Comparing natural hydrogels to self-assembling peptides in spinal cord injury treatment: a systematic review

Background: In many cases, central nervous system (CNS) injury is unchanging due to the absence of neuronal regeneration and repair capabilities. In recent years, regenerative medicine, and especially hydrogels, has reached a significant amount of attention for their promising results for the treatment of spinal cord injury (SCI) currently considered permanent. Hydrogels are categorized based on their foundation: synthetic, natural, and combination. The objective of this study was to compare the properties and efficacy of commonly used hydrogels, like collagen, and other natural peptides with synthetic self-assembling peptide hydrogels in the treatment of SCI. Methods: Articles were searched in PubMed, Scopus, Web of Science, and Embase. All studies from 1985 until January 2020 were included in the primary search. Eligible articles were included based on the following criteria: administering hydrogels (both natural and synthetic) for SCI treatment, solely focusing on spinal cord injury treatment, and published in a peer-reviewed journal. Data on axonal regeneration, revascularization, elasticity, drug delivery efficacy, and porosity were extracted. Results: A total of 24 articles were included for full-text review and data extraction. There was only one experimental study comparing collagen I (natural hydrogel) and polyethylene glycol (PEG) in an in vitro setting. The included study suggested the behavior of cells with PEG is more expectable in the injury site, which makes it a more reliable scaffold for neurites. Conclusions: There is limited research comparing and evaluating both types of natural and self-assembling peptides (SAPs) in the same animal or in vitro study, despite its importance. Although we assume that the remodeling of natural scaffolds may lead to a stable hydrogel, there was not a definitive conclusion that synthetic hydrogels are more beneficial than natural hydrogels in neuronal regeneration.

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Chimeric Self-assembling Nanofiber Containing Bone Marrow Homing Peptide’s Motif Induces Motor Neuron Recovery in Animal Model of Chronic Spinal Cord Injury; an In Vitro and In Vivo Investigation

Molecular Neurobiology ◽

10.1007/s12035-015-9266-3 ◽

2015 ◽

Vol 53 (5) ◽

pp. 3298-3308 ◽

Cited By ~ 21

Author(s):

Shima Tavakol ◽

Reza Saber ◽

Elham Hoveizi ◽

Hadi Aligholi ◽

Jafar Ai ◽

...

Keyword(s):

Spinal Cord ◽

Bone Marrow ◽

Spinal Cord Injury ◽

Animal Model ◽

Motor Neuron ◽

Chronic Spinal Cord Injury ◽

Self Assembling ◽

Cord Injury

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RGMa inhibition promotes axonal growth and recovery after spinal cord injury

The Journal of Cell Biology ◽

10.1083/jcb.200508143 ◽

2006 ◽

Vol 173 (1) ◽

pp. 47-58 ◽

Cited By ~ 168

Author(s):

Katsuhiko Hata ◽

Masashi Fujitani ◽

Yuichi Yasuda ◽

Hideo Doya ◽

Tomoko Saito ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Axonal Growth ◽

Axonal Guidance ◽

Neural Tube Closure ◽

Cns Injury ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Cord Injury

Repulsive guidance molecule (RGM) is a protein implicated in both axonal guidance and neural tube closure. We report RGMa as a potent inhibitor of axon regeneration in the adult central nervous system (CNS). RGMa inhibits mammalian CNS neurite outgrowth by a mechanism dependent on the activation of the RhoA–Rho kinase pathway. RGMa expression is observed in oligodendrocytes, myelinated fibers, and neurons of the adult rat spinal cord and is induced around the injury site after spinal cord injury. We developed an antibody to RGMa that efficiently blocks the effect of RGMa in vitro. Intrathecal administration of the antibody to rats with thoracic spinal cord hemisection results in significant axonal growth of the corticospinal tract and improves functional recovery. Thus, RGMa plays an important role in limiting axonal regeneration after CNS injury and the RGMa antibody offers a possible therapeutic agent in clinical conditions characterized by a failure of CNS regeneration.

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Knockdown of long non-coding RNA LEF1-AS1 attenuates apoptosis and inflammatory injury of microglia cells following spinal cord injury

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-020-02041-6 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Sheng-Yu Cui ◽

Wei Zhang ◽

Zhi-Ming Cui ◽

Hong Yi ◽

Da-Wei Xu ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Cell Viability ◽

Microglial Cells ◽

Protective Effects ◽

Loss Of Function ◽

Sprague Dawley ◽

Cord Injury ◽

Apoptosis And Inflammation

Abstract Background Spinal cord injury (SCI) is associated with health burden both at personal and societal levels. Recent assessments on the role of lncRNAs in SCI regulation have matured. Therefore, to comprehensively explore the function of lncRNA LEF1-AS1 in SCI, there is an urgent need to understand its occurrence and development. Methods Using in vitro experiments, we used lipopolysaccharide (LPS) to treat and establish the SCI model primarily on microglial cells. Gain- and loss of function assays of LEF1-AS1 and miR-222-5p were conducted. Cell viability and apoptosis of microglial cells were assessed via CCK8 assay and flow cytometry, respectively. Adult Sprague-Dawley (SD) rats were randomly divided into four groups: Control, SCI, sh-NC, and sh-LEF-AS1 groups. ELISA test was used to determine the expression of TNF-α and IL-6, whereas the protein level of apoptotic-related markers (Bcl-2, Bax, and cleaved caspase-3) was assessed using Western blot technique. Results We revealed that LncRNA LEF1-AS1 was distinctly upregulated, whereas miR-222-5p was significantly downregulated in LPS-treated SCI and microglial cells. However, LEF1-AS1 knockdown enhanced cell viability, inhibited apoptosis, as well as inflammation of LPS-mediated microglial cells. On the contrary, miR-222-5p upregulation decreased cell viability, promoted apoptosis, and inflammation of microglial cells. Mechanistically, LEF1-AS1 served as a competitive endogenous RNA (ceRNA) by sponging miR-222-5p, targeting RAMP3. RAMP3 overexpression attenuated LEF1-AS1-mediated protective effects on LPS-mediated microglial cells from apoptosis and inflammation. Conclusion In summary, these findings ascertain that knockdown of LEF1-AS1 impedes SCI progression via the miR-222-5p/RAMP3 axis.

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Spinal‐Cord Injury Treatment: Effective Modulation of CNS Inhibitory Microenvironment using Bioinspired Hybrid‐Nanoscaffold‐Based Therapeutic Interventions (Adv. Mater. 43/2020)

Advanced Materials ◽

10.1002/adma.202070325 ◽

2020 ◽

Vol 32 (43) ◽

pp. 2070325

Author(s):

Letao Yang ◽

Brian M. Conley ◽

Susana R. Cerqueira ◽

Thanapat Pongkulapa ◽

Shenqiang Wang ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Therapeutic Interventions ◽

Cord Injury ◽

Injury Treatment

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A Collagen-Based Scaffold for Promoting Neural Plasticity in a Rat Model of Spinal Cord Injury

Polymers ◽

10.3390/polym12102245 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2245

Author(s):

Jue-Zong Yeh ◽

Ding-Han Wang ◽

Juin-Hong Cherng ◽

Yi-Wen Wang ◽

Gang-Yi Fan ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Rat Model ◽

Neural Plasticity ◽

Collagen Scaffold ◽

Glial Scar ◽

Beneficial Effects ◽

Cord Injury

In spinal cord injury (SCI) therapy, glial scarring formed by activated astrocytes is a primary problem that needs to be solved to enhance axonal regeneration. In this study, we developed and used a collagen scaffold for glial scar replacement to create an appropriate environment in an SCI rat model and determined whether neural plasticity can be manipulated using this approach. We used four experimental groups, as follows: SCI-collagen scaffold, SCI control, normal spinal cord-collagen scaffold, and normal control. The collagen scaffold showed excellent in vitro and in vivo biocompatibility. Immunofluorescence staining revealed increased expression of neurofilament and fibronectin and reduced expression of glial fibrillary acidic protein and anti-chondroitin sulfate in the collagen scaffold-treated SCI rats at 1 and 4 weeks post-implantation compared with that in untreated SCI control. This indicates that the collagen scaffold implantation promoted neuronal survival and axonal growth within the injured site and prevented glial scar formation by controlling astrocyte production for their normal functioning. Our study highlights the feasibility of using the collagen scaffold in SCI repair. The collagen scaffold was found to exert beneficial effects on neuronal activity and may help in manipulating synaptic plasticity, implying its great potential for clinical application in SCI.

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