Fabrication and characterization of dexamethasone-releasing polylactic acid nanospheres for treatment of hearing loss

Aim and Background: Chronic inflammation in the inner ear is the main reason for hearing loss as it causes oxidative stress, activation of apoptosis, and dysfunction of the cell mitochondria. In recent years, sustained drug delivery methods have emerged as a promising approach for the treatment of inner ear diseases. The goal of the present study was to prepare a nanoparticulate-based drug delivery system for the delivery of an anti_x0002_inflammatory drug into the inner ear. For this purpose, dexamethasone-loaded polylactic acid (PLA) nanospheres were fabricated for the first time, and evaluated for this application. Methods: The dexamethasone-loaded PLA nanospheres were fabricated by W/O/W double emulsion technique. Then, the prepared nanospheres were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and release studies. Results and discussion: The SEM images showed the spherical shape of the prepared PLA nanoparticles. Also, it was observed that by reducing the PLA concentration, the mean size of the obtained nanospheres was decreased, which can be attributed to the change in the viscosity of the solution. The FTIR analysis revealed that dexamethasone has been successfully loaded into the nanoparticles and had no chemical interaction with the PLA polymer. The system showed a high encapsulation efficiency and a good release profile in the first days of the experiment. Conclusion: The findings of this study showed a promising potential of the prepared delivery system for controlling the inflammation of the inner ear and treatment of hearing loss.