Decellularized porcine peripheral nerve based injectable hydrogels as a Schwann cell carrier for injured spinal cord regeneration.

Objective.To develop a clinically relevant injectable hydrogel derived from decellularized porcine peripheral nerves and with mechanical properties comparable to native central nervous system (CNS) tissue to be used as a delivery vehicle for Schwann cell transplantation to treat spinal cord injury (SCI).Approach.Porcine peripheral nerves (sciatic and peroneal) were decellularized by chemical decellularization using a sodium deoxycholate and DNase (SDD) method previously developed by our group. The decellularized nerves were delipidated using dichloromethane and ethanol solvent and then digested using pepsin enzyme to form injectable hydrogel formulations. Genipin was used as a crosslinker to enhance mechanical properties. The injectability, mechanical properties, and gelation kinetics of the hydrogels were further analyzed using rheology. Schwann cells encapsulated within the injectable hydrogel formulations were passed through a 25-gauge needle and cell viability was assessed using live/dead staining. The ability of the hydrogel to maintain Schwann cell viability against an inflammatory milieu was assessedin vitrousing inflamed astrocytes co-cultured with Schwann cells.Mainresults. The SDD method effectively removes cells and retains extracellular matrix in decellularized tissues. Using rheological studies, we found that delipidation of decellularized porcine peripheral nerves using dichloromethane and ethanol solvent improves gelation kinetics and mechanical strength of hydrogels. The delipidated and decellularized hydrogels crosslinked using genipin mimicked the mechanical strength of CNS tissue. The hydrogels were found to have shear thinning properties desirable for injectable formulations and they also maintained higher Schwann cell viability during injection compared to saline controls. Usingin vitroco-culture experiments, we found that the genipin-crosslinked hydrogels also protected Schwann cells from astrocyte-mediated inflammation.Significance. Injectable hydrogels developed using delipidated and decellularized porcine peripheral nerves are a potential clinically relevant solution to deliver Schwann cells, and possibly other therapeutic cells, at the SCI site by maintaining higher cellular viability and increasing therapeutic efficacy for SCI treatment.

Il34 rescues metronidazole-induced impairment of spinal cord regeneration in zebrafish central nervous system.

Metronidazole (MTZ), a commonly used anti-infective drug in clinical practice, has also been employed as a prodrug in cell-targeted ablation systems in scientific research, exhibiting significant application value. However, it has been demonstrated that MTZ can induce neurotoxic symptoms to some extent during its use, and there is currently a lack of effective means to circumvent its toxicity in both clinical and research settings, which limits its application. Therefore, exploring the specific mechanisms underlying MTZ-induced neurotoxic symptoms and elucidating countermeasures will enhance the practical value of MTZ. In this study, using a zebrafish spinal cord injury regeneration model, we confirmed that MTZ neurotoxicity leads to impaired axon regeneration in the central nervous system. By overexpressing il34 in the central nervous system of zebrafish, we eliminated the inhibitory effect of MTZ on axonal regeneration and demonstrated that the pro-regenerative effect against MTZ neurotoxicity is not caused by excessive macrophages/microglia chemoattracted by interleukin 34(Il34). Transcriptome sequencing analysis and GO enrichment analysis of differentially expressed genes between groups revealed that Il34 may counteract MTZ neurotoxicity and promote spinal cord injury repair through biological processes that enhance cellular adhesion and cell location. In summary, our work uncovers a possible cause of MTZ neurotoxicity and provides a new perspective for eliminating MTZ toxicity.

Neutrophil immune profile guides spinal cord regeneration in zebrafish.

Spinal cord injury triggers a strong innate inflammatory response in both non-regenerative mammals and regenerative zebrafish. Neutrophils are the first immune population to be recruited to the injury site. Yet, their role in the repair process, particularly in a regenerative context, remains largely unknown. Here, we show that, following rapid recruitment to the injured spinal cord, neutrophils mostly reverse migrate throughout the zebrafish body. In addition, promoting neutrophil inflammation resolution by inhibiting Cxcr4 boosts cellular and functional regeneration. Neutrophil-specific RNA-seq analysis reveals an enhanced activation state that correlates with a transient increase in tnf-α expression in macrophage/microglia populations. Conversely, blocking neutrophil recruitment through Cxcr1/2 inhibition diminishes the presence of macrophage/microglia at the injury site and impairs spinal cord regeneration. Altogether, these findings provide new insights into the role of neutrophils in spinal cord regeneration, emphasizing the significant impact of their immune profile on the outcome of the repair process.

Advances in electroactive bioscaffolds for repairing spinal cord injury.

Spinal cord injury (SCI) is a devastating neurological disorder, leading to loss of motor or somatosensory function, which is the most challenging worldwide medical problem. Re-establishment of intact neural circuits is the basis of spinal cord regeneration. Considering the crucial role of electrical signals in the nervous system, electroactive bioscaffolds have been widely developed for SCI repair. They can produce conductive pathways and a pro-regenerative microenvironment at the lesion site similar to that of the natural spinal cord, leading to neuronal regeneration and axonal growth, and functionally reactivating the damaged neural circuits. In this review, we first demonstrate the pathophysiological characteristics induced by SCI. Then, the crucial role of electrical signals in SCI repair is introduced. Based on a comprehensive analysis of these characteristics, recent advances in the electroactive bioscaffolds for SCI repair are summarized, focusing on both the conductive bioscaffolds and piezoelectric bioscaffolds, used independently or in combination with external electronic stimulation. Finally, thoughts on challenges and opportunities that may shape the future of bioscaffolds in SCI repair are concluded.

Injectable, Electroconductive, Free Radical Scavenging Silk Fibroin/Black Phosphorus/Glycyrrhizic Acid Nanocomposite Hydrogel for Enhancing Spinal Cord Repair.

Spinal cord injury (SCI) often leads to a severe permanent disability. A poor inflammatory microenvironment and nerve electric signal conduction block are the main reasons for difficulty in spinal cord nerve regeneration. In this study, black phosphorus (BP) and glycyrrhizic acid (GA) are integrated into methacrylate-modified silk fibroin (SF) to construct a bifunctional injectable hydrogel (SF/BP/GA) with appropriate conductivity and the ability to inhibit inflammation to promote neuronal regeneration after SCI. This work discovers that the SF/BP/GA hydrogel can reduce the oxidative damage mediated by oxygen free radicals, promote the polarization of macrophages toward the anti-inflammatory M2 phenotype, reduce the expression of inflammatory factors, and improve the inflammatory microenvironment. Moreover, it induces neural stem cell (NSC) differentiation and neurosphere formation, restores signal conduction at the SCI site in vivo, and ameliorates motor function in mice with spinal cord hemisection, revealing a significant neural repair effect. An injectable, electroconductive, free-radical-scavenging hydrogel is a promising therapeutic strategy for SCI repair.

Differential Roles of Diet on Development and Spinal Cord Regeneration in Larval Zebrafish.

The zebrafish is a powerful model organism for studying development and regeneration. However, there is a lack of a standardized reference diet for developmental and regeneration experiments. Most studies evaluate the rate of growth, survival, and fecundity. In this study, we compare three diets and their effects on growth and regeneration after a spinal cord injury (SCI). Fish were fed daily for 1 week with daily measurements of overall length and width of spinal injury. Fish fed a live rotifer diet grew 32%, whereas a commercially available diet only led to a 4% increase in body length. Similarly, differences in rate of regeneration were observed with over 80% of rotifer-fed larvae forming a glial bridge after injury compared to <10% of zebrafish fed with the commercial diet. Our data highlight the need for establishing a standardized diet for regeneration studies to improve research reproducibility.

Injectable Hydrogel To Deliver Bone Mesenchymal Stem Cells Preloaded with Azithromycin To Promote Spinal Cord Repair.

Spinal cord injury is a disease that causes severe damage to the central nervous system. Currently, there is no cure for spinal cord injury. Azithromycin is commonly used as an antibiotic, but it can also exert anti-inflammatory effects by down-regulating M1-type macrophage genes and up-regulating M2-type macrophage genes, which may make it effective for treating spinal cord injury. Bone mesenchymal stem cells possess tissue regenerative capabilities that may help promote the repair of the injured spinal cord. In this study, our objective was to explore the potential of promoting repair in the injured spinal cord by delivering bone mesenchymal stem cells that had internalized nanoparticles preloaded with azithromycin. To achieve this objective, we formulated azithromycin into nanoparticles along with a trans-activating transcriptional activator, which should enhance nanoparticle uptake by bone mesenchymal stem cells. These stem cells were then incorporated into an injectable hydrogel. The therapeutic effects of this formulation were analyzed in vitro using a mouse microglial cell line and a human neuroblastoma cell line, as well as in vivo using a rat model of spinal cord injury. The results showed that the formulation exhibited anti-inflammatory and neuroprotective effects in vitro as well as therapeutic effects in vivo. These results highlight the potential of a hydrogel containing bone mesenchymal stem cells preloaded with azithromycin and trans-activating transcriptional activator to mitigate spinal cord injury and promote tissue repair.

Fabrication of multifunctional silk nanofibril/hyaluronic acid scaffold for spinal cord repair.

Bioactive scaffolds accurately mimicking the structure and composition of the extracellular matrix have garnered significant interest in tissue engineering. In this study, we developed a platform utilizing natural silk nanofibrils, hyaluronic acid, and basic fibroblast growth factor for the purpose of promoting spinal cord regeneration by creating an optimal microenvironment. The bioactive scaffold exhibited notable characteristics such as high porosity and hydrophilicity, attributed to its unique nanostructure, high connectivity, and polysaccharide composition. Furthermore, the pore size of the scaffold can be adjusted within the range of 90 µm to 120 µm by varying the content of hyaluronic acid. In vitro, human umbilical vein endothelial cells were seeded into the scaffold, demonstrating enhanced cell viability. The scaffold facilitated cell proliferation and migration. In vivo experiments on rats indicated that the scaffold had a beneficial impact on spinal cord regeneration, creating a conducive environment for motor function recovery of the rats. This effect may be attributed to the scaffold's ability to stimulate axon growth and neuronal survival, as well as inhibit the formation of glial scars, as evidenced by the decreased expression of growth associated protein-43, microtubule-associated protein 2, and neurofilament-200. This study presents a promising method to develop a feasible bioscaffold for the treatment of spinal cord injury.

Injectable, self-healing hyaluronic acid-based hydrogels for spinal cord injury repair.

The cystic cavity that develops following spinal cord injury is a major obstacle for repairing spinal cord injury (SCI). The injectable self-healing biomaterials treatment is a promising strategy to enhance tissue repair after traumatic spinal cord injury. Herein, a natural extracellular matrix (ECM) biopolymer hyaluronic acid-based hydrogel was developed based on multiple dynamic covalent bonds. The hydrogels exhibited excellent injectable and self-healing properties, could be effectively injected into the injury site, and filled the lesion cavity to accelerate the tissue repair of traumatic SCI. Moreover, the hydrogels were compatible with cells and various tissues and possessed proper stiffness matched with nervous tissue. Additionally, when implanted into the injured spinal cord site, the hyaluronic acid-based hydrogel promoted axonal regeneration and functional recovery by accelerating remyelination, axon regeneration, and angiogenesis. Overall, the injectable self-healing hyaluronic acid-based hydrogels are ideal biomaterials for treating traumatic SCI.

Hesperidin guided injured spinal cord neural regeneration with a combination of MWCNT-collagen-hyaluronic acid composite: In-vitro analysis.

Restoring the lost bioelectrical signal transmission along with the appropriate microenvironment is one of the major clinical challenges in spinal cord regeneration. In the current research, we developed a polysaccharide-based protein composite Multiwalled Carbon Nanotubes (MWCNTs)/ Collagen (Col)/ Hyaluronic acid (HA) composite with Hesperidin (Hes) natural compound to investigate its combined therapeutic effect along with biocompatibility, antioxidant activity, and electrical conductivity. The multifunctional composites were characterized via FT-IR, XRD, SEM, HR-TEM, BET, C.V, and EIS techniques. The electrical conductivity and modulus of the MWCNT-Col-HA-Hes were 0.06 S/cm and 12.3 kPa, similar to the native spinal cord. The in-vitro Cytotoxicity, cell viability, antioxidant property, and cell migration ability of the prepared composites were investigated with a PC-12 cell line. In-vitro studies revealed that the multifunctional composites show higher cell viability, antioxidant, and cell migration properties than the control cells. Reduction of ROS level indicates that the Hes presence in the composite could reduce the cell stress by protecting it from oxidative damage and promoting cell migration towards the lesion site. The developed multifunctional composite can provide the antioxidant microenvironment with compatibility and mimic the native spinal cord by providing appropriate conductivity and mechanical strength for spinal cord tissue regeneration.

Mechanical Ablation of Larval Zebrafish Spinal Cord.

Unlike mammals, adult and larval zebrafish exhibit robust regeneration following traumatic spinal cord injury. This remarkable regenerative capacity, combined with exquisite imaging capabilities and an abundance of powerful genetic techniques, has established the zebrafish as an important vertebrate model for the study of neural regeneration. Here, we describe a protocol for the complete mechanical ablation of the larval zebrafish spinal cord. With practice, this protocol can be used to reproducibly injure upward of 100 samples per hour, facilitating the high-throughput screening of factors involved in spinal cord regeneration and repair.

Advances in Conductive Hydrogel for Spinal Cord Injury Repair and Regeneration.

Spinal cord injury (SCI) treatment represents a major challenge in clinical practice. In recent years, the rapid development of neural tissue engineering technology has provided a new therapeutic approach for spinal cord injury repair. Implanting functionalized electroconductive hydrogels (ECH) in the injury area has been shown to promote axonal regeneration and facilitate the generation of neuronal circuits by reshaping the microenvironment of SCI. ECH not only facilitate intercellular electrical signaling but, when combined with electrical stimulation, enable the transmission of electrical signals to electroactive tissue and activate bioelectric signaling pathways, thereby promoting neural tissue repair. Therefore, the implantation of ECH into damaged tissues can effectively restore physiological functions related to electrical conduction. This article focuses on the dynamic pathophysiological changes in the SCI microenvironment and discusses the mechanisms of electrical stimulation/signal in the process of SCI repair. By examining electrical activity during nerve repair, we provide insights into the mechanisms behind electrical stimulation and signaling during SCI repair. We classify conductive biomaterials, and offer an overview of the current applications and research progress of conductive hydrogels in spinal cord repair and regeneration, aiming to provide a reference for future explorations and developments in spinal cord regeneration strategies.

Artificially reprogrammed stem cells deliver transcytosable nanocomplexes for improved spinal cord repair.

Stem cell transplantation holds great promise for restoring function after spinal cord injury (SCI), but its therapeutic efficacy heavily depends on the innate capabilities of the cells and the microenvironment at the lesion site. Herein, a potent cell therapeutic (NCs@SCs) is engineered by artificially reprogramming bone marrow mesenchymal stem cells (BMSCs) with oxidation-responsive transcytosable gene-delivery nanocomplexes (NCs), which endows cells with robust oxidative stress resistance and improved cytokine secretion. NCs@SCs can accumulate in the injured spinal cord after intravenous administration via chemotaxis and boost successive transcytosis to deliver NCs to neurons, augmenting ciliary neurotrophic factor (CNTF) production in both BMSCs and neurons in response to elevated ROS levels. Furthermore, NCs@SCs can actively sense and eliminate ROS and re-educate recruited M1-like macrophages into the anti-inflammatory M2 phenotype via a paracrine pathway, ultimately reshaping the inflammatory microenvironment. Synergistically, NCs@SCs exhibit durable survival and provide neuroprotection against secondary damage, enabling significant locomotor function recovery in SCI rats. Transcriptome analysis reveals that regulation of the ROS/MAPK signaling pathway is involved in SCI therapy by NCs@SCs. This study presents a nanomaterial-mediated cell-reprogramming approach for developing live cell therapeutics, showing significant potential in the treatment of SCI and other neuro-injury disorders.

In toto imaging of glial JNK signaling during larval zebrafish spinal cord regeneration.

Identification of signaling events that contribute to innate spinal cord regeneration in zebrafish can uncover new targets for modulating injury responses of the mammalian central nervous system. Using a chemical screen, we identify JNK signaling as a necessary regulator of glial cell cycling and tissue bridging during spinal cord regeneration in larval zebrafish. With a kinase translocation reporter, we visualize and quantify JNK signaling dynamics at single-cell resolution in glial cell populations in developing larvae and during injury-induced regeneration. Glial JNK signaling is patterned in time and space during development and regeneration, decreasing globally as the tissue matures and increasing in the rostral cord stump upon transection injury. Thus, dynamic and regional regulation of JNK signaling help to direct glial cell behaviors during innate spinal cord regeneration.

A 3D-Printed Dual Driving Forces Scaffold with Self-Promoted Cell Absorption for Spinal Cord Injury Repair.

Stem cells play critical roles in cell therapies and tissue engineering for nerve repair. However, achieving effective delivery of high cell density remains a challenge. Here, a novel cell delivery platform termed the hyper expansion scaffold (HES) is developed to enable high cell loading. HES facilitated self-promoted and efficient cell absorption via a dual driving force model. In vitro tests revealed that the HES rapidly expanded 80-fold in size upon absorbing 2.6 million human amniotic epithelial stem cells (hAESCs) within 2 min, representing over a 400% increase in loading capacity versus controls. This enhanced uptake benefited from macroscopic swelling forces as well as microscale capillary action. In spinal cord injury (SCI) rats, HES-hAESCs promoted functional recovery and axonal projection by reducing neuroinflammation and improving the neurotrophic microenvironment surrounding the lesions. In summary, the dual driving forces model provides a new rationale for engineering hydrogel scaffolds to facilitate self-promoted cell absorption. The HES platform demonstrates great potential as a powerful and efficient vehicle for delivering high densities of hAESCs to promote clinical treatment and repair of SCI.

The Impact of Biomaterial Surface Properties on Engineering Neural Tissue for Spinal Cord Regeneration.

Tissue engineering for spinal cord injury (SCI) remains a complex and challenging task. Biomaterial scaffolds have been suggested as a potential solution for supporting cell survival and differentiation at the injury site. However, different biomaterials display multiple properties that significantly impact neural tissue at a cellular level. Here, we evaluated the behavior of different cell lines seeded on chitosan (CHI), poly (ε-caprolactone) (PCL), and poly (L-lactic acid) (PLLA) scaffolds. We demonstrated that the surface properties of a material play a crucial role in cell morphology and differentiation. While the direct contact of a polymer with the cells did not cause cytotoxicity or inhibit the spread of neural progenitor cells derived from neurospheres (NPCdn), neonatal rat spinal cord cells (SCC) and NPCdn only attached and matured on PCL and PLLA surfaces. Scanning electron microscopy and computational analysis suggested that cells attached to the material's surface emerged into distinct morphological populations. Flow cytometry revealed a higher differentiation of neural progenitor cells derived from human induced pluripotent stem cells (hiPSC-NPC) into glial cells on all biomaterials. Immunofluorescence assays demonstrated that PCL and PLLA guided neuronal differentiation and network development in SCC. Our data emphasize the importance of selecting appropriate biomaterials for tissue engineering in SCI treatment.

Robust and Multifunctional Nanoparticles Assembled from Natural Polyphenols and Metformin for Efficient Spinal Cord Regeneration.

The treatment of spinal cord injury (SCI) remains unsatisfactory owing to the complex pathophysiological microenvironments at the injury site and the limited regenerative potential of the central nervous system. Metformin has been proven in clinical and animal experiments to repair damaged structures and functions by promoting endogenous neurogenesis. However, in the early stage of acute SCI, the adverse pathophysiological microenvironment of the injury sites, such as reactive oxygen species and inflammatory factor storm, can prevent the activation of endogenous neural stem cells (NSCs) and the differentiation of NSCs into neurons, decreasing the whole repair effect. To address those issues, a series of robust and multifunctional natural polyphenol-metformin nanoparticles (polyphenol-Met NPs) were fabricated with pH-responsiveness and excellent antioxidative capacities. The resulting NPs possessed several favorable advantages: First, the NPs were composed of active ingredients with different biological properties, without the need for carriers; second, the pH-responsiveness feature could allow targeted drug delivery at the injured site; more importantly, NPs enabled drugs with different performances to exhibit strong synergistic effects. The results demonstrated that the improved microenvironment by natural polyphenols boosted the differentiation of activated NSCs into neurons and oligodendrocytes, which could efficiently repair the injured nerve structures and enhance the functional recovery of the SCI rats. This work highlighted the design and fabrication of robust and multifunctional NPs for SCI treatment via efficient microenvironmental regulation and targeted NSCs activation.

Three-dimensional nanofibrous sponges with aligned architecture and controlled hierarchy regulate neural stem cell fate for spinal cord regeneration.

Background: Spinal cord injury (SCI) induces neuronal death and disrupts the nerve fiber bundles, which leads to severe neurological dysfunction and even permanent paralysis. A strategy combining biomimetic nanomaterial scaffolds with neural stem cell (NSC) transplantation holds promise for SCI treatment. Methods: Innovative three-dimensional (3D) nanofibrous sponges (NSs) were designed and developed by a combination of directional electrospinning and subsequent gas-foaming treatment. Immunofluorescence, mRNA sequencing, magnetic resonance imaging, electrophysiological analysis, and behavioral tests were used to investigate the in vitro and in vivo regenerative effects of the 3D NSs. Results: The generated 3D NSs exhibited uniaxially aligned nano-architecture and highly controllable hierarchical structure with super-high porosity (99%), outstanding hydrophilicity, and reasonable mechanical performance. They facilitated cell infiltration, induced cell alignment, promoted neuronal differentiation of NSCs, and enhanced their maturation mediated through cellular adhesion molecule pathways. In vivo, the NSC-seeded 3D NSs efficiently promoted axon reinnervation and remyelination in a rat SCI model, with new "neural relays" developing across the lesion gap. These histological changes were associated with regain of function, including increasing the neurological motor scores of SCI rats, from approximately 2 to 16 (out of 21), and decreasing the sensing time in the tape test from 140 s to 36 s. Additionally, the scaffolds led to restoration of ascending and descending electrophysiological signalling. Conclusion: The as-fabricated 3D NSs effectively regulate NSC fates, and an advanced combination of 3D NS design and transplanted NSCs enables their use as an ideal tissue-engineered scaffold for SCI repair.

Role of Axon Guidance Molecules in Ascending and Descending Paths in Spinal Cord Regeneration.

Axon guidance molecules (AGM) are critical regulators of neural development and play a vital role in guiding axons to their target regions during spinal cord development. The correct wiring of neural circuits depends on these molecules' precise expression and function. Defects in axonal pathfinding, growth cone navigation, axonal branching, and synapse formation have far-reaching implications for neuronal circuit construction and function after CNS traumas, such as spinal cord injury (SCI), which affect the expression or activity of AGM. Ascending and descending paths in the spinal cord have been found to include many AGM, including Netrins, Slits, Semaphorins (Sema), Ephrins, and their receptors. In contrast to the repulsive signals like Slits and Semaphorins, which restrict axonal growth and guide axons away from unsuitable locations, Netrins are appealing guidance cues that encourage axonal growth and guidance. Defects in motor function and sensory processing can result from changes in the expression or activity of Ephrins or their receptors, which play an essential role in axonal guidance and synaptic plasticity in the spinal cord. Herein, we highlighted the expressions, functions, and mechanisms of AGM in ascending and descending spinal cord tracts, which can help us identify novel therapeutic targets to improve axonal regeneration and functional recovery after SCI.

Enhanced spinal cord regeneration by gelatin/alginate hydrogel scaffolds containing human endometrial stem cells and curcumin-loaded PLGA nanoparticles in rat.

Spinal cord injury (SCI) is a serious problem with a high prevalence worldwide. The weak capability of the spinal cord for regeneration in association with upregulation of inflammatory factors is two key obstacles against a full SCI repair. Curcumin is a natural substance with anti-inflammatory and neuroprotective effects. Here, we have used a combined strategy using stem cells and hybrid hydrogel scaffolds loaded with curcumin for SCI repair. Curcumin-loaded PLGA nanoparticles were prepared, characterized, and encapsulated into gelatin/alginate hydrogel scaffolds, which were then seeded by human endometrial stem cells (hEnSCs). The resulting construct was studied using in vitro and in vivo experiments on rat models. DLS, SEM, Zeta potential, and FTIR data confirmed the successful addition of curcumin to PLGA nanoparticles. SEM analyses indicated the successful addition of curcumin-loaded nanoparticles into the gelatin/alginate scaffold, as well as the adherence of the seeded EnSCs. Based on the results, the prepared constructs not only allowed the controlled release of curcumin but also could support the survival and growth of hEnSCs. Based on the results of BBB and histological experiments, the highest BBB score was related to the combined strategy, consistent with histological outcomes, in which our hEnSC-seeded gelatin/alginate scaffold containing curcumin-loaded nanoparticles led to improved structures of the white and gray matters in the SCI site, being indicative of the superior nerve fiber regeneration, compared to other studied groups. These results indicate the efficiency of the proposed method for SCI repair and broaden the scope for subsequent studies on spinal cord regeneration.