Search Results (744)

Background: Surgical management of trauma in the maxillofacial complex can result in iatrogenic nerve injuries, particularly involving the infraorbital, inferior alveolar, and mental nerves. Paresthesia is a common postoperative complication, often attributed to the anatomical positioning of these nerve structures, making them vulnerable to injury. Among current therapeutic options for nerve injuries, low-level laser therapy (LLLT) has shown promising results in published studies. Objectives: This prospective observational study evaluated the effects of LLLT on nerve recovery following maxillofacial trauma surgery. Methods: A total of 21 participants, with a median age of 35 years and no gender-based selection criteria, were enrolled. Cases included zygomaticomaxillary complex and mandibular osteosynthesis; analyses were within-subject across time. Postoperative laser therapy was administered to both groups using the DUO MMO device (MMOptics, São Carlos, Brazil), delivering infrared light along the pathways of the inferior alveolar, infraorbital, and mental nerves. Nerve function was assessed regularly using a Visual Analog Scale (VAS) and the Brush Stroke Direction (BSD) test to evaluate sensory recovery. Results: Compared with baseline (15 days post-op, pre-LLLT), VAS scores showed significant reductions at sessions 7 and 10, and BSD responses increased over time. Conclusion: After multiplicity control, only the session 10 comparison remained significant. These observational findings support the feasibility of multi-session LLLT after maxillofacial trauma; controlled trials are warranted to determine efficacy. Full article

Peripheral nerve injury (PNI) poses a major clinical challenge, frequently resulting in chronic pain, muscle atrophy, and long-term functional impairment. While autologous nerve grafting remains the gold standard for repairing long-gap defects, its application is limited by donor-site morbidity and limited tissue availability. Nerve guidance conduits (NGCs) have emerged as promising alternatives; however, their efficacy remains suboptimal, primarily because most fail to recapitulate the spatiotemporally coordinated regenerative microenvironment required for robust axonal extension, timely remyelination, and durable neurovascular integration. Key limitations of current designs include an inability to balance the bioactivity of natural materials with the tunability of synthetic polymers, insufficient nutrient and oxygen delivery for long-gap repair, and a lack of dynamic, stage-specific regulation of the healing process. Consequently, microenvironment reconstruction represents the central bottleneck to achieving effective regeneration. This review synthesizes recent advances in purposefully rebuilding the NGC microenvironment across three interdependent dimensions: (i) activation and functional regulation of Schwann cells; (ii) immunomodulation to resolve inflammation while promoting repair; (iii) angiogenesis to ensure metabolic support. We place special emphasis on biomaterial strategies, particularly advanced hydrogels that integrate physical, biochemical, and dynamic cues for spatiotemporally programmed regeneration. Finally, we outline design principles and translational considerations for next-generation NGCs aimed at closing the efficacy gap with autografts. Full article

Perineural invasion (PNI), defined by cancer spreading or invading into the nerve, links to severe pain, recurrence, and poor prognosis. PNI contributes to nerve damage, Schwann cell activation, and sensory neuron dysfunction. Soluble tumor necrosis factor α (solTNFα) binds to TNFR1 to drive inflammation and nerve injury, playing a key role in cancer progression and pain. This study, using a mouse sciatic nerve PNI model, explored whether blocking solTNFα-TNFR1 signaling via TNFR1 knockout or pharmacological inhibition by XPro1595 could reduce PNI-associated pain. Data showed that XPro1595, but not TNFR1 knockout, reduced tumor burden, alleviated mechanical allodynia, and improved muscle function and locomotion, primarily in females. Histological analysis in females showed that XPro1595 increased the number of myelin and dendritic cells while reducing axonal damage that resulted from PNI. In the tumor zone outside the nerve truck, XPro1595 reduced T cell and increased macrophage and dendritic cell numbers. Transcriptomic analysis revealed that XPro1595 in females with PNI upregulated mitochondrial, myelination, motor function, and immune regulation gene pathways while it downregulated inflammatory, extracellular matrix, and tumor progression pathways. Overall, we demonstrated that XPro1595 exhibited antitumor, neuroprotective, and analgesic properties in female mice, likely by promoting neuronal regeneration and mitochondrial function, while reducing inflammation and extracellular remodeling. Full article

Background: Alpha-linolenic acid (ALA) is an essential fatty acid from the omega-3 family that plays an important role in skin homeostasis. It is known for its anti-inflammatory properties, which can contribute to wound healing. Neurotrophins, such as Brain-Derived Neurotrophic Factor (BDNF), may also play an important role in the skin, influencing nerve regeneration and pain modulation. Objectives: This article aims to explore the therapeutic effect of ALA on wound healing in streptozotocin-induced hyperglycemic mice, with an emphasis on the involvement of neurotrophins. Methods: We used keratinocyte cultures exposed or not to ALA and male C57BL6-J mice, which were randomly divided into four groups: non-hyperglycemic treated with vehicle; non-hyperglycemic treated with ALA; hyperglycemic treated with vehicle; and hyperglycemic treated with ALA. The treatment was administered continuously via a subcutaneous osmotic pump. Results: We found that controlled ALA administration potentiates the wound healing process in hyperglycemic mice by accelerating the inflammatory phase and promoting early granulation tissue formation (73.2% ± 0.7 vs. 92.2% ± 2.8 on day 7, n = 5; p < 0.05). This is supported by the balance between the expression of vimentin, CD31, and MMP-9. Furthermore, ALA modulates proteins linked to peripheral neurogenesis and gliogenesis, such as BDNF, NTRK2, SOX-10, CNTF, CTNFR, and STAT-3. It may also promote wound healing and nerve regeneration at the wound site in hyperglycemic animals. In non-hyperglycemic mice, ALA improves the quality of scars but does not accelerate the wound healing process, even with the positive modulation of certain genes relevant to skin healing. Conclusions: Alpha-linolenic acid improves skin wound healing and increases gene expression related to nerve regeneration in wounds of hyperglycemic mice. Full article

Corneal nerves play a crucial role in maintaining ocular surface homeostasis by supporting the functional integrity of corneal epithelial, stromal, and endothelial cells; modulating tear secretion; and facilitating sensory responses essential for overall ocular health. With advancing age, these highly specialized peripheral sensory fibers undergo progressive attrition and morphologic distortion driven by the canonical hallmarks of aging including genomic instability, impaired proteostasis, mitochondrial dysfunction, and chronic low-grade inflammation. The resulting neuro-immune dysregulation reduces trophic support, delays wound healing, and predisposes older adults to dry-eye disease, neurotrophic keratopathy, and postsurgical hypoesthesia. Age-exacerbating cofactors including diabetes, dyslipidemia, neurodegenerative disorders, topical preservatives, chronic contact-lens wear, herpes zoster ophthalmicus, and ocular-surface hypoxia further accelerate sub-basal nerve rarefaction and functional decline. This review provides an overview of age-related physiological alterations in ocular surface nerves, with a particular emphasis on corneal innervation. It also discusses risk factors that speed up these changes. Given the inherently limited regenerative capacity of corneal nerves and their inability to fully restore to baseline conditions following injury or degeneration, it is critical to identify and develop effective strategies aimed at mitigating or delaying physiological nerve degeneration and promoting nerve regeneration. This review also brings up emerging therapeutic strategies, including regenerative medicine, neuroprotective agents, and lifestyle interventions aimed at mitigating age-related corneal nerve degeneration. Full article

Visual impairment impacts nearly half a billion people globally. Corrective glasses, artificial lens replacement, and medical management have markedly improved the management of diseases inherent to the eye, such as refractive errors, cataracts, and glaucoma. However, therapeutic strategies for retinopathies, optic nerve damage, and distal optic pathways remain limited. The complex optic apparatus comprises multiple neural structures that transmit information from the retina to the diencephalon to the cortex. Over the last few decades, innovations have emerged to address the loss of function at each step of this pathway. Given the retina’s lack of regenerative potential, novel treatment options have focused on replacing lost retinal cell types through cellular replacement with stem cells, restoring lost gene function with genetic engineering, and imparting new light sensation capabilities with optogenetics. Additionally, retinal neuroprosthetics have shown efficacy in restoring functional vision, and neuroprosthetic devices targeting the optic nerve, thalamus, and cortex are in early stages of development. Non-invasive neuromodulation has also shown some promise in modulating the visual cortex. Recently, the first in-human whole-eye transplant was performed. While functional vision was not restored, the feasibility of such a transplant with viable tissue graft at one year was demonstrated. Subsequent studies are now focused on guidance cues for axonal regeneration past the graft site to reach the lateral geniculate nucleus. Although the methods discussed above have shown promise individually, improvements in vision have been modest at best. Achieving the goal of restoration of functional vision will clearly require further development of cellular therapies, genetic engineering, transplantation, and neuromodulation. A concerted multidisciplinary effort involving scientists, engineers, ophthalmologists, neurosurgeons, and reconstructive surgeons will be necessary to restore vision for patients with vision loss from these challenging pathologies. In this expert review article, we describe the current literature in visual neurorestoration with respect to cellular therapeutics, genetic therapies, optogenetics, neuroprosthetics, non-invasive neuromodulation, and whole-eye transplant. Full article

This study evaluated the effect of irradiation of different energy densities in low-level laser therapy (LLLT) and exogenous nerve growth factor (NGF) on Schwann cells (SCs). SCs (SCL 4.1/F7) exposed to LLLT (4 or 80 J/cm²) and NGF (25 ng/mL) were evaluated on days 1, 3, and 7. Cell viability (MTT), proliferation (crystal violet) and morphology (SEM—Scanning Electron Microscopy) on the polyhydroxybutyrate (PHB) scaffold were compared among five study groups: Control; L4. 4 J/cm² LLLT; L80. 80 J/cm² LLLT; L4N. 4 J/cm² LLLT + NGF; and L80N. 80 J/cm² LLLT + NGF. Viability and proliferation increased over time in groups treated exclusively with LLLT, with 4 J/cm² reduced cell viability on the third day. The NGF exposition showed a reduction in cell viability and proliferation. The SCs remained attached to the PHB scaffold during the 7 days analyzed. The LLLT energy densities did not modify SC behavior, except for a reduction in cell viability after irradiation of 4 J/cm² on the third day. Consistently, SC exposure to exogenous NGF significantly reduced proliferation and viability in all periods analyzed. Morphological changes were observed, and NGF exposure appears to have helped cells intertwine with PHB scaffold fibers. Full article

Counteracting neurodegenerative diseases (NDs) presents a multifaceted challenge in the aging societies of Western countries. Each year, millions of people worldwide are affected by such ailments as Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), multiple sclerosis (MS), spinal cord injury, ischemic stroke, motor neuron disease, spinal muscular atrophy, spinocerebellar ataxia, and amyotrophic lateral sclerosis (ALS). Advancements in modern biomaterial technologies present substantial opportunities for the field of regenerative medicine. Nevertheless, limitations arise from the requirement that biomaterial design be tailored to the specific biological parameters of the target cell types with which they are intended to interact. Such an opportunity creates nanomaterials involving nanoparticles. The surface chemistry of nanoparticles, especially when functionalized with bioactive agents, enhances biocompatibility and facilitates interactions with nervous cells. Herein, we review contemporary strategies in the application of biomaterials for nerve regeneration, with particular emphasis on nanomaterials and biocompatible polyelectrolyte layers, which the authors identify as having the most significant potential to drive transformative advances in regenerative medicine in the near future. Full article

Cannabidiol (CBD) is a non-psychotropic compound found in plants of the Cannabis genus, extensively studied for its therapeutic potential. Research has shown that CBD possesses anti-inflammatory, antioxidant, and regenerative properties, and may contribute to the recovery of neural and bone tissues. In light of the aging population and the resulting rise in neurodegenerative and osteodegenerative conditions, exploring novel therapeutic strategies that promote cellular regeneration is increasingly important. This review aims to compile and critically analyze key studies published in recent decades regarding the effects of CBD on the regeneration of the central and peripheral nervous systems, as well as bone tissue. Findings from in vivo studies indicate that CBD can attenuate inflammatory responses, inhibit oxidative stress, and modulate cellular pathways involved in tissue repair, thereby supporting neuronal and bone regeneration. Moreover, evidence suggests that CBD may protect cells from structural damage, enhancing the functional recovery of affected tissues. Despite scientific advances highlighting cannabidiol as a promising agent for bone and nerve regeneration, its therapeutic application still faces significant limitations. The primary challenge lies in the lack of robust clinical trials in humans, as most existing evidence is derived from in vitro and in vivo studies, making it difficult to confirm its efficacy and safety in clinical contexts. Additionally, CBD’s low bioavailability—due to first-pass hepatic metabolism—hinders dose standardization and reduces the predictability of therapeutic outcomes. Compounding these issues are regulatory constraints and the persistent social stigma surrounding cannabis-derived compounds, which further impede their integration and acceptance in regenerative medicine. Therefore, future research is essential to validate the therapeutic benefits of CBD and to establish its clinical applicability in treating neurological and bone disorders. Full article

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes, marked by Schwann cell dysfunction, demyelination, and impaired nerve regeneration. Although Schwann cells undergo phenotypic changes under hyperglycemic conditions, the underlying molecular mechanisms remain unclear. This study aimed to examine the effects of high glucose on Schwann cell phenotype and assess the involvement of the mTOR signaling pathway. Primary Schwann cells were isolated from rat sciatic nerves and cultured in media containing 5 mM (control), 25 mM, or 50 mM glucose for five days. Immunofluorescence staining and corrected total cell fluorescence (CTCF) analysis were used to evaluate expression of key markers: c-Jun, Krox-20, p75^NTR, MBP, mTOR, phosphorylated mTOR (Ser2448), and AKR1B1. Among these, significant changes were observed in MBP (p = 0.002), total mTOR (p = 0.001), and phosphorylated mTOR (Ser2448) (p = 0.0179), indicating impaired mTOR activation and loss of myelin protein expression. Non-significant changes in the other markers are discussed as preliminary observations. These findings highlight mTOR dysregulation and impaired myelin protein expression as central features of Schwann cell responses to hyperglycemia, which may contribute to the development of DPN. Full article

Peripheral nerve injuries remain a major clinical problem, and cell-free therapies using stem cell-derived bioproducts have emerged as promising alternatives. This study evaluated the influence of neurogenic differentiation and passage number on the secretomic and exosomal profile of human dental pulp stem cells (hDPCSs). Conditioned media from undifferentiated and neurodifferentiated hDPSCs, and exosomes derived from undifferentiated hDPSCs at passages 4 and 7, were analyzed using multiplex immunoassays, RT-PCR, and scanning electron microscopy (SEM). Neurodifferentiated hDPSCs at early passages secreted higher levels of neurotrophic, angiogenic and immunomodulatory factors, including FGF-2, IL-6, IL-8, and PDGF-AA. Exosomes from early-passage undifferentiated cells showed a more abundant and relevant neuroregenerative mRNA cargo in comparison to the later passages. Both cell types and exosomes adhered to the Reaxon^® nerve guidance conduit, confirming the permissive nature of the materials regarding cells and cellular products, allowing adhesion and survival. Neurite outgrowth assays performed on neurodifferentiated hDPSCs confirmed functional neural behavior. In later passages, a decline in secretory and exosomal activity was noted. These results highlight the relevance of early-passage hDPSCs as a source of bioactive factors and support their application in cell-free approaches for peripheral nerve regeneration. Full article

Corneal regeneration has gained growing interest in recent years, largely due to the limitations of conventional treatments and the persistent shortage of donor tissue. Among the emerging strategies, extracellular vehicles (EVs), especially those derived from mesenchymal stromal cells (MSCs), have shown great promise as a cell-free therapeutic approach. These nanoscale vesicles contribute to corneal healing by modulating inflammation, supporting epithelial and stromal regeneration, and promoting nerve repair. Their therapeutic potential is largely attributed to the diverse and bioactive proteomic cargo they carry, including growth factors, cytokines, and proteins involved in extracellular matrix remodeling. This review presents a comprehensive examination of the proteomic landscape of EVs in the context of corneal regenerative medicine. We explore the biological functions of EVs in corneal epithelial repair, stromal remodeling, and neurodegeneration. In addition, we discuss advanced proteomic profiling techniques such as mass spectrometry (MS) and liquid chromatography–mass spectrometry (LC-MS/MS), which have been used to identify and characterize the protein contents of EVs. This review also compares the proteomic profiles of EVs derived from various MSC sources, including adipose tissue, bone marrow, and umbilical cord, and considers how environmental cues, such as hypoxia and inflammation, influence their protein composition. By consolidating current findings, this article aims to provide valuable insights for advancing the next generation of cell-free therapies for corneal repair and regeneration. Full article

Glottic insufficiency, often caused by laryngeal nerve injury, impairs voice quality and breathing. Current treatments, such as hyaluronic acid injection, require frequent reapplication every 3–6 months. This study aimed to investigate the therapeutic potential of small extracellular vesicles (sEVs) derived from Wharton’s Jelly mesenchymal stem cells (WJMSCs) incorporated into genipin-crosslinked gelatin hydrogels (GCGHs) for promoting vocal fold fibroblast (VFFs) regeneration in vitro. WJMSCs were isolated from umbilical cords, expanded to passage 4, and used for sEV isolation via tangential flow filtration (TFF). The sEVs (585.89 ± 298.93 µg/mL) were characterized using bicinchoninic acid assay (BCA), nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and Western blot. Seven concentrations of sEVs were tested on VFFs to evaluate cytotoxicity and proliferation, identifying 75 µg/mL as the optimal dose. GCGHs were then combined with WJMSCs and sEVs and evaluated for physicochemical properties, degradation, biocompatibility, and immune response. The hydrogels were injectable within 20 min and degraded in approximately 42 ± 0.72 days. The optimal sEV concentration significantly enhanced VFFs proliferation (166.59% ± 28.11) and cell viability (86.16% ± 8.55, p < 0.05). GCGH-MSCs showed the highest VFFs viability (82.04% ± 10.51) and matrix contraction (85.98% ± 1.25) compared to other groups. All hydrogel variants demonstrated minimal immune response when co-cultured with peripheral blood mononuclear cells (PBMCs). GCGH is a promising scaffold for delivering WJMSCs and sEVs to support VFF regeneration, with demonstrated biocompatibility and regenerative potential. Further in vivo studies are warranted to validate these findings. Full article

Objective: Molecular biology techniques were employed to investigate the effects of thrombospondin-4 (Thbs4) expression in dorsal root ganglion (DRG) on peripheral nerve injury repair and regeneration, as well as to elucidate the underlying molecular mechanisms. Methods: A sciatic nerve transection model in rat was established to analyze Thbs4 expression and localization in DRG tissues after injury. Both siRNA and adeno-associated virus (AAV) were used to knockdown or overexpress Thbs4. The effects of knockdown and overexpression of Thbs4 on axon growth were assessed using immunofluorescence staining. The roles of Thbs4 in peripheral nerve injury repair and regeneration were determined using behavioral assays, electrophysiological recordings, and transmission electron microscopy. Results: Thbs4 was primarily localized in the cell membrane and cytoplasm of DRG neurons but was also found in the intercellular spaces. In vitro experiments demonstrated that Thbs4 overexpression promoted axonal regeneration and reduced neuronal apoptosis. They also showed that Thbs4 overexpression accelerated sciatic nerve regeneration and enhanced the recovery of motor and sensory functions. Conversely, Thbs4 knockdown had the opposite effects. This study also showed that the knockdown or overexpression of Thbs4 significantly altered the expression of NF-κB and ERK signaling pathways, suggesting their involvement in peripheral nerve repair and regeneration. Conclusions: Thbs4 expression in DRG tissues is significantly altered following sciatic nerve injury. The NF-κB and ERK may be involved in regulating the repair and regeneration of the peripheral nerve by Thbs4. Full article

This study aimed to evaluate the regenerative effects of various microcurrent waveforms in cast-induced gastrocnemius muscle atrophy in rabbits, integrating both in vitro and in vivo analyses. After two weeks of enforced hindlimb immobilization via casting, twenty-four rabbits were divided into four groups and treated for two weeks: Group-1 (control) received sham microcurrent, Group-2 was treated with a square waveform microcurrent, Group-3 with a sine waveform, and Group-4 with a triangular waveform. Treatments were administered daily for one hour. Calf circumference, muscle thickness (via ultrasound), tibial nerve CMAP, muscle fiber CSA, and protein expression (via Western blot analysis) were assessed. Among the groups, the sine waveform microcurrent resulted in significantly enhanced recovery across all measured parameters (p < 0.05), showing superior improvements in muscle thickness, CMAP amplitude, and fiber CSA. Immunohistochemical analysis revealed increased expression of proliferation and angiogenesis markers, including BrdU, PCNA, VEGF, and PECAM-1, while Western blotting demonstrated robust upregulation of myogenic regulatory factors such as MyoD and myogenin. Furthermore, levels of inflammatory and apoptotic markers, including TNF-α, NF-κB, and cleaved caspase-3, and stress response proteins, including p-CHK1 and p-CHK2, were markedly reduced. Collectively, these findings indicate that sine waveform microcurrent stimulation most effectively promotes muscle regeneration in both dexamethasone-induced C2C12 myoblasts and cast-induced muscle atrophy, underscoring its therapeutic potential and warranting further studies to optimize clinical application parameters. Full article