title: Slow-releasing rapamycin-coated bionic peripheral nerve scaffold promotes the regeneration of rat sciatic nerve after injury.
abstract: OBJECTIVE
  To investigate the effect of locally slow-released rapamycin (RAPA) from the bionic peripheral nerve scaffold on rat sciatic nerve regeneration in the early phase of nerve injury.
  
  
  METHODS
  Slow-releasing RAPA-polyhydroxy alcohol (PLGA) microspheres were prepared and tested for microsphere diameter and slow-release effect in vitro after loading onto nerve scaffold. A total of 48 male SD rats were randomly divided into control group and 3 experimental groups as follows: group 1: RAPA-PLGA scaffold; group 2: RAPA scaffold; and group 3: scaffold alone. In the control group, a 15mm sciatic nerve was excised and religated reversely. In the experimental groups, the scaffolds were used to bridge a defect of 15mm sciatic nerve. The outcome of nerve regeneration was evaluated using neurophysiological and neuromuscular morphological techniques.
  
  
  RESULTS
  The RAPA-PLGA microspheres displayed a smooth exterior. The slow-release of RAPA in group 1 lasted for 14days. The sciatic nerve function index (SFI) and electrophysiological and morphological features were examined 12weeks after the surgery in all groups to reveal various degrees of ipsilateral sciatic nerve regeneration. The SFI values at 12weeks showed no significant difference between the RAPA-PLGA scaffold and control groups; morphological observations revealed that the outcomes of nerve regeneration in the above 2 groups were similar and significantly better than those in the RAPA scaffold and scaffold alone groups.
  
  
  CONCLUSIONS
  RAPA-PLGA microsphere-loaded bionic peripheral nerve scaffold gradually released RAPA locally in the early phase of sciatic nerve regeneration, reduced the secondary nerve injury, and evidently promoted the regeneration of peripheral nerve.
authors.affiliation: Department of Anatomy, Histology and Embryology, The Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Tan
authors.initials: T
authors.lastname: Ding
authors.affiliation: Institute of Orthopedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Anatomy, Histology and Embryology, The Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Jun-Bin
authors.initials: JB
authors.lastname: Yin
authors.affiliation: Department of Anatomy, Histology and Embryology, The Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Anatomy, Histology and Embryology, The Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Ya-Cheng
authors.initials: YC
authors.lastname: Lu
authors.affiliation: College of Health Sciences, University of Wyoming, 1000 E. University Ave, Laramie, WY 82071, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Ren
authors.affiliation: Department of Anatomy, Histology and Embryology, The Fourth Military Medical University, Xi'an 710032, PR China. Electronic address: prof_liyunqing@126.com.
authors.forename: Yun-Qing
authors.initials: YQ
authors.lastname: Li
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002478:Cells, Cultured; D003692:Delayed-Action Preparations; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D019344:Lactic Acid / Q000737:chemistry; D008297:Male; D008863:Microspheres; D009416:Nerve Regeneration / Q000502:physiology*; D010525:Peripheral Nerves / Q000502:physiology*; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000166:cytology* / Q000187:drug effects* / Q000293:injuries; D020123:Sirolimus / Q000494:pharmacology*; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D007166:Immunosuppressive Agents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D020123:Sirolimus
keywords: PLGA; Peripheral nerve; RAPA; Scaffold; Slow-releasing; Tissue engineering