Schwann Cell Migration through Magnetic Actuation Mediated by Fluorescent–Magnetic Bifunctional Fe3O4·Rhodamine 6G@Polydopamine Superparticles
Authors: Yang Wang
Hao Xu
Yi Liu
Laijin Lu
Jingyan Ren
Ting Liu
Jiayi Zhang
Shulin Du
Hao Zhang
Journal: ACS Chemical Neuroscience (2020)
Discipline: NEUROSCIENCE & BEHAVIOR
Keywords: Fe3O4 superparticles; Peripheral nerve regeneration; Schwann cells; gene expression profile; magnetic actuation
Affiliations: Department of Hand Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P. R. China, State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, P. R. China, Departments of Geriatrics, The First Hospital of Jilin University, Changchun, Jilin 130021, P. R. China, Institute of Translational Medicine, The First Hospital of Jilin University, Changchun, Jilin 130021, P. R. China

Abstract:  Peripheral nerve injuries always cause dysfunction but without ideal strategies to assist the treatment and recovery successfully. The primary way to repair the peripheral nerve injuries is to bridge the lesions by promoting axon regeneration. Schwann cells acting as neuroglial cells play a pivotal role during axonal regeneration. The orderly and organized migration of Schwann cells is beneficial for the extracellular matrix connection and Büngner bands formation, which greatly promote the regeneration of axons by offering mechanical support and growth factors. Thus, the use of Schwann cells as therapeutic cells offers us an attractive method for neurorepair therapies, and the ability to direct and manipulate Schwann cell migration and distribution is of great significance in the field of cell therapy in regards to the repair and regeneration of the peripheral nerve. Herein, we design and characterize a type of novel fluorescent-magnetic bifunctional Fe3O4·Rhodamine 6G (R6G)@polydopamine (PDA) superparticles (SPs) and systematically study the biological behaviors of Fe3O4·R6G@PDA SP uptake by Schwann cells. The results demonstrate that our tailor-made Fe3O4·R6G@PDA SPs can be endocytosed by Schwann cells and then highly magnetize Schwann cells by virtue of their excellent biocompatibility. Furthermore, remote-controlling and noninvasive magnetic targeting migration of Schwann cells can be achieved on the basis of the high magnetic responsiveness of Fe3O4·R6G@PDA SPs. At the end, gene expression profile analysis is performed to explore the mechanism of Schwann cells' magnetic targeting migration. The results indicate that cells can sense external magnetic mechanical forces and transduce into intracellular biochemical signaling, which stimulate gene expression associated with Schwann cell migration. 

Retracted: No

PubPeer comments:
  The high-resolution transmission electron microscopy (HRTEM) images show that the Fe3O4u00b7R6G@PDA SPs have a uniform size distribution with a Fe3O4u00b7R6G SP core size of 50 nm and a thin PDA shell of about 6.0 nm (Figure 1a,b). ![file] From [Wang et al (2020)] :  The custom made Fe3O4u00b7Rhodamine 6G@PDA SPs (FMSPs) used in this work are fabricated in-house by coating preassembled Fe3O4u00b7Rhodamine 6G SPs with PDA. HRTEM images show that the FMSPs possess a uniform size with a core size of 50 nm and PDA shell of approximately 10 nm (Fig. 2a, b). Fig 2:  TEM (a) and HRTEM (b) images of FMSPs. ![file] The TEM images appear to show the same particles in these two studies but the HRTEM images and the text specify different PDA shell thickness. I assume that the TEM images are indicative but may not represent the exact formulation used here. , 
 The reused images between different two papers has significantly changed the contrast ![file] , 
 The TEM images in two different papers are identical, however, the contrast has been changed. ![file] , 
 #3 There is uncertainty, then, whether the FMSP has a  PDA shell of approximately **10** nm as in Fig 2(b), or  PDA thicknesses... **15.5** nm as in Fig S2(c). ,