Researchers have revealed the development of a drug which may aid in healing a damaged spine. This is the first time something like a drug has offered help.
The drug works on the nerve cells which have been detached and sends connections across that break. It helped injured rats to move their hind legs again and also restored control of their bladders.
A neuroscience professor at Case Western Reserve University in Ohio, the leader of the study, Jerry Silver, said this was an unprecedented recovery.
Presently, there is no method of healing a broken spine. Some patients experience re-growth of the nerve cells, but this does not usually occur. All the available cures require invasive surgery, including stem cell injections, neurostimulator implants or nerve tissue transplants.
Professor Silver’s team have devised an injectable compound and no surgery is required.
One of the main problems with the repair of a crushed spine is scar tissue. The body is able to reproduce quite a lot of it, and even when nerve cells attempt to send out small growths across the breaks, they are overcome by the scar tissue.
The main problem is proteoglycans, which are molecules. They have a sugary coating and this allows them to grab the delicate axons that are grown by nerve cells to connect to other nerves.
Professor Silver said that they discovered that damaged nerve fibres have a receptor which is able to see the proteoglycan molecules and they stick to it so tightly that they are unable to move.
Jared Cregg and Bradley Lang, two graduate students, had the idea to design a compound which would prevent the nerve cells from detecting the sticky proteoglycans. They produced one which fits into the nerve cell receptor, similar to a docking port, which prevents it from sticking to the proteoglycan.
Professor Silver was not very positive about this design as it appeared to be too far-fetched. He was unsure about injecting a compound under the skin, which would aid nerves elsewhere within the body. However, it worked.
It has been named intracellular sigma peptide, or ISP. The compound was injected into 26 rats with crushed spines, on a daily basis. It helped 21 of them to regain either some bladder control or movement, or both.
People who have suffered injuries to their spinal cord normally have a problem with bladder control. It often results in them becoming incontinent and they may even lose the ability to urinate, which forces them to live with a permanent catheter.
Dr Elizabeth Bradbury of King’s College in London was not involved in the study, but stated that for most patients who are paralyzed, the loss of leg movement is something they can cope with, but the dysfunction of urinary and genital organs is often demoralising and debilitating. This results in most spinal injured patients to rank recovery of sexual, bowel and bladder function, much higher than being able to walk again.
Professor Silver believes that ISP may be effective in other diseases which cause scarring, such as multiple sclerosis and heart attacks.
He said that prior to testing the compound in people, it will have to be tested on a larger animal, like a pig.
The team also has to determine the side effects related to the injection as it will travel throughout the body.
Image Credit: Michael Dorausch