Nanostructure and biomolecule interactions: Characterizing the complex

Stefan Gunnarsson

Research output: ThesisDoctoral Thesis (compilation)

220 Downloads (Pure)


This thesis presents the results of studies done on various biomolecules and their interactions with nanomaterials. The biomolecule sources are everything from purified, single proteins to the complicated mixture of blood serum and cell culture media. Similarly, the nanomaterial sources vary from spherical titanium dioxide, gold, and polystyrene nanoparticles to novel nanowires of gallium arsenide or gallium phosphide. Regardless of the biomolecules or nanomaterials, they interact in ways that require careful characterization in case the environment and organisms are exposed to theses increasingly common materials. The adsorbed protein layer on a nanostructure is called the protein corona and the nanomaterial together with its adsorbed biomolecules is called a complex.
We show that when titanium dioxide nanoparticles are mixed with blood serum, a broad range of complex sizes are formed.
Traditionally, the protein corona has been considered homogeneous for specific nanoparticle and serum concentration ratio.
However, our results show that the corona varies with the complexes’ size.
We also look at the effect protein has on very low concentration of 20 nm gold nanoparticles in cell culture medium. Using a
combination of analytical techniques, we show that in protein enriched cell culture medium, the nanoparticles are stable. In cell
culture medium without added protein, the nanoparticles aggregate slowly. We describe the aggregation rate and the aggregate
morphology and identify arginine, an aggregation inducing amino acid in the biomolecular corona.
Furthermore, we study the binding of purified proteins on nanowires by cryo-transmission electron microscopy, X-ray based
analytical techniques, and by changes in the sedimentation rate of nanowires with and without adsorbed protein layer. By rotating
the electron microscope stage during imaging, we can image irregularities in the protein corona formed by the large, cross shaped protein laminin.
Finally, we study the effect of various nanostructures on the activity of the enzyme myeloperoxidase. The nanostructures’ effect
was highly dependent on the complexity of the environment. The effect ranged from almost total inactivation to increasing the
activity up to three-fold.
Original languageEnglish
Awarding Institution
  • Department of Chemistry
  • Cedervall, Tommy, Supervisor
  • Snogerup-Linse, Sara, Supervisor
  • Mikkelsen, Anders, Supervisor
Award date2018 Oct 10
Place of PublicationLund
Print ISBNs978-91-7422-592-1
Electronic ISBNs978-91-7422-601-0
Publication statusPublished - 2018 Sep

Bibliographical note

Defence details
Date: 2018-10-10
Time: 10:00
Place: Kemicentrum Lecture Hall B, Naturvetarvägen 14, Lund
External reviewer(s)
Name: Höök, Fredrik
Title: Professor
Affiliation: Biological Physics, Department of Physics, Chalmers University of Technology, Sweden

Subject classification (UKÄ)

  • Biochemistry and Molecular Biology


  • Nanostructures
  • Proteins
  • Lipids
  • Protein corona
  • Aggregation
  • Sedimentation
  • Diffusion
  • Electron microscopy
  • Enzyme activity
  • Nanowires
  • Nanoparticles


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