New research by CÚRAM, The Science Foundation Ireland Centre for Research in Medical Devices, based at NUI Galway, will allow for improved treatment options for patients with nerve damage. The study was recently published in the prestigious Advanced Functional Materials journal.
Treatment of peripheral nerve injuries that can result in the loss of motor or sensory function remains a major problem worldwide. In recent years, different strategies have been used in an attempt to improve regeneration and functional recovery in the injured peripheral nervous system, which consists of the nerves outside of the brain and spinal cord, using artificial nerve grafts. However, there has been little investigation into changes that occur at the molecular level as a result of these interventions.
The study explored the differences in peripheral nerve repair that result from using biomaterial conduits (artificial nerve grafts) to support recovery, compared with the use of two different types of conduit-materials, namely collagen and the chemical compound, polymer PLGA, in an effort to understand fundamental differences in their repair mechanisms at the molecular level in the early stages of repair. Both collagen and PLGA have previously provided the desired result for the repair of damaged nerves.
Past attempts to improve artificial nerve grafts have often failed to translate to the clinic, due to this limited understanding of the biological response. Recovery of damaged nerves in the peripheral nervous system is quite robust with the use of suturing, and nerves are known to be able to regenerate across relatively short distances, less than 0.5 mm. For treatment of larger gaps between damaged nerves however, the primary treatment methods used are auto/allograft or the use of hollow artificial nerve grafts. Autograft (the use of the patients own tissue), despite being the gold standard for repair, has a number of limitations. These include limited supply of donor tissue, risk of neuroma formation (a disorganised growth of nerve cells at the site of a nerve injury), mismatch in size, and the distribution of nerve tissue in the central nervous system between the donor nerve and the injury site.
The results presented in the study support the hypothesis that regeneration in large peripheral nerve injuries is affected by the material used. The team found that each material selectively activates different regenerative pathways and alters different biological functions throughout the artificial nerve grafts. The analysis also highlights some of the existing deficiencies in conduit-mediated repair in comparison to the use of the patients own tissue.
Professor Abhay Pandit, Scientific director of CÚRAM and lead author of the research paper, explains: “Numerous studies have identified that the choice of conduit material used can have an influence on the level of nerve regeneration. We now have a clearer understanding of how the body responds to the use of these two biomaterials, which paves the way for the development of specific peripheral nerve regeneration strategies using biomaterial conduits, based on the biomaterial used. Our findings suggest that by supplementing the expression of certain proteins on the biomaterial of choice, we can potentially attain the regeneration equivalent or even superior to autograft using biomaterial conduits.”
This study focused on a non-critical nerve injury and did not incorporate the effect of increasing gap distance on the regenerative response. To address this question, further research on the effect of increasing gap distance on the regenerative response is underway at NUI Galway, which will be published at a future date.
To read the full study in Advanced Functional Materials, visit: http://onlinelibrary.wiley.com/doi/10.1002/adfm.201702170/abstract
National University of Ireland