Biomedical Engineering Reference
In-Depth Information
The conjugation of pristine BCN-nanoparticles to those of BCN-nanoparticles
exposed to protein media that mimic in vitro culture conditions (i.e., medium with
10 % serum) and the biological fluids present in vivo (i.e
.
, 100 % serum) were
compared. The fluorescence microscopy images confirmed a high number of the
pristine BCN-NPs conjugated to the azide-functionalized substrate, whereas there
were few 10 % or 100 % serum corona BCN-NPs that had attached to the azide-
functionalized substrates. Using quantitative analysis, it was found that the number
of conjugated nanoparticles and therefore the targeting efficiencies for the 10 % and
100 % serum corona BCN-NPs were lower than that of the pristine BCN-
nanoparticles by 94 and 99 %, respectively (see Fig.
3.7
for details) [
44
].
The protein corona can also reduce the capability of contrast agents [
45
]. To
probe the effects of a protein corona on the MRI contrast efficiency, the interactions
of proteins with superparamagnetic iron oxide NPs (SPIONs) with various surface
chemistries and sizes were explored [
45
]. It was observed that the different physi-
cochemical characteristics of the dextran coatings on the SPIONs lead to the
formation of protein corona of different composition. It was revealed that the
transverse relaxivity, which determines the efficiency of negative contrast agents,
was very much dependent on the functional group and the surface charge of the
SPIONs coating. The presence of the protein corona did not alter the relaxivity of
plain SPIONs, while it slightly increased the relaxivity of the negatively charged
SPIONs and dramatically decreased the relaxivity of the positively charged ones,
which was coupled with the formation of particle agglomerates in the presence of
the proteins in this case [
45
].
3.7 Conclusion
Based on the aforementioned results, one can conclude that the field of protein
corona and its applications is still in its childhood and very poorly understood.
There are also several new issues (e.g., slight temperature changes and cell vision
effect) which should be considered in details during future investigations.
Fig. 3.7
(continued) NP delivery; the protein corona covers the targeting ligands on the NP,
preventing the ligands from binding to their targets on the CM. (
C
) Fluorescence microscopy
images of 5 mm by 5 mm silicon substrates after incubation with pristine BCN-NPs and those
coated with a protein corona. (a) Little non-specific binding of pristine BCN-NPs to the azide-free
substrate occurred. (b) Numerous pristine BCN-NPs were conjugated to the azide-functionalized
substrate. (c and d) Few 10 % (c) or 100 % (d) corona BCN-NPs were visible on the azide-
functionalized substrates.
Arrows
designate individual NPs (Adapted from [
44
])
