Endosomal escape cell-penetrating peptides significantly enhance pharmacological effectiveness and CNS activity of systemically administered antisense oligonucleotides

Mohadeseh Dastpeyman, Ramin Sharifi, Azin Amin, John A. Karas, Brittany Cuic, Yijun Pan, Joseph A. Nicolazzo, Bradley J. Turner, Fazel Shabanpoor

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)


Antisense oligonucleotides (ASOs) are an emerging class of gene-specific therapeutics for diseases associated with the central nervous system (CNS). However, ASO delivery across the blood–brain barrier (BBB) to their CNS target cells remains a major challenge. Since ASOs are mainly taken up into the brain capillary endothelial cells interface through endosomal routes, entrapment in the endosomal compartment is a major obstacle for efficient CNS delivery of ASOs. Therefore, we evaluated the effectiveness of a panel of cell-penetrating peptides (CPPs) bearing several endosomal escape domains for the intracellular delivery, endosomal release and antisense activity of FDA-approved Spinraza (Nusinersen), an ASO used to treat spinal muscular atrophy (SMA). We identified a CPP, HA2-ApoE(131–150), which, when conjugated to Nusinersen, showed efficient endosomal escape capability and significantly increased the level of full-length functional mRNA of the survival motor neuron 2 (SMN2) gene in SMA patient-derived fibroblasts. Treatment of SMN2 transgenic adult mice with this CPP-PMO conjugate resulted in a significant increase in the level of full-length SMN2 in the brain and spinal cord. This work provides proof-of-principle that integration of endosomal escape domains with CPPs enables higher cytosolic delivery of ASOs, and more importantly enhances the efficiency of BBB-permeability and CNS activity of systemically administered ASOs.

Original languageEnglish
Article number120398
Number of pages10
JournalInternational Journal of Pharmaceutics
Publication statusPublished - 15 Apr 2021


  • Antisense oligonucleotides
  • Antisense Therapy
  • Blood-brain barrier
  • Cell-penetrating peptides
  • Endosomal escape

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