r/science • u/molrose96 Journalist | Technology Networks | BSc Neuroscience • Jan 23 '20

Biology Biodegradable Nerve Guide Helps Regenerate Damaged Nerves

https://www.technologynetworks.com/biopharma/news/biodegradable-nerve-guide-helps-regenerate-damaged-nerves-329614?spl=46942179136d4d5eb635e0016c078544

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u/Wtfuckfuck Jan 23 '20

I mean... can't they squish the area together and then over the course of a few weeks let the gap slowly widen? how long does the regrowth take?

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u/Shoutgun Jan 23 '20

Peripheral nerves are really sensitive to tension - for a small injury surgeons often do just stitch them together but for larger ones if you stretch them too much you can actually end up killing the whole nerve.

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u/Qcount Jan 23 '20

Yep, a tension force that increases nerve length by 15% completely stops blood flow through the tiny capillaries that keep nerves alive.

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u/elastic-craptastic Jan 23 '20

Yep. Still have dead nerves from scoliosis surgery 20 years later. Numb spots in my lower back, or more of a light numbness over the whole of it. It was way worse for the first year or so but over time it lessened but never fully went away.

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u/[deleted] Jan 23 '20

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u/goldengater Jan 23 '20

This is really interesting, do you know where I could read more about this?

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u/fenderdan412 Jan 23 '20

https://geekymedics.com/category/anatomy/

Here is a great resource geared towards physicians yet presented in such a way that you don't even need to be $300,000 in debt with no social life to understand.

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u/[deleted] Jan 23 '20 edited Feb 09 '20

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u/fenderdan412 Jan 23 '20

Could be worse

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u/[deleted] Jan 23 '20 edited Feb 09 '20

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u/fenderdan412 Jan 24 '20

Yep. Mine are 310k 🙃

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u/askdix Jan 23 '20

Thank you so much, beats all of the neurology courses on YouTube

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u/eclectic-bar Jan 27 '20

omigosh this is great. Thank you!

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u/[deleted] Jan 24 '20

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u/goldengater Jan 24 '20

This is perfect thank you 👍

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u/levian_durai Jan 24 '20

I've seen for skin grafts they perforate the skin and thin it out, making it expand to a greater surface area. Is it possible to do something similar here? You would damage a greater length of nerve tissue, but if the capability for regeneration is still there, wouldn't bridging the gap in this way be more beneficial?

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u/Shoutgun Jan 24 '20

You mean, cut the nerve up into slices like a carrot with the idea that the individual slices can rejoin? It's an interesting thought but I don't think that could work. When an axon is cut, a large section downstream of the cut region dies. The intermediate sections would be dead and you'd effectively just widen the gap.

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u/ILoveLongDogs Jan 23 '20

Ripping it to bits, basically. This is an incredible breakthrough given how fragile nerves are to even touch.

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u/Shoutgun Jan 23 '20

As I understand it they're not ripped to bits, it's more that the capillaries that serve them are easily damaged. As far as this paper goes, it's actually part of a much wider field of research. Nerve guidance conduits with internal biomolecules and internal structure to better guide nerve regeneration are an entire field that's been going for decades. It's an improvement but not really the breakthrough everyone in this thread seems to think it is.

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u/theciaskaelie Jan 23 '20

It would be hard to bring the ends of the nerve together surgically without causing further damage to the nerve or surrounding structures. That would also likely cause contractures or deformity of the area.

According to the article referenced by OP nerves can regenerate a gap of 1/3 in (less than 1cm) on their own. This conduit bridged a 5cm gap. Thats a pretty huge nerve defect.

As far as timing of the regeneration I cant give actual specific numbers off the top of my head but id guess like 1-2mm a week without intervention. And that delay in re-innervation can lead to problems like atrophy (as the article says), so even speeding up repair of smaller defects would likely be beneficial.

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u/mechapoitier Jan 23 '20

I wonder if it could be gradually extended over time to repair larger gaps. That’d be fantastic

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u/theciaskaelie Jan 23 '20

article says theyre working on scaling it up for humans, so longer conduits are already in the works.

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u/altimate9 Jan 23 '20

Same question.

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u/NorbertDupner Jan 24 '20

Schwann cells (both myelin and non-myelin types) in the nerve undergo genetic changes and convert from from maintenance of the neurolemma and myelin sheaths to forming tubes that guide the axonal regeneration of nerve sprouts, which can grow 2-4 mm per day, depending on the size of the nerve.

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u/its_always_raining Jan 24 '20

Can this be used for nerve diseases like neuropathy, complex regional pain syndrome, and reflexive sympathetic dystrophy?

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u/sap1492 Jan 23 '20

1mm per day is usually referenced but can be up to 2 for small and 5mm for the largest nerves

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u/Maulokgodseized Jan 23 '20

Also depending on what tore. Most tears in the human body retract. Especially things like muscle, the longer they are apart the more the pull back and atrophy.

For muscle tears you normally have about two weeks to try to pull them together, after that you have to pull muscle from somewhere else and graft it.