Feasibility of Superparamagnetic Nanoparticles for Drug Delivery to the Inner Ear

摘要

The inner ear is difficult to treat with therapeutic substances because of blood supply limitations and the transducing and supporting cells being bathed in inaccessible perilymphatic and endolymphatic fluids. The purpose of this study was to determine the feasibility of using external magnetic fields to pull superparamagnetic nanoparticles with an associated gene across the Round Window Membrane (RWM) and into the perilymph. Silica-encapsulated magnetite nanoparticles (Si-MNP; 30 nm diameter) were synthesized, characterized and tested for biocompatibility in a non-dividing cell model and in organotypic (three day mouse pup) Organ of Corti (OC) cultures. Particles were internalized without magnetic attraction and cells were indistinguishable from control cells. The MATH-1 gene was inserted into a plasmid with promoters to facilitate intracochlear transfection and this plasmid was tested for viability in a non-dividing cell line. Studies are ongoing to combine the plasmid with Si-MNP in a carrier nanoparticle for RWM transport and release of plasmid in the perilymph.