Preparation of Snake Neurotoxin Nanocapsules and the Analgesic Mechanism of P38 Mitogen-Activated Protein Kinase Signal Pathway Combining Snake Neurotoxin Nanocapsules with Gabapentin

Abstract

This study aimed to explore the analgesic effect of snake neurotoxin combined with gabapentin (Gab) on neuropathic pain in rats with chronic compression injury (CCI) of the sciatic nerve based on the nanotechnology. Firstly, various solutions were prepared to obtain the inner water phase, the oil phase, the outer water phase, and the dilution phase. Poly(lactic-co-glycolic) Acid (PLGA) and polyethylene glycol-poly(lactic-co-glycolic) acid (PEG-PLGA) were added to the prepared oil phase solution to obtain the PLGA snake neurotoxin nanocapsule and PEG-PLGA snake neurotoxin nanocapsule, respectively. After the nanocapsules were obtained, a rat CCI model was further modelled, and the reactive oxygen species (ROS) content in the rat brain tissue was analyzed and tested by the kit, and the optimal physical conditions for preparing the nanocapsules were tested. In order to test the effect of nanocapsules on the p38 mitogen-activated protein kinase (MAPK) signaling pathway, the rats were divided into Control group, Sham group, CCI group, Gabapentin (Gab) group, and PEG-PLGA snake neurotoxin nanocapsule + Gab group. The rats in different groups were given abdominal injections to compare relevant indicators of signal pathway. In the experiment, neuropathic pain was related to changes in ROS content, and snake neurotoxin nanocapsules could reduce the ROS content; PLGA snake neurotoxin nanocapsules and PEG-PLGA snake neurotoxin nanocapsules had encapsulation efficiencys of 24.7% and 22.8% and drug loading of 3.28% and 3.02%, respectively, and the particle sizes of prepared nanocapsules were 760 nm~1,150 nm. Besides, the phase transition temperature of about 50 °C and the light time of 1 h can accelerate the release of nanocapsules to the greatest extent; and the snake neurotoxin could inhibit the activation of p38 MAPK signaling pathway so as to play the analgesic effects on neuropathic pain.