Nerve conduits for nerve reconstruction

Peripheral Nerve Conduit: Materials and Structures

Peripheral nerve injuries (PNIs) are the most common injury types to affect the nervous system. Restoration of nerve function after PNI is a challenging medical issue. Extended gaps in transected peripheral nerves are only repaired using autologous nerve grafting. This technique, however, in which nerve tissue is harvested from a donor site and grafted onto a recipient site in the same body, has many limitations and disadvantages. Recent studies have revealed artificial nerve conduits as a promising alternative technique to substitute autologous nerves. This Review summarizes different types of artificial nerve grafts used to repair peripheral nerve injuries. These include synthetic and natural polymers with biological factors. Then, desirable properties of nerve guides are discussed based on their functionality and effectiveness. In the final part of this Review, fabrication methods and commercially available nerve guides are described.

An evaluation using techniques to assess muscle and nerve regeneration of a flexible glass wrap in the repair of peripheral nerves

In this study a flexible biodegradable wrap is compared with microsurgical epineurial suturing in the repair of cleanly divided peripheral nerves. Five groups of twelve sheep were used; one control group and four neurotmesis and repair groups. The four repair groups were; (1) Epineurial suture repair using a microscope and 9/0 polyamide; (2) Wrap secured by Tisseel glue; (3) Wrap secured by polycaprolactone glue; (4) Wrap secured by suturing. Regeneration of the median nerve was assessed by electromyography, nerve conduction studies, wet muscle mass measurements, and morphometry. The results suggested that nerve regeneration in the wrap+Tisseel glue group was as good as that in the epineurial repair group. The use of polycaprolactone glue is not recommended in nerve repair. Placement of the wrap was easy to learn and quick to carry out under direct vision. The wrap used in this study could prove to be a useful alternative to epineurial suturing to repair peripheral nerves and may have a particularly unique role in the developing world and battlefield.

Nanofunctionalisation for the treatment of peripheral nervous system injuries

A construct based on the electrostatic layer-by-layer self assembly technique has been fabricated, to be used as a tailored device to encourage nerve regeneration. A multilayered nanocoating composed by three precursor bilayers of cationic and anionic polyelectrolytes followed by bilayers of poly-D-lysine (PDL) and antibody specific to Transforming Growth Factor beta1 (anti-TGF-beta1) has been deposited on HYAFF 11. Initially the assembly process has been monitored by quartz crystal microbalance (QCM) in order to select the optimal working conditions for nanocoating deposition. Structural studies of the resulting multilayers confirmed stepwise deposition of anti-TGF-beta1 with an average layer thickness of 2.6 nm and an average layer mass of 117 ng. Atomic Force Microscopy has been used to characterize multilayer uniformity. Finally, the immunological activity of the multilayered structure has been assessed. The results show that anti-TGF-beta1 can be included in its active form in a predetermined multilayered structure onto HYAFF11 with quantitative control of layer thickness and weight, providing a high potential tool in tissue engineering.