TARGETING MAGNETIC NANOCARRIERS IN THE HEAD FOR DRUG DELIVERY AND BIOSENSING APPLICATIONS

Magnetic nanocarriers have proven to be effective vehicles for transporting therapeutic and diagnostic agents in the body. Their main advantage is their ability to be manipulated by external magnets to direct them to specific targets in the body. In this dissertation, I study the transport, safety and efficacy of moving drug coated magnetic nanocarriers in different types of tissue. Movement of magnetic nanocarriers of sizes ranging from 100 nm to 1µm with different biocompatible coatings (Starch, PEG, Lipid and Chitosan) was quantified in different tissue types using an automated cryostat system. The safety of moving magnetic nanocarriers in live rodent brain tissue was assessed using electrophysiology, calcium imaging and immunohistochemistry. Moving magnetic nanocarriers in brain tissue did not significantly affect the firing ability of single neurons, synaptic connectivity and the overall functioning of the neuron network. As part of efficacy studies, steroid-eluting magnetic nanoparticles were targeted using external magnets to the inner ear of mice to counter hearing loss caused by cisplatin chemotherapeutics. This targeted steroid delivery to the cochlea significantly reduced the change in hearing threshold at 32 KHz caused by cisplatin injections and protected the hair cells from significant damage. Finally, I explore the potential of spin-transfer torque nano-oscillators, which are multi-layered ferromagnetic nanocarriers, as high-resolution in vivo wireless biosensors. These nanocarriers have been shown to detect action potentials from crayfish lateral giant neurons and that the microwave magnetic signals from these devices can be detected wirelessly by near field induction