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Biocompatibility of Amine‐Functionalized Silica Nanoparticles: The Role of Surface Coverage
Author(s) -
Hsiao ILun,
FritschDecker Susanne,
Leidner Arnold,
AlRawi Marco,
Hug Vanessa,
Diabaté Silvia,
Grage Stephan L,
Meffert Matthias,
Stoeger Tobias,
Gerthsen Dagmar,
Ulrich Anne S.,
Niemeyer Christof M.,
Weiss Carsten
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201805400
Subject(s) - biocompatibility , silanol , surface modification , nanomaterials , amine gas treating , amorphous silica , cytotoxicity , nanoparticle , in vivo , nanotechnology , chemistry , materials science , biophysics , in vitro , chemical engineering , organic chemistry , biochemistry , catalysis , microbiology and biotechnology , engineering , biology
Here, amorphous silica nanoparticles (NPs), one of the most abundant nanomaterials, are used as an example to illustrate the utmost importance of surface coverage by functional groups which critically determines biocompatibility. Silica NPs are functionalized with increasing amounts of amino groups, and the number of surface exposed groups is quantified and characterized by detailed NMR and fluorescamine binding studies. Subsequent biocompatibility studies in the absence of serum demonstrate that, irrespective of surface modification, both plain and amine‐modified silica NPs trigger cell death in RAW 264.7 macrophages. The in vitro results can be confirmed in vivo and are predictive for the inflammatory potential in murine lungs. In the presence of serum proteins, on the other hand, a replacement of only 10% of surface‐active silanol groups by amines is sufficient to suppress cytotoxicity, emphasizing the relevance of exposure conditions. Mechanistic investigations identify a key role of lysosomal injury for cytotoxicity only in the presence, but not in the absence, of serum proteins. In conclusion, this work shows the critical need to rigorously characterize the surface coverage of NPs by their constituent functional groups, as well as the impact of serum, to reliably establish quantitative nanostructure activity relationships and develop safe nanomaterials.