Graphene oxide-PLGA hybrid nanofibres for the local delivery of IGF-1 and BDNF in spinal cord repair
Authors: Qiuju Li
Qinyi Liu
Xiaoyu Yang
Chuan Fu
Weijian Kong
Yue Ma
Su Pan
Zhiping Qi
Shuang Zheng
Journal: Artificial Cells Nanomedicine and Biotechnology (2019)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Spinal cord injury; brain derived neurotrophic factor; graphene oxide; insulin-like growth factor 1; neural stem cells
Affiliations: a Department of Orthopedic Surgery , The Second Hospital of Jilin University , Changchun TX , PR China., b Department of Gynecological Oncology , The First Hospital of Jilin University , Changchun TX , PR China.

Abstract:  Spinal cord injury (SCI) can lead to permanent and severe functional impairment below the lesion level and is still one of the most challenging clinical problems. The treatment of SCI has progressed with the development of tissue engineering techniques. Insulin-like growth factor 1 (IGF-1) and brain-derived neurotrophic factor (BDNF) are growth factors closely related to nerve regeneration. In this study, IGF-1 and BDNF were successfully immobilized on biodegradable graphene oxide (GO)-incorporated PLGA (PLGA/GO) electrospun nanofibres. The effect of PLGA/GO nanofibres with immobilized IGF-1 and BDNF on neurogenesis was investigated in vitro and in vivo utilizing MTT assays, immunofluorescence, motor function detection and histology observations. We demonstrated that PLGA/GO nanofibres loaded with IGF-1 and BDNF not only protected NSCs from oxidative stress induced by H2O2 but also enhanced NSC proliferation and neuronal differentiation in vitro. The in vivo study of an SCI animal model demonstrated that local delivery of IGF-1 and BDNF immobilized to PLGA/GO nanofibres significantly improved functional locomotor recovery, reduced cavity formation and increased the number of neurons at the injury site. Our study indicated that PLGA/GO is an effective carrier for IGF-1 and BDNF delivery and that immobilization of IGF-1 and BDNF onto PLGA/GO nanofibres has a great potential as a nerve implant for spinal cord injury applications. 

Retracted: No

PubPeer comments:
 The histology images, although ostensibly from rats in different groups, share too many micro-anatomical structures (highlighted). In particular images B C and D E are remarkably similar (shown below). Even an accidental tear in the tissue from the processing carries over between slides (blue arrows). This suggests that these are adjacent slides from the same animal; that we are looking at four sections from the same spinal cord. Have the authors accidentally uploaded the wrong images? ![file] Images in paper ![file] B C, similarities highlighted ![file] D E similarities (arrows denote the start and far end of the accidental tear) , 
 #1 Expression of Concern [17 March 2020] .  After publication of this article, questions about the scientific integrity of the article content were brought to the Publisher and Editoru2019s attention. We have reached out to the authors requesting that they supply information that would confirm the articleu2019s integrity, but the authors have not responded to our queries within the requested timeframe. Therefore, as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. ------------------------------------------------------------------- Retracted [May 22 2020] .  We, the Editors and Publisher of the journal Artificial Cells, Nanomedicine, and Biotechnology, have retracted the following article:  Zhiliang Guo, Lanlan Li, Yu Gao, Xiaoyun Zhang and Min Cheng. (2019). Overexpression of lncRNA ANRIL aggravated hydrogen peroxide-disposed injury in PC-12 cells via inhibiting miR-499a PDCD4 axis-mediated PI3K Akt mTOR p70S6K pathway. 47:1, 2624u20132633. DOI: 10.1080 21691401.2019.1629953  Since publication, concerns have been raised about the integrity of the data in the article. When approached for an explanation, the authors checked their data and confirmed there are fundamental errors present. Therefore, they have agreed to the retraction of this article. The authors apologise for this oversight. , 
 Important to note that there was a correction on March 11: https: www.tandfonline.com doi pdf 10.1080 21691401.2020.1738654 ,