A novel approach for targeted delivery to motoneurons using cholera toxin-B modified protocells

Maria A. Gonzalez Porras, Paul N. Durfee, Ashley M. Gregory, Gary C. Sieck, C. Jeffrey Brinker, Carlos B. Mantilla

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Background Trophic interactions between muscle fibers and motoneurons at the neuromuscular junction (NMJ) play a critical role in determining motor function throughout development, ageing, injury, or disease. Treatment of neuromuscular disorders is hindered by the inability to selectively target motoneurons with pharmacological and genetic interventions. New method We describe a novel delivery system to motoneurons using mesoporous silica nanoparticles encapsulated within a lipid bilayer (protocells) and modified with the atoxic subunit B of the cholera toxin (CTB) that binds to gangliosides present on neuronal membranes. Results CTB modified protocells showed significantly greater motoneuron uptake compared to unmodified protocells after 24 h of treatment (60% vs. 15%, respectively). CTB-protocells showed specific uptake by motoneurons compared to muscle cells and demonstrated cargo release of a surrogate drug. Protocells showed a lack of cytotoxicity and unimpaired cellular proliferation. In isolated diaphragm muscle-phrenic nerve preparations, preferential axon terminal uptake of CTB-modified protocells was observed compared to uptake in surrounding muscle tissue. A larger proportion of axon terminals displayed uptake following treatment with CTB-protocells compared to unmodified protocells (40% vs. 6%, respectively). Comparison with existing method(s) Current motoneuron targeting strategies lack the functionality to load and deliver multiple cargos. CTB-protocells capitalizes on the advantages of liposomes and mesoporous silica nanoparticles allowing a large loading capacity and cargo release. The ability of CTB-protocells to target motoneurons at the NMJ confers a great advantage over existing methods. Conclusions CTB-protocells constitute a viable targeted motoneuron delivery system for drugs and genes facilitating various therapies for neuromuscular diseases.

Original languageEnglish (US)
Pages (from-to)160-174
Number of pages15
JournalJournal of Neuroscience Methods
StatePublished - Nov 1 2016


  • Cholera toxin B
  • Diaphragm
  • Drug delivery system
  • Mesoporous silica nanoparticles
  • Motoneurons
  • Nanoparticles
  • Nanotechnology
  • Neuromuscular junction
  • Phrenic nerve

ASJC Scopus subject areas

  • General Neuroscience


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