Acupoint electrical stimulation with implantable carbon nanotube electrodes mitigates sciatic nerve injury-induced...

Sciatic nerve injury (SNI) is a common form of peripheral nerve injury that often leads to persistent atrophy of denervated skeletal muscle. To address this issue, we developed an implantable electrode made of carbon nanotube fibers (CNTFs) for targeted acupoint electrical stimulation (AES) at the Huantiao acupoint (GB30) in SNI rats. CNTFs offer high tensile strength, excellent electrical conductivity, and proven biocompatibility. Following 21 consecutive days of AES intervention, we evaluated therapeutic effects through behavioral tests, morphological analysis, and biochemical assays. Compared to the SNI group, the AES group showed significantly improved hindlimb motor performance; increased gastrocnemius wet weight ratio; enlarged myofiber cross-sectional area; enhanced muscle histomorphology; reduced expression of pro-inflammatory and atrophy-related markers, including tumor necrosis factor-α, muscle RING-finger protein-1, and muscle atrophy F-box/atrogin-1; and upregulation of insulin-like growth factor-1 in denervated skeletal muscle. Importantly, histopathological examination and enzyme-linked immunosorbent assay confirmed thein vivobiocompatibility of the implanted CNTF electrodes, without chronic inflammation, fibrosis, or systemic toxicity. Electrochemical impedance measurements confirmed that the CNTFs maintained low impedance over the 21 d implantation period, indicating goodin vivostability. Collectively, these findings demonstrate that the minimally invasive implantable AES system is an effective therapeutic strategy against SNI-induced muscle atrophy in rats.