Get access
Advertisement

Layer-by-Layer Coated Gold Nanoparticles: Size-Dependent Delivery of DNA into Cells

Authors

  • Asmaa Elbakry,

    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    Current affiliation:
    1. Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Nasr City, Cairo, Egypt
    Search for more papers by this author
  • Eva-Christina Wurster,

    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    Search for more papers by this author
  • Alaa Zaky,

    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    Current affiliation:
    1. Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Nasr City, Cairo, Egypt
    Search for more papers by this author
  • Renate Liebl,

    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    Search for more papers by this author
  • Edith Schindler,

    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    Search for more papers by this author
  • Petra Bauer-Kreisel,

    1. Department of Trauma, Hand, Plastic and Reconstructive Surgery, University of Würzburg, 97080 Würzburg, Germany
    Search for more papers by this author
  • Torsten Blunk,

    1. Department of Trauma, Hand, Plastic and Reconstructive Surgery, University of Würzburg, 97080 Würzburg, Germany
    Search for more papers by this author
  • Reinhard Rachel,

    1. Centre for Electron Microscopy at the Institute for Anatomy, University of Regensburg, 93053 Regensburg, Germany
    Search for more papers by this author
  • Achim Goepferich,

    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    Search for more papers by this author
  • Miriam Breunig

    Corresponding author
    1. Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
    • Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany.
    Search for more papers by this author

Abstract

Because nanoparticles are finding uses in myriad biomedical applications, including the delivery of nucleic acids, a detailed knowledge of their interaction with the biological system is of utmost importance. Here the size-dependent uptake of gold nanoparticles (AuNPs) (20, 30, 50 and 80 nm), coated with a layer-by-layer approach with nucleic acid and poly(ethylene imine) (PEI), into a variety of mammalian cell lines is studied. In contrast to other studies, the optimal particle diameter for cellular uptake is determined but also the number of therapeutic cargo molecules per cell. It is found that 20 nm AuNPs, with diameters of about 32 nm after the coating process and about 88 nm including the protein corona after incubation in cell culture medium, yield the highest number of nanoparticles and therapeutic DNA molecules per cell. Interestingly, PEI, which is known for its toxicity, can be applied at significantly higher concentrations than its IC50 value, most likely because it is tightly bound to the AuNP surface and/or covered by a protein corona. These results are important for the future design of nanomaterials for the delivery of nucleic acids in two ways. They demonstrate that changes in the nanoparticle size can lead to significant differences in the number of therapeutic molecules delivered per cell, and they reveal that the toxicity of polyelectrolytes can be modulated by an appropriate binding to the nanoparticle surface.

Get access to the full text of this article

Ancillary