Corona Composition Can Affect the Mechanisms Cells Use to Internalize Nanoparticles

Nanosized
objects, such as nanoparticles and other drug carriers
used in nanomedicine, once in contact with biological environments
are modified by adsorption of biomolecules on their surface. The presence
of this corona strongly affects the following interactions at cell
and organism levels. It has been shown that corona proteins can be
recognized by cell receptors. However, it is not known whether the
composition of this acquired layer can also affect the mechanisms
nanoparticles use to enter cells. This is of particular importance
when considering that the same nanoparticles can form different coronas
for instance in vitro when exposed to cells in different
serum amounts or in vivo depending on the exposure
or administration route. Thus, in this work, different coronas were
formed on 50 nm silica by exposing them to different serum concentrations.
The uptake efficiency in HeLa cells was compared, and the uptake mechanisms
were characterized using transport inhibitors and RNA interference.
The results showed that the nanoparticles were internalized by cells via different mechanisms when different coronas were formed,
and only for one corona condition was uptake mediated by the LDL receptor.
This suggested that coronas of different composition can be recognized
differently by cell receptors, and this in turn leads to internalization via different mechanisms. Similar studies were performed
using other cells, including A549 cells and primary HUVEC, and different
nanoparticles, namely 100 nm liposomes and 200 nm silica. Overall,
the results confirmed that the corona composition can affect the mechanisms
of nanoparticle uptake by cells.