Disruption of the Blood-Spinal Cord Barrier using Low-Intensity Focused Ultrasound in a Rat Model

This study introduces a method for disrupting the blood-spinal cord barrier (BSCB) in rats using low-intensity focused ultrasound (LIFU). The technique involves using ultrasonic pulsations at lower intensities than ultrasound and is being tested as a reversible and precise neuromodulatory technology. The method involves administering microbubbles (MBs) intravenously, followed by LIFU sonication to create transient gaps in the capillaries of the spinal cord, allowing substances like drugs to penetrate into the spinal parenchyma. The confirmation of BSCB disruption is visually evaluated by observing the extravasation of Evans blue dye (EBD) into the spinal cord, identifiable by its rich blue color.

• 1
  The concurrent application of LIFU sonication and MB administration is an effective technique for localized BSCB disruption, indicated by the presence of EBD extravasation into the spinal parenchyma.
• 2
  All rats that received MB administration and LIFU sonication show apparent extravasation of EBD into the spinal cord, while negative controls that received MBs and EBD with no LIFU sonication do not.
• 3
  H&E analysis revealed no neuronal damage, hemorrhage, or cavity lesions present in the sonicated locations, supporting the safety of this procedure.