Use of Solid Lipid Nanoparticles for the Treatment of Acute Acoustic Stress-Induced Cochlea Damage.

To study the effects of drug delivery using solid lipid nanoparticles in the treatment of acute noise exposure-induced cochlea damage. The solid lipid nanoparticles (SLNs) were used as carriers to effectively encapsulate the drug clozapine, improve drug stability in the carrier system, and increase drug bioavailability in vivo. Solid lipid nanoparticles carrying clozapine were produced by ultrasonic technology. The clozapine solution or sulphate SLN was administered though intratympanic or intravenous injection on the first day of noise exposure Guinea pigs were exposed to 110 dB sound pressure level (SPL) noise (2 h per day with center frequencies of 0.25-4.0 kHz for 4 days). After noise exposure, the guinea pigs were subjected to auditory brainstem response (ABR) threshold measurements. Reactive oxygen species (ROS) levels were detected in the cochlea by electron spin resonance (ESR), and outer hair cell counts (OHCs) were obtained using silver nitrate (AgNO₃). SLN particles carrying clozapine exhibited protective effects on the cochlea. The threshold shift and ROS production in treated animals, especially in animals treated with clozapine SLN through intraperitoneal injection, were significantly lower than those in untreated animals.