Real-Time, in Vivo Correlation of Molecular Structure with Drug Distribution in the Brain Striatum Following Convection Enhanced Delivery

ACS Chem Neurosci. 2019 May 15;10(5):2287-2298. doi: 10.1021/acschemneuro.8b00607. Epub 2019 Mar 6.


The blood-brain barrier (BBB) represents a major obstacle in delivering therapeutics to brain lesions. Convection-enhanced delivery (CED), a method that bypasses the BBB through direct, cannula-mediated drug delivery, is one solution to maintaining increased, effective drug concentration at these lesions. CED was recently proven safe in a phase I clinical trial against diffuse intrinsic pontine glioma (DIPG), a childhood cancer. Unfortunately, the exact relationship between drug size, charge, and pharmacokinetic behavior in the brain parenchyma are difficult to observe in vivo. PET imaging of CED-delivered agents allows us to determine these relationships. In this study, we label different modifications of the PDGFRA inhibitor dasatinib with fluorine-18 or via a nanofiber-zirconium-89 system so that the effect of drug structure on post-CED behavior can accurately be tracked in vivo, via PET. Relatively unchanged bioactivity is confirmed in patient- and animal-model-derived cell lines of DIPG. In naïve mice, significant individual variability in CED drug clearance is observed, highlighting a need to accurately understand drug behavior during clinical translation. Generally, the half-life for a drug to clear from a CED site is short for low molecular weight dasatinib analogs that bare different charge; 1-3 (1, 32.2 min (95% CI: 27.7-37.8), 2, 44.8 min (27.3-80.8), and 3, 71.7 min (48.6-127.6) minutes) and is much longer for a dasatinib-nanofiber conjugate, 5, (42.8-57.0 days). Positron emission tomography allows us to accurately measure the effect of drug size and charge in monitoring real-time drug behavior in the brain parenchyma of live specimens.

Keywords: DIPG; PET-labeling; convection-enhanced delivery; drug design.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacokinetics*
  • Antineoplastic Agents / therapeutic use
  • Blood-Brain Barrier / drug effects*
  • Blood-Brain Barrier / metabolism
  • Brain Stem Neoplasms / drug therapy
  • Brain Stem Neoplasms / metabolism
  • Brain Stem Neoplasms / pathology
  • Cell Line
  • Cell Proliferation / drug effects
  • Corpus Striatum / drug effects*
  • Corpus Striatum / metabolism
  • Dasatinib / pharmacokinetics*
  • Dasatinib / therapeutic use
  • Diffuse Intrinsic Pontine Glioma / drug therapy
  • Diffuse Intrinsic Pontine Glioma / metabolism
  • Diffuse Intrinsic Pontine Glioma / pathology
  • Drug Delivery Systems
  • Humans
  • Mice
  • Molecular Structure
  • Tissue Distribution


  • Antineoplastic Agents
  • Dasatinib