Search Results (31)

Background/Objectives: Nerve injuries cause functional loss and psychosocial issues due to prolonged rehabilitation. Recently, 3D-modeled nerve conduits have been used to aid in surgical planning. This study investigated the impact of 3D-bioprinted PLA, chitosan, alginate, and collagen conduits on nerve regeneration in a rat sciatic nerve crush injury model. Methods: This study, conducted at Kütahya University of Health Sciences, involves 50 rats were divided into four groups: (1) sham-operated controls, (2) sciatic nerve injury without treatment, (3) injury treated with a PLA conduit, and (4) injury treated with 3D-printed tubes composed of chitosan and alginate. The procedures were performed, blood was collected, and the rats were sacrificed after two months. Weekly checks for infection, scar healing, and motor responses were performed. Results: Rats with nerve conduits showed less macroscopic scarring. Weekly assessments of motor nerve recovery showed no movement restrictions in limbs treated with PLA conduits, graft conduits, or conduits bridging retracted nerve stumps, based on responses to stimulus checks. An infection developed in the sciatic nerve and surrounding muscle tissue of one rat with a bio-graft conduit, prompting histopathological examination to investigate its cause. Conclusions: This proof-of-principle study demonstrates the feasibility of using 3D-printed biocompatible nerve conduits for peripheral nerve repair, providing a basis for future, more comprehensive investigations. Full article

Peripheral nerve injuries (PNIs) are a significant clinical challenge, often resulting in persistent sensory and motor deficits despite surgical repair. Autologous nerve grafts remain the gold standard for repair; however, outcomes are frequently suboptimal due to donor site morbidity and inconsistent functional recovery. A major obstacle in nerve regeneration is the formation of postoperative adhesions and fibrosis, which impede healing and necessitate revision surgeries. Nerve protectors from biological, synthetic, and hybrid materials offer a promising tissue engineering strategy to enhance nerve regeneration. These protectors are applied as a protective barrier when a nerve is severed without the gap, allowing for direct repair. They provide mechanical support and reduce scarring. Biocompatible biological wraps, including vascularized fat flaps, vein wraps, collagen-based materials, human amniotic membrane (hAM), porcine small intestinal submucosa (PSIS), and chitosan, modulate immune responses and promote vascularization. Synthetic alternatives, like polycaprolactone (PCL), provide mechanical stability with controlled degradation. Hybrid wraps, such as PCL-amnion, combine the benefits of both. Despite optimistic results, the heterogeneity of study methodologies hinders direct comparisons and standardization. This review highlights the latest developments in nerve wraps, their clinical applications, limitations, and future potential, guiding clinicians in selecting the most appropriate materials for peripheral nerve repair. Full article

Peripheral nerve injury disrupts the function of the peripheral nervous system, leading to sensory, motor, and autonomic deficits. While peripheral nerves possess an intrinsic regenerative capacity, complete sensory and motor recovery remains challenging due to the unpredictable nature of the healing process, which is influenced by the extent of the injury, age, and timely intervention. Recent advances in microsurgical techniques, imaging technologies, and a deeper understanding of nerve microanatomy have enhanced functional outcomes in nerve repair. Nerve injury initiates complex pathophysiological responses, including Wallerian degeneration, macrophage activation, Schwann cell dedifferentiation, and axonal sprouting. Complete nerve disruptions require surgical intervention to restore nerve continuity and function. Direct nerve repair is the gold standard for clean transections with minimal nerve gaps. However, in cases with larger nerve gaps or when direct repair is not feasible, alternatives such as autologous nerve grafting, vascularized nerve grafts, nerve conduits, allografts, and nerve transfers may be employed. Autologous nerve grafts provide excellent biocompatibility but are limited by donor site morbidity and availability. Vascularized grafts are used for large nerve gaps and poorly vascularized recipient beds, while nerve conduits serve as a promising solution for smaller gaps. Nerve transfers are utilized when neither direct repair nor grafting is possible, often involving re-routing intact regional nerves to restore function. Nerve conduits play a pivotal role in nerve regeneration by bridging nerve gaps, with significant advancements made in material composition and design. Emerging trends in nerve regeneration include the use of 3D bioprinting for personalized conduits, gene therapy for targeted growth factor delivery, and nanotechnology for nanofiber-based conduits and stem cell therapy. Advancements in molecular sciences have provided critical insights into the cellular and biochemical mechanisms underlying nerve repair, leading to targeted therapies that enhance axonal regeneration, remyelination, and functional recovery in peripheral nerve injuries. This review explores the current strategies for the therapeutic management of peripheral nerve injuries, highlighting their indications, benefits, and limitations, while emphasizing the need for tailored approaches based on injury severity and patient factors. Full article

Background/Objectives: The regeneration of the facial nerve using low-level laser therapy (LLLT) has been infrequently reported. Polydeoxyribonucleotides (PDRNs), a blend of short deoxyribonucleotide polymers known for their non-toxic and non-allergic properties, are recognized as a stimulator of cell growth that enhances cell proliferation and supports wound healing. This study investigates the synergistic effect of the topical sustained release of PDRN/F-127 and LLLT on facial nerve regeneration following crush injury-induced paralysis in rats. Methods: The main trunk of the facial nerve was compressed for 1 min using a hemostat. Animals were divided into five groups: a control group (n = 4), group I (Pluronic F-127 only, n = 4), group II (Pluronic F-127/PDRN, n = 4), group III (Pluronic F-127 + LLLT, n = 4), and group IV (Pluronic F-127/PDRN + LLLT, n = 4). We measured the recovery of vibrissa fibrillation, action potential, and facial nerve blood flow (FNBF). Results: Group IV exhibited a comparatively faster development of vibrissa fibrillation over time than the other groups. After the intervention, significant differences in vibrissa fibrillation values were observed at all time points (p = 0.0028) according to the repeated one-way ANOVA. Regarding the threshold of action potential, all five groups revealed a significant difference (one-way ANOVA, p < 0.0001; multiple comparisons via Tukey’s test). Among the groups, group IV showed a significantly reduced threshold of action potential compared to the other groups. Group IV showed the most notable recovery in FNBF compared to the other groups. One-way ANOVA showed a significant difference (p < 0.0001; multiple comparisons by Dunnett’s test). Conclusions: These findings suggest that PDRN and LLLT may work together synergistically to enhance peripheral nerve regeneration. Future studies should investigate the underlying molecular mechanisms and evaluate the potential clinical applications of this combined treatment strategy. Full article

Background/Objectives: The increasing complexity of spinal oncology procedures, particularly in en-bloc tumor resections, creates challenges in tissue perfusion assessment due to extended operative times and extensive surgical dissection. Real-time visualization of tissue perfusion can be achieved with ICG using commercially available handheld imaging systems, offering potential advantages in spinal oncology cases. This study assessed the utility of ICG in analyzing soft-tissue viability during complex spine procedures extending beyond 7.5 h, with a particular focus on oncologic resections. Methods: Three cases that required over 7.5 h of operative time were chosen for ICG utilization. These cases included an en-bloc malignant peripheral nerve sheath tumor resection, an en-bloc resection of a malignant epithelioid neoplasm, and a long-segment fusion revision for pseudoarthrosis. At the conclusion of the critical portion of the procedure, a handheld intraoperative fluorescence camera was utilized to visualize the tissue penetration of intravenous ICG. Results: Prior to injecting ICG, devascularized tissue was not clearly visible. Injecting ICG allowed clear separation of vascularized (fluorescing) and devascularized (non-fluorescing) tissues. One region of non-florescent tissue was later confirmed to be devascularized with MRI and experienced postoperative infection. Conclusions: As the complexity of spinal oncology procedures increases, ICG fluorescence imaging offers a novel method for real-time assessment of tissue perfusion. This technique may be particularly valuable in extensive tumor resections, post-radiation cases, and revision surgeries where tissue viability is at risk. Further investigation in the spinal oncology population could help establish whether early identification of poorly perfused tissues impacts wound healing outcomes. Full article

Objectives: Vitamin B complexes are frequently used in clinical practice for peripheral nerve trauma. However, there is a lack of scientific data on their effectiveness. This study aims to investigate the impact of the vitamin B complex on nerve recovery in a rat model of peripheral nerve paralysis. Materials and Methods: Sixty male Wistar Albino rats were divided into six groups. Models of nerve injury, including blunt trauma, nerve incision, and autograft, were performed on all rats approximately 1 cm distal to the sciatic notch. B-complex vitamins were injected intraperitoneally at 0.2 mL/day to the treatment groups. The control groups were given 0.2 mL/day saline. After 1 month, the study was terminated, electromyography (EMG) was performed to measure the conduction velocity, and nerve tissue was taken from the repair line. The sciatic function indexes (SFIs) were calculated and analyzed. The histopathological samples were stained with hematoxylin and eosin and Toluidine blue and examined with a light microscope. Pathologically, myelination, fibrosis, edema, and mast cell densities in the nervous tissue were evaluated. Results: The vitamin B treatment groups demonstrated significant improvements in SFI compared to the control groups, indicating functional improvement in nerve damage (p < 0.05). In the nerve graft group, the vitamin B group showed a shorter latency, higher velocity, and larger peak-to-peak compared to the controls (p < 0.05). In the nerve transection group, the vitamin B group had better latency, velocity, and peak-to-peak values than the controls (p < 0.05). In the crush injury group, the vitamin B group exhibited an improved latency, velocity, and peak-to-peak compared to the controls (p < 0.05). Better myelination, less fibrosis, edema, and mast cells were also in the vitamin B group (p < 0.05). Conclusions: Vitamin B treatment significantly improves nerve healing and function in peripheral nerve injuries. It enhances nerve conduction, reduces fibrosis, and promotes myelination, indicating its therapeutic potential in nerve regeneration. Full article

The regenerative capacity of the peripheral nervous system is limited, and peripheral nerve injuries often result in incomplete healing and poor outcomes even after repair. Transection injuries that induce a nerve gap necessitate microsurgical intervention; however, even the current gold standard of repair, autologous nerve graft, frequently results in poor functional recovery. Several interventions have been developed to augment the surgical repair of peripheral nerves, and the application of functional biomaterials, local delivery of bioactive substances, electrical stimulation, and allografts are among the most promising approaches to enhance innate healing across a nerve gap. Biocompatible polymers with optimized degradation rates, topographic features, and other functions provided by their composition have been incorporated into novel nerve conduits (NCs). Many of these allow for the delivery of drugs, neurotrophic factors, and whole cells locally to nerve repair sites, mitigating adverse effects that limit their systemic use. The electrical stimulation of repaired nerves in the perioperative period has shown benefits to healing and recovery in human trials, and novel biomaterials to enhance these effects show promise in preclinical models. The use of acellular nerve allografts (ANAs) circumvents the morbidity of donor nerve harvest necessitated by the use of autografts, and improvements in tissue-processing techniques may allow for more readily available and cost-effective options. Each of these interventions aid in neural regeneration after repair when applied independently, and their differing forms, benefits, and methods of application present ample opportunity for synergistic effects when applied in combination. Full article

Neurofibromas, rare benign tumors of the peripheral nerve sheath, present diagnostic challenges, particularly in diabetic patients with toe ulcers. This case involves a 55-year-old female with type 2 diabetes mellitus who developed an enlarging ulcer on her right second toe. The initial evaluation suggested a diabetic ulcer; however, advanced imaging revealed a mass-like lesion. Partial excision and biopsy confirmed a neurofibroma with spindle cells within the myxoid stroma and S100 protein expression. One month later, total excision and Z-plasty reconstruction were performed under general anesthesia. The patient’s postoperative recovery was uneventful, and the patient was discharged without complications. Follow-up revealed successful healing with no recurrence or functional issues. This case highlights the importance of considering neurofibromas in the differential diagnosis of diabetic toe ulcers to avoid misdiagnosis and ensure appropriate management. Full article

The field of peripheral nerve regeneration is a dynamic and rapidly evolving area of research that continues to captivate the attention of neuroscientists worldwide. The quest for effective treatments and therapies to enhance the healing of peripheral nerves has gained significant momentum in recent years, as evidenced by the substantial increase in publications dedicated to this field. This surge in interest reflects the growing recognition of the importance of peripheral nerve recovery and the urgent need to develop innovative strategies to address nerve injuries. In this context, this article aims to contribute to the existing knowledge by providing a comprehensive review that encompasses both biomaterial and clinical perspectives. By exploring the utilization of nerve guidance conduits and pharmacotherapy, this article seeks to shed light on the remarkable advancements made in the field of peripheral nerve regeneration. Nerve guidance conduits, which act as artificial channels to guide regenerating nerves, have shown promising results in facilitating nerve regrowth and functional recovery. Additionally, pharmacotherapy approaches have emerged as potential avenues for promoting nerve regeneration, with various therapeutic agents being investigated for their neuroprotective and regenerative properties. The pursuit of advancing the field of peripheral nerve regeneration necessitates persistent investment in research and development. Continued exploration of innovative treatments, coupled with a deeper understanding of the intricate processes involved in nerve regeneration, holds the promise of unlocking the complete potential of these groundbreaking interventions. By fostering collaboration among scientists, clinicians, and industry partners, we can accelerate progress in this field, bringing us closer to the realization of transformative therapies that restore function and quality of life for individuals affected by peripheral nerve injuries. Full article

Background: Peripheral neuropathy is caused by a malfunction in the axons and myelin sheaths of peripheral nerves and motor and sensory neurons. In this context, nonpharmacological treatments with antioxidant potential have attracted much attention due to the issues that some conventional pharmaceutical therapy can generate. Most of these treatments contain lipoic acid, but issues have emerged regarding its use. Considering this, the present study evaluated the beneficial effects of nutraceuticals based on Gastrodiae elata dry extract 10:1 or lipoic acid in combination with other substances (such as citicholine, B vitamins, and acetyl L-carnitine). Method: To assess the combination’s absorption and biodistribution and exclude cytotoxicity, its bioavailability was first examined in a 3D intestinal barrier model that replicated oral ingestion. Subsequently, a 3D model of nerve tissue was constructed to investigate the impacts of the new combination on the significant pathways dysregulated in peripheral neuropathy. Results: Our findings show that the novel combination outperformed in initial pain relief response and in recovering the mechanism of nerve healing following Schwann cell injury by successfully crossing the gut barrier and reaching the target site. Conclusion: This article describes a potential alternative nutraceutical approach supporting the effectiveness of combinations with Gastrodiae elata extract in decreasing neuropathy and regulating pain pathways. Full article

Myc is one of the most well-known oncogenes driving tumorigenesis in a wide variety of tissues. From the brain to blood, its deregulation derails physiological pathways that grant the correct functioning of the cell. Its action is carried out at the gene expression level, where Myc governs basically every aspect of transcription. Indeed, in addition to its role as a canonical, chromatin-bound transcription factor, Myc rules RNA polymerase II (RNAPII) transcriptional pause–release, elongation and termination and mRNA capping. For this reason, it is evident that minimal perturbations of Myc function mirror malignant cell behavior and, consistently, a large body of literature mainly focuses on Myc malfunctioning. In healthy cells, Myc controls molecular mechanisms involved in pivotal functions, such as cell cycle (and proliferation thereof), apoptosis, metabolism and cell size, angiogenesis, differentiation and stem cell self-renewal. In this latter regard, Myc has been found to also regulate tissue regeneration, a hot topic in the research fields of aging and regenerative medicine. Indeed, Myc appears to have a role in wound healing, in peripheral nerves and in liver, pancreas and even heart recovery. Herein, we discuss the state of the art of Myc’s role in tissue regeneration, giving an overview of its potent action beyond cancer. Full article

Human-adipose-tissue-derived mesenchymal stromal cells (AD-MSCs) are currently being tested as autologous-cell-based therapies for use in tissue healing and regeneration. Recent studies have also demonstrated that AD-MSC-derived exosomes contribute to tissue repair and peripheral nerve regeneration. Subcutaneous abdominal adipose tissue (AAT) is divided into two layers: the superficial layer (sAAT) and the deep layer (dAAT). However, it is unclear whether there are particular characteristics of each layer in terms of AD-MSC regenerative potential. Using AD-MSCs purified and characterized from three abdominoplasties, we compared their secretomes and exosome functions to identify which layer may be most suitable as a source for cell therapy. Phenotypical analysis of the AD-MSCs containing stromal vascular fraction did not reveal any difference between the two layers. The AD-MSC secretomes showed a very similar pattern of cytokine content and both layers were able to release exosomes with identical characteristics. However, compared to the secretome, the released exosomes showed better biological properties. Interestingly, dAAT exosomes appeared to be more effective on neuromodulation, whereas neither sAAT nor dAAT-derived exosomes had significant effects on endothelial function. It thus appears that AD-MSC-derived exosomes from the two abdominal adipose tissue layers possess different features for cell therapy. Full article

Background: Schwann cells (SCs) are glial cells involved in peripheral axon myelination. SCs also play a strategic role after peripheral nerve injury, regulating local inflammation and axon regeneration. Our previous studies demonstrated the presence of cholinergic receptors in SCs. In particular, the α7 nicotinic acetylcholine receptors (nAChRs) are expressed in SCs after peripheral axotomy, suggesting their involvement in the regulation of SC-regenerating properties. To clarify the role that α7 nAChRs may play after peripheral axon damage, in this study we investigated the signal transduction pathways triggered by receptor activation and the effects produced by their activation. Methods: Both ionotropic and metabotropic cholinergic signaling were analyzed by calcium imaging and Western blot analysis, respectively, following α7 nAChR activation. In addition, the expression of c-Jun and α7 nAChRs was evaluated by immunocytochemistry and Western blot analysis. Finally, the cell migration was studied by a wound healing assay. Results: Activation of α7 nAChRs, activated by the selective partial agonist ICH3, did not induce calcium mobilization but positively modulated the PI3K/AKT/mTORC1 axis. Activation of the mTORC1 complex was also supported by the up-regulated expression of its specific p-p70 S6K^Thr389 target. Moreover, up-regulation of p-AMPK^Thr172, a negative regulator of myelination, was also observed concomitantly to an increased nuclear accumulation of the transcription factor c-Jun. Cell migration and morphology analyses proved that α7 nAChR activation also promotes SC migration. Conclusions: Our data demonstrate that α7 nAChRs, expressed by SCs only after peripheral axon damage and/or in an inflammatory microenvironment, contribute to improve the SCs regenerating properties. Indeed, α7 nAChR stimulation leads to an upregulation of c-Jun expression and promotes Schwann cell migration by non-canonical pathways involving the mTORC1 activity. Full article

NK-4 plays a key role in the treatment of various diseases, such as in hay fever to expect anti-allergic effects, in bacterial infections and gum abscesses to expect anti-inflammatory effects, in scratches, cuts, and mouth sores from bites inside the mouth for enhanced wound healing, in herpes simplex virus (HSV)-1 infections for antiviral effects, and in peripheral nerve disease that causes tingling pain and numbness in hands and feet, while NK-4 is used also to expect antioxidative and neuroprotective effects. We review all therapeutic directions for the cyanine dye NK-4, as well as the pharmacological mechanism of NK-4 in animal models of related diseases. Currently, NK-4, which is sold as an over-the-counter drug in drugstores, is approved for treating allergic diseases, loss of appetite, sleepiness, anemia, peripheral neuropathy, acute suppurative diseases, wounds, heat injuries, frostbite, and tinea pedis in Japan. The therapeutic effects of NK-4’s antioxidative and neuroprotective properties in animal models are now under development, and we hope to apply these pharmacological effects of NK-4 to the treatment of more diseases. All experimental data suggest that different kinds of utility of NK-4 in the treatment of diseases can be developed based on the various pharmacological properties of NK-4. It is expected that NK-4 could be developed in more therapeutic strategies to treat many types of diseases, such as neurodegenerative and retinal degenerative diseases. Full article

Axons in the peripheral nervous system have the ability to repair themselves after damage, whereas axons in the central nervous system are unable to do so. A common and important characteristic of damage to the spinal cord, brain, and peripheral nerves is the disruption of axonal regrowth. Interestingly, intrinsic growth factors play a significant role in the axonal regeneration of injured nerves. Various factors such as proteomic profile, microtubule stability, ribosomal location, and signalling pathways mark a line between the central and peripheral axons’ capacity for self-renewal. Unfortunately, glial scar development, myelin-associated inhibitor molecules, lack of neurotrophic factors, and inflammatory reactions are among the factors that restrict axonal regeneration. Molecular pathways such as cAMP, MAPK, JAK/STAT, ATF3/CREB, BMP/SMAD, AKT/mTORC1/p70S6K, PI3K/AKT, GSK-3β/CLASP, BDNF/Trk, Ras/ERK, integrin/FAK, RhoA/ROCK/LIMK, and POSTN/integrin are activated after nerve injury and are considered significant players in axonal regeneration. In addition to the aforementioned pathways, growth factors, microRNAs, and astrocytes are also commendable participants in regeneration. In this review, we discuss the detailed mechanism of each pathway along with key players that can be potentially valuable targets to help achieve quick axonal healing. We also identify the prospective targets that could help close knowledge gaps in the molecular pathways underlying regeneration and shed light on the creation of more powerful strategies to encourage axonal regeneration after nervous system injury. Full article