Distribution of polymer nanoparticles by convection-enhanced delivery to brain tumors

J Control Release. 2016 Jun 28;232:103-12. doi: 10.1016/j.jconrel.2016.04.006. Epub 2016 Apr 8.


Glioblastoma multiforme (GBM) is a fatal brain tumor characterized by infiltration beyond the margins of the main tumor mass and local recurrence after surgery. The blood-brain barrier (BBB) poses the most significant hurdle to brain tumor treatment. Convection-enhanced delivery (CED) allows for local administration of agents, overcoming the restrictions of the BBB. Recently, polymer nanoparticles have been demonstrated to penetrate readily through the healthy brain when delivered by CED, and size has been shown to be a critical factor for nanoparticle penetration. Because these brain-penetrating nanoparticles (BPNPs) have high potential for treatment of intracranial tumors since they offer the potential for cell targeting and controlled drug release after administration, here we investigated the intratumoral CED infusions of PLGA BPNPs in animals bearing either U87 or RG2 intracranial tumors. We demonstrate that the overall volume of distribution of these BPNPs was similar to that observed in healthy brains; however, the presence of tumors resulted in asymmetric and heterogeneous distribution patterns, with substantial leakage into the peritumoral tissue. Together, our results suggest that CED of BPNPs should be optimized by accounting for tumor geometry, in terms of location, size and presence of necrotic regions, to determine the ideal infusion site and parameters for individual tumors.

Keywords: Convection-enhanced delivery (CED); Poly(lactide-co-glycolide); Polymer nanoparticles.

MeSH terms

  • Animals
  • Brain / metabolism
  • Brain / pathology
  • Brain Neoplasms / drug therapy
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Cell Line, Tumor
  • Convection*
  • Drug Delivery Systems*
  • Glioblastoma / drug therapy
  • Glioblastoma / metabolism
  • Green Fluorescent Proteins / administration & dosage
  • Green Fluorescent Proteins / pharmacokinetics
  • Humans
  • Lactic Acid / administration & dosage*
  • Male
  • Nanoparticles / administration & dosage*
  • Polyglycolic Acid / administration & dosage*
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Rats, Inbred F344
  • Rats, Nude
  • Rats, Sprague-Dawley
  • Tumor Burden


  • Green Fluorescent Proteins
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid