Sustained release of exosomes loaded into polydopamine-modified chitin conduits promotes peripheral nerve regeneration in rats.

Exosomes derived from mesenchymal stem cells are of therapeutic interest because of their important role in intracellular communication and biological regulation. On the basis of previously studied nerve conduits, we designed a polydopamine-modified chitin conduit loaded with mesenchymal stem cell-derived exosomes that release the exosomes in a sustained and stable manner. In vitro experiments revealed that rat mesenchymal stem cell-derived exosomes enhanced Schwann cell proliferation and secretion of neurotrophic and growth factors, increased the expression of Jun and Sox2 genes, decreased the expression of Mbp and Krox20 genes in Schwann cells, and reprogrammed Schwann cells to a repair phenotype.

Chitin conduits modified with DNA-peptide coating promote the peripheral nerve regeneration.

Peripheral nerve injury (PNI) is one of the common clinical injuries which needs to be addressed. Previous studies demonstrated the effectiveness of using biodegradable chitin (CT) conduits small gap tubulization technology as a substitute for traditional epineurial neurorrhaphy. Aiming to improve the effectiveness of CT conduits in repairing PNI, we modified their surface with a DNA-peptide coating.

Chitin scaffold combined with autologous small nerve repairs sciatic nerve defects.

Although autologous nerve transplantation is the gold standard for treating peripheral nerve defects, it has many clinical limitations. As an alternative, various tissue-engineered nerve grafts have been developed to substitute for autologous nerves. In this study, a novel nerve graft composed of chitin scaffolds and a small autologous nerve was used to repair sciatic nerve defects in rats.

Aligned fibrin/functionalized self-assembling peptide interpenetrating nanofiber hydrogel presenting multi-cues promotes peripheral nerve functional recovery.

Nerve guidance conduits with hollow lumen fail to regenerate critical-sized peripheral nerve defects (15 mm in rats and 25 mm in humans), which can be improved by a beneficial intraluminal microenvironment. However, individual cues provided by intraluminal filling materials are inadequate to eliminate the functional gap between regenerated nerves and normal nerves. Herein, an aligned fibrin/functionalized self-assembling peptide (AFG/fSAP) interpenetrating nanofiber hydrogel that exerting synergistic topographical and biochemical cues for peripheral nerve regeneration is constructed via electrospinning and molecular self-assembly.

Combining chitin biological conduits with small autogenous nerves and platelet-rich plasma for the repair of sciatic nerve defects in rats.

Aims: Peripheral nerve defects are often difficult to recover from, and there is no optimal repair method. Therefore, it is important to explore new methods of repairing peripheral nerve defects. This study explored the efficacy of nerve grafts constructed from chitin biological conduits combined with small autogenous nerves (SANs) and platelet-rich plasma (PRP) for repairing 10-mm sciatic nerve defects in rats.

A fully biodegradable and self-electrified device for neuroregenerative medicine.

Peripheral nerve regeneration remains one of the greatest challenges in regenerative medicine. Deprivation of sensory and/or motor functions often occurs with severe injuries even treated by the most advanced microsurgical intervention. Although electrical stimulation represents an essential nonpharmacological therapy that proved to be beneficial for nerve regeneration, the postoperative delivery at surgical sites remains daunting.

A novel tissue engineered nerve graft constructed with autologous vein and nerve microtissue repairs a long-segment sciatic nerve defect.

Veins are easy to obtain, have low immunogenicity, and induce a relatively weak inflammatory response. Therefore, veins have the potential to be used as conduits for nerve regeneration. However, because of the presence of venous valves and the great elasticity of the venous wall, the vein is not conducive to nerve regeneration.

Self-assembling peptide hydrogels functionalized with LN- and BDNF- mimicking epitopes synergistically enhance peripheral nerve regeneration.

The regenerative capacity of the peripheral nervous system is closely related to the role that Schwann cells (SCs) play in construction of the basement membrane containing multiple extracellular matrix proteins and secretion of neurotrophic factors, including laminin (LN) and brain-derived neurotrophic factor (BDNF). Here, we developed a self-assembling peptide (SAP) nanofiber hydrogel based on self-assembling backbone Ac-(RADA)-NH (RAD) dual-functionalized with laminin-derived motif IKVAV (IKV) and a BDNF-mimetic peptide epitope RGIDKRHWNSQ (RGI) for peripheral nerve regeneration, with the hydrogel providing a three-dimensional (3D) microenvironment for SCs and neurites. Circular dichroism (CD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were used to characterize the secondary structures, microscopic structures, and morphologies of self-assembling nanofiber hydrogels.

Aligned chitosan nanofiber hydrogel grafted with peptides mimicking bioactive brain-derived neurotrophic factor and vascular endothelial growth factor repair long-distance sciatic nerve defects in rats.

Autologous nerve transplantation, which is the gold standard for clinical treatment of peripheral nerve injury, still has many limitations. In this study, aligned chitosan fiber hydrogel (ACG) grafted with a bioactive peptide mixture consisting of RGI (Ac-RGIDKRHWNSQGG) and KLT (Ac-KLTWQELYQLKYKGIGG), designated as ACG-RGI/KLT, was used as nerve conduit filler to repair sciatic nerve defects in rats. : Chitosan nanofiber hydrogel was prepared by a combination of electrospinning and mechanical stretching methods, and was then grafted with RGI and KLT, which are peptides mimicking brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), respectively.

Evaluation of the Crushed Sciatic Nerve and Denervated Muscle with Multimodality Ultrasound Techniques: An Animal Study.

This study was aimed at evaluating the value of multimodality ultrasound techniques in the detection of crushed sciatic nerve and denervated muscle in rabbits. Fifty healthy male New Zealand white rabbits were randomly divided into five groups (n = 10 in each group): four crushed injury groups at 1, 2, 4 and 8 wk post-sciatic nerve crushed injury, and a control group without crush injury. The crushed sciatic nerve and denervated muscle were measured with conventional ultrasound, shear wave elastography and contrast-enhanced ultrasonography, and the results were compared with the histopathological parameters.

Synergistic effects of dual-presenting VEGF- and BDNF-mimetic peptide epitopes from self-assembling peptide hydrogels on peripheral nerve regeneration.

The crosstalk between vascularization and nerve regeneration in the peripheral nervous system has recently been suggested to play an important role in the treatment of peripheral nerve injury. Regenerative strategies via synergistic delivery of multiple biochemical cues have received growing attention, especially the combination of pro-angiogenic factors and neurotrophic factors. Here we developed a self-assembling peptide nanofiber hydrogel dual-functionalized with vascular endothelial growth factor (VEGF)- and brain-derived neurotrophic factor (BDNF)-mimetic peptide epitopes for peripheral nerve reconstruction.

Exosomes from Human Gingiva-Derived Mesenchymal Stem Cells Combined with Biodegradable Chitin Conduits Promote Rat Sciatic Nerve Regeneration.

At present, repair methods for peripheral nerve injury often fail to get satisfactory result. Although various strategies have been adopted to investigate the microenvironment after peripheral nerve injury, the underlying molecular mechanisms of neurite outgrowth remain unclear. In this study, we evaluate the effects of exosomes from gingival mesenchymal stem cells (GMSCs) combined with biodegradable chitin conduits on peripheral nerve regeneration.

Increased recruitment of endogenous stem cells and chondrogenic differentiation by a composite scaffold containing bone marrow homing peptide for cartilage regeneration.

Even small cartilage defects could finally degenerate to osteoarthritis if left untreated, owing to the poor self-healing ability of articular cartilage. Stem cell transplantation has been well implemented as a common approach in cartilage tissue engineering but has technical complexity and safety concerns. The stem cell homing-based technique emerged as an alternative promising therapy for cartilage repair to overcome traditional limitations.

In Situ Articular Cartilage Regeneration through Endogenous Reparative Cell Homing Using a Functional Bone Marrow-Specific Scaffolding System.

In situ tissue regeneration by homing endogenous reparative cells to the injury site has been extensively researched as a promising alternative strategy to facilitate tissue repair. In this study, a promising scaffolding system DCM-RAD/SKP, which integrated a decellularized cartilage matrix (DCM)-derived scaffold with a functionalized self-assembly Ac-(RADA)-CONH/Ac-(RADA)GGSKPPGTSS-CONH (RAD/SKP) peptide nanofiber hydrogel, was designed for repairing rabbit osteochondral defect. In vitro experiments showed that rabbit bone marrow stem cells migrated into and have higher affinity toward the functional scaffolding system DCM-RAD/SKP than the control scaffolds.

Bioactive Self-Assembling Peptide Hydrogels Functionalized with Brain-Derived Neurotrophic Factor and Nerve Growth Factor Mimicking Peptides Synergistically Promote Peripheral Nerve Regeneration.

Various artificial materials have been fabricated as alternatives to autologous nerve grafts in peripheral nerve regeneration, and these afford positive recovery effects without the disadvantages of the gold standard. In this study, we prepared a three-dimensional functionalized self-assembling peptide nanofiber hydrogel containing two neurotrophic peptides (CTDIKGKCTGACDGKQC and RGIDKRHWNSQ derived from nerve growth factor and brain-derived neurotrophic factor, respectively) that reflected the structure and properties of the neural extracellular matrix. The material was used to promote axonal regrowth and functional recovery.

Value of Adjuvant Radiotherapy for Thymoma with Myasthenia Gravis after Extended Thymectomy.

Background: The co-existence of myasthenia gravis (MG) and thymoma makes the surgical treatment more complicated and adjuvant radiation more controversial. The aim of this study was to investigate adjuvant radiotherapy for thymoma with MG after extended thymectomy.

Methods: A total of 181 patients with both MG and thymoma were recruited between 2003 and 2014 at Tongren Hospital, China.

Roles of neural stem cells in the repair of peripheral nerve injury.

Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury.

Mechanisms and treatment of painful neuromas.

A painful neuroma is a common complication of a peripheral nerve injury or amputation, and it can cause tremendous pain that is resistant to most analgesics. Furthermore, painful neuromas have a high postoperative recurrence rate. Painful neuromas are often accompanied by functional disorders, drastically reducing the patient's quality of life.

[Clinical study of optic neuritis combined with viral hepatitis].

Objective: To investigate the clinical manifestation, management and prognosis of optic neuritis combined with viral hepatitis.

Methods: Retrospective study case series. Clinical data from twenty patients with optic neuritis combined with hepatitis who were hospitalized in Beijing Tongren Hospital neural eye ward from September 2003 to June 2010 were collected, the clinical characteristics and visual field changes in the group of patients were summarized, and comparison between the vision before and after treatment was made by the Wingerchuk vision classification.

Somatosensory disinhibition in patients with paroxysmal kinesigenic dyskinesia.

Background: Paroxysmal kinesigenic dyskinesia (PKD) is characterized by recurrent brief episodes of chorea and dystonia induced by sudden movement. Whether the central nervous system is hyper- or hypoexcitable in PKD remains undetermined. The aim of our study was to compare the somatosensory evoked potential (SEP) recovery cycle, a marker of somatosensory system excitability, in PKD patients and controls.

Event-related potentials in adolescents with different cognitive styles: field dependence and field independence.

Field dependence/independence (FD/FI) is an important dimension of personality and cognitive styles. Different ability in mobilizing and/or allocating mental-attentional capacity was considered to be the most possible explanation for the FDI cognitive style. Many studies on characterizing the functional neuroanatomy of attentional control indicated the existence of a dissociable sub-process of conflict-monitoring and "cognitive control" system.

Elevated plasma S100B concentration is associated with mesial temporal lobe epilepsy in Han Chinese: a case-control study.

Mesial temporal lobe epilepsy (MTLE) is a common type of intractable epilepsy characterized by astroglial gliosis. The S100B was viewed as an astrocyte marker and experimental studies indicated that S100B might be involved in the pathophysiology of temporal lobe epilepsy. In this study, we measured plasma S100B levels by ELISA in 28 patients with MTLE and 28 healthy controls and found that patients showed significantly elevated S100B levels compared with healthy controls (P=0.

[Clinical characteristics of non-arteritic anterior ischemic optic neuropathy].

Objective: To evaluate the demographic, risk factors and clinical characteristics of non-arteritic anterior ischemic optic neuropathy (NAION) and provide clinical guidance for this blindness disease.

Methods: Retrospective study was used to investigate the data, which consists of 96 NAION consecutive patients in neurology department of our hospital from 2005 to 2008.

Results: The average age of NAION patients is 50.

[Clinical characteristic of optic neuritis and its relevancy with human leukocyte antigen].

Objective: To investigate clinical characteristics of optic neuritis and its association with HLA (human leukocyte antigen).

Method: The clinical data of 42 patients with optic neuritis were collected and flow polymerase chain reaction-reverse sequence specific oligonucleotide probe (PCR-rSSOP) was used to determine the genotype of HLA-DRB1.

Results: Two patients confirmed as Leber hereditary optic neuropathy by gene sequencing were excluded from the study.