It takes a brave person to step outside their comfort zone. Scientist Gillian Hendy is braver than most. She left a job and postponed a wedding in Ireland to do research at the world-renowned Langer Lab (USA). During her time there, she has learnt whole new biological processes, braved hurricanes, and thanks to hard work could well have found a material that can speed up nerve regeneration in damaged limbs.
Gillian Hendy is 29 years old, but looking at her curriculum vitae it is hard to believe it. She is an electrochemist by training and, although she would deny it, an adventurer by nature.
Right now, Dr Hendy is involved in a three-year EU-supported Marie Curie International Outgoing Fellowship organised between her home institution, the National University of Ireland Maynooth, and Robert Langer's Lab at the Koch Institute, Massachusetts Institute of Technology's (MIT). She is helping to develop novel biomaterials for tissue engineering that may one day considerably improve the treatment of degenerative brain diseases.
Tissue engineering is a process to facilitate the re-growth of damaged or diseased tissues in the human body (i.e. bones, skin and muscles) by introducing a biological support or scaffold created in the lab which is usually surgically removed after the successful treatment.
Dr Hendy is working on new, biodegradable materials for tissue engineering, capable of releasing drugs into the area where the material would be implanted. The researcher's project – Conducting organic materials for tissue engineering and drug delivery (COMET) – is looking in particular into the use of these materials in peripheral nerve regeneration, such as in limbs, which could lead to faster recovery after injury.
"People can recover from peripheral nerve injury because the nerve cells naturally have the potential to regenerate, but they need guidance so that the neurotransmitters – the body's chemical signals that tell muscles to move – can continue to transmit their signal to the muscle.
"But if the nerve is severely injured, regeneration can take a long time so a replacement path has to be implanted to stimulate the muscles (make them contract) or else they will atrophy," says Dr Hendy. "We're trying to regenerate nerves faster to stop muscle dying and speed up patient recovery."
Stimulating new approach
Today, if someone has a gunshot wound and there is a large gap between the nerves surgeons take a replacement from, say, the patient's foot and implant it in the injured area to trick the nerves into regenerating by following the path of the implanted nerve.
This has its disadvantages and limitations as the patient needs to undergo multiple surgeries and also loses sensation in the area where the nerve has been removed. It can be an invasive process from start to finish, and according to Dr Hendy, like robbing Peter to pay Paul.
"Our work is all about finding a better way of doing this. But the big problem we face is finding a suitably conductive material (polymer) that is also biodegradable and biocompatible (the body is happy to receive it)," she explains. "Metal-based materials are highly conductive but not biodegradable, and they have to be removed afterwards. Other materials dissolve in the body – so don't need removing – but are less conductive so the electro-stimulation we put through the scaffold 'fizzles out'."
The material – made of polypyrrole– currently being tested (outside the body) at MIT works well in the drug delivery of neurotransmitters. The next step, suggests Dr Hendy, will be to test the new scaffold and electrochemical double-punch in vitro for peripheral nerve regeneration. "And from there the natural step will be to try and extend the results to treat neurodegenerative brain diseases like Alzheimer's and Parkinson's."
It is still early days, stresses the young scientist, and using electro-stimulation in the brain would involve major risks – to motor function, speech, etc. – but the neurotransmitters in peripheral nerves are not miles off those involved in the brain, and the processes Dr Hendy and MIT colleagues are working on show potential. In the coming months, the researcher hopes to publish some early results in the journal Advanced Materials.