In vivo Targeted Drug Delivery to the Brain using MRI Guidance of Focused Ultrasound
Treat L, McDannold N, Hynynen K, Vykhodtseva N, Zhang Y, Tam K
Harvard Medical School and Brigham & Women's Hospital, Harvard-MIT Division of Health Sciences and Technology
We investigated the effect of focused ultrasound on the absorption of liposome-encapsulated doxorubicin in the rodent brain and the use of MRI as an indicator of blood-brain barrier permeability. By applying focused ultrasound in the presence of microbubbles, we achieved targeted drug delivery to the brain in vivo. Tissue drug concentrations in sonicated brain were significantly different from unexposed control samples (p = 0.01) and corresponded with cytotoxic levels measured in various human tumors. Increased MR signal enhancement at the focal location on contrast-enhanced T1w FSE images correlated with increased penetration of doxorubicin into brain tissue (r = 0.85).