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BACKGROUND: Current studies have shown that ultrasound-guided paravertebrospinai nerve block widely used has a significant effect in the clinical treatment of thoracolumbar zoster-associated pain. OBJECTIVE: To systematically evaluate the efficacy and safety of ultrasound-guided paravertebral nerve block in the treatment of thoracolumbar zoster-associated pain and to provide reference for clinical treatment. METHODS: We searched relevant literature in PubMed, The Cochrane Library, EMBASE, China National Knowledge Infrastructure (CNKI), WanFang Data, China Science and Technology Journal Database (VIP) and Chinese Biomedical Literature Database (CBM). The limit of searching time was from inception until January 1, 2019. Randomized controlled trials addressing ultrasound-guided paravertebral nerve block (experimental group) versus drug therapy (control group) for the treatment of acute zoster-associated pain or postherpetic neuralgia were collected according to the criteria for inclusion and exclusion. Literature quality was assessed according to Cochrane Handbook 5.1.0 bias risk assessment tool. The literature data were analyzed using Revman 5.3 software through a Meta-analysis. RESULTS AND CONCLUSION: A total of 11 randomized controlled trials involving 916 patients met the inclusion criteria. The results of Meta-analysis showed that compared with the control group, the ultrasound-guided paravertebral nerve block group had better analgesic effect and the optimal analgesic effect appeared within 1-4 weeks. A random effects model was then used [1st week: Mean difference (MD)=-0.91, 95% confidence interval (Cl) (-1.22, -0.61), P < 0.000 01; 2nd week: MD=-1.11, 95%C/(-1.52, -0.70), P < 0.000 01; 3rd week: MD=-1.26, 95%C/(-1.79, -0.74), P < 0.000 01; 4th week: MD=-0.90, 95%C/(-1.57, -0.24), P=0.007], At the same time, the quality of sleep and the effective rate of treatment were improved, and a fixed effects model was used [odds ratio=3.63, 95%C/(2.38, 5.53), P < 0.000 01]. The statistical results showed significant difference. There was no increase in post-treatment adverse reactions. Therefore, ultrasound-guided paravertebral nerve block is safe and effective for the treatment of zoster-associated pain in the thoracolumbar region.
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Objective: To explore a green route for the fabrication of thermo-sensitive chitosan nerve conduits, improve the mechanical properties and decrease the degradation rate of the chitosan nerve conduits. Methods: Taking advantage of the ionic specific effect of the thermo-sensitive chitosan, the strengthened chitosan nerve conduits were obtained by immersing the gel-casted conduits in salt solution for ion-induced phase transition, and rinsing, lyophilization, and 60Co sterilization afterwards. The nerve conduits after immersing in NaCl solutions for 0, 4, 12, 24, 36, 48, and 72 hours were obtained and characterized the general observation, diameters and mechanical properties. According to the above results, the optimal sample was chosen and characterized the microstructure, degradation properties, and cytocompatibility. The left sciatic nerve defect 15 mm in length was made in 20 male Sprague Dawley rats. The autologous nerves (control group, n=10) and the nerve conduits (experimental group, n=10) were used to repair the defects. At 8 weeks after operation, the compound muscle action potential (CMAP) was measured. The regenerated nerves were investigated by gross observation and toluidine blue staining. The gastrocnemius muscle was observed by HE staining. Results: With the increased ionic phase transition time, the color of the conduit was gradually deepened and the diameter was gradually decreased, which showed no difference during 12 hours. The tensile strength of the nerve conduit was increased gradually. The ultimate tensile strength showed significant difference between the 48 hours and 12, 24, and 36 hours groups ( P0.05). As a result, the nerve conduit after ion-induced phase transition for 48 hours was chosen for further study. The scanning electron microscope (SEM) images showed that the nerve conduit had a uniform porous structure. The degradation rate of the the nerve conduit after ion-induced phase transition for 48 hours was significantly decreased as compared with that of the conduit without ion-induced phase transition. The nerve conduit could support the attachment and proliferation of rat Schwann cells on the inner surface. The animal experiments showed that at 8 weeks after operation, the CMAPs of the experimental and control groups were (3.5±0.9) and (4.3±1.1) m/V, respectively, which showed no significant difference between the two groups ( P0.05］. The nerve conduit of the experimental group could repair the nerve defect. There was no significant difference between the experimental and control groups in terms of the histomorphology of the regenerated nerve fibers and the gastrocnemius muscle. Conclusion: The green route for the fabrication of thermo-sensitive chitosan nerve conduits is free of any toxic reagents, and has simple steps, which is beneficial to the industrial transformation of the chitosan nerve conduit products. The prepared chitosan nerve conduit can be applied to rat peripheral nerve defect repair and nerve tissue engineering.
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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.
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Chitosan (CS) is known as a polysaccharide with positive charge and good biocompatibility.Researches showed that CS possesses the advantages of nontoxicity,biodegradability,plasticity and good biocompatibility,and therefore it can be used to repair of neural injury and serve as a biological carrier scaffold in engineered nerve tissue.Recently,the research is performed for the modification of CS structure or mix the CS with different materials to prepare the multiple compound and biological vector to offer three-dimensional scaffold and environment for the reconstruction of defective neural tissue and culture of neural stem cells.In addition,CS engineered biological materials are confirmed to possess the better performance,more diverse functions and more dominant effect on the regeneration of neural tissue,so it is predicted a more extensive application prospect in neural repair and regeneration.The basic properties and biological functions of CS,and its application in neural tissue engineering are reviewed.
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BACKGROUND:Three-dimensional self-assembling peptide nanofiber hydrogel scaffold can simulate the in vivo microenvironment and provide a structural model for cells, which promotes the right composition of extracel ular matrix and cel growth, as wel as improves the cel functions. OBJECTIVE:To review the fundamental research and the experimental study of the self-assembling peptide nanofiber scaffold in the nerve tissue engineering. METHODS:Literatures concerning basic and experimental studies on the self-assembling peptide nanofiber scaffold in the nerve tissue engineering were reviewed via searching PubMed and VIP databases (2000/2013) using the key words of“self-assembling peptide, nanofiber scaffold, RADA16, nerve tissue engineering, neural stem cel . RESULTS AND CONCLUSION:Self-assembling peptide nanofiber scaffold is a novel and ideal tissue engineering material which provides new method for nerve injury repairing, for it not only solves the problem of poor compatibility between the material and cells, but also plays a much more pivotal role in maintaining three-dimensional properties, promoting cel activities and mimicking the extracel ular matrix, which is superior to other materials. However, there stil exist some chal enges in the area of self-assembling peptides, including short-term issues such as integrating of self-assembling peptide with bio-macromolecular material or relatively developed traditional transplant;and long-term issues such as adapting immune system in vivo, treating targets within cells and anticipating the future fate of highly integrated scaffolds.
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This study examined the effect of IKVAV peptide nanofiber on proliferation,adhesion and differentiation into neurocytes of bone marrow stromal cells(BMSCs).IKVAV Peptide-amphiphile was synthesized and purified.Then,hydrogen chloride was added to the diluted aqueous solutions of PA to induce spontaneous formation of nanofiber in vitro.The resultant samples was observed under transmission electron microscope.BMSCs were cultured with IKVAV peptide nanofiber.The effect of IKVAV nanofiber on the proliferation,adhesion and induction differentiation of BMSCs was observed by inverted microscopy,calcein-AM/PI staining,cell counting and immunofluorescence staining.The results demonstrated that IKVAV peptide-amphiphile could self-assemble to form nanofiber gel.BMSCs cultured in combination with IKVAV peptide nanofiber gel grew well and the percentage of live cells was over 90%.IKVAV peptide nanofiber gel exerted no influence on the proliferation of BMSCs and could promote the adhesion of BMSCs and raise the ratio of neurons when BMSCs were induced to differentiate into neurocytes.It is concluded that BMSCs could proliferate and adhere well and yield more neurons during when induced to differente into neurocytes on IKVAV peptide nanofiber gel.
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The nerve tissue engineering is to apply scalfolds and seed cells for the treatment of injury or disease of nerve system by restoring their anatomic structures and funetiorm.The scaffolds played important roles in supporting and conducting axonal regeneration.They could also limit the in-growth of scar tissue and hence help to build the connection between axonal and target cell.Self-assembling peptide scaffold is one of the excellent material used is nerve tissue engineering.This article reviews the self-assembling peptide based scaffolds for nerve tissue engineering and discusses the unsolved problems in the fields and the trend d the related research in the future.
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The nerve tissue engineering (NTE) has been applied in the treatment of central nerve system injury or disease to restore its anatomic structure and function, in which the nervous scaffolds played important roles in supporting and nourishing the nerve tissues. Development, challenge confronted and foreground of research on scaffolds material in the nerve tissue engineering are reviewed in this article.