title: Tissue-engineered conduit promotes sciatic nerve regeneration following radiation-induced injury as monitored by magnetic resonance imaging.
abstract: OBJECTIVE
  To observe the longitudinal changes in peripheral nerve repaired with chitosan conduits in a rat model of radiation-induced neuropathy.
  
  
  METHODS
  Four months after 40 Gy radiation to the right lower limbs, forty-two rats were divided randomly into three groups. Chitosan conduits were implanted with (group A, n=12) or without (group B, n=12) mesenchymal stem cells (MSCs), and untreated controls (group C, n=12). Following sciatic nerve MR imaging (including T2WI and Gd-DTPA enhanced T1WI), functional evaluation and electrophysiological exam were performed two-monthly, final histological assessments were done at the end of one year. The differences among the experimental and control groups were statistically analysed with Fisher's PLSD or t-test.
  
  
  RESULTS
  The compound muscle action potentials (CMAPs) and sciatic function index (SFI) had declined since 4 months after radiation injury. The focal nerve enlargement and hyperintensity, the perineurium and connecting muscle enhancement were demonstrated by MR neurography images. After chitosan tube implantation, the normalized signal intensities (SIs) in group A were declined more rapidly than SIs in other groups. The histological assessments indicated that group A had better remyelination, combined with higher CMAPs amplitude and SFI score than other groups.
  
  
  CONCLUSIONS
  A single fraction dose of 40 Gy can be used to establish a rat model of sciatic nerve injury. Longitudinal electrophysiological examination and MR neurography are useful to evaluate the post-irradiation sciatic neuropathy. The rats with tissue-engineered conduits implantation showed some improvement of lower limb function, accompanied by a normalization of (T1W/T2W) MR signal.
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China. Electronic address: 846681160@qq.com.
authors.forename: Chengde
authors.initials: C
authors.lastname: Liao
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zheng
authors.affiliation: Shanghai Qisheng Biological Preparation Co, LTD, No.1008, Wucao Road, Shanghai, 201106, China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Wei
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China.
authors.forename: Guangshun
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China.
authors.forename: Zhuolin
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Tumor Hospital, No. 519 Kunzhou Road, Kunming 650118, Yunnan, China.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D048271:Chitosan / Q000737:chemistry; D008279:Magnetic Resonance Imaging; D045164:Mesenchymal Stem Cell Transplantation; D009416:Nerve Regeneration; D059348:Peripheral Nerve Injuries / Q000000981:diagnostic imaging / Q000628:therapy*; D019736:Prostheses and Implants; D011832:Radiation Injuries / Q000000981:diagnostic imaging / Q000628:therapy*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000000981:diagnostic imaging / Q000254:growth & development* / Q000473:pathology; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D048271:Chitosan
keywords: Experimental; Magnetic resonance imaging; Mesenchymal stem cells; Nerve conduit; Peripheral nerve injury; Radiation injuries