Multifunctional Peptide-PEG Intercalating Conjugates: Programmatic of Gene Delivery to the Blood-Brain Barrier



To enhance transfection efficacy of pDNA through the application of multifunctional peptide-PEG-tris-acridine conjugates (pPAC) and the formation of biodegradable core-shell polyplexes for gene delivery to the blood-brain barrier (BBB).


pPAC-mediated transfection was compositionally optimized in mouse BBB cells (bEnd.3). Cellular uptake and trafficking, and brain accumulation of pDNA was evaluated by fluorescent imaging and histochemistry. We constructed anti-MRP4 siRNA-producing vectors and evaluated the efficacy of MRP4 down-regulation of MRP4 by Western blot and qPCR, and its effect on the uptake of 3H-AZT, an MRP4 substrate.


A core-shell gene delivery system (GDS) was assembled from pDNA and pPAC, carrying multifunctional peptides with NLS, TAT, and brain-specific BH, or ApoE sequences, and biodegradable pLPEI polyamine. This GDS demonstrated better cellular and nuclear accumulation, and a 25-fold higher transfection efficacy in slow-dividing bEnd.3 cells compared to ExGen500. Inclusion of brain-targeting pPAC enhanced in vivo accumulation of functional pDNA in brain capillaries. Treatment by encapsulated anti-MRP4 siRNA-producing pDNA caused transient down-regulation of MRP4, and, after intravenous injection in Balb/c mice, enhanced AZT uptake in the brain by 230–270%.


The pPAC represent novel efficient components of GDS that could find various gene therapy applications, including genetic modulation of the BBB.

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Apolipoprotein E-derived peptide


blood-brain barrier


brain capillary endothelial cells


brain-homing peptide


bovine serum albumin




drug efflux transporters


dynamic light scattering


chemoluminescence detection kit


gene delivery system


green fluorescent protein


highly active antiretroviral therapy


high performance liquid chromatography


linear polyethylenimine


SV40 nuclear localization signal peptide


Nucleoside reverse transcriptase inhibitors


Polyacrylamide gel electrophoresis


Poly(ethylene glycol)


HIV-1 trans-activator of transcription peptide


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This work was supported by NIH grants NS050660 and NS063879 (S.V.V.). Authors are grateful to Mrs. Huai-Yun Han, Arin Zeman, and Galya Warren for excellent technical help in conducting some experiments. The assistance of UNMC Confocal Microscopy and Protein Analysis Core facilities is greatly appreciated.

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Correspondence to Serguei V. Vinogradov.

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Zhang, H., Gerson, T., Varney, M.L. et al. Multifunctional Peptide-PEG Intercalating Conjugates: Programmatic of Gene Delivery to the Blood-Brain Barrier. Pharm Res 27, 2528–2543 (2010).

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  • ApoE peptide
  • AZT
  • blood-brain barrier
  • brain capillary endothelial cells
  • brain-homing peptide
  • intercalating complex
  • MRP4
  • NLS peptide
  • peptide-PEG conjugate
  • plasmid DNA
  • TAT peptide