Nanomaterial safety is becoming an increasingly
debatable issue that has intensified over the past several
years. The small size and particular shape, large surface
area and surface activity, which make nanomaterials
attractive in many applications, may contribute to their
toxicological profile. Regarding their safety assessment
nanomaterials cannot be treated in the same manner
as chemical compounds. Therefore, the establishment
of principles and test procedures to ensure the safe
use of nanomaterials in the marketplace is urgently
required. Magnetite nanoparticles (MNPs) are used
with the intent to be utilized in bioscience for targeted
delivery applications because they offer benefits such
as separation and gathering of materials of interest in
the presence of a magnetic force (1). Accordingly, for
such a purpose, sufficient data regarding the toxicity
and biological fate of the MNPs should be collected. In
this study synthesized MNPs with an average size of
8.0 ± 2.0 nm were evaluated for their genotoxic effect
to study their potential chronic toxicity, however the
same particles were patented to be used as a single
dose treatment for iron deficiency anemia and did not
show any apparent toxicity on experimental animals
during in vivo acute, sub-acute and chronic toxicity
testing (2). Experience with non-nano substances
taught us that mechanisms of genotoxic effects could
be diverse. Application of standard genotoxic methods
to nanomaterials and the interpretation of results are
of highest consideration. Thus a practical approach is
the use of a battery of standard genotoxicity testing
methods covering wide ranges of mechanisms (3). In
the presented work a comparative study for number of
in vitro mutagenicity and genotoxicity investigations
were performed including a bacterial reverse mutation
test (Ames test), Single Cell Gel Electrophoresis
assay (SCGE; comet assay), and standard karyotyping
detection of chromosomal aberrations. Several studies
on different types of synthesized MNPs have already
proven their biocompatibility at the cellular level (4,5),
yet detection of gene mutation and DNA damage at the
molecular level are still to be investigated.
Gentotoxicity studies on nanomaterials concluded
that the particle size and charges, concentration, coating
surfactant aggregation and surface properties of the
nanoparticles, have profound influence on interpreting
the genotoxicity testing. Small particle size (high
surface area/mass) with high absorption capacity causes
coating of the particles with proteins and nutrients from
the culture media. This could obscure the essential
nutrients for cell division in in vitro genotoxicity tests
and influence cell proliferation leading to false positive
results (6). In other cases, particles surface energy
enhances catalytic activities leading to production of
genotoxic reactive oxygen species. In the presented
study, we tried to provide some characteristics of the
chemical composition and physiochemical properties
of the synthesized MNPs to draw a valid conclusion
about their potential genetic side effects in comparison
to other studies. Our aim is to help at improving our
understanding of the underlying toxic mechanisms of
MNPs. Such findings will have practical consequences
in the risk assessment processes as well as the
biomedical applications of these substances at the
nanomaterials level.