Mechanism of Hydrogen Sulfide Drug-Loaded Nanoparticles Promoting the Repair of Spinal Cord Injury in Rats Through Mammalian Target of Rapamycin/Signal Transducer and Activator of Transcription 3 Signaling Pathway

Abstract

To explore the effect of hydrogen sulfide (H2S) drug-loaded nanoparticles (H2S-NPs) on the mTOR/STAT3 signaling pathway in rats and its mechanism on repair of spinal cord injury (SCI), a new H2S-NP (G16MPG-ADT) was prepared and synthesized. The rats were selected as the research objects to explore the mechanism of SCI repair. The G16MPG-ADT NPs were evaluated by average particle size (APS), dispersion coefficient (DC), drug loading content (DLC), drug loading efficacy (DLE), in vitro release (IV-R), and acute toxicity (AT). It was found that G16MPG-ADT nanoparticles had a uniform particle size distribution with a unimodal distribution, with an average particle size of 186.5 nm and a dispersion coefficient of 0.129; within the concentration range of 8~56 μg/L, there was a good linear relationship with the peak area; and the release rate of the nanoparticles within 16 h~32 h was higher than 50%. G16MPG-ADT NP injection treatment was performed on rats with SCI. Western blotting (WB) and immunofluorescence staining were adopted to analyze the expression levels of mammalian target of rapamycin (mTOR) and signal transducers and activators of transcription (STAT3) protein and the growth of neurites. It was found that G16MPG-ADT can increase mTOR and STAT3 protein levels and promote nerve growth after SCI. Finally, the Basso, Beattie and Bresnahan locomotor rating (BBB) score was to evaluate the recovery effect of rats after treatment. It was found that the recovery effect was excellent after G16MPG-ADT treatment. In summary, G16MPG-ADT has a good effect on SCI repair in rats and can be promoted in the clinic.