Biopharmaceutical modulatory effects of newly engineered bile acid-Tyloxapol nanogels for attenuation of cytotoxicity in auditory cells

This study presents novel thermoresponsive nanogels composed of chenodeoxycholic acid and Tyloxapol for potential inner ear drug delivery. The nanogels exhibit non-Newtonian, shear-thinning fluid behaviour and rapid gelation at body temperature. Biocompatibility studies were conducted on auditory and macrophage cell lines. Nanogels had a minimal impact on cellular viability, glycolysis, and mitochondrial respiration of auditory cells after 24 h of exposure. However, mitochondrial function analysis in macrophages revealed a significant decrease in oxidative phosphorylation and coupling efficiency after nanogel exposure, accompanied by increased proton leakage. Despite these metabolic disruptions, glycolysis remained unaffected. The Poloxamer matrix appears to be responsible for these effects, independent of the presence of bile acids or Tyloxapol. This study highlights the potential of bile acid-enriched nanogels in drug delivery, particularly their biocompatibility and injectability while acknowledging challenges related to mitochondrial dysfunction in immune cells. These findings suggest that thermoresponsive bile acid and Tyloxapol nanogels have the potential to be safe and effective drug delivery vehicles for inner ear applications.