80
the zebrafish embryo. The mortality increased over the concentration over 0.1 μg/
ml, and delayed hatching and malformation appeared within 0.01 and 0.05 μg/ml.
The highest concentrations of nanoparticles were more toxic than equivalent doses
of ions (Bai et al. 2010). The malformation of the posterior swim bladder was
associated to downregulation of Wnt-signaling, identified by the authors as the
pathogenetic mechanism (Xu et al. 2017).
The embryonic toxicity of iron oxide nanoparticles was possibly species-specific. In zebrafish, toxicity in terms of mortality, hatching delay, and malformation
appeared at concentration of ca 10 μg/ml (Zhu et al. 2012). In Xenopus laevis, the
toxic doses were much higher, with LC50 > 1000 μg/ml (Nations et al. 2011).
Other nanoparticles, tested with zebrafish embryonic test, are the quantum dots,
powerful fluorescent probes whose usefulness in imaging living organisms is limited
by their toxicity. The cadium/selenium quantum dots in a shell of zinc confirmed
their toxicity for the zebrafish embryo, which was greater for “aged” quantum dots,
obtained simulating the process occurring in the soil, which causes the erosion of
the shell of zinc and the dissolution of toxic species. A similar degree of toxicity
was retained by the cadium/selenium quantum dots; further data confirm the role
played by dissolution in causing embryonic toxicity (Lacave et al. 2016; Wiecinski
et al. 2013).
Nanoparticles based on organic polymers, lipids, and non-metal oxides are usually engineered for special purposes, such as drug delivery, transfection, labeling of
cells and tissues, obtaining advanced materials for bioremediation. Non-metal
oxides, such as Cerium oxide and nanoporous silica functionalized with amine
groups, were not toxic (Matos et al. 2016; Van Hoecke et al. 2009). Quinoxalinebased polymer dots are powerful probes for in vivo imaging and cellular labeling
without the need of specific targeting. They were not toxic when tested with the
zebrafish embryonic test (Liu et al. 2015). Other organic nanoparticles were
conceived for drug transport and delivery, such as polyphenylene and polyamidoamine
dendrimer, liposomes and the nanocapsules. The safer among them, as tested with
the zebrafish embryonic test, were the polyphenylene dendrimers (Stangenberg
et al. 2015), the phosphatidylcholine liposomes (Sieber et al. 2017) and the
nanocapsules with a double shell of hyaluronic acid and protamine (Teijeiro-Valiño
et al. 2017). All these appeared to be suitable platforms for drug and molecules
release, and the nanocapsules were also tested for their ability to cross the chorion,
as a representative biological barrier. They were able to cross the chorion and persist
in circulation. On the contrary, the polyamidoamine dendrimers displayed lethal
and sublethal embryo toxicity, higher for positively charged dendrimers (Calienni
et al. 2017). The liposomes with positive charges at the surface had also severe
embryotoxicity (Sieber et al. 2017).
A. G. Cattaneo
the zebrafish embryo. The mortality increased over the concentration over 0.1 μg/
ml, and delayed hatching and malformation appeared within 0.01 and 0.05 μg/ml.
The highest concentrations of nanoparticles were more toxic than equivalent doses
of ions (Bai et al. 2010). The malformation of the posterior swim bladder was
associated to downregulation of Wnt-signaling, identified by the authors as the
pathogenetic mechanism (Xu et al. 2017).
The embryonic toxicity of iron oxide nanoparticles was possibly species-specific. In zebrafish, toxicity in terms of mortality, hatching delay, and malformation
appeared at concentration of ca 10 μg/ml (Zhu et al. 2012). In Xenopus laevis, the
toxic doses were much higher, with LC50 > 1000 μg/ml (Nations et al. 2011).
Other nanoparticles, tested with zebrafish embryonic test, are the quantum dots,
powerful fluorescent probes whose usefulness in imaging living organisms is limited
by their toxicity. The cadium/selenium quantum dots in a shell of zinc confirmed
their toxicity for the zebrafish embryo, which was greater for “aged” quantum dots,
obtained simulating the process occurring in the soil, which causes the erosion of
the shell of zinc and the dissolution of toxic species. A similar degree of toxicity
was retained by the cadium/selenium quantum dots; further data confirm the role
played by dissolution in causing embryonic toxicity (Lacave et al. 2016; Wiecinski
et al. 2013).
Nanoparticles based on organic polymers, lipids, and non-metal oxides are usually engineered for special purposes, such as drug delivery, transfection, labeling of
cells and tissues, obtaining advanced materials for bioremediation. Non-metal
oxides, such as Cerium oxide and nanoporous silica functionalized with amine
groups, were not toxic (Matos et al. 2016; Van Hoecke et al. 2009). Quinoxalinebased polymer dots are powerful probes for in vivo imaging and cellular labeling
without the need of specific targeting. They were not toxic when tested with the
zebrafish embryonic test (Liu et al. 2015). Other organic nanoparticles were
conceived for drug transport and delivery, such as polyphenylene and polyamidoamine
dendrimer, liposomes and the nanocapsules. The safer among them, as tested with
the zebrafish embryonic test, were the polyphenylene dendrimers (Stangenberg
et al. 2015), the phosphatidylcholine liposomes (Sieber et al. 2017) and the
nanocapsules with a double shell of hyaluronic acid and protamine (Teijeiro-Valiño
et al. 2017). All these appeared to be suitable platforms for drug and molecules
release, and the nanocapsules were also tested for their ability to cross the chorion,
as a representative biological barrier. They were able to cross the chorion and persist
in circulation. On the contrary, the polyamidoamine dendrimers displayed lethal
and sublethal embryo toxicity, higher for positively charged dendrimers (Calienni
et al. 2017). The liposomes with positive charges at the surface had also severe
embryotoxicity (Sieber et al. 2017).
A. G. Cattaneo