Peripheral nerve regeneration through the nerve tubulization technique

Transection of peripheral nerve results in a loss of function at the target organ that can rarely be recovered without surgical repais. Such an intervention usualy involves nerve autografting but is complicated by problems such as the need for secondary surgery, a limited donor nerve supply and loss of sensitivity in the donor nerve area. An alternative approach involving repair by nerve tubulization has been extensively used to study substances that may improve the regenerative process. An interesting feature of the tubulization technique is the possibility of filling the tube with substances that can enhance regeneration. Such substances include collagen, laminin, hyaluronic acid, fibronectin and more recently, glycosaminoglycans alone or with collagen. Biopolymers, purified glial cells, and neurothophic factors have also been tested. By using the tubulation technique, it has been possible to increase the number of regenerating fibers and the gap between the stumps. In this review, we discuss some of the basic concepts of this technique, as well as recent advances in this field.

Effects of aggrecan on schwann cell migration in vitro and nerve regeneration in vivo

Although the role of many small proteoglycans in regeneration of the nervous system has been established, little is known about the involvement of large proteoglycans. In this study, we evaluated the effects of aggrecan, a high molecular mass proteoglycan, on Schwann cells in vitro and investigated its effects on axonal regeneration after sciatic nerve tubulization. The number of regenerated axons and their morphometrical parameters were determined in vivo. Aggrecan increased the number and viability of Schwann cells in vitro. Similarly, the number of regenerated fibers increased significantly when aggrecan was applied in vivo, but there were no alterations in the morphometrical parameters. These results indicate that aggrecan contributes to the regeneration of peripheral axons and has a positive effect on the Schwann cells.