protein
chemical_list: D024042:Collagen Type I; D005353:Fibronectins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein; C485184:enhanced green fluorescent protein