Autologous nerve segment-bridging regeneration chambers for the repair of sciatic nerve defects

Proximal and distal nerve defects exhibit chemotactic growth over certain distances. Our previous studies demonstrated that Schwann cells survive in autologous nerve segments that are bridged by regeneration chambers and secrete various bioactive substances. However, more data are required to determine the required length of regeneration chambers for chemotaxis and nutrition of neural regeneration, as well as the length of repaired nerve defects to replace the effect of autologous nerve grafting. In the present study, sciatic nerve defects of 12, 16, 20 mm were repaired using a regeneration chamber of 6, 8, and 10 mm in length respectively. These were bridged with autologous nerve segments. Results showed that the bridging of two 6-mm long regeneration chambers to repair a 12-mm nerve defect exhibited similar effects to autologous nerve grafting.

Chemoattractive capacity of different lengths of nerve fragments bridging regeneration chambers for the repair of sciatic nerve defects

A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects. In this study, we compared the efficacy of different lengths （6, 8, 10 mm） of nerve fragments bridging 6-mm regeneration chambers for the repair of 12-mm-long nerve defects. At 16 weeks after the regeneration chamber was implanted, the number, diameter and myelin sheath thickness of the regenerated nerve fibers, as well as the conduction velocity of the sciatic nerve and gastrocnemius muscle wet weight ratio, were similar to that observed with autologous nerve transplantation. Our results demonstrate that 6-, 8-and 10-mm-long nerve fragments bridging 6-mm regeneration chambers effectively repair 12-mm-long nerve defects. Because the chemoattractive capacity is not affected by the length of the nerve fragment, we suggest adopting 6-mm-long nerve fragments for the repair of peripheral nerve defects.

Human umbilical cord mesenchymal stem cell-loaded amniotic membrane for the repair of radial nerve injury

In this study, we loaded human umbilical cord mesenchymal stem cells onto human amniotic membrane with epithelial cells to prepare nerve conduits, i.e., a relatively closed nerve regeneration chamber. After neurolysis, the injured radial nerve was enwrapped with the prepared nerve conduit, which was fixed to the epineurium by sutures, with the cell on the inner surface of the conduit. Simultaneously, a 1.0 mL aliquot of human umbilical cord mesenchymal stem cell suspension was injected into the distal and proximal ends of the injured radial nerve with 1.0 cm intervals. A total of 1.75 x 107 cells were seeded on the amniotic membrane. In the control group, patients received only neurolysis. At 12 weeks after cell transplantation, more than 80% of patients exhibited obvious improvements in muscular strength, and touch and pain sensations. In contrast, these improvements were observed only in 55-65% of control patients. At 8 and 12 weeks, muscular electrophysiological function in the region dominated by the injured radial nerve was significantly better in the transplantation group than the control group. After cell transplantation, no immunological rejections were observed. These findings suggest that human umbilical cord mesenchymal stem cell-loaded amniotic membrane can be used for the repair of radial nerve injury.

Complement components of nerve regeneration conditioned fluid influence the microenvironment of nerve regeneration

Nerve regeneration conditioned fluid is secreted by nerve stumps inside a nerve regeneration chamber.A better understanding of the proteinogram of nerve regeneration conditioned fluid can provide evidence for studying the role of the microenvironment in peripheral nerve regeneration.In this study,we used cylindrical silicone tubes as the nerve regeneration chamber model for the repair of injured rat sciatic nerve.Isobaric tags for relative and absolute quantitation proteomics technology and western blot analysis confirmed that there were more than 10 complement components（complement factor I,C1q-A,C1q-B,C2,C3,C4,C5,C7,C8β and complement factor D） in the nerve regeneration conditioned fluid and each varied at different time points.These findings suggest that all these complement components have a functional role in nerve regeneration.