Environmental Engineering Reference
In-Depth Information
stabilized under physiological conditions, biocompatible and to present high mag-
netization. Magnetite (Fe
3
O
4
) and maghemite (
-Fe
2
O
3
) are the most suitable iron
oxide nanoparticles employed for biomedical applications because they are bio-
compatible, have low toxicity in the human body and show a superparamagnetic
behavior.
Therefore, synthesis of magnetic iron oxide nanoparticles with tailored proper-
ties has attracted considerable scientific and technological interest. Various synthe-
sis routes were developed for producing magnetic particles, such as
co-precipitation, microemulsion method, thermal decomposition of different
organic precursors, spray pyrolysis, and sol-gel method.
In the recent years, combustion synthesis has been often reported as a useful
method for the preparation of metal oxide nanopowders. Still, there are very few
papers dealing with combustion synthesis of Fe
3
O
4
nanopowders and virtually there
are no studies on the in vitro toxicity of the as-prepared iron oxide nanoparticles. In
2012, Iano
γ
et al. [
46
] reported a simple combustion technique for the preparation
of Fe
3
O
4
nanopowders, which is based on conducting the combustion reaction
inside a round bottom flask and evolving gases are bubbled in a beaker filled with
water.
For biomedical applications, magnetic iron oxide nanoparticles must be dis-
persed in biocompatible media in order to obtain stable colloidal suspensions. In
order to prevent the particle aggregation and to improve the biocompatibility and
stability, nanoparticles are coated with various surfactants: poly(ethylene glycol),
oleic acid, poly(acrylic acid), gluconic acid, other polymers, liposome and fatty
acids.
In this study, we investigated the influence of colloidal suspensions of magnetic
iron oxide nanoparticles on tumor (breast cancer cell line SK-BR-3) and normal
(adult bone marrow-derived mesenchymal stem cells (MSCs)) cell lines cultivated
in vitro conditions. The MNPs used for the preparation of colloidal suspensions
were synthesized using a new version of the combustion method.
As far as we know, this could be the first evaluation of the toxic effects of
combustion synthesized magnetic iron oxide nanoparticles. For comparison, mag-
netite nanoparticles were also prepared by the well-known co-precipitation route.
The influence of different concentrations on MNPs on cellular morphology, ultra-
structure expression of phenotypical markers, and viability were examined in order
to establish whether the combustion synthesized nanoparticles may be used for
in vitro and in vivo applications.
ș
7.3.2 Results and Discussion
7.3.2.1 Characterization of Fe
3
O
4
Nanoparticles
The main characteristics of iron oxide nanopowders prepared by combustion
synthesis (powder 1) and co-precipitation (powder 2) are shown in Table
7.2
.
