Stimulating peripheral nerve regrowth to preserve muscle tissue
Stimulating peripheral nerve regrowth to preserve muscle tissue lead image
Peripheral nerve injuries can take a long time to fully heal, which can introduce additional complications in muscle tissue. If the distance between the injured nerve and the muscle it connects to is large, the muscle can waste away before the regenerated neurites reach it, limiting full recovery.
“Despite advances in microsurgery in the modern era, the outcome after peripheral nerve repair is still limited by the speed of neurite regeneration,” said researcher Shih-Heng Chen.
“At a speed of less than a millimeter per day, this is prohibitively slow for preventing muscle atrophy.”
To improve nerve growth, Chen et al. developed a technique using adipose-derived stem cells. Instead of injecting the cells directly, the technique uses extracellular vesicles (EVs) — lipid-enclosed sacs exuded by the stem cells — to deliver chemical signaling to the nerves to promote growth. The EVs were mixed with a hydrogel and injected at the injury site.
Initial cellular tests found the EV hydrogel promoted the growth of neurites and sped up the migration and proliferation of Schwann cells. Follow-up testing in rats showed improved sciatic nerve repair in the rats that received the treatment compared to the control group. Treated rats had thicker myelin sheath and larger fascicles on the repaired nerves. Additional tests of the electric potential and contraction force of the target muscles and the conduction velocity of the nerve showed improvements in the treated rats.
“The results of our cell and animal experiments showed that the EV-loaded hydrogel can promote peripheral nerve regeneration,” Chen said.
Source: “Thermosensitive hydrogel carrying extracellular vesicles from adipose-derived stem cells promotes peripheral nerve regeneration after microsurgical repair,” by Shih-Heng Chen, Huang-Kai Kao, Jing-Ru Wun, Pang-Yun Chou, Zhi-Yu Chen, Sung-Tsang Hsieh, Hsu-Wei Fang, and Feng-Huei Lin, APL Bioengineering (2022). The article can be accessed at https://doi.org/10.1063/5.0118862 .
