Nerve grafts are able to adapt to surrounding biomechanical environments if the nerve graft itself exhibits appropriate biomechanical properties （load, elastic modulus, etc.）. The present study was designed to deter...Nerve grafts are able to adapt to surrounding biomechanical environments if the nerve graft itself exhibits appropriate biomechanical properties （load, elastic modulus, etc.）. The present study was designed to determine the differences in biomechanical properties between fresh and chemically acellularized sciatic nerve grafts. Two different chemical methods were used to establish acellular nerve grafts. The nerve was chemically extracted in the Sondell method with a combination of Triton X-100 （nonionic detergent） and sodium deoxycholate （anionic detergent）, and in the modified method with a combination of Triton X-200 （anionic detergent）, sulfobetaine-10 （SB-10, amphoteric detergents）, and sulfobetaine-16 （SB-16, amphoteric detergents）. Following acellularization, hematoxylin-eosin staining and scanning electron microscopy demonstrated that the effect of acellularization via the modified method was similar to the traditional Sondell method. However, effects of demyelination and nerve fiber tube integrity were superior to the traditional Sondell method. Biomechanical testing showed that peripheral nerve graft treated using the chemical method resulted in decreased biomechanical properties （ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture） compared with fresh nerves, but the differences had no statistical significance （P 〉 0.05）. These results demonstrated no significant effect on biomechanical properties of nerves treated using the chemical method. In conclusion, nerve grafts treated via the modified method removed Schwann cells, preserved neural structures, and ensured biomechanical properties of the nerve graft, which could be more appropriate for implantation studies.展开更多
Nerve grafting has always been necessary when the contralateral C7 nerve root is transferred to treat brachial plexus injury. Acellular nerve allograft is a promising alternative for the treatment of nerve defects, an...Nerve grafting has always been necessary when the contralateral C7 nerve root is transferred to treat brachial plexus injury. Acellular nerve allograft is a promising alternative for the treatment of nerve defects, and results were improved by grafts laden with differentiated adipose stem cells. However, use of these tissue-engineered nerve grafts has not been reported for the treatment of brachial plexus injury. The aim of the present study was to evaluate the outcome of acellular nerve allografts seeded with differentiated adipose stem cells to improve nerve regeneration in a rat model in which the contralateral C7 nerve was transferred to repair an upper brachial plexus injury. Differentiated adipose stem cells were obtained from Sprague-Dawley rats and transdifferentiated into a Schwann cell-like phenotype. Acellular nerve allografts were prepared from 15-mm bilateral sections of rat sciatic nerves. Rats were randomly divided into three groups: acellular nerve allograft, acellular nerve allograft + differentiated adipose stem cells, and autograft. The upper brachial plexus injury model was established by traction applied away from the intervertebral foramen with micro-hemostat forceps. Acellular nerve allografts with or without seeded cells were used to bridge the gap between the contralateral C7 nerve root and C5–6 nerve. Histological staining, electrophysiology, and neurological function tests were used to evaluate the effect of nerve repair 16 weeks after surgery. Results showed that the onset of discernible functional recovery occurred earlier in the autograft group first, followed by the acellular nerve allograft + differentiated adipose stem cells group, and then the acellular nerve allograft group;moreover, there was a significant difference between autograft and acellular nerve allograft groups. Compared with the acellular nerve allograft group, compound muscle action potential, motor conduction velocity, positivity for neurofilament and S100, diameter of regenerating axons, myelin sheath thickness,展开更多
Peripheral nerve injury causes a high rate of disability and a huge economic burden, and is currently one of the serious health problems in the world. The use of nerve grafts plays a vital role in repairing nerve defe...Peripheral nerve injury causes a high rate of disability and a huge economic burden, and is currently one of the serious health problems in the world. The use of nerve grafts plays a vital role in repairing nerve defects. Acellular nerve grafts have been widely used in many experimental models as a peripheral nerve substitute. The purpose of this study was to test the biomechanical properties of acellular nerve grafts. Methods Thirty-four fresh sciatic nerves were obtained from 17 adult male Wistar rats （age of 3 months） and randomly assigned to 3 groups： normal control group, nerve segments underwent no treatment and were put in phosphate buffered saline （pH 7.4） and stored at 4℃ until further use; physical method group, nerve segments were frozen at -196℃ and then thawed at 37℃; and chemical method group, nerve segments were chemically extracted with the detergents Triton X-200, sulfobetaine-10 （SB-10） and sulfobetaine-16 （SB-16）. After the acellularization process was completed, the structural changes of in the sciatic nerves in each group were observed by hematoxylin-eosin staining and field emission scanning electron microscopy, then biomechanical properties were tested using a mechanical apparatus （Endura TEC ELF 3200, Bose, Boston, USA）. Results Hematoxylin-eosin staining and field emission scanning electron microscopy demonstrated that the effects of acellularization, demyelination, and integrity of nerve fiber tube of the chemical method were better than that of the physical method. Biomechanical testing showed that peripheral nerve grafts treated with the chemical method resulted in some decreased biomechanical properties （ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture） compared with normal control nerves, but the differences were not statistically significant （P 〉0.05）. Conclusion Nerve treated with the chemical method may be more appropriate for use in implantation than nerve treated with the physical method.展开更多
基金the Tianjin Research Program of Applied Foundation and Advanced Technology(A study on the mechanism of self immune factor in vertebral disc inflammation),No.09JCZDJC19600
文摘Nerve grafts are able to adapt to surrounding biomechanical environments if the nerve graft itself exhibits appropriate biomechanical properties （load, elastic modulus, etc.）. The present study was designed to determine the differences in biomechanical properties between fresh and chemically acellularized sciatic nerve grafts. Two different chemical methods were used to establish acellular nerve grafts. The nerve was chemically extracted in the Sondell method with a combination of Triton X-100 （nonionic detergent） and sodium deoxycholate （anionic detergent）, and in the modified method with a combination of Triton X-200 （anionic detergent）, sulfobetaine-10 （SB-10, amphoteric detergents）, and sulfobetaine-16 （SB-16, amphoteric detergents）. Following acellularization, hematoxylin-eosin staining and scanning electron microscopy demonstrated that the effect of acellularization via the modified method was similar to the traditional Sondell method. However, effects of demyelination and nerve fiber tube integrity were superior to the traditional Sondell method. Biomechanical testing showed that peripheral nerve graft treated using the chemical method resulted in decreased biomechanical properties （ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture） compared with fresh nerves, but the differences had no statistical significance （P 〉 0.05）. These results demonstrated no significant effect on biomechanical properties of nerves treated using the chemical method. In conclusion, nerve grafts treated via the modified method removed Schwann cells, preserved neural structures, and ensured biomechanical properties of the nerve graft, which could be more appropriate for implantation studies.
基金supported by the National Natural Science Foundation of China,No.81601057(to JTY)
文摘Nerve grafting has always been necessary when the contralateral C7 nerve root is transferred to treat brachial plexus injury. Acellular nerve allograft is a promising alternative for the treatment of nerve defects, and results were improved by grafts laden with differentiated adipose stem cells. However, use of these tissue-engineered nerve grafts has not been reported for the treatment of brachial plexus injury. The aim of the present study was to evaluate the outcome of acellular nerve allografts seeded with differentiated adipose stem cells to improve nerve regeneration in a rat model in which the contralateral C7 nerve was transferred to repair an upper brachial plexus injury. Differentiated adipose stem cells were obtained from Sprague-Dawley rats and transdifferentiated into a Schwann cell-like phenotype. Acellular nerve allografts were prepared from 15-mm bilateral sections of rat sciatic nerves. Rats were randomly divided into three groups: acellular nerve allograft, acellular nerve allograft + differentiated adipose stem cells, and autograft. The upper brachial plexus injury model was established by traction applied away from the intervertebral foramen with micro-hemostat forceps. Acellular nerve allografts with or without seeded cells were used to bridge the gap between the contralateral C7 nerve root and C5–6 nerve. Histological staining, electrophysiology, and neurological function tests were used to evaluate the effect of nerve repair 16 weeks after surgery. Results showed that the onset of discernible functional recovery occurred earlier in the autograft group first, followed by the acellular nerve allograft + differentiated adipose stem cells group, and then the acellular nerve allograft group;moreover, there was a significant difference between autograft and acellular nerve allograft groups. Compared with the acellular nerve allograft group, compound muscle action potential, motor conduction velocity, positivity for neurofilament and S100, diameter of regenerating axons, myelin sheath thickness,
基金the National Natural Science Foundation of China，the Research Program of Applied Foundation and Advanced Technology of Tianjin
文摘Peripheral nerve injury causes a high rate of disability and a huge economic burden, and is currently one of the serious health problems in the world. The use of nerve grafts plays a vital role in repairing nerve defects. Acellular nerve grafts have been widely used in many experimental models as a peripheral nerve substitute. The purpose of this study was to test the biomechanical properties of acellular nerve grafts. Methods Thirty-four fresh sciatic nerves were obtained from 17 adult male Wistar rats （age of 3 months） and randomly assigned to 3 groups： normal control group, nerve segments underwent no treatment and were put in phosphate buffered saline （pH 7.4） and stored at 4℃ until further use; physical method group, nerve segments were frozen at -196℃ and then thawed at 37℃; and chemical method group, nerve segments were chemically extracted with the detergents Triton X-200, sulfobetaine-10 （SB-10） and sulfobetaine-16 （SB-16）. After the acellularization process was completed, the structural changes of in the sciatic nerves in each group were observed by hematoxylin-eosin staining and field emission scanning electron microscopy, then biomechanical properties were tested using a mechanical apparatus （Endura TEC ELF 3200, Bose, Boston, USA）. Results Hematoxylin-eosin staining and field emission scanning electron microscopy demonstrated that the effects of acellularization, demyelination, and integrity of nerve fiber tube of the chemical method were better than that of the physical method. Biomechanical testing showed that peripheral nerve grafts treated with the chemical method resulted in some decreased biomechanical properties （ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture） compared with normal control nerves, but the differences were not statistically significant （P 〉0.05）. Conclusion Nerve treated with the chemical method may be more appropriate for use in implantation than nerve treated with the physical method.
