Pharmaceutical Research

, Volume 25, Issue 11, pp 2657–2665 | Cite as

Can Ultrasound Solve the Transport Barrier of the Neural Retina?

  • Liesbeth Peeters
  • Ine Lentacker
  • Roosmarijn E. Vandenbroucke
  • Bart Lucas
  • Joseph Demeester
  • Niek N. Sanders
  • Stefaan C. De Smedt
Research Paper



Intravitreal injection of nonviral gene complexes may be promising in the treatment of retinal diseases. This study investigates the permeation of lipoplexes and polystyrene nanospheres through the neural retina and their uptake by the retinal pigment epithelium (RPE) either with or without ultrasound application.

Materials and Methods

Anterior parts and vitreous of bovine eyes were removed. The neural retina was left intact or peeled away from the RPE. (Non)pegylated lipoplexes and pegylated nanospheres were applied. After 2 h incubation, the RPE cells were detached and analyzed for particle uptake by flow cytometry and confocal microscopy.


The neural retina is a significant transport barrier for pegylated nanospheres and (non)pegylated lipoplexes. Applying ultrasound improved the permeation of the nanoparticles up to 130 nm.


Delivery of liposomal DNA complexes to the RPE cells is strongly limited by the neural retina. Ultrasound energy may be a useful tool to improve the neural retina permeability, given the nucleic acid carriers are small enough. Our results underline the importance to design and develop very small carriers for the delivery of nucleic acids to the neural retina and the RPE after intravitreal injection.


lipoplexes non viral gene therapy ocular drug delivery pegylation ultrasound 



This work was supported by a grant from the Fund for Research in Ophthalmology Belgium. The post-doctoral fellowship of N.N. Sandres is supported by the Fund for Scientific Research (FWO). The authors like to thank Caroline Vandenbroecke, Christophe Delaye, Bart Leroy and Jan Philippé for their contribution. We acknowledge Ghent University (BOF) and FP7 of the European Union for financial support.


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Liesbeth Peeters
    • 1
  • Ine Lentacker
    • 1
  • Roosmarijn E. Vandenbroucke
    • 1
  • Bart Lucas
    • 1
  • Joseph Demeester
    • 1
  • Niek N. Sanders
    • 1
  • Stefaan C. De Smedt
    • 1
  1. 1.Laboratory of General Biochemistry and Physical PharmacyGhent UniversityGhentBelgium

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