After an 'artificial conduit' was placed across a severed arm nerve... Hand function returned a year later [Health LAB]

[Financial News] Researchers confirmed the possibility of restoring a monkey's damaged arm nerve to normal function within a year by connecting it with a conduit. The finding raises hopes that the technology could eventually be used as a material for artificial nerve-regeneration medical devices.  
According to the Korea Institute of Science and Technology (KIST) on the 21st, a research team led by Jung Young-mi, a principal research scientist at KIST's Center for Biomaterials Research, worked with a research team led by Park Jong-woong, a professor of orthopedic surgery at Korea University (KU) College of Medicine, and the Korea Research Institute of Bioscience and Biotechnology (KRIBB) National Primate Research Center. Together, they developed a multi-fascicular artificial nerve guidance conduit (MFNGC), modeled on the branching structure of peripheral nerves, and confirmed the potential for nerve regeneration and hand-function recovery over 12 months in a monkey model of arm-nerve injury. 
According to the research team, when nerves in the hand or arm are severely severed in an industrial accident or traffic accident, autologous nerve grafting is the standard treatment if the gap between the ends is extensive. The procedure involves removing a healthy nerve from another part of the patient's body and transplanting it. However, it requires sacrificing a healthy nerve, and the amount available for transplantation is limited.
The researchers analyzed the nerve structure of a rhesus macaque's wrist, whose hand is similar to a human hand in structure and function, and created three small channels inside a single large conduit. They implanted the conduit in a 15 mm defect in the rhesus macaque's median nerve and tracked nerve regeneration and changes in hand function for 12 months. Over time, the monkeys took less time to pick up small pieces of food with their fingers, and their motor-impairment scores improved. Tests measuring muscle responses to electrical stimulation of the nerve also showed that signals had reappeared in most animals by six months after surgery.
After 12 months, newly grown nerves inside the conduit had become organized into multiple fascicles, like a real nerve, and myelin sheaths surrounding the nerve fibers had re-formed. The molecular weight of the poly(L-lactide-co-ε-caprolactone) (PLCL) conduit material had decreased by about 94% from its pre-implantation level, and no clear chronic inflammatory response was observed. The findings confirmed the material's potential as a medical device that provides a pathway while the nerve grows and gradually breaks down inside the body afterward.
The study is significant because it confirmed the potential for nerve regeneration and hand-function recovery over one year in a primate using only a nerve-like structure and biodegradable material, without cells or growth factors. Since the approach does not require cell culture or separate cryopreservation, it could facilitate commercialization. If further studies validate its efficacy and safety and standardize the manufacturing process and regulatory requirements, it could be developed into a domestically developed nerve-regeneration medical device that addresses the limitations of autologous nerve grafting.
Jung Young-mi, a principal research scientist at KIST, said, "We confirmed the regenerative potential of an artificial nerve guidance conduit modeled on the fascicular structure of actual nerves in a primate whose hand structure is similar to that of humans," adding, "We will expand the scale of validation and connect the findings to the clinical application of a domestically developed nerve-regeneration medical device."
The findings were published in the latest issue of the international journal Bioactive Materials (IF 23.6, top 1.88% in the JCR).
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