title: Enhanced neovascular formation in a novel hydrogel matrix consisting of citric Acid and collagen.
abstract: BACKGROUND
  Three-dimensional regenerative tissue with large bulk generally requires blood perfusion through a vascular network to maintain its viability, and one promising approach is induction of neovascular growth from the recipient bed into the tissue. To induce ingrowth of a vascular network, it is necessary to furnish the regenerative tissue with a scaffold structure for neovasculature and a delivery system for an angiogenic growth factor. As such a scaffold structure, the present study created novel hydrogel materials by chemically cross-linking alkali-treated collagen (AlCol) with trisuccinimidyl citrate (TSC).
  
  
  METHODS
  Many prototypes, consisting of several concentrations of TSC and AlCol, were implanted into the subfascial space of the rat rectus muscle, and 7 days later, the implanted materials were excised for histological analysis. Cross-sections were stained and neovascular development in the materials was evaluated by measuring vessel density, length and number of joints and branches.
  
  
  RESULTS
  Significant ingrowth of vascularized granulation was observed in some materials, which surpassed the angiogenic ability of Matrigel(TM). Further, combination with basic fibroblast growth factor (bFGF) significantly increased the vascular formation in these gels.
  
  
  CONCLUSIONS
  The TSC-AlCol gel functioned as a favorable scaffold for neovascular formation and also as a reservoir for controlled delivery of bFGF.
authors.affiliation: Division of Vascular Surgery, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan ; Division of Tissue Engineering, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Nagayoshi
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Taguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koyama
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takato
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Miyata
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nagawa
keywords: basic fibroblast growth factor; citric acid; collagen; hydrogel; neovasucular formation
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