On Friday I discussed some recent developments in use of stem cells to repair spinal cord damage, but central nervous system damage is not the only cause of paralysis; every year many thousands of people become paralysed in a limb due to peripheral nerve damage.
A difference between peripheral nerve damage and central nervous system damage is that in peripheral nerve damage a limited degree of nerve regeneration is often possible, and surgery can be used to reconned severed nerves if the gap is small enough. However, the techniques currently available, while useful, are not always successful.
Over on the Neurophilosophy blog science blogger Mo has written a fascinating account of how surgeons at the Hannover Medical School have developed artificial nerve grafts made from hollowed-out pig veins filled with spider silk fibres and, in a series of experiments in sheep, showed that the grafts can enhance the regeneration of peripheral nerves over distances of up to 6cm. This work builds on discoveries made in previous research studies undertaken in rats by the same group of scientists.
Commenting on this breakthrough, Mo writes that:
These findings could have important applications in reconstructive nerve surgery. This is the first time that a large animal model has been used to study nerve regeneration, and the study is the first in which a defect longer than 2cm in length has been successfully repaired. The spider silk constructs enhanced nerve regeneration at least as effectively as the sheeps’ own nerves, and would be advantageous in the clinic, because transplanting large lengths of a patient’s own nerves is unfeasible.”
It is a fascinating piece of research, and I strongly recommend that you read Mo’s full discussion of it here.