title: Omentum-wrapped scaffold with longitudinally oriented micro-channels promotes axonal regeneration and motor functional recovery in rats.
abstract: BACKGROUND
  Tissue-engineered nerve scaffolds hold great potential in bridging large peripheral nerve defects. However, insufficient vascularization of nerve scaffolds limited neural tissues survival and regeneration, which hampered the successful implantation and clinical application of nerve scaffolds. The omentum possesses a high vascularization capacity and enhances regeneration and maturation of tissues and constructs to which it is applied. However, combined application of nerve scaffolds and omentum on axonal regeneration and functional recovery in the treatment of large peripheral nerve defects has rarely been investigated thus far.
  
  
  METHODS
  In the present study, an omentum-wrapped collagen-chitosan scaffold was used to bridge a 15-mm-long sciatic nerve defect in rats. Rats that received nerve autografts or scaffolds alone were served as positive control or negative control, respectively. The axonal regeneration and functional recovery were examined by a combination of walking track analysis, electrophysiological assessment, Fluoro-Gold (FG) retrograde tracing, as well as morphometric analyses to both regenerated nerves and target muscles.
  
  
  RESULTS
  The results demonstrated that axonal regeneration and functional recovery were in the similar range between the omentum-wrapping group and the autograft group, which were significantly better than those in the scaffold alone group. Further investigation showed that the protein levels of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were significantly higher in the omentum-wrapping group than those in the scaffold alone group in the early weeks after surgery.
  
  
  CONCLUSIONS
  These findings indicate that the omentum-wrapped scaffold is capable of enhancing axonal regeneration and functional recovery, which might be served as a potent alternative to nerve autografts. The beneficial effect of omentum-wrapping on nerve regeneration might be related with the proteins produced by omentum.
authors.affiliation: Institution of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Yong-Guang
authors.initials: YG
authors.lastname: Zhang
authors.forename: Jing-Hui
authors.initials: JH
authors.lastname: Huang
authors.forename: Xue-Yu
authors.initials: XY
authors.lastname: Hu
authors.forename: Qing-Song
authors.initials: QS
authors.lastname: Sheng
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Zhuo-Jing
authors.initials: ZJ
authors.lastname: Luo
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D055724:Electrophysiological Phenomena; D005786:Gene Expression Regulation; D008297:Male; D055806:Microvessels / Q000473:pathology; D009043:Motor Activity / Q000502:physiology*; D009132:Muscles / Q000473:pathology; D018919:Neovascularization, Physiologic / Q000235:genetics; D009414:Nerve Growth Factors / Q000378:metabolism; D009416:Nerve Regeneration / Q000235:genetics / Q000502:physiology*; D009852:Omentum / Q000637:transplantation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D012584:Sciatic Nerve / Q000098:blood supply / Q000503:physiopathology; D013266:Stilbamidines / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D013266:Stilbamidines; D042461:Vascular Endothelial Growth Factor A