The Development of Inner Ear Membrane Analog for Experimental Otorhinolaryngology.

The aim of the investigation was to develop and evaluate a model of the human round window membrane (mRWM) of the inner ear that is suitable for representative studies of drug permeation and cytotoxicity.

Biological part of the study: Several substrate options were tested to create the mRWM, including 2 variants of Viscoll collagen membranes (IMTEK, Russia) and a multi-component G-Derm membrane (G-DERM, Russia). In the first variant, only HaCaT epithelial cells were seeded on the membranes, and in the second variant, primary human dermal fibroblasts were seeded together with HaCaT epithelial cells (sequential application). The obtained mRWM were evaluated by morphological criteria using histochemical methods. As a result, the decision was made to use mRWM constructed on Viscoll membranes with the inclusion of both primary fibroblasts and human epithelial cells.

Technical part of the study: A series of scientific experiments has been performed on the obtained mRWM aimed at studying the permeability and developing modes of electrophysical action on this biological barrier while maintaining its morphological and functional integrity and ensuring accelerated passage of dexamethasone through it. To accelerate the passage of dexamethasone across the mRWM, the electrophysical system initiated targeted iontophoresis of negatively charged dexamethasone molecules in parallel with electroporation of cell membranes in the sample. After the exposure, the residual viability of mRWM was assessed by histochemical staining with calcein and propidium iodide. The change in dexamethasone concentration after passage across the mRWM was assessed using a highly sensitive chromatograph.

Conclusion: During the optimization of the mRWM fabrication protocol and the selection of suitable substrate components and cellular material, the model based on a thin Viscoll collagen membrane has been chosen as a substrate and primary human dermal fibroblasts and epithelial cells of the HaCaT line as a cellular material. The obtained experimental samples of mRWM represent a semipermeable membrane with living cells on the surface and are an alternative analog of the native structure, reproducing its geometric and morphofunctional characteristics. In addition, there has been demonstrated a method of using the for preclinical studies of electrophysical devices designed for accelerated passage of target substances through this membrane using electroporative and iontophoretic effects.