title: Drug delivery across the blood-brain barrier using focused ultrasound.
abstract: BACKGROUND
  The presence of the blood-brain barrier (BBB) is a significant impediment to the delivery of therapeutic agents to the brain for treatment of brain diseases. Focused ultrasound (FUS) has been developed as a noninvasive method for transiently increasing the permeability of the BBB to promote drug delivery to targeted regions of the brain.
  
  
  METHODS
  The present review briefly compares the methods used to promote drug delivery to the brain and describes the benefits and limitations of FUS technology. We summarize the experimental data which shows that FUS, combined with intravascular microbubbles, increases therapeutic agent delivery into the brain leading to significant reductions in pathology in preclinical models of disease. The potential for translation of this technology to the clinic is also discussed.
  
  
  CONCLUSIONS
  The introduction of magnetic resonance imaging guidance and intravascular administration of microbubbles to FUS treatments permits the consistent, transient and targeted opening of the BBB. The development of feedback systems and real-time monitoring techniques improve the safety of BBB opening. Successful clinical translation of FUS has the potential to revolutionize the treatment of brain disease resulting in effective, less-invasive treatments without the need for expensive drug development.
authors.affiliation: Sunnybrook Research Institute, Physical Sciences , 2075 Bayview Avenue, S665, Toronto, ON M4N 3M5 , Canada +1 416 480 5765 ; khynynen@sri.utoronto.ca.
authors.forename: Alison
authors.initials: A
authors.lastname: Burgess
authors.forename: Kullervo
authors.initials: K
authors.lastname: Hynynen
mesh_terms: D001692:Biological Transport; D001812:Blood-Brain Barrier / Q000187:drug effects; D001921:Brain / Q000187:drug effects*; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D004364:Pharmaceutical Preparations