Biomedical Engineering Reference
In-Depth Information
The adsorption of albumin on single-wall carbon nanotube and silica
nanoparticles showed an anti-inflammatory response in the macrophages.
Pre-coating with Pluronic F127 prevents the adsorption of albumin and hence
decreased the anti-inflammatory properties [
4
]. These studies should be considered
as preliminary investigation, and more studies are required to better understand the
role of each protein in the corona and the cumulative effects of the entire corona on
the biological response of nanoparticles.
The interaction of nanoparticles with blood proteins can cause contact toxicity in
the form of thrombosis and hypersensitivity [
36
,
37
]. There are indications that the
biocompatibility of a material is improved when the surface favors albumin adsorp-
tion [
38
], and NP can reside more time in contact with biological entities enhancing
their possible therapeutic or diagnostic uses. However, making NP invisible to the
immune system and more penetrating may also alter their toxicity profile. Antibody
experiments show that anti-BSA recognizes BSA at the NP surface.
3.5 Protein Denature or Fibrillation
The nanoparticle can influence the protein fibrillation process [
4
]. Amyloidogenic
proteins are a group of proteins which under certain conditions can form insoluble
fibrils. The aggregated fibrils precipitate as plaques. These aggregates are the
source of protein-misfolded diseases such as Alzheimer, Parkinson, and dialysis-
related amyloidosis. There are some reports of enhancement of fibrillation of
amyloidogenic protein
-2-microglobulin at acidic condition due to the presence
of carbon nanotube, cerium oxide, and poly(ethylene glycol) (PEG)-coated quan-
tum dots [
4
]. Thioflavin T is an effective fibrillation assay. The binding of thioflavin
T to protein will induce fluorescence property which can be detected easily.
Nanoparticles in some cases have inhibited the fibrillation. Hydrated fullerene
(C60) in animal studies showed anti-amyloidogenic properties by inhibiting the
fibrillation of amyloid-beta 25-35 peptide [
39
]. This is very promising for more
investigation of nanoparticles as a cure of hard-to-treat diseases such as Alzheimer
and Parkinson. It is also shown that slight temperature changes (i.e., in the physio-
logical range) can have a crucial effect on the protein fibrillation process [
40
]. The
amino acid sequence of 17-24 (i.e., KLVFFAED) amyloid-beta monomers, which
is recognized as main hydrophobic backbone, has a crucial role in the fibrillation
process [
41
]; in this case, both experimental (using monoclonal antibody) and
molecular dynamic (MD) simulation methods confirmed the better availability/
exposure of this sequence at higher physiological temperatures compared to the
lower temperature (see Fig.
3.5
). Using various types of nanoparticles, the “dual”
fibrillation kinetics can be observed; for instance, it was revealed that hydrophobic
nanoparticles (e.g., polystyrene) have the capability to show dual effects (e.g.,
acceleratory and inhibitory) on fibrillation process by slight
β
temperature
