Peripheral nerve injury repair by electrical stimulation combined with graphene-based scaffolds.

Peripheral nerve injury (PNI) is a common clinical problem, which due to poor recovery often leads to limb dysfunction and sensory abnormalities in patients. Tissue-engineered nerve guidance conduits (NGCs) that are designed and fabricated from different materials are the potential alternative to nerve autografts. However, translation of these NGCs from lab to commercial scale has not been well achieved. Complete functional recovery with the aid of NGCs in PNI becomes a topic of general interest in tissue engineering and regeneration medicine. Electrical stimulation (ES) has been widely used for many years as an effective physical method to promote nerve repair in both pre-clinical and clinical settings. Similarly, ES of conductive and electroactive materials with a broad range of electrical properties has been shown to facilitate the guidance of axons and enhance the regeneration. Graphene and its derivatives possess unique physicochemical and biological properties, which make them a promising outlook for the development of synthetic scaffolds or NGCs for PNI repair, especially in combination with ES. Considering the discussion regarding ES for the treatment of PNI must continue into further detail, herein, we focus on the role of ES in PNI repair and the molecular mechanism behind the ES therapy for PNI, providing a summary of recent advances in context of graphene-based scaffolds (GBSs) in combination with ES. Future perspectives and some challenges faced in developing GBSs are also highlighted with the aim of promoting their clinical applications.

Reduced Graphene Oxide Fibers Combined with Electrical Stimulation Promote Peripheral Nerve Regeneration.

Background: The treatment of long-gap peripheral nerve injury (PNI) is still a substantial clinical problem. Graphene-based scaffolds possess extracellular matrix (ECM) characteristic and can conduct electrical signals, therefore have been investigated for repairing PNI. Combined with electrical stimulation (ES), a well performance should be expected. We aimed to determine the effects of reduced graphene oxide fibers (rGOFs) combined with ES on PNI repair in vivo. Methods: rGOFs were prepared by one-step dimensionally confined hydrothermal strategy (DCH). Surface characteristics, chemical compositions, electrical and mechanical properties of the samples were characterized. The biocompatibility of the rGOFs were systematically explored both in vitro and in vivo. Total of 54 Sprague-Dawley (SD) rats were randomized into 6 experimental groups: a silicone conduit (S), S+ES, S+rGOFs-filled conduit (SGC), SGC+ES, nerve autograft, and sham groups for a 10-mm sciatic defect. Functional and histological recovery of the regenerated sciatic nerve at 12 weeks after surgery in each group of SD rats were evaluated. Results: rGOFs exhibited aligned micro- and nano-channels with excellent mechanical and electrical properties. They are biocompatible in vitro and in vivo. All 6 groups exhibited PNI repair outcomes in view of neurological and morphological recovery. The SGC+ES group achieved similar therapeutic effects as nerve autograft group (P > 0.05), significantly outperformed other treatment groups. Immunohistochemical analysis showed that the expression of proteins related to axonal regeneration and angiogenesis were relatively higher in the SGC+ES. Conclusion: The rGOFs had good biocompatibility combined with excellent electrical and mechanical properties. Combined with ES, the rGOFs provided superior motor nerve recovery for a 10-mm nerve gap in a murine acute transection injury model, indicating its excellent repairing ability. That the similar therapeutic effects as autologous nerve transplantation make us believe this method is a promising way to treat peripheral nerve defects, which is expected to guide clinical practice in the future.

Fe-doped carbon dots: a novel biocompatible nanoplatform for multi-level cancer therapy.

BACKGROUND: Tumor treatment still remains a clinical challenge, requiring the development of biocompatible and efficient anti-tumor nanodrugs. Carbon dots (CDs) has become promising nanomedicines for cancer therapy due to its low cytotoxicity and easy customization. RESULTS: Herein, we introduced a novel type of "green" nanodrug for multi-level cancer therapy utilizing Fe-doped carbon dots (Fe-CDs) derived from iron nutrient supplement. With no requirement for target moieties or external stimuli, the sole intravenous administration of Fe-CDs demonstrated unexpected anti-tumor activity, completely suppressing tumor growth in mice. Continuous administration of Fe-CDs for several weeks showed no toxic effects in vivo, highlighting its exceptional biocompatibility. The as-synthesized Fe-CDs could selectively induce tumor cells apoptosis by BAX/Caspase 9/Caspase 3/PARP signal pathways and activate antitumoral macrophages by inhibiting the IL-10/Arg-1 axis, contributing to its significant tumor immunotherapy effect. Additionally, the epithelial-mesenchymal transition (EMT) process was inhibited under the treatment of Fe-CDs by MAPK/Snail pathways, indicating the capacity of Fe-CDs to inhibit tumor recurrence and metastasis. CONCLUSIONS: A three-level tumor treatment strategy from direct killing to activating immunity to inhibiting metastasis was achieved based on "green" Fe-CDs. Our findings reveal the broad clinical potential of Fe-CDs as a novel candidate for anti-tumor nanodrugs and nanoplatform.

Exploiting synergistic effect of CO/NO gases for soft tissue transplantation using a hydrogel patch.

Autologous skin flap transplantation is a common method for repairing complex soft tissue defects caused by cancer, trauma, and congenital malformations. Limited blood supply range and post-transplantation ischemia-reperfusion injury can lead to distal necrosis of the flap and long-term functional loss, which severely restricts the decision-making regarding the optimal surgical plan. To address this issue, we develop a hydrogel patch that releases carbon monoxide and nitric oxide gases on demand, to afford a timely blood supply for skin flap transplantation during surgery. Using an ischemia-reperfusion dorsal skin flap model in rats, we show that the hydrogel patch maintains the immediate opening of blood flow channels in transplanted tissue and effective blood perfusion throughout the perioperative period, activating perfusion of the hemodynamic donor site. We demonstrate that the hydrogel patch promotes distal vascularization and long-term functional reconstruction of transplanted tissues by inhibiting inflammatory damage and accelerating blood vessel formation.

Renal-friendly Li+-doped carbonized polymer dots activate Schwann cell autophagy for promoting peripheral nerve regeneration.

Activation of autophagy in Schwann cells (SCs) has emerged as a powerful trigger for peripheral nerve injury (PNI) repair. Lithium ion (Li+) is a classical autophagy activator that plays an important role in promoting axonal extension and remyelination. However, the therapeutic window of existing lithium drugs is extremely narrow, and the adverse side effects, especially nephrotoxicity, severely limit their therapeutic value. Herein, Li+-doped carbonized polymer dots (Li-CPDs) was synthesized for the first time to change the pharmacokinetics of Li+ from occupying epithelial sodium channels to lipid raft-mediated endocytosis. The in-vivo results confirmed that Li-CPDs could accelerate the removal of myelin debris and promote nerve regeneration via activating autophagy of SCs. Moreover, Li-CPDs exhibited almost no renal toxicity compared to that of raw lithium drugs. Thus, Li-CPDs could serve as a promising Li+-based nanomedicine for PNI regeneration with improved biosafety. STATEMENT OF SIGNIFICANCE: Regardless of the fact that lithium drugs have been used in treatment of mental illness such as manic depression, the systemic side effects and renal metabolic toxicity still seriously restrict their clinical application. Since Li+ and Na+ compete for ion channels of cell membrane, the cell entry efficiency is extremely low and easily affected by body fluctuations, which seems to be an unsolvable problem. Herein, we rationally exploited the endocytotic features of CPDs to develop Li-CPDs. The Li-CPDs improved the entry pathway, greatly reduced nephrotoxicity, and inherited the biological function of Li+ to activate autophagy for promoting peripheral nerve regeneration. Due to the BBB-crossing property of Li-CPDs, it also showed application prospects in future research on central nervous system diseases.

Microfluidic Manipulation for Biomedical Applications in the Central and Peripheral Nervous Systems.

Physical injuries and neurodegenerative diseases often lead to irreversible damage to the organizational structure of the central nervous system (CNS) and peripheral nervous system (PNS), culminating in physiological malfunctions. Investigating these complex and diverse biological processes at the macro and micro levels will help to identify the cellular and molecular mechanisms associated with nerve degeneration and regeneration, thereby providing new options for the development of new therapeutic strategies for the functional recovery of the nervous system. Due to their distinct advantages, modern microfluidic platforms have significant potential for high-throughput cell and organoid cultures in vitro, the synthesis of a variety of tissue engineering scaffolds and drug carriers, and observing the delivery of drugs at the desired speed to the desired location in real time. In this review, we first introduce the types of nerve damage and the repair mechanisms of the CNS and PNS; then, we summarize the development of microfluidic platforms and their application in drug carriers. We also describe a variety of damage models, tissue engineering scaffolds, and drug carriers for nerve injury repair based on the application of microfluidic platforms. Finally, we discuss remaining challenges and future perspectives with regard to the promotion of nerve injury repair based on engineered microfluidic platform technology.

S-Doped carbonized polymer dots inhibit early myocardial fibrosis by regulating mitochondrial function.

Myocardial fibrosis (MF) is a critical pathological lesion in the progression of various acute and chronic cardiovascular diseases. However, there is still a lack of clinically effective drugs and treatments for MF therapies. Herein, for the first time, we developed fluorescent sulfur-doped carbonized polymer dots (S-CPDs) as new nano-antioxidants to reduce the cardiomyocyte damage caused by reactive oxygen species (ROS) in the early stage of fibrotic lesions. In vitro results suggested that the pre-protection of S-CPDs significantly increased the survival rate of H9c2 cells under severe oxidative stress, inhibited the isoproterenol (ISO)-induced hypertrophy of myocardial cells through improving the content of mitochondria related proteins and adenosine triphosphate (ATP) in cells. Moreover, S-CPD administration could effectively decrease cardiac hypertrophy and promote heart function in MF rat models. The rapid internalization, high biocompatibility and fluorescence imaging potential of S-CPDs revealed their promising application prospects in the diagnoses and treatments of cardiovascular diseases.

Morinda officinalis polysaccharide attenuates osteoporosis in rats underwent bilateral ovariectomy by suppressing the PGC-1α/PPARγ pathway.

OBJECTIVE: Osteoporosis (OP) is a widespread disease that causes risks of spine and hip fractures. Morinda officinalis polysaccharide (MOP) shows therapeutic potential in OP. This article intended to understand the mechanism by which MOP impacts bone mineral density (BMD) and serum trace elements in OP rats. METHODS: OP rat models were established by bilateral ovariectomy (OVX). Rats were intragastrically administered with MOP or ZLN005 [the activator of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)] since the first day after operation for 8 weeks. Microstructural changes in OP rats were analyzed using micro-computed tomography system. Contents of serum Zn, Cu, Fe, and Mg in rats were measured. Levels of serum superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), GSH, and malondialdehyde (MDA) in rats were determined by Enzyme-linked immunosorbent assay. Protein levels of PGC-1α and peroxisome proliferator-activated receptor γ (PPARγ) in cartilage tissues of rats were determined via Western blotting. RESULTS: MOP enhanced BMD, bone volume per trabecular volume (BV/TV), Tb.N, and Tb.Th and reduced Tb.Sp in the distal femur of OVX rats, elevated levels of serum Cu, Fe, and Mg and contents of SOD, GSH, and GSH-PX and decreased MDA content. Moreover, MOP suppressed the PGC-1α/PPARγ pathway. Activation of PGC-1α partially abolished the action of MOP on ameliorating OP in OVX rats and strengthening anti-oxidation ability. CONCLUSION: MOP mitigated OP in OVX rats by inhibiting the PGC-1α/PPARγ pathway.

Efficacy and safety of filgotinib in patients with rheumatoid arthritis and inadequate response to disease-modifying antirheumatic drugs (DMARDs): A meta-analysis of randomized controlled trials.

BACKGROUND: Filgotinib has been approved for the treatment of rheumatoid arthritis (RA) in adults who respond inadequately to disease-modifying antirheumatic drugs (DMARDs) in Europe and Japan. Several randomized controlled trials (RCTs) have investigated its efficacy and safety in adult patients with RA. This meta-analysis aimed to study the efficacy and safety of filgotinib in patients with RA withan inadequate response to methotrexateor other DMARDs. METHODS: A systematic literature search was conducted to identify articles in PubMed, MEDLINE, EMBASE, and Cochrane Library from inceptionto December 1, 2021. Outcomes of interest included ACR20/50/70 responses, DAS28-CRP ≤ 3.2, SF-36 PCS Score, FACIT-fatigue, SDAI,CDAI, and HAQ-DI, which were assessed after treatment. The safety outcomes included treatment-emergent adverse events (TEAEs) and serious TEAEs. Odds ratios (ORs) with 95% confidence intervals (CI) were pooled for categorical variables, and the mean difference with 95%CI were pooled for continuous variables. We used Review Manager 5.3 for the standard meta-analysis. This study followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). RESULTS: Four RCTs comparing filgotinib (200 and 100 mg once daily) with placebo were identified. Compared with placebo, 200 and 100 mg filgotinib was more effective in achieving ACR20/50/70 responses and other outcomes at weeks 12 and 24 (P < 0.05), with no significant difference in safety outcomes (P > 0.05). Filgotinib 200 mg performed better than filgotinib 100 mg in terms of ACR20/50 responses, DAS28-CRP ≤ 3.2, SDAI, and CDAI at weeks 12 and 24, and caused fewer serious TEAEs than the 100 mg dose. CONCLUSIONS: Filgotinib is effective in the treatment of RA, and the 200 mg dose has a more beneficialprofile thanthe 100 mg dose.

SPIONs mediated magnetic actuation promotes nerve regeneration by inducing and maintaining repair-supportive phenotypes in Schwann cells.

BACKGROUND: Schwann cells, the glial cells in the peripheral nervous system, are highly plastic. In response to nerve injury, Schwann cells are reprogrammed to a series of specialized repair-promoting phenotypes, known as repair Schwann cells, which play a pivotal role in nerve regeneration. However, repair Schwann cells represent a transient and unstable cell state, and these cells progressively lose their repair phenotypes and repair-supportive capacity; the transience of this state is one of the key reasons for regeneration failure in humans. Therefore, the ability to control the phenotypic stability of repair Schwann cells is of great practical importance as well as biological interest. RESULTS: We designed and prepared a type of fluorescent-magnetic bifunctional superparamagnetic iron oxide nanoparticles (SPIONs). In the present study, we established rat sciatic nerve injury models, then applied SPIONs to Schwann cells and established an effective SPION-mediated magnetic actuation system targeting the sciatic nerves. Our results demonstrate that magnetic actuation mediated by SPIONs can induce and maintain repair-supportive phenotypes of Schwann cells, thereby promoting regeneration and functional recovery of the sciatic nerve after crush injury. CONCLUSIONS: Our research indicate that Schwann cells can sense these external, magnetically driven mechanical forces and transduce them to intracellular biochemical signals that promote nerve regeneration by inducing and maintaining the repair phenotypes of Schwann cells. We hope that this study will provide a new therapeutic strategy to promote the regeneration and repair of injured peripheral nerves.

A Dual-Modal Magnetic Resonance/Photoacoustic Imaging Tracer for Long-Term High-Precision Tracking and Facilitating Repair of Peripheral Nerve Injuries.

Neuroanatomical tracing is considered a crucial technique to assess the axonal regeneration level after injury, but traditional tracers do not meet the needs of in vivo neural tracing in deep tissues. Magnetic resonance (MR) and photoacoustic (PA) imaging have high spatial resolution, great penetration depth, and rich contrast. Fe3 O4 nanoparticles may work well as a dual-modal diagnosis probe for neural tracers, with the potential to improve nerve regeneration. The present study combines antegrade neural tracing imaging therapy for the peripheral nervous system. Fe3 O4 @COOH nanoparticles are successfully conjugated with biotinylated dextran amine (BDA) to produce antegrade nano-neural tracers, which are encapsulated by microfluidic droplets to control leakage and allow sustained, slow release. They have many notable advantages over traditional tracers, including dual-modal real-time MR/PA imaging in vivo, long-duration release effect, and limitation of uncontrolled leakage. These multifunctional anterograde neural tracers have potential neurotherapeutic function, are reliable and may be used as a new platform for peripheral nerve injury imaging and treatment integration.

Molecular Etiology in Thumb Polydactyly in Mutated GLI3 Mouse Gene.

Sporadic thumb polydactyly with nonfamily inheritance is the most common in clinical work. This study focused on characterization of GLI3 gene function. We constructed the plasmid with p.m948i point mutation of GLI3 and transfected it into mouse embryonic fibroblasts (MEFs) to study the effects and potential mechanism of the mutant gene. The RNA of GLI3 mutant cells was extracted and analyzed by transcriptome sequencing and bioinformatics. Finally, we constructed cbx3 overexpression plasmid, designed siRNA for gene silencing, and transfected it into the MEFs. Cell proliferation and invasion ability of the MEFs were examined. The results showed that there were 2,452 differential expression genes in the MEFs transfected with GLI3 mutant plasmid compared with wild-type MEFs. The results of differential expression analysis showed that the cbx3 gene was significantly up-regulated. Overexpression of cbx3 in MEFs promoted cell proliferation and invasion, while siRNA knockdown of cbx3 expression reduced proliferation and invasion. GLI3 gene mutation in MEFs resulted in cbx3 up-regulation and promoted MEF proliferation and invasion. This study further clarified the potential function of GLI3 in limb development, established a new relationship between gene mutation and polydactyly, and preliminarily clarified the possible signal pathway, all of which have laid a foundation for further study on the etiology of polydactyl.

IL1R2 polymorphisms and their interaction are associated with osteoporosis susceptibility in the Chinese Han population.

AIMS: Interleukin 1 (IL-1) inhibitory receptor type 2 (IL1R2) serves as a negative regulator of IL-1 signalling and is involved in the pathogenesis of osteoporosis. This study aimed to determine the correlation between IL1R2 polymorphism and osteoporosis susceptibility in the Chinese Han population. METHODS: We recruited 594 osteoporosis patients and 599 healthy controls. Six single nucleotide polymorphisms (SNPs) in IL1R2 were selected for genotyping using the Agena MassARRAY platform. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis with adjustment for age and sex. Linkage disequilibrium analysis was plotted using Haploview v4.2. Multifactor dimension reduction (MDR) was performed to estimate the SNP-SNP interactions of IL1R2 variants. RESULTS: Rs11674595 (OR = 1.86, p = 0.020), rs2072472 (OR = 1.26, p = 0.019) and rs4851527 (OR = 0.78, p = 0.007) were related to the risk of osteoporosis. Moreover, the contribution of IL1R2 polymorphisms to osteoporosis risk was associated with age, sex and body mass index. We found the relationships of Trs11674595 Ars4851527 (OR = 0.80, p = 0.015), Crs11674595 Grs4851527 (OR = 1.22, p = 0.043) and Ars3218977 Grs2072472 (OR = 1.25, p = 0.022) haplotypes to osteoporosis occurrence, and a potential accumulated effect of IL1R2 SNPs (testing accuracy = 0.5783 and cross validation consistency = 10/10) on osteoporosis susceptibility. CONCLUSION: IL1R2 polymorphisms (rs11674595, rs4851527, rs2072472 and rs3218977) may contribute to osteoporosis risk in the Chinese Han population. Our findings may increase our understanding of the effects of IL1R2 polymorphisms on the predisposition to osteoporosis.

The use of the posterior interosseous artery flap and anterolateral thigh flap for post-traumatic soft tissue reconstruction of the hand.

ABSTRACT: The purpose of this study was to examine the differences between the use of a posterior interosseous artery (PIA) flap and an anterolateral thigh (ALT) flap for post-traumatic, medium-sized soft tissue reconstruction of the hand based on flap characteristics, postoperative complications, and aesthetic outcomes.From October, 2010 to March, 2016, 62 patients undergoing soft tissue reconstruction of the hand with 30 PIA flaps and 32 ALT flaps were included in this study. The 62 patients were divided into the PIA flap group and the ALT flap group. The differences between the 2 groups were analyzed.The 62 patients included 52 males and 10 females, and the mean age at the time of surgery was 41 years. The flap failure rate was 13.3% (4/30) in the PIA flap group and 9.4% (3/32) in the ALT flap group. No significant differences in flap failure rate, recipient site complication rate, or donor site complication rate were observed between the 2 groups. However, the operative time (136 min vs 229 min) and aesthetic outcomes (flap bulk swelling, 0 cases vs 31 cases) were statistically significantly different.Both the pedicled PIA flap and the free ALT flap were comparable for the reconstruction of post-traumatic, medium-sized soft tissue defects of the hand according to the evaluated outcomes of postoperative complications. Based on the surgical characteristics of the flap and the evaluation of aesthetic outcomes, the pedicled PIA flap was significantly superior to the free ALT flap.

Repair of a severe palm injury with anterolateral thigh and ilioinguinal flaps: A case report.

BACKGROUND: In daily life and work, there are more and more patients with trauma to the hand, which often results in skin and soft tissue defects. Although there are many repair methods, the function and appearance of the fingers will be adversely affected if the repair is inadequate. CASE SUMMARY: In the present report we describe an 18-year-old male patient whose right hand was mangled by a machine. X-ray imaging showed that a right hand bone (middle finger) was absent and the alignment was poor. After hospitalization, he was diagnosed with a severe right hand injury, skin and soft tissue defects, partial finger defects, and a skin degloving injury. He underwent reconstructive surgery with anterolateral thigh and ilioinguinal flaps. After two repair operations, satisfactory results were obtained, including good fracture healing, good skin flap shape, and good wrist joint function. CONCLUSION: This case highlights the good effect of anterolateral thigh and ilioinguinal flaps repair technique on severe palm injury.

Vascularized Capitate Transposition for the Treatment of Stage IIIB Kienböck Disease.

PURPOSE: The treatment of Kienböck disease (KD) continues to be controversial. In this study, we report the long-term follow-up outcomes of patients who were diagnosed with stage IIIB KD treated with vascularized capitate transposition. METHODS: A total of 16 patients were retrospectively reviewed. Baseline clinical information was extracted from medical records, and wrist function was clinically evaluated, including x-ray images. RESULTS: At the final follow-up, wrist pain was severe in 0 patients, moderate in 2 patients, mild in 5 patients, and absent in 9 patients. The mean postoperative active flexion and extension of the affected wrist was significantly improved after surgery compared with before surgery. The postoperative and preoperative mean grip strength was 35 kg and 27 kg, respectively. The Disabilities of the Arm, Shoulder, and Hand score was significantly improved after surgery compared with before surgery. CONCLUSIONS: Vascularized capitate transposition for the treatment of Lichtman stage IIIB KD is feasible and associated with improvements in wrist function and pain. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Resveratrol regulates the recovery of rat sciatic nerve crush injury by promoting the autophagy of Schwann cells.

Resveratrol has the ability to promote functional recovery after sciatic nerve crush injury (SNCI), though the mechanism through which this occurs in not fully understood. Resveratrol can promote autophagy, a key process in Wallerian degeneration; thus, we hypothesized that resveratrol could promote recovery from SNCI by promoting Schwann cell autophagy and acceleration of Wallerian degeneration. Motor function recovery was assessed by calculating Sciatic Function Indexes (SFIs) at days 7, 14, 21, 28 post SNCI. Autophagy and myelin clearance were assessed by microtubule-associated protein light chain 3B (LC3B) and myelin protein zero (MPZ) immunofluorescence and Western blot analysis on the fourth day after SNCI. The autophagy of Schwann cells following resveratrol administration was quantified by immunofluorescence in RSC96 cells. Immunofluorescence and Transmission electron microscopy (TEM) were also used in Resveratrol treated sciatic nerve four days post-SNCI to find LC3B positive areas and typical double membrane structures represent for autophagy. The SNCI+resveratrol (crush+Res) groups recovered faster than the SNCI+vehicles (crush+V) group. On day four, almost all of the myelin had regenerated in the crush+Res rats, while the crush+V group's myelin remained intact and the expression levels of LC3-II/I was the highest. On day 28 post-injury, both the control and crush+Res groups' myelin neurofibers reached peak numbers as did the thickness of the myelin sheath. Both in vitro and in vivo immunofluorescence showed that LC3B was colocalized with Schwann cells. This is the first study to observe that resveratrol can promote recovery from SCNI by accelerating the myelin clearance process by promoting autophagy of Schwann cells.

[ARTICLE WITHDRAWN] Study Brain Derived Neurotrophic Factor Gene Modified Schwann Cells Combined Chitosan Materials Treatment Peripheral Nerve Injury.

THIS ARTICLE WAS WITHDRAWN BY THE PUBLISHER IN January 2021.

Growth and elongation of axons through mechanical tension mediated by fluorescent-magnetic bifunctional Fe3O4·Rhodamine 6G@PDA superparticles.

BACKGROUND: The primary strategy to repair peripheral nerve injuries is to bridge the lesions by promoting axon regeneration. Thus, the ability to direct and manipulate neuronal cell axon regeneration has been one of the top priorities in the field of neuroscience. A recent innovative approach for remotely guiding neuronal regeneration is to incorporate magnetic nanoparticles (MNPs) into cells and transfer the resulting MNP-loaded cells into a magnetically sensitive environment to respond to an external magnetic field. To realize this intention, the synthesis and preparation of ideal MNPs is an important challenge to overcome. RESULTS: In this study, we designed and prepared novel fluorescent-magnetic bifunctional Fe3O4·Rhodamine 6G@polydopamine superparticles (FMSPs) as neural regeneration therapeutics. With the help of their excellent biocompatibility and ability to interact with neural cells, our in-house fabricated FMSPs can be endocytosed into cells, transported along the axons, and then aggregated in the growth cones. As a result, the mechanical forces generated by FMSPs can promote the growth and elongation of axons and stimulate gene expression associated with neuron growth under external magnetic fields. CONCLUSIONS: Our work demonstrates that FMSPs can be used as a novel stimulator to promote noninvasive neural regeneration through cell magnetic actuation.