An artificial nerve conduit containing gallium and cells improved recovery from a 15-millimeter gap in aged rats
An artificial nerve conduit containing gallium and cells improved recovery from a 15-millimeter gap in aged rats
On August 25, Advanced Science published a study of a 15-millimeter sciatic nerve defect in 21-month-old rats. The authors placed gallium-containing nanoparticles, mesenchymal stem cells derived from maxillofacial tissue, and aligned microfibers inside an artificial conduit. After 10–16 weeks, they assessed paw sensation and movement, myelin formation, and nerve signal conduction.
Autologous nerve grafting remains the clinical standard for repairing a long peripheral nerve gap. The graft provides cells and an extracellular scaffold for growth, but it requires a second operation and is limited by the amount of available donor tissue. An artificial conduit is intended to guide regenerating nerve fibers across the gap.
After injury, Schwann cells, which support nerve fibers, clear the damaged area, create a path for regenerating fibers, and then form new myelin, the sheath that speeds nerve signal conduction. In injured nerves from aged rats, the authors found fewer myelinating Schwann cells and signs of ferroptosis. Ferroptosis is a form of cell death in which iron and oxidation products damage lipids in the cell membrane.
A 2025 study had already shown that aged Schwann cells are delayed in the transition from a repair state back to myelination. The authors of the new study tested whether conditions at the injury site itself could be changed. Ga-PTA nanoparticles containing gallium broke down more rapidly in the presence of both iron ions and hydrogen peroxide, releasing gallium. In a cell model of aged Schwann cells, they reduced the levels of oxidants and ferrous iron.
In the nerves of aged rats, Ga-PTA reduced the iron signal, but the myelin area had not increased by week 16. The researchers therefore added these cells to the conduit, where they acquired features of Schwann cells. The aligned microfibers oriented the cells and created a path across the gap.
The conduit containing gallium, cells, and microfibers was compared with a conduit containing cells alone and with an autologous nerve graft. In rats treated with the complete construct, the authors recorded recovery of responses to cold and heat, ankle movement, grip strength, myelin, and gait. After 16 weeks, conduction velocity in the regenerated nerve was 38.3 ± 4.2 m/s; in the autologous nerve graft group, it was 41.8 ± 4.7 m/s.
Each component had a distinct role in this design. Gallium reduced signs of ferroptosis at the injury site, the cells acquired Schwann cell properties, and the microfibers guided their growth across the gap. The combined construct was evaluated by nerve structure, sensation, paw movement, and signal conduction.