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Interaction with Human Serum Proteins Reveals Biocompatibility of Phosphocholine-Functionalized SPIONs and Formation of Albumin-Decorated Nanoparticles
journal contribution
posted on 2020-07-03, 16:33 authored by Irene Russo Krauss, Alessandra Picariello, Giuseppe Vitiello, Augusta De Santis, Alexandros Koutsioubas, Judith E. Houston, Giovanna Fragneto, Luigi PaduanoNanoparticles
(NPs) are increasingly exploited as diagnostic and
therapeutic devices in medicine. Among them, superparamagnetic nanoparticles
(SPIONs) represent very promising tools for magnetic resonance imaging,
local heaters for hyperthermia, and nanoplatforms for multimodal imaging
and theranostics. However, the use of NPs, including SPIONs, in medicine
presents several issues: first, the encounter with the biological
world and proteins in particular. Indeed, nanoparticles can suffer
from protein adsorption, which can affect NP functionality and biocompatibility.
In this respect, we have investigated the interaction of small SPIONs
covered by an amphiphilic double layer of oleic acid/oleylamine and
1-octadecanoyl-sn-glycero-3-phosphocholine with two
abundant human plasma proteins, human serum albumin (HSA) and human
transferrin. By means of spectroscopic and scattering techniques,
we analyzed the effect of SPIONs on protein structure and the binding
affinities, and only found strong binding in the case of HSA. In no
case did SPIONs alter the protein structure significantly. We structurally
characterized HSA/SPIONs complexes by means of light and neutron scattering,
highlighting the formation of a monolayer of protein molecules on
the NP surface. Their interaction with lipid bilayers mimicking biological
membranes was investigated by means of neutron reflectivity. We show
that HSA/SPIONs do not affect lipid bilayer features and could be
further exploited as a nanoplatform for future applications. Overall,
our findings point toward a high biocompatibility of phosphocholine-decorated
SPIONs and support their use in nanomedicine.