Objective To investigate the differences in biomechanical properties between fresh and chemically extracted acellular peri pheral nerve. Methods Thirty-six sciatic nerves were harvested from 18 adult male Wistar rats of 3 months old and randomly assigned into 3 groups (n=12 per group): normal control group (group A), the nerve segments received no treatment; Sondell method group (group B), the nerve segments were chemically extracted with the detergents of Triton X-100 and sodium deoxycholate; and improved method group (group C), chemically extracted acellular treatment of nerve was done with the detergents of Triton X-200, Sulfobetaine-10 (SB-10), and SB-16. After the acellularization, the structural changes of nerves in each group were observed by HE staining and field emission scanning electron microscope,then the biomechanical properties of nerves were tested using mechanical apparatus (Endura TEC ELF 3200). Results HE staining and field emission scanning electron microscope showed that the effect of acellularization of group C was similar to that of group B, but the effects of demyel ination and integrity of nerve fiber tube of group C were better than those of group B; the structure of broken nerves was more chaotic than before biomechanical test. The biomechanical test showed that the ultimate load, ultimate stress, ultimate strain, mechanical work to fracture in group A were the largest, the next was group C, the least was group B; the tenacity and elastic modulus in group C were the largest, the next was group B, the least was group A; but the differences were not significant (P gt; 0.05). Conclusion Compared with Sondell method, the nerve treated by improved method is more appropriate for use in vivo.
Objective To investigate the clinical features, treatment methods, and prognostic influence factors of patients with malignant peripheral nerve sheath tumor (MPNST). MethodsA retrospective analysis was conducted on 96 MPNST patients treated between January 1, 2015 and December 31, 2021. There were 46 males and 50 females, aged between 15 and 87 years (mean, 48.2 years). The tumors were located in the trunk in 50 cases, extremities in 39 cases, and head and neck in 7 cases. The maximum tumor diameter was <5 cm in 49 cases, ≥5 cm in 32 cases, with 15 cases missing data. Tumor depth was deep in 77 cases and superficial in 19 cases. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) histological grading was G1 in 9 cases, G2 in 12 cases, and G3 in 34 cases, with 41 cases missing data. There were 37 recurrent MPNST cases, 32 cases with neurofibromatosis type 1 (NF1), and 26 cases in stage Ⅳ. Postoperative adjuvant radiotherapy was administered to 25 patients, perioperative chemotherapy to 45 patients, and anlotinib-targeted therapy to 30 patients. R0 resection was achieved in 73 cases. Patients were divided into groups based on the presence or absence of NF1, and baseline data between the two groups were compared. Kaplan-Meier curves were generated to assess disease-free survival (DFS) and overall survival (OS) based on various factors (age, gender, presence of NF1, recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, tumor location, tumor size, tumor depth, perioperative chemotherapy, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy), and differences between survival curves were analyzed using the Log-Rank test. Multivariate COX proportional hazards regression was used to identify independent prognostic factors for MPNST. Results Patients with NF1 had a significantly higher proportion of superficial tumors and lower FNCLCC grade compared to those without NF1 (P<0.05); no significant difference was found for other variables (P<0.05). Kaplan-Meier analysis showed that recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, perioperative chemotherapy, and anlotinib-targeted therapy were factors influencing 1-year DFS (P<0.05), while stage Ⅳ MPNST, FNCLCC grade, and perioperative chemotherapy were factors affecting 3-year OS (P<0.05). Multivariate COX proportional hazards regression analysis revealed that recurrent MPNST and high-grade FNCLCC (G3) were independent prognostic factors for 1-year DFS (P<0.05), while stage Ⅳ MPNST, superficial tumor depth, age over 60 years, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy were independent prognostic factors for 3-year OS (P<0.05). Conclusion MPNST patients with NF1 tend to have more superficial tumors and lower FNCLCC grades. FNCLCC grade, R0 resection, and adjuvant therapies, including radiotherapy and anlotinib-targeted therapy, are closely associated with MPNST prognosis. Complete surgical resection should be prioritized in clinical management, along with adjuvant treatments such as radiotherapy and targeted therapy of anlotinib to improve patient outcomes.
Objective To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. Methods The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs (n=7) and GGTA1 gene-edited pigs (n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. Results IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves (P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference (P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs (P<0.05). Conclusion The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Objective To review the research progress of graphene and its derivatives in repair of peripheral nerve defect. Methods The related literature of graphene and its derivatives in repair of peripheral nerve defect in recent years was extensively reviewed. Results It is confirmed by in vitro and in vivo experiments that graphene and its derivatives can promote cell adhesion, proliferation, differentiation and neurite growth effectively. They have good electrical conductivity, excellent mechanical properties, larger specific surface area, and other advantages when compared with traditional materials. The three-dimensional scaffold can improve the effect of nerve repair. Conclusion The metabolic pathways and long-term reaction of graphene and its derivatives in the body are unclear. How to regulate their biodegradation and explain the electric coupling reaction mechanism between cells and materials also need to be further explored.
Objective To explore the clinical features, surgical treatment, and effectiveness of neurofibromas associated with neurofibromatosis type 1 (NF1). Methods A clinical data of 41 patients with NF1 admitted between December 2018 and April 2024 was retrospectively analyzed. There were 15 males and 26 females, with an average age of 27.5 years (range, 5-61 years). Only one type of neurofibroma existed in 3 patients and the rest of the patients had more than two types of neurofibromas. Fourteen patients had total resection of multiple cutaneous neurofibromas (CNF). Eighteen patients of diffuse neurofibromas underwent total, near-total, or subtotal resection. Among the 13 patients of localized nodular neurofibromas, 9 of benign tumors underwent total sub-capsular resection and 4 of malignant peripheral nerve sheath tumor (MPNST) underwent maginal resection, and only 1 underwent postoperative radiotherapy and chemotherapy. Among the 15 patients of plexiform neurofibromas (PNF), 5 patients underwent both superficial and deep PNF resection, 2 underwent the superficial PNF resection, and 8 underwent the large nodular lesions in the deep PNF resection. There were 8 MPNST, of which 7 cases underwent total sub-capsular resection and large tumor capsule resection under neurophysiological monitoring, and 1 case with the tumor located on the top of the head underwent wide resection and skin grafting. One patient underwent proton knife therapy after surgery, 2 patients did not receive radiotherapy, and the remaining patients received conventional radiotherapy. Results All patients were followed up after surgery, and the follow-up time was 3-66 months, with an average of 25.0 months. Patients with CNF recovered satisfactorily after surgery, and there was no recurrence during follow-up. Patients with diffuse neurofibromas relieved preoperative symptoms after surgery. Three patients with diffuse neurofibromas located in the head and face recurred during follow-up. The patients with benign localized nodular neurofibromas recovered well after surgery, and only 1 patient had transient regional neuralgia after surgery. Among the patients with MPNST, 2 patients died of recurrence and lung metastasis, while the remaining 2 patients had no recurrence and metastasis during follow-up. All preoperative symptoms disappeared in patients with benign PNF, and no tumor recurrence was observed during follow-up. Two patients with PNF located in the brachial plexus had difficulty in shoulder abduction after surgery, 1 patient with PNF located in vagus developed hoarseness after surgery. Among the 8 patients with MPNST in PNF, 1 died of lung metastases and 1 died of systemic failure. The remaining 6 patients were in stable condition during follow-up, and no tumor recurrence or metastasis was observed. Conclusion According to the clinical features of neurofibromas in patients with NF1, choosing appropriate surgical approaches can obtain good effectiveness. Because of the difficulty of completely resection, diffuse neurofibromas, especially those located in the head and face, are prone to recurrence after surgery. MPNST has the worst prognosis, high incidence of recurrence/metastasis, and short survival period. Total resection combined with radiotherapy can decrease local recurrence.
ObjectiveTo describe the research progress of silk-based biomaterials in peripheral nerve repair and provide useful ideals to accelerate the regeneration of large-size peripheral nerve injury. Methods The relative documents about silk-based biomaterials used in peripheral nerve regeneration were reviewed and the different strategies that could accelerate peripheral nerve regeneration through building bioactive microenvironment with silk fibroin were discussed. Results Many silk fibroin tissue engineered nerve conduits have been developed to provide multiple biomimetic microstructures, and different microstructures have different mechanisms of promoting nerve repair. Biomimetic porous structures favor the nutrient exchange at wound sites and inhibit the invasion of scar tissue. The aligned structures can induce the directional growth of nerve tissue, while the multiple channels promote the axon elongation. When the fillers are introduced to the conduits, better growth, migration, and differentiation of nerve cells can be achieved. Besides biomimetic structures, different nerve growth factors and bioactive drugs can be loaded on silk carriers and released slowly at nerve wounds, providing suitable biochemical cues. Both the biomimetic structures and the loaded bioactive ingredients optimize the niches of peripheral nerves, resulting in quicker and better nerve repair. With silk biomaterials as a platform, fusing multiple ways to achieve the multidimensional regulation of nerve microenvironments is becoming a critical strategy in repairing large-size peripheral nerve injury. Conclusion Silk-based biomaterials are useful platforms to achieve the design of biomimetic hierarchical microstructures and the co-loading of various bioactive ingredients. Silk fibroin nerve conduits provide suitable microenvironment to accelerate functional recovery of peripheral nerves. Different optimizing strategies are available for silk fibroin biomaterials to favor the nerve regeneration, which would satisfy the needs of various nerve tissue repair. Bioactive silk conduits have promising future in large-size peripheral nerve regeneration.
ObjectiveTo review recent research progress in the use of auxiliary components of nerve conduits for the treatment of peripheral nerve injuries. MethodsAn extensive review of recent domestic and international literature was conducted to evaluate the role of auxiliary components in nerve conduits for peripheral nerve repair, with a focus on their effects and underlying mechanisms. ResultsBy incorporating auxiliary components such as bioactive molecules, therapeutic cells, and their derivatives, nerve conduits can create a more biomimetic regenerative microenvironment. This is achieved by providing neurotrophic support, modulating the immune microenvironment, improving blood and oxygen supply, and offering directional guidance for nerve regeneration. Consequently, the nerve conduit is transformed from a simple physical scaffold into an active, bio-functional repair system, which enhances the effectiveness for PNI. ConclusionWhile nerve conduits augmented with auxiliary components demonstrate improved effectiveness, further advancements are required in drug delivery systems and the integration of cellular components. Moreover, most current studies are based on animal or in vitro experiments. Randomized controlled clinical trials are necessary to validate their clinical effectiveness.
ObjectiveTo investigate the effects of exosomes from adipose-derived stem cells (ADSCs) on peripheral nerve regeneration, and to find a new treatment for peripheral nerve injury. MethodsThirty-six adult Sprague Dawley (SD) rats (male or female, weighing 220-240 g) were randomly divided into 3 groups (n=12). Group A was the control group; group B was sciatic nerve injury group; group C was sciatic nerve injury combined with exosomes from ADSCs treatment group. The sciatic nerve was only exposed without injury in group A, and the sciatic nerve crush injury model was prepared in groups B and C. The SD rats in groups A and B were injected with PBS solution of 200 μL via tail veins; the SD rats in group C were injected with pure PBS solution of 200 μL containing 100 μg exosomes from ADSCs, once a week and injected for 12 weeks. At 1 week after the end of the injection, the rats were killed and the sciatic nerves were taken at the part of injury. The sciatic nerve fiber bundles were observed by HE staining; the SCs apoptosis of the sciatic nerve tissue were detected by TUNEL staining; the ultrastructure and SCs autophagy of the sciatic nerve were observed by transmission electron microscope. ResultsGross observation showed that there was no obvious abnormality in the injured limbs of group A, but there were the injured limbs paralysis and muscle atrophy in groups B and C, and the degree of paralysis and muscle atrophy in group C were lighter than those in group B. HE staining showed that the perineurium of group A was regular; the perineurium of group B was irregular, and there were a lot of cell-free structures and tissue fragments in group B; the perineurium of group C was more complete, and significantly well than that of group B. TUNEL staining showed that the SCs apoptosis was significantly increased in groups B and C than in group A, in group B than in group C (P<0.01). Transmission electron microscope observation showed that the SCs autophagosomes in groups B and C were significantly increased than those in group A, but the autophagosomes in group C were significantly lower than those in group B. ConclusionThe exosomes from ADSCs can promote the peripheral nerve regeneration. The mechanism may be related to reducing SCs apoptosis, inhibiting SCs autophagy, and reducing nerve Wallerian degeneration.
ObjectiveTo explore the preparation method, physical and chemical properties, and biocompatibility of a conductive composite scaffold based on polypyrrole/silk fibroin (PPy/SF) fiber with " shell-core” structure, and to provide a preliminary research basis for the application in the field of tissue engineered neuroscience.Methods The conductive fibers with " shell-core” structure were prepared by three-dimensional printing combined with in-situ polymerization. PPy/SF fiber-based conductive composite scaffolds were formed by electrospinning. In addition, core-free PPy conductive fibers and SF electrospinning fibers were prepared. The stability, biomechanics, electrical conductivity, degradation performance, and biological activity of each material were tested to analyze the comprehensive properties of fiber-based conductive composite scaffolds.ResultsCompared with pure core-free PPy conductive fibers and SF electrospinning fibers, the PPy/SF fiber-based conductive composite scaffolds with " shell-core” structure could better maintain the stability performance, enhance the mechanical stretchability of the composite scaffolds, maintain long-term electrical activity, and improve the anti-degradation performance. At the same time, PPy/SF conductive composite scaffolds were suitable for NIH3T3 cells attachment, conducive to cell proliferation, and had good biological activity.ConclusionPPy/SF fiber-based conductive composite scaffolds meet the needs of conductivity, stability, and biological activity of artificial nerve grafts, and provide a new idea for the development of a new generation of high-performance and multi-functional composite materials.
Schwanns cell (SC) was isolated from sciatic nerve of adult rat with Wallerine degeneration. After culture, SC-serum free culture media (SCSFCM) was obtained. By ultrafiltration with PM-10 Amicon Membrane, electrophoresis with DiscPAGE,and electrical wash-out with Biotrap apparatus, D-band protein was isolated from the SC-SFCM. The D-band protein in the concentration of 25ng/ml could affect the survival of the spinal anterior horn neuron in vitro, prominently and itsactivity was not changed after being frozen. The molecular weight of the protein ranged from 43 to 67 Kd. The D-band protein might be a neurotrophic substancedifferent from the known SCderived neurotrophic factors (NTF). Its concentration with biological activity was high enough to be detected. The advantages of MTT in assessment of NTF activity were also discussed.