Developing bio-artificial organs for repairing spinal-cord injury
11 November 2014
Authors: Sharon Kelly, project manager, Network of Excellence for Functional Biomaterials (NFB); Carolyn Holladay, senior researcher, Vornia; and Keith Feerick, research associate, NFB
According to the World Health Organization, nearly 500,000 people suffer a spinal-cord injury (SCI) per year worldwide (‘Spinal cord injury’, WHO fact sheet N°384, November 2013). As a consequence of mobility barriers, people who experience injury to their spinal cord largely become dependent on caregivers and 20-30% of them develop depression, which impairs functional and overall health improvements. The development of secondary health conditions is also common (2).
Altogether, these impairments result in people being excluded from fully participating in society after their injury, with the adult unemployment rate exceeding 60% and child enrollment in school also negatively affected (2).
The costs related to SCI correlate to the level of injury. The higher-up on the spinal cord that the injury occurs, the higher the costs as the patient typically has less movement. The indirect costs related to loss of earnings often exceed the direct costs. Ultimately, people with SCI have a two-to-five times’ probability of premature death (2).
It goes without saying, then, that a successful therapeutic approach regarding SCI, where functionality of neuronal tissue is re-established through the use of stem cells delivered within a structural biomaterial, would be of invaluable socioeconomical impact to the millions of people affected directly and indirectly by spinal-cord injuries.
Neurograft conduit for spinal-cord injury
The NeuroGraft collaborative consortium proposes a novel multichannel conduit system, which will aid functional regeneration following SCI. The NeuroGraft conduit will contain stem cells to promote nerve regeneration, and an anti-inflammatory agent. Limited regeneration occurs spontaneously following SCI, however the addition of stem cells will further enhance the regenerative potential of neurons guided through the conduit. Transplanted stem cells promote motor neuron and sensory neuron regeneration by releasing growth factors and this factor secretion provides a better environment for nerve regeneration.
Inflammatory processes following SCI have limited the success of promising stem cell transplantation therapies in recent times. The NeuroGraft prototype developed at National University of Ireland Galway is a multichannel collagen conduit which will address the primary (neurodegenerative) and secondary (inflammatory) pathological events following SCI. Transplantation of stem cells encapsulated or grown on the surface of a conduit system increases cell survival, migration and differentiation in vivo. Secondary cascades following traumatic injury to the central nervous system further inhibits recovery by activating the innate immune response, apoptosis and necrosis.
The ultimate design involves a conduit that may be loaded with anti-inflammatory agents and stem cells when complete and this combination bio-artificial organ will have a huge impact in the area of spinal cord regeneration as there is no comparable product on the market.
In Europe, there are approximately 330,000 people living with SCI and more than 11,000 new cases annually (1). The costs to the European healthcare system in maintaining, treating and rehabilitating these patients is over €15.5 billion per year (1). Should a European treatment for spinal cord injury become available, it will have significant financial value in addition to the value to the patient’s quality of life.
The advantages of NeuroGraft are that in addition to administration of an anti-inflammatory cytokine, the conduit itself is capable of reducing the inflammatory response following SCI.
All five partners in the consortium have a critical role to play in the creation of the conduit which is explained in the diagram below. As well as NUI Galway’s academic role, there are four small- and medium-sized enterprises (Vornia Limited, Stemmatters, NAMSA and Obelis) from four different countries (Ireland, Portugal, France and Belgium), making this project a true European effort to create a conduit for SCI.
See the Neurograft website for more details.
1. http://assembly.coe.int/Documents/AdoptedText/ta02/EREC1560.htm, Parliamentary Assembly, Council of Europe recommendation 1560
2. www.who.int/medicentre/factsheets/fs384/en/, WHO – Spinal cord injury, Fact sheet N°384, Nov 2013