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The use of antioxidants could thus prove an effective medication to prevent or facilitate recovery from oxidative stress-induced sensorineural hearing loss (SNHL). One promising strategy to prevent SNHL is developing probucol (PB)-based nanoparticles using encapsulation technology and administering them to the inner ear via the established intratympanic route. The preclinical, clinical and epidemiological studies support that PB is a proven antioxidant that could effectively prevent oxidative stress in different study models. Such findings suggest its applicability in preventing oxidative stress within the inner ear and its associated neural cells. However, several hurdles, such as overcoming the blood-labyrinth barrier, ensuring sustained release, minimising systemic side effects and optimising targeted delivery in the intricate inner ear structures, must be overcome to efficiently deliver PB to the inner ear. This review explores the background and pathogenesis of hearing loss, the potential of PB in treating oxidative stress and its cellular mechanisms, and the obstacles linked to inner ear drug delivery for effectively introducing PB to the inner ear. [ABSTRACT FROM AUTHOR]

Hearing loss is a widespread condition, affecting people from a range of demographics. Gene therapy is an emerging method for the amelioration of this condition. Challenges associated with the delivery of genes to various sites within the ear remain a significant challenge. In the present work, a novel polymer nanoparticle delivery system was developed, incorporating a bile acid excipient. Bile acids have previously been shown to improve drug delivery through their permeation enhancing properties; however, few studies report their use in gene delivery systems. Nanoparticles were developed with sodium alginate and poly-L-lysine through an ionotropic gelation method. Various surfactants including Tween-80 and poly-ethylene glycol 6000 were incorporated to both improve the solubility of the bile acid, ursodiol, and to modify nanoparticle properties. The evaluation of the nanoparticle's safety profiles was the primary outcome of this study. The secondary aims were to perform genetic studies, such as transfection efficiency. The nanoparticles generated in this study demonstrated formulation-dependent variability in particle size ranging from 30 to 300 nm. Several of the developed formulations demonstrated suitable safety profiles; further, the introduction of bile acid helped to reduce toxicity. Transfection efficiency for all formulations remained low, potentially due to poor plasmid release inside the cell. Poor transfection efficiency is one of the key pitfalls associated with polymer nanoparticles Overall the present study developed nanoparticles with suitable safety profiles but limited efficacy. The use of modified polymers, additional excipients, and cell-targeting peptides are potential methods that may be explored in future studies to help further improve gene delivery. [ABSTRACT FROM AUTHOR]