OBJECTIVE: To investigate the effect of folic acid coated-crosslinked urethane-doped polyester elastomer (fCUPE) nerve conduit in repairing long distance peripheral nerve injury. METHODS: Thirty-six 3-month-old male Sprague Dawley rats weighing 180-220 g were randomly assigned to 3 groups, each consisting of 12 rats: CUPE nerve conduit transplantation group (group A), fCUPE nerve conduit transplantation group (group B), and autologous nerve transplantation group (group C), the contralateral healthy limb of group C served as the control group (group D). A 20-mm-long sciatic nerve defect model was established in rats, and corresponding materials were used to repair the nerve defect according to the group. The sciatic function index (SFI) of groups A-C was calculated using the Bain formula at 1, 2, and 3 months after operation. The nerve conduction velocity (NCV) of the affected side in groups A-D was assessed using neuroelectrophysiological techniques. At 3 months after operation, the regenerated nerve tissue was collected from groups A-C for S-100 immunohistochemical staining and Schwann cell count in groups A and B to compare the level of nerve repair and regeneration in each group. RESULTS: At 3 months after operation, the nerve conduits in all groups partially degraded. There was no significant adhesion between the nerve and the conduit and the surrounding tissues, the conduit was well connected with the distal and proximal nerves, and the nerve-like tissues in the conduit could be observed when the nerve conduit stents were cut off. SFI in group A was significantly higher than that in group C at each time point after operation and was significantly higher than that in group B at 2 and 3 months after operation ( P<0.05). There was no significant difference in SFI between groups B and C at each time point after operation ( P>0.05). NCV in group A was significantly slower than that in the other 3 groups at each time point after operation ( P<0.05). The NCV of groups B and C were slower than that of group D, but the difference was significant only at 1 month after operation ( P<0.05). There was no significant difference between groups B and C at each time point after operation ( P>0.05). Immunohistochemical staining showed that the nerve tissue of group A had an abnormal cavo-like structure, light tissue staining, and many non-Schwann cells. In group B, a large quantity of normal neural structures was observed, the staining was deeper than that in group A, and the distribution of dedifferentiated Schwann cells was obvious. In group C, the nerve bundles were arranged neatly, and the tissue staining was the deepest. The number of Schwann cells in group B was (727.50±57.60) cells/mm ², which was significantly more than that in group A [(298.33±153.12) cells/mm ²] ( t=6.139, P<0.001). CONCLUSION The fCUPE nerve conduit is effective in repairing long-distance sciatic nerve defects and is comparable to autologous nerve grafts. It has the potential to be used as a substitute material for peripheral nerve defect transplantation.
Rats ; Animals ; Male ; Rats, Sprague-Dawley ; Polyesters ; Peripheral Nerve Injuries/surgery* ; Elastomers ; Urethane ; Sciatic Nerve/injuries* ; Carbamates ; Nerve Tissue ; Nerve Regeneration/physiology*

mRNAs of alpha-adrenoceptor (α-AR) subtypes are found in neurons in dorsal root ganglion (DRG) and change after peripheral nerve injury. In this study, the distribution of α-AR subtype proteins was studied in L5 DRG of normal rats and rats with chronic constriction injury of sciatic nerve (CCI). Using immunofluorescence technique, it was found that α1A-, α1B-, and α2A-AR proteins were expressed in large, medium, and small size neurons in normal DRG, and significantly increased in all size neurons 14 days after CCI. α1D- and α2C-AR was also expressed in all size neurons in normal DRG. However, α1D-AR was significantly increased and α2C-AR was decreased in small size neurons 14 days post CCI. α2B-AR neurons were not detectable in normal and CCI DRG. Co-expression of α1A- and α2A-AR in the same neuron was observed in normal DRG and increased post CCI. Collectively, these results indicated that there is distinct distribution of α-AR subtypes in DRG neurons, and the distribution and levels of expression of α-AR subtypes change differently after CCI. The up-regulation of α-AR subtypes in DRG neurons may play an important role in the process of generating and transmitting neuropathic pain.
Animals ; Cell Size ; Chronic Disease ; Constriction, Pathologic ; Fluorescent Antibody Technique ; Ganglia, Spinal ; metabolism ; pathology ; Male ; Microscopy, Confocal ; Neurons ; metabolism ; pathology ; Pain Measurement ; methods ; Pain Threshold ; Protein Isoforms ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, alpha-1 ; metabolism ; Receptors, Adrenergic, alpha-2 ; metabolism ; Sciatic Nerve ; injuries ; surgery

There have been many attempts for regeneration of peripheral nerve injury. In this study, we examined the in vivo effects of non-differentiated and neuronal differentiated adipose-derived stem cells (ADSCs) in inducing the neuronal regeneration in the Sprague-Dawley (SD) rats undergoing nerve defect bridged with the PCL nanotubes. Then, we performed immunohistochemical and histopathologic examinations, as well as the electromyography, in three groups: the control group (14 sciatic nerves transplanted with the PCL nanotube scaffold), the experimental group I (14 sciatic nerves with the non-differentiated ADSCs at a density of 7x105 cells/0.1 mL) and the experimental group II (14 sciatic nerves with the neuronal differentiated ADSCs at 7x105 cells/0.1 mL). Six weeks postoperatively, the degree of the neuronal induction and that of immunoreactivity to nestin, MAP-2 and GFAP was significantly higher in the experimental group I and II as compared with the control group. In addition, the nerve conduction velocity (NCV) was significantly higher in the experimental group I and II as compared with the control group (P=0.021 and P=0.020, respectively). On the other hand, there was no significant difference in the NCV between the two experimental groups (P>0.05). Thus, our results will contribute to treating patients with peripheral nerve defects using PCL nanotubes with ADSCs.
Adipose Tissue/cytology ; Animals ; Cell Differentiation ; Electromyography ; Male ; Nanotubes ; *Nerve Regeneration ; Nerve Tissue Proteins/immunology ; Nestin/immunology ; Neural Conduction/physiology ; Peripheral Nerve Injuries/*surgery ; Phosphoprotein Phosphatases/immunology ; Polyesters/*therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/injuries/surgery ; Stem Cell Transplantation/*methods ; Stem Cells/*cytology ; Tissue Engineering/methods

OBJECTIVETo discuss the operative effects and evaluate how the waiting time before surgery influence the outcome of complex acetabular fractures.

METHODSFrom January 2006 to December 2008, 33 patients, 28 males and 5 females, with complex acetabular fractures were operated in our hospital. All of them were followed up for an average 24 months (ranged, 14 to 47 months). The average age was 42 years (ranged,27 to 57 years). According to the waiting time before surgery, all patients were divided into two groups, namely preoperative waiting time of more than 14 days group and preoperative waiting time of less than 14 days group. Postoperative reduction quality and long-term radiographic results were evaluated according to the Matta radiological systems. The modified Merle d' Aubigne-postel hip scoring system was used for evaluating the functional outcomes. The Mos SF-36 was used to evaluate the quality of life.

RESULTSAnatomical reduction in 28 cases, good in 4 cases, and poor in 1 case. According to the mean Merle d'Aubigne and Postel Score, 22 patients got excellent result, 4 good, 4 fair and 3 bad. Average score of the Mos SF-36 was (70.63 +/- 17.03). When time was measured as a categorical variable, an anatomical reduction and an excellent or good functional outcome were more likely if surgery was performed within 14 days. Postoperative complications: iatrogenic injuries of sciatic nerve in 2 cases, heterotopic ossification in 6 cases,traumatic osteoarthritis in 3 cases, and femoral head necrosis in 1 case.

CONCLUSIONGood image evaluation,correct approaches, appropriate time before surgery and approach, early functional rehabilitation are essential for better outcomes in the treatment of complex acetabular fractures, of which, time to surgery is a crucial and controllable prognostic factor.

Acetabulum ; injuries ; physiopathology ; surgery ; Adult ; Case-Control Studies ; Female ; Fracture Fixation, Internal ; adverse effects ; methods ; Fractures, Bone ; diagnostic imaging ; physiopathology ; surgery ; Humans ; Male ; Middle Aged ; Ossification, Heterotopic ; prevention & control ; Osteoarthritis ; prevention & control ; Postoperative Complications ; prevention & control ; Radiography ; Sciatic Nerve ; injuries ; Time Factors

OBJECTIVETo culture interleukin-1beta (IL-1beta)-activated Schwann cells (SCs) with human hair keratins (HHKs) for artificial nerve bridge construction.

METHODSSCs purified by primary culture with or without IL-1beta activation were cultured with HHKs decorated by extracellular matrix (ECM), and the artificial nerve bridge was implanted into the defect of rat sciatic nerve. The morphology of the SCs cultured with HHKs was monitored by inverted microscope, scanning electron microscope and evaluated by immunocytochemical staining, and the expression of nerve growth factor (NGF) in the sciatic nerve was observed by in situ hybridization.

RESULTSActivated SCs showed better ability to adhere to the HHKs and grew well. The HHKs component in the artificial nerve bridge underwent degradation in the sciatic nerve defect after 3 to 4 weeks, and IL-1beta activation resulted in enhanced NGF expression in the SCs.

CONCLUSIONThe constructed artificial nerve bridge by three-dimensional culture of IL-1beta-activiated SCs with HHKs decorated by ECM promotes the repair of sciatic nerve defects and accelerates sciatic nerve regeneration.

Animals ; Animals, Newborn ; Axons ; physiology ; Cell Culture Techniques ; Cell Movement ; physiology ; Cells, Cultured ; Hair ; chemistry ; Humans ; Interleukin-1beta ; pharmacology ; Keratins ; pharmacology ; Microscopy, Electron, Scanning ; Nerve Growth Factor ; biosynthesis ; Nerve Regeneration ; drug effects ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; drug effects ; metabolism ; ultrastructure ; Sciatic Nerve ; injuries ; physiopathology ; surgery ; Tissue Engineering ; methods

OBJECTIVETo test a nerve bridge substitute for peripheral nerve repair by tissue-engineering approach.

METHODSAn artificial nerve fabricated with a scroll of amnion derivative (ZQ membrane) and cultured autogenous Schwann cell was sutured to bridge sciatic nerve defect of 2.5 cm in length in rats. The specimens were assessed with tracking study, histology, electrophysiological technique, NF200, and synaptophysin-38 (SYP) immuno histochemical staining 3 months postoperatively.

RESULTSThe regenerated nerve sprouted 3 months after the operation. The regenerated nerve fibers were plentiful and could grow into the recipient nerve and target muscle's motor end plate (MEP) areas to reinnervate target muscle, and reconstruct function of nerve-muscle junction. Functional recovery could reach to 40%-60% of normal control. Nerve-muscle conduction velocity (N-MCV) arrived at 21.77 +/- 1.15 m/s.

CONCLUSIONSA tissue engineering material fabricated with a scroll of ZQ membrane and cultured autologous Schwann cell may be a useful substitute for nerve repair.

Amnion ; cytology ; Animals ; Cells, Cultured ; Female ; Male ; Nerve Regeneration ; physiology ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; Sciatic Nerve ; injuries ; surgery ; Tissue Engineering ; methods

OBJECTIVETo describe the rule of the schwann cell proliferation after peripheral nerve injury in detail and to discover the effect of neuroanastomosis.

METHODSThe model of rat sciatic injury was made, with neuroanastomosis on the left side and right side untreated. Then draw the materials 24, 48 h, 4, 7, 14, 21 d after surgery. And immunohistological stain counted the schwann cell per view with Qwin software of Leica Ltd.

RESULTSThe number of schwann cell increased obviously 4 d after surgery and reached the peak in 7 d. Then it fell down and the neuroanastomosis group changed slower and fibroblast hyperplasia in the untreated.

CONCLUSIONSThe axon support is essential for the schwann cell. The precise rule is help for study on neurotrophic factor.

Anastomosis, Surgical ; Animals ; Cell Proliferation ; Immunohistochemistry ; Male ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; Sciatic Nerve ; injuries ; pathology ; surgery ; Time Factors

OBJECTIVETo observe the treating effect of collage-heparin sulfate after the 10 mm rat sciatic nerve defect was bridged by it.

METHODSA new kind of nervous tissue engineering scaffold was produced by freeze-drying technique from collagen-heparin sulfate. Thirty-two SD rats were randomly divided into A, B, C and D groups. Sciatic nerve defect in group A was bridged by collagen-heparin sulfate. In group B, sciatic nerve was bridged by auto-nerve transplantation. Group C was the blank control group. Animals in group D were normal. And 10 mm sciatic nerve defect was bridged in the experiment. Thirty-six weeks after the operation, the experimental animals were detected by HRP labeled retrograde trace, HE staining, toluidine staining, silvering staining, S100, GAP-43 and NF immunohistological staining, MBP immunofluorescence staining and transmission electron microscope to observe the nerve regeneration inducing effect of this new scaffold.

RESULTSNine months after operation, the collage-heparin sulfate scaffold was replaced by newly regenerated nerve. The number of HRP labeled spinal cord anterior horn cells and the area of sensation nerve fiber at the posterior horn were similar with that was repaired by auto-nerve. GAP-43, NF and S100 labeled regenerated nerve fiber had passed the total scaffold and entered the distal terminal. The regenerated nerve fibers were paralleled, lineage arranged, coincide with the prearranged regenerating "channel" in the collagen-heparin sulfate scaffold. MBP immunofluorescence staining also proved that the newly regenerated nerve fiber could be ensheathed. In the experimental group, the area of myelinated nerve fiber and the thickness of the myelin sheath had no obvious difference with that of the group repaired by auto-nerve, except that the density of the regenerated myelinated sheath fiber was lower than that of the control group.

CONCLUSIONNervous tissue engineering scaffold produced by collagen-heparin sulfate can guide the regeneration of nerve fibers. The nerve function recovers fine. This kind of material has great application potential.

Animals ; Biocompatible Materials ; Heparitin Sulfate ; Male ; Prosthesis Implantation ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; pathology ; surgery ; Sulfuric Acid Esters ; Tissue Engineering ; methods

OBJECTIVETo investigate the possibility of bridging small peripheral nerve gap using a de-acetyl chitosan conduit.

METHODSThe sciatic nerves of right sides were cut at SD rats. They were divided into 5 Groups randomly; Group A: epineurium suture in situ (n = 24); Group B: biological conduit with a small gap for bridging the peripheral nerve (n = 24, with 5 mm gap); Group C: epineurium suture with distal stump rotated 180 degrees (n = 24); Group D: bridging the nerve by biological conduits with a small gap, but the distal stump rotated 180 degrees (n = 24, with 5 mm gap); Group E: biological conduit with a small gap for bridging the peripheral nerve with NGF (n = 24). Electrophysiological examination, histological examination and myelinated axon counting were applied after 2, 4, 6, 8 weeks after operation respectively.

RESULTSRegenerated nerve fibers were seen in the distal nerve segments of all 5 groups; The nerve conduction velocity of small gap group (group B, D) was faster than that of corresponding simple epineurium suture group (group A, C) at all 2, 4, 6, 8 week time point (P < 0.05). The myelinated axon counting of small gap group (group B, D) was faster than that of corresponding simple epineurium suture group (group A, C) at all 4, 6, 8 week time point (P < 0.01), and there was no statistically significant difference at 2 week time point.

CONCLUSIONThe repair effects of chitin conduit bridging peripheral nerve with small gap (5 mm) are better than that of epineurium suture directly, and possess the potential to substitute the epineurium suture.

Animals ; Biocompatible Materials ; Chitosan ; Male ; Nerve Regeneration ; Neurosurgical Procedures ; instrumentation ; methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; physiology ; surgery

OBJECTIVETo observe the biomechanic properties of sciatic nerve at the suture site in rats following repairing.

METHODSThe right sciatic nerves of 40 white Sprague-Dawley 300-350 gm rats were exposed, cut and then repaired with 10-0 nylon sutures, laced in the epineurium. 0, 1, 3, 6 weeks after operation, the tensile strength of the sciatic nerves were measured, the data analyzed statistically.

RESULTSThe load-elongation curves for both the normal unoperated and operated nerves had the similar shape. The tensile strength of the 0 week was significant difference to 1, 3 and 6 weeks (P < 0.01). No significant difference was found among 1, 3 and 6 weeks.

CONCLUSIONThe tensile strength of the injured nerves are recovered in the first week and resistant in 6 weeks after repairing.

Animals ; Elasticity ; Male ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; physiology ; surgery ; Tensile Strength ; Time Factors