Radio Frequency Stimulation of Gold Nanoparticles For Improved Brain Drug Delivery

The ability to externally stimulate gold nanoparticles (GNPs) that are linked to drugs can improve targeted drug delivery to help patients with Parkinson’s disease to increase the activity levels of their basal ganglia to regain motor skills that were once lost. This paper analyzes 5 nm GNPs due to their biocompatibility and ability to cross the blood-brain barrier (BBB). Studies have shown GNPs heat up when exposed to radiofrequency (RF) electromagnetic fields which could be used to release dopamine-related drugs directly in a patient’s basal ganglia to increase activity. However, GNP stimulation often requires a high power output which could damage tissues. A series of methods were used to first characterize the GNPs to ensure the size and viability of the sample. Then, different stimulation tests were run to evaluate the temperature change of GNPs to determine if stimulation is possible in a frequency range that does not require a high power output. The most successful stimulation method utilized a waveguide, which was able to consistently heat GNPs 0.4 C in 15 minutes more than the negative control. The methodology was then tested within the brain of a perfused rat by using magnetic resonance thermometry (MRT). Two scans were taken at different times to solve for the differential pixel value to evaluate whether the brain cooled down over time after being theoretically stimulated initially. While the initial results of these scans were inconclusive, there was much to be improved throughout the process, warranting further research.