Biomedical Engineering Reference
In-Depth Information
(Gratton et al. 2008; Kim et al. 2010a; Stella 2011; Zhang et al. 2011). However, Liu et al. (2012) has
shown the opposite.
The partial dissolution of metal NPs can release toxic metal ions, and this fact should be
taken into account when interpreting results obtained with these types of NPs (Doak et al. 2009).
Moreover, some transition metal ions released from certain NPs can induce the formation of ROS.
The redox state of iron also modifies the cellular uptake of iron NPs and, thus, their genotoxicity
(Singh et al. 2012).
17.8 CONCLUSION
The term NP is too broad, covering a wide range of particles with very distinct physical and chemi-
cal properties. Genotoxicological studies with NPs give conflicting results. This is probably due to
their different properties, which have a great impact on their potential interactions with living cells
or tissues; the different genotoxicity assays used; measuring different endpoints; and the different
experimental conditions applied. Even the dose metrics vary between studies. Taking all of these
variables into account, it is very difficult to compare different studies and to achieve general conclu-
sions. Moreover, there is a lack of in vivo genotoxicity studies.
A thorough physiochemical characterization of NPs before testing and a battery approach includ-
ing in vitro and in vivo genotoxicity studies are necessary to get reliable and comparable results.
NPs should be characterized and tested in a representative physiological environment; this implies
the development or adaptation of technologies to enable genotoxicity tests and physicochemical
characterizations in such conditions.
Reliable experiments with well-characterized NPs will help researchers to develop new non-
genotoxic NPs. Some genotoxic effects, specifically those induced by the production of ROS, can
be mitigated by the use of antioxidants (Toduka et al. 2012). However, it should not be forgotten that
genotoxic NPs could be useful for some medical purposes.
NPs per se can be used as a therapeutic agent, but they can also be a carrier of them. In the lat-
ter case, the cargo can play a critical role in the genotoxicity response (Lewis et al. 2010); a new
genotoxicity test should be performed.
Taking into account the increasing production of different NPs in terms of the physicochemical
parameters described, there will be a large number of samples to be tested in the near future. A
proper screening method to test their genotoxicity would also be needed.
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