Targeted neural stem cell-derived extracellular vesicles loaded with Sinomenine alleviate diabetic peripheral neuropathy via WNT5a/TRPV1 pathway modulation.

Background: Diabetic peripheral neuropathy (DPN) is one of the most prevalent and debilitating complications of diabetes, marked by chronic neuroinflammation, immune dysregulation, and progressive neuronal degeneration. Current treatments offer limited efficacy, largely focusing on symptomatic relief rather than addressing the underlying disease mechanisms. There is a critical need for disease-modifying therapies that target the molecular basis of DPN.

Results: In this study, we developed a novel targeted nanotherapeutic system-ZH-1c-EVs@SIN-composed of neural stem cell-derived extracellular vesicles (NSC-EVs) modified with the ZH-1c aptamer and loaded with the anti-inflammatory compound sinomenine (SIN). This system was specifically designed to target microglia and inhibit the WNT5a/TRPV1 signaling pathway. Transcriptomic profiling of microglia revealed key gene networks implicated in DPN pathology and responsive to SIN treatment. Functional assays demonstrated that ZH-1c-EVs@SIN facilitated a shift in microglial phenotype from pro-inflammatory M1 to anti-inflammatory M2, significantly reduced inflammatory cytokine expression, and restored levels of neuronal regulatory proteins. Nanoparticle tracking analysis and transmission electron microscopy confirmed optimal vesicle size and morphology, while fluorescence imaging showed efficient uptake by microglia. In vivo studies in a murine model of DPN revealed marked improvements in pain-related behavior and histopathological signs of nerve damage.

Conclusion: ZH-1c-EVs@SIN represents a promising therapeutic strategy for DPN, offering targeted immunomodulation and enhanced neural repair via regulation of the WNT5a/TRPV1 signaling axis. This nano-delivery platform introduces a novel and precise approach to intervening in diabetic neuropathy and may be applicable to other neuroinflammatory conditions.