A Dual Receptor Targeting- and BBB Penetrating- Peptide Functionalized Polyethyleneimine Nanocomplex for Secretory Endostatin Gene Delivery to Malignant Glioma

Int J Nanomedicine. 2020 Nov 12:15:8875-8892. doi: 10.2147/IJN.S270208. eCollection 2020.

Abstract

Purpose: Vascular endothelial growth factor receptor 2 (VEGFR-2) and neuropilin-1 (NRP-1) are two prominent synergistic receptors overexpressed on new blood vessels in glioma and may be promising targets for antiglioma therapy. The aim of this study was to design a dual receptor targeting and blood-brain barrier (BBB) penetrating peptide-modified polyethyleneimine (PEI) nanocomplex that can efficiently deliver the angiogenesis-inhibiting secretory endostatin gene (pVAXI-En) to treat glioma.

Materials and methods: We first constructed the tandem peptide TAT-AT7 by conjugating AT7 to TAT and evaluated its binding affinity to VEGFR-2 and NRP-1, vasculature-targeting ability and BBB crossing capacity. Then, TAT-AT7-modified PEI polymer (PPTA) was synthesized, and a pVAXI-En-loaded PPTA nanocomplex (PPTA/pVAXI-En) was prepared. The physicochemical properties, cytotoxicity, transfection efficiency, capacities to cross the BBB and BTB (blood-tumor barrier) and glioma-targeting properties of PPTA/pVAXI-En were investigated. Moreover, the in vivo anti-angiogenic behaviors and anti-glioma effects of PPTA/pVAXI-En were evaluated in nude mice.

Results: The binding affinity of TAT-AT7 to VEGFR-2 and NRP-1 was approximately 3 to 10 times greater than that of AT7 or TAT. The cellular uptake of TAT-AT7 in endothelial cells was 5-fold and 119-fold greater than that of TAT and AT7 alone, respectively. TAT-AT7 also displayed remarkable efficiency in penetrating the BBB and glioma tissue in vivo. PPTA/pVAXI-En exhibited lower cytotoxicity, stronger BBB and BTB traversing abilities, higher selective glioma targeting and better gene transfection efficiency than PEI/pVAXI-En. More importantly, PPTA/pVAXI-En significantly suppressed the tube formation and migration of endothelial cells, inhibited glioma growth, and reduced the microvasculature in orthotopic U87 glioma-bearing nude mice.

Conclusion: Our study demonstrates that PPTA/pVAXI-En can be exploited as an efficient dual-targeting nanocomplex to cross the BBB and BTB, and hence it represents a feasible and promising nonviral gene delivery system for effective glioma therapy.

Keywords: VEGFR-2 and NRP-1 targeting; anti-angiogenesis; gene delivery system; glioma penetration; multifunctional peptide.

MeSH terms

  • Animals
  • Blood-Brain Barrier / metabolism*
  • Brain Neoplasms / genetics
  • Brain Neoplasms / pathology
  • Brain Neoplasms / therapy
  • Cell Line, Tumor
  • Drug Carriers / chemistry
  • Endostatins / chemistry
  • Endostatins / genetics*
  • Genetic Therapy
  • Glioma / genetics
  • Glioma / pathology*
  • Glioma / therapy
  • Humans
  • Mice
  • Mice, Nude
  • Molecular Targeted Therapy
  • Nanostructures / chemistry*
  • Neuropilin-1 / metabolism*
  • Peptides / chemistry*
  • Permeability
  • Polyethyleneimine / chemistry*
  • Transfection
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism*

Substances

  • Drug Carriers
  • Endostatins
  • Peptides
  • Neuropilin-1
  • Polyethyleneimine
  • Vascular Endothelial Growth Factor Receptor-2

Grants and funding

This work was supported by the National Natural Science Foundation of China grant [grant numbers 81302686]; the Primary Research & Development Plan of Shandong Province [grant number 2016GSF201083]; and the Major Project of Science and Technology of Shandong Province [grant number 2015ZDJS04001].