Effect of combination of acellular nerve grafts and stem cells for sciatic nerve regeneration:a Meta-analysis / 中国组织工程研究

ABSTRACT

BACKGROUND:Acellular nerve scaffolds have the three-dimensional structure of natural nerves and low immunogenicity,but their effect on long nerve defects is still not ideal.Therefore,it is necessary to construct tissueengineered nerve using acellular nerve and seed cells in order to improve the therapeutic effect.OBJECTIVE:To systemically review the efficacy of combination of acellular nerve grafts (ANGs) and mesenchymal stem cells (MSCs) or Schwann cells (SCs) transplantation in the treatment of sciatic nerve defects in a rat model.METHODS:Randomized controlled trials (RCTs) about the effects of combination of ANGs and MSCs or SCs transplantation for sciatic nerve defects in rats were searched in PubMed,The Cochrane Library,EMbase,CNKI,WanFang and VIP from inception to July 2016.Three reviewers independently screened literature according to the inclusion and exclusion criteria,extracted data,and assessed the risk of bias of included studies.Then,a Meta-analysis was performed using Review Manger5.3 software.RESULTS AND CONCLUSION:A total of 10 RCTs involving 252 rats were included.The results of meta-analysis showed thatcompared with the control group (simple acellular nerve scaffold group),the sciatic functional index (SFI) of the combined group (combination of ANGs and MSCs or SCs transplantation) were superior at 2 weeks [SMD=2.73,95％ CI (1.92,3.45),P ＜ 0.000 01],4 weeks [SMD=4.57,95％ CI (3.43,5.70),P ＜ 0.000 01],6 weeks [SMD=1.62,95％CI (0.18,3.06),P=-0.03],8 weeks [SMD=4.90,95％ CI (2.96,6.84),P ＜ 0.000 01] after surgery.The nerve conduction velocity [SMD=1.39,95％ CI (0.99,1.78),P ＜ 0.000 01),latency period (MD=-0.98,95％ CI (-1.19,-0.76),P ＜ 0.000 01],and amplitude [SMD=1.23,95％ CI (0.62,1.85),P ＜ 0.000 1] were superior at 12 weeks after surgery.The myelin sheath thickness was superior at 8 weeks [MD=0.14,95％ CI (0.07,0.21),P ＜ 0.000 1],12 weeks [SMD=1.85,95％ CI (1.63,2.08),P ＜ 0.000 01] and the number of myelinated nerve fibers were superior at 12 weeks [SMD=3.59,95％CI (2.63,4.55),P ＜ 0.000 01] after surgery.The gastrocnemius wet weight was superior at 8 weeks after surgery [SMD=4.22,95％ CI (2.40,6.03),P ＜ 0.000 01].Current evidence indicates that the combination of ANGs and MSCs or SCs can promote the regeneration and functional recovery of the peripheral nerve.Due to the limited quality of the included studies,the above conclusion should be verified by conducting high-quality and large-scale RCTs.