Measuring Drug Release Induced by Thermal and Non-thermal Effects of Ultrasound in a Nanodrug Delivery System

In this work, a dialysis membrane experiment was performed to determine release rates from doxorubicin (DOX)-loaded gold nanoparticles (GNPs) for two treatments: (1) mechanical stimulation with a low intensity pulsed ultrasound (LIPUS) transducer (non-thermal DOX release), and (2) heating with a hot water bath (thermal DOX release). DOX release was quantified by performing a fluorescence-to-concentration calibration, and curve-fitting techniques were applied to study DOX release rate kinetics for thermal and non-thermal release. For both thermal and non-thermal release rate data a second order exponential fit was found to show good agreement. From this, a release rate equation for thermal and non-thermal mechanisms of LIPUS-induced DOX release from GNP drug carriers was established.