Gene delivery to the spinal cord using MRI-guided focused ultrasound

Gene Ther. 2015 Jul;22(7):568-77. doi: 10.1038/gt.2015.25. Epub 2015 Apr 23.

Abstract

Non-invasive gene delivery across the blood-spinal cord barrier (BSCB) remains a challenge for treatment of spinal cord injury and disease. Here, we demonstrate the use of magnetic resonance image-guided focused ultrasound (MRIgFUS) to mediate non-surgical gene delivery to the spinal cord using self-complementary adeno-associated virus serotype 9 (scAAV9). scAAV9 encoding green fluorescent protein (GFP) was injected intravenously in rats at three dosages: 4 × 10(8), 2 × 10(9) and 7 × 10(9) vector genomes per gram (VG g(-1)). MRIgFUS allowed for transient, targeted permeabilization of the BSCB through the interaction of focused ultrasound (FUS) with systemically injected Definity lipid-shelled microbubbles. Viral delivery at 2 × 10(9) and 7 × 10(9) VG g(-1) leads to robust GFP expression in FUS-targeted regions of the spinal cord. At a dose of 2 × 10(9) VG g(-1), GFP expression was found in 36% of oligodendrocytes, and in 87% of neurons in FUS-treated areas. FUS applications to the spinal cord could address a long-term goal of gene therapy: delivering vectors from the circulation to diseased areas in a non-invasive manner.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dependovirus
  • Genetic Therapy*
  • Green Fluorescent Proteins / genetics*
  • Green Fluorescent Proteins / metabolism
  • Magnetic Resonance Imaging / methods
  • Male
  • Neurons / metabolism
  • Oligodendroglia
  • Rats, Wistar
  • Spinal Cord / immunology
  • Spinal Cord / metabolism*
  • Spinal Cord Diseases / genetics
  • Spinal Cord Diseases / therapy*
  • Ultrasonography / methods

Substances

  • Green Fluorescent Proteins