Pharmaceutical Research

, Volume 30, Issue 7, pp 1758–1767 | Cite as

Surface Analysis of PEGylated Nano-Shields on Nanoparticles Installed by Hydrophobic Anchors

  • M. F. Ebbesen
  • B. Whitehead
  • B. Ballarin-Gonzalez
  • P. Kingshott
  • K. A. Howard
Research Paper



This work describes a method for functionalisation of nanoparticle surfaces with hydrophilic “nano-shields” and the application of advanced surface characterisation to determine PEG amount and accumulation at the outmost 10 nm surface that is the predominant factor in determining protein and cellular interactions.


Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were prepared with a hydrophilic PEGylated “nano-shield” inserted at different levels by hydrophobic anchoring using either a phospholipid-PEG conjugate or the copolymer PLGA-block-PEG by an emulsification/diffusion method. Surface and bulk analysis was performed including X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance spectroscopy (NMR) and zeta potential. Cellular uptake was investigated in RAW 264.7 macrophages by flow cytometry.


Sub-micron nanoparticles were formed and the combination of (NMR) and XPS revealed increasing PEG levels at the particle surface at higher PLGA-b-PEG copolymer levels. Reduced cellular interaction with RAW 264.7 cells was demonstrated that correlated with greater surface presentation of PEG.


This work demonstrates a versatile procedure for decorating nanoparticle surfaces with hydrophilic “nano-shields”. XPS in combination with NMR enabled precise determination of PEG at the outmost surface to predict and optimize the biological performance of nanoparticle-based drug delivery.


nanoparticles PEG stealth surface analysis XPS 



We thank the Lundbeck Foundation for supporting this work through the grant: Lundbeck Foundation Nanomedicine Center for Individualised Management of Tissue Damage and Regeneration.


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • M. F. Ebbesen
    • 1
  • B. Whitehead
    • 1
  • B. Ballarin-Gonzalez
    • 1
  • P. Kingshott
    • 2
  • K. A. Howard
    • 1
  1. 1.Interdisciplinary Nanoscience Center (iNANO) Department of Molecular Biology and GeneticsUniversity of AarhusAarhus CDenmark
  2. 2.Industrial Research Institute Swinburne (IRIS)Faculty of Engineering & Industrial SciencesSwinburne University of TechnologyHawthornAustralia

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