Objective To review the research progress on silk fibroin (SF)-nerve guidance conduits (NGCs) for peripheral nerve injury (PNI) repair. Methods To review the recent literature on PNI and SF-NGCs, expound the concepts and treatment strategies of PNI, and summarize the construction of SF-NGCs and its application in PNI repair. Results Autologous nerve transplantation remains the “gold standard” for treating severe PNI. However, it’s clinical applications are constrained by the limitations of limited donors and donor area damage. Natural SF exhibits good biocompatibility, low immunogenicity, and excellent physicochemical properties, making it an ideal candidate for the construction of NGCs. SF-NGCs constructed using different technologies have been found to have better biocompatibility and bioactivity. Their configurations can facilitate nerve regeneration by enhancing regenerative guidance and axonal extension. Besides, the adhesion, proliferation and differentiation of neurons and Schwann cells related to PNI repair can be effectively promote by NGCs. This accelerates the speed of nerve regeneration and improves the efficiency of repair. In addition, SF-NGCs can be used as regenerative scaffolds to provide biological templates for nerve repair. Conclusion The biodegradable natural SF has been extensively studied and demonstrated promising application prospects in the field of NGCs. It might be an effective and viable alternative to the “gold standard” for PNI treatment.
Objective To know the possibility of nerveregeneration after artery sleeve anastomosis and end-to-side suture Methods Seventy-five SD rats were divided into 5 groups. First, the distal end ofsevered peroneal nerve was sutured end-to -side with artery sleeve anastomosis withnormal nerve tibial trunk in groups A, B, C and D. Second, the tibial epineurium at the suture site was not removed in group A; the epineurium at the suturesite was removed(windowing) in group B; the distal end of pre-injured peroneal nerve was sutured after 14 days and windowing was done in group C; and the neural growth factor was injected into artery sleeve and windowing was done in group D. While the distal end of severed peroneal nerve was sutured end to side directly with normal nerve tibial trunk and windowing was done in group E. The histological observation was made and the number of nerve fibers was recorded after 4, 8 and 12 weeks of operation.Results After 4 weeks, there existed the regeneration of axons and myeline sheaths in groups C, D, E, and no nerve fiber regeneration was seen in group A. After 8 weeks, the regenerating nerve fibers were significantly more in groups C, D and E than in group B and ingroup E than groups C and D(Plt;0.05). After 12 weeks, the regenerating nervefibers were significantly more in groups C，D and E than in group B(Plt;0.05).Conclusion End-to-side coaptation with artery sleeve anastomosis is a new valuable method in repair of peripheral nerve injuries.
OBJECTIVE: To explore the possibility to bridge peripheral nerve defects by xenogeneic acellular nerve basal lamina scaffolds. METHODS: Thirty SD rats were randomly divided into 5 groups; in each group, the left sciatic nerves were bridged respectively by predegenerated or fresh xenogeneic acellular nerve basal lamina scaffolds, autogenous nerve grafting, fresh xenogeneic nerve grafting or without bridging. Two kinds of acellular nerve basal lamina scaffolds, extracted by 3% Triton X-100 and 4% deoxycholate sodium from either fresh rabbit tibial nerves or predegenerated ones for 2 weeks, were transplanted to bridge 15 mm rat sciatic nerve gaps. Six months after the grafting, the recovery of function was evaluated by gait analysis, pinch test, morphological and morphometric analysis. RESULTS: The sciatic nerve function indexes (SFI) were -30.7% +/- 6.8% in rats treated with xenogeneic acellular nerve, -36.2% +/- 9.7% with xenogeneic predegenerated acellular nerve, and -33.9% +/- 11.3% with autograft respectively (P gt; 0.05). The number of regenerative myelinated axons, diameter of myelinated fibers and thickness of myelin sheath in acellular xenograft were satisfactory when compared with that in autograft. Regenerated microfascicles distributed in the center of degenerated and acellular nerve group. The regenerated nerve fibers had normal morphological and structural characters under transmission electron microscope. The number and diameter of myelinated fibers in degenerated accellular nerve group was similar to that of autograft group (P gt; 0.05). Whereas the thickness of myelin sheath in degenerated accellular nerve group was significantly less than that of autograft group (P lt; 0.05). CONCLUSION: The above results indicate that xenogeneic acellular nerve basal lamina scaffolds extracted by chemical procedure can be successfully used to repair nerve defects without any immunosuppressants.
Objective To investigate the effect of extract of ginkgo biloba leaves (EGb50) on the prol iferation of SCs cultured in vitro. Methods The SCs were isolated from 3-day-old SD rats’ sciatic nerves by the method of enzyme gradationdigestion (n=20) and the purified 2nd passage of SCs were divided into 2 groups: the experimental group, in which SCs were cultured in FBS-DMEM medium with EGb50 (terminal concentration: 50 μg/mL); the control group, in which SCs were cultured in the FBS-DMEM medium without EGb50. The absorbance (A) value was detected by the 2, 3-bis- (2-methoxy-4-nitro-5- sulfophenyl)-2H-tetrazol ium-5-carboxanil ide (XTT) method 1, 3, 5, 7 and 9 days after culture, then the growth curves was drawn. Cell cycle was detected by flow cytometry (FCM). Disintegration per minute (DPM) of SCs was detected by the method of 3H-thymine nucleoside (3H-TdR) 2 and 3 days after culture and nerve growth factor (NGF) synthesis in SCs culture media was detected by ELISA method. Results Most SCs were spindle-shaped with a purity above 90%. XTT detection showed that A value of SCs in the control group was gradually increased 3 days after culture, reached the peak 5 days after culture and gradually decreased from then; the A value in the experimental group experienced the similar changes, but it was higher than that in the control group at each time point (P lt; 0.01). 3H-TdR showed that the DPM of the experimental group was 1 961.78 ± 231.13 and 4 601.51 ± 605.08 at 2 and 3 days after culture, while for the control group, the A value was 1 347.15 ± 121.57 and 3 740.42 ± 158.73 at the same time point, indicating a significant difference between two groups (P lt; 0.01). FCM observation indicated that the SCs prol iferation index of the experimental group and the control group was 18.6% ± 3.2% and 9.7% ± 2.9%, indicating a significant difference between two groups (P lt; 0.01). ELISA observation showed that the NGF concentration in the experimental and the control group was (0.065 6 ± 0.003 9) ng/mL and (0.038 6 ± 0.003 6) ng/mL, indicating a significant difference (P lt; 0.01). Conclusion EGb50 is capable of enhancing the prol iferation of SCs cultured in vitro, which may be one of the important mechanisms to promote peripheral nerve regeneration.
ObjectiveTo investigate the effects of bone marrow mesenchymal stem cells (BMSCs) transplantation for treating spinal cord injury (SCI) in rat and the cytokine expression changes in the local injury tissues. MethodsBMSCs were separated from Sprague Dawley (SD) rat and cultured with the whole bone marrow culture method. rAd-EGFP was used to transfect the 5th generation BMSCs for green fluorescent protein (GFP) label. Twelve SD rats were randomly divided into experimental group (n=6) and control group (n=6). After the T10 SCI model was established with Allen's impact device in 2 groups, 1×106 GFP-labeled BMSCs and PBS were administered by subarachnoid injection in situ in experimental group and control group, respectively. Basso-Beattie-Bresnahan (BBB) score was used to detect the motor function at immediat, 1, 2, 3, 4, and 5 weeks after SCI. At 5 weeks, the spinal cord tissues were harvested for the histological and immunofluorescent staining examinations to measure the expressions of neural marker molecules, including Nestin, glial fibrillary acidic protein (GFAP), and neuron-specific nuclear protein (NeuN). Cytokine was analyzed with antibody array. ResultsAt 5 weeks, 2 rats died of urinary tract infection in 2 groups respectively, the other rats survived to the end of experiment. BBB score of experimental group was significantly higher than that of control group at 1, 2, 3, 4, and 5 weeks (P < 0.05). At 5 weeks, histological results showed that there were many cells with regular arrangement in the experimental group; there were less cells with irregular arrangement in the control group. Compared with the control group, Nestin and NeuN expressions significantly increased (P < 0.05), and GFAP expression significantly decreased (P < 0.05) in the experimental group. Leptin and ciliary neurotrophic factor levels were higher in the experimental group than the control group, but granulocyte-macrophage colony-stimulating factor, tumor necrosis factorα, interleukin 1β, and tissue inhibitor of metalloproteinases 1 levels were lower in the experimental group than the control group. ConclusionBMSCs transplantation can improve survival and regeneration of nerve cells and enhances the recovery of nerve function by regulating secretion of cytokines from grafted BMSCs.
Objective To investigate the effect of repairing bone defect with tissue engineered bone seeded with the autologous red bone marrow (ARBM) and wrapped by the pedicled fascial flap and provide experimental foundation for cl inicalappl ication. Methods Thirty-two New Zealand white rabbits (male and/or female) aged 4-5 months old and weighing2.0-2.5 kg were used to make the experimental model of bilateral 2 cm defect of the long bone and the periosteum in the radius. The tissue engineered bone was prepared by seeding the ARBM obtained from the rabbits on the osteoinductive absorbing material containing BMP. The left side of the experimental model underwent the implantation of autologous tissue engineered bone serving as the control group (group A). While the right side was designed as the experimental group (group B), one 5 cm × 3 cm fascial flap pedicled on the nameless blood vessel along with its capillary network adjacent to the bone defect was prepared using microsurgical technology, and the autologous tissue engineered bone wrapped by the fascial flap was used to fill the bone defect. At 4, 8, 12, and 16 weeks after operation, X-ray exam, absorbance (A) value test, gross morphology and histology observation, morphology quantitative analysis of bone in the reparative area, vascular image analysis on the boundary area were conducted. Results X-ray films, gross morphology observation, and histology observation: group B was superior to group A in terms of the growth of blood vessel into the implant, the quantity and the speed of the bone trabecula and the cartilage tissue formation, the development of mature bone structure, the remolding of shaft structure, the reopen of marrow cavity, and the absorbance and degradation of the implant. A value: there was significant difference between two groups 8, 12, and 16 weeks after operation (P lt; 0.05), and there were significant differences among those three time points in groups A and B (P lt; 0.05). For the ratio of neonatal trabecula area to the total reparative area, there were significant differences between two groups 4, 8, 12, and 16 weeks after operation (P lt; 0.05), and there were significant differences among those four time points in group B (P lt; 0.05).For the vascular regenerative area in per unit area of the junctional zone, group B was superior to group A 4, 8, 12, and 16 weeks after operation (P lt; 0.05). Conclusion Tissue engineered bone, seeded with the ARBM and wrapped by the pedicled fascial flap, has a sound reparative effect on bone defect due to its dual role of constructing vascularization and inducing membrane guided tissue regeneration.
Objective To explore the changes of calcitonin gene-related peptide (CGRP) and substance P (SP) levels after end-toend and end-to-side neurorrhaphy. Methods Twenty female Wistar rats were divided into 4 experimental groups and control group. In the experimental groups, common peroneal nerves were transected on both sides. End-to-side coaptation was performed on the left, while end-to-end coaptation on the right. After 1, 2, 4 and 27 weeks, the rats were sacrificed, and immunoreactivities of CGRP and SP in suture sites, lumbar spine and dorsal root ganglia(DRGs) were evaluated respectively. Results The expression ofCGRP and SP decreased in dorsal horn and DRGs within 1 week postoperatively. After 4 -27 weeks, CGRP and SP in dorsal horn could return to almost normal level, but they had little recovery in DRGs. Although the trend of change between end-to-end and end-to-side was coincident, in most experimental groups, thereexisted differences in the dorsal horn between end-to-end and end-to-side. The sciatic nerve stained by acetylcholinesterase, SP, CGRP and PGP 9.5 showed that the fibers could pass through the suture site of either end-to-end or end-to-side. Conclusion Nerve regeneration can be achieved by end-to-side neurorrhaphy, andthe mechanism of sensory nerve recovery of these two methods is similar. But the recovery in end-to-side coaptation is insufficient to some degree.
ObjectiveTo investigate the regularity of myelin degeneration and regeneration and the difference of axonal density between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesue monkey. MethodsNine adult rhesue monkeys (male or female, weighing 3.5-4.5 kg) were selected to establish the model of rat sciatic nerve transaction injury. The tibial nerve and common peroneal nerve of 5 mm in length were harvested at 5 mm from injury site as controls in 3 monkeys; the distal tibial nerve and common peroneal nerve were repaired with 9-0 suture immediately in the other 6 monkeys. And the gross observation and neural electrophysiological examination were performed at 3 and 8 weeks after repair respectively. Then, distal tibial nerve and common peroneal nerve at anastomotic site were harvested to observe the myelin sheath changes, and to calculate the number of axon counts and axonal density by staining with Luxol Fast Blue. ResultsAtrophy of the lower limb muscle and various degrees of plantar ulcer were observed. Gross observation showed nerve enlargement at anastomosis site, the peripheral connective tissue hyperplasia, and obvious adhesion. The compound muscle action potential (CMAP) of tibial nerve and common peroneal nerve could not be detected at 3 weeks; the CMAP amplitude of common peroneal nerve was less than that of the tibial nerve at 8 weeks. Different degrees of axonal degeneration was shown in the tibial nerve and common peroneal nerve, especially in the common peroneal nerve. The average axonal density of common peroneal nerve was lower than that of tibial nerve at 3 weeks (13.2% vs. 44.5%) and at 8 weeks (10.3% vs. 35.3%) after repair. ConclusionThe regeneration of tibial nerve is better and faster than that of common peroneal nerve, and gastrocnemius muscle CMAP recovers quicker, and amplitude is higher, which is the reason of better recovery of tibial nerve.
ObjectiveTo summarize the progress of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and evolution of surgical procedure improvement, so as to summarize experience in selecting appropriate surgical method for patients. MethodThe domestic and foreign literature on the evolution of ALPPS surgical procedure improvement in recent years was reviewed. ResultsIn the decade since the emergence of ALPPS, the ALPPS had been rapidly developed in the hepatobiliary surgery. The ALPPS promoted a rapid increase in future liver remnant during a relatively shorter period to contribute to resectability of liver tumors and reduce the rate of postoperative liver failure, the patients with intermediate to advanced and huge liver cancer could obtain the surgical radical resection. In recent years, the domestic and foreign experts had refined the ALPPS procedure, which mainly focused on the operation of hepatic section separation and hepatic artery flow restriction in stage Ⅰ surgery, including partial ALPPS, radiofrequency ablation ALPPS, tourniquet ALPPS, transcatheter arterial embolization ALPPS, hepatic artery ringed and operation ALPPS, as well as laparoscopic ALPPS and robotic ALPPS with minimally invasive approach. ConclusionsDespite the ongoing controversy over ALPPS, with the continuous progress and innovation of improved procedures and the utilization of laparoscope and robot in surgery, the trauma of ALPPS surgery has a further reduction, and the morbidity and mortality have gradually been decreased. It is believed that with the continuous advancement and improvement of ALPPS surgery technology, the indications and safety of ALPPS will be further enhanced, bringing hope to more patients with intermediate to advanced liver cancer with huge tumors.
ObjectiveTo investigate the co-transplantation of C57-green fluorescent protein (GFP) mouse epidermis and dermis cells subcutaneously to induce the hair follicle regeneration. MethodC57-GFP mouse epidermis and dermis were harvested for isolation the mouse epidermis and dermis cells. The morphology of epidermis and dermis mixed cells at ratio of 1:1 of adult mouse, dermis cells of adult mouse, cultured 3rd generation dermis cells were observed by fluorescence microscope. Immunocytochemistry staining was used to detect hair follicle stem cells markers in cultured 3rd generation dermis cells from new born C57-GFP mouse. And then the epidermis and dermis mixed cells of adult mouse (group A), dermis cells of adult mouse (group B), cultured 3rd generation dermis cells of new born mouse (group C), and saline (group D) were transplanted subcutaneously into Balb/c nude mice. The skin surface of nude mice were observed at 4, 5, 6 weeks of transplantation and hair follicle formation were detected at 6 weeks by immunohistochemistry staining. ResultsThe isolated C57-GFP mouse epidermis and dermis cells strongly expressed the GFP under the fluorescence microscope. Immunocytochemistry staining for hair follicle stem cells markers in cultured 3rd generation dermis cells showed strong expression of Vimentin and α-smooth muscle actin, indicating that the cells were dermal sheath cells; some cells expressed CD133, Versican, and cytokeratin 15. After transplanted for 4-6 weeks, the skin became black at the injection site in group A, indicating new hair follicle formation. However, no color change was observed in groups B, C, and D. Immunohistochemical staining showed that new complete hair follicles structures formed in group A. GFP expression could be only observed in the hair follicle dermal sheath and outer root sheath in group B, and it could also be observed in the hair follicle dermal sheath, outer root sheath, dermal papilla cells, and sweat gland in group C. The expression of GFP was negative in group D. ConclusionsCo-transplantation of mouse epidermis and dermis cells can induce the hair follicle regeneration by means of interaction of each other. And transplantation of isolated dermis cells or cultured dermis cells individually only partly involved in the hair follicles formation.