Conference PaperPDF Available

Biodistribution and toxicity of nanomaterials in vivo: effects of composition, size, surface functionalization and route of exposure

Authors:
  • Baylor Scott and White Health
Biodistribution and Toxicity of Nanomaterials In Vivo: Effects of Composition, Size,
Surface Functionalization and Route of Exposure
S. Harper*, B.L.S. Maddux**, J.E. Hutchison***, C. Usenko**** and R. Tanguay*****
* Oregon State University, Corvallis, OR, USA, harpers@science.oregonstate.edu
** Oregon Nanoscience and Microtechnologies Institute, USA, bmaddux@uoregon.edu
***University of Oregon, Eugene, OR, USA, hutch@uoregon.edu
**** Oregon State University, Corvallis, OR, USA, tuckercr@science.oregonstate.edu
***** Oregon State University, Corvallis, OR, USA, Robert.Tanguay@oregonstate.edu
ABSTRACT
Rapid, relevant and efficient testing strategies are
necessary to evaluate nanoparticle-biological interactions of
emerging nanoparticles/nanomaterials due to the
anticipated, unprecedented growth of the nanotechnology
industry. Here we present an approach that utilizes a
dynamic whole animal (embryonic zebrafish) assay to
identify in vivo responses to nanomaterial exposure and to
define physicochemical properties that result in adverse
biological consequences. Our results demonstrate the
utility of this model as an effective and accurate tool to
assess the biological activity and toxic potential of
nanomaterials in a short period of time with minimal cost.
Keywords: nanotoxicology, carbon fullerene, metal oxide,
fluorescent, gold nanoparticles
1 PROACTIVE NANOTECHNOLOGY
Atomic level manipulation, a hallmark of the promising
nanotechnology industry, should permit control over
nanomaterial physicochemical properties as well as their
interactions with biological systems. Thus, it should be
feasible to minimize adverse biological interactions once
the physicochemical properties that dictate those
interactions are identified. Engineers and scientists must
work together to provide this critical information to
industry so that they can proactively design nanomaterials
with enhanced performance and minimal hazard.
2 MODEL SYSTEM FOR TESTING
NANOPARTICLE-BIOLOGICAL
INTERACTIONS
Numerous biological models have been employed for
toxicological evaluations. Like many models, much of the
anatomy and physiology of fish is highly homologous to
humans [1]. Zebrafish have been successfully used as an in
vivo model organism for predictive toxicology and are now
proving invaluable for the pharmaceutical and
biotechnology industries for evaluating integrated system
effects [2, 3]. A remarkable similarity in cellular structure,
signaling processes, anatomy and physiology exists among
zebrafish and other high-order vertebrates [4]. In addition,
zebrafish possess all of the classical sense modalities,
including vision, olfaction, taste, touch, balance and
hearing; and their sensory pathways share an overall
homology with humans.
2.1 Inherent Advantages
Numerous features of zebrafish biology (e.g. small size,
rapid embryonic development, short life cycle), make this
model system logistically attractive to rapidly evaluate
nanoparticle-biological interactions [5]. Females produce
hundreds of eggs weekly, so large sample sizes are easily
achieved for statistically powerful dose-response studies
[6]. This abundant supply of embryos also makes it
possible to simultaneously assess the toxicity of a large
number of nanomaterials in a short period of time.
Zebrafish embryos develop externally and are optically
transparent so it is possible to resolve individual cells in
vivo across a broad range of developmental stages or
throughout the duration of an experimental exposure using
simple microscopic techniques. Resolution of specific cell
populations can be increased by the use of transgenic
zebrafish models that express fluorescent reporter genes in
cell types of interest [7]. Finally, assay volumes using the
zebrafish model are small; thus, only limited amounts of
nanoparticles/nanomaterials are needed to evaluate
biological responses.
2.2 Rationale for Exposure of Embryonic Life
Stage
We investigate whole animal biological responses (i.e.
organismal uptake, systemic distribution and toxicological
effects) by detailing the effects of nanoparticle exposure on
embryonic zebrafish. Our experimental design tests for
nanomaterial toxicity during early vertebrate development
for two important reasons. First, fundamental processes of
development are highly conserved across species [8].
Second, vertebrates at the earliest life stages are often more
responsive to perturbation [9]. Highly coordinated cell-to-
cell communications and molecular signaling are required
for normal development. Nanomaterials that interact with
NSTI-Nanotech 2007, www.nsti.org, ISBN 1420061836 Vol. 2, 2007
666
molecular signaling pathways, intercellular interactions, or
normal cellular processes can be identified by evaluating
the response of actively developing organisms to
nanomaterial exposure.
3 NANOPARTICLES/NANOMATERIALS
To investigate the relative importance of size and
surface functionalization on the toxic potential of
nanomaterials, we evaluated carbon fullerenes (C70, C60 and
hydroxylated C60) in embryonic zebrafish. Fullerenes C60
have proposed uses in fuel cells, groundwater remediation,
cosmetics and drug delivery. C70 is a common by-product
of C60 synthesis, and will therefore likely be found in
products containing C60 unless extensive purification steps
are taken. C70 is slightly larger than C60, as it contains 10
more carbon atoms than C60. Differences in toxicity
between these two fullerenes were used to evaluate the
influence of size. Surface functionalization of C60 with
hydroxyl groups produces a more water soluble derivative
C60(OH)24. Similarly to C60, hydroxylated C60 has proposed
uses in groundwater remediation and drug delivery [10, 11].
Differences in toxicity between C60 and C60(OH)24 were
used to evaluate the influence of surface functionalization.
Gold nanoparticles (AuNPs) were also used to test the
influence of size and surface functionalization on toxic
potential. Our choice of two core sizes (0.8 and 1.5nm)
with one of three surface groups [neutral charge = 2-(2-
mercaptoethoxy) ethanol (MEE), positive charge = N,N,N-
trimethylammoniumethanethiol (TMAT), and negative
charge = 2-mercaptoethanesulfonate (MES)] allowed us to
also investigate the influence nanoparticle charge on toxic
potential. During the last decade, methods have been
developed to synthesize a library of ligand-functionalized
gold nanoparticles (AuNPs) that have precise size, shape
and purity[12]. These materials have potential applications
in optics, electronics, in vivo molecular imaging and
therapeutics.
To investigate the importance of chemical composition
on nanoparticle-biological interactions, we evaluated 11
dispersions of nanoparticulate metal oxides [aluminum
oxide, titanium (IV) oxide, zirconium (IV) oxide, cerium
(IV) oxide, gadolinium (III) oxide, dysprosium (III) oxide,
yttrium (III) oxide, homium (III) oxide, samarium (III)
oxide, silicon dioxide-alumina doped and erbium (III)
oxide]. We chose to evaluate commercially available
materials for two important reasons. First, nanoparticles
produced on a large-scale are not expected to be pure.
Second, nanoparticles that are currently commercially
available are already being used for industrial applications
[13]. Nano-sized metals and metal oxides have unique
properties useful for novel applications in electronics,
healthcare, optics, technology and engineering industries.
Some metallic nanoparticles, particularly bimetallics, are
currently being tested for remediation of organic
groundwater contamination, chelation of toxic metals and
in vivo biomedical imaging. Nanoparticulate metal oxides
also offer many advantages for sensors, catalysis and
microelectronics applications.
In vivo biodistribution of nanomaterials was
investigated using polystyrene and CdSe fluorescent
nanomaterials (FluoSphere® and Qdots®, respectively).
Qdots® (605ITK-carboxyl QDs, 605ITK-amino(PEG) QDs
and 605ITK-organic QDs) were generously donated by, and
FluoSphere® (0.02μm sulfate, carboxylate, and aldehyde-
sulfate modified fluorescent spheres) were purchased from
Invitrogen/Molecular Probes (Eugene, OR). Both
nanomaterials have novel applications in the fields of
biomedical imaging, drug delivery and electronics. These
engineered materials demonstrate a wide range of
physicochemical properties dependent upon inherent
characteristics and environmental conditions. The intent of
these studies was to identify how those properties affected
nanoparticle uptake and biodistribution.
4 EXPERIMENTAL DESIGN
These studies aimed to investigate the effects of
nanomaterial exposure on vertebrate systems using the
unique advantages of the embryonic zebrafish model.
Screening level toxicological testing was performed to
determine in vivo responses to, and biological consequences
of, nanomaterial exposure. Those results were used to
identify inherent physicochemical properties that result in
adverse biological consequences. Fluorescent
nanomaterials were used to investigate how parameters
such as surface functionalization, chemical composition and
route of exposure (dermal, injection and oral) influence in
vivo biodistribution.
4.1 Exposure Protocols for In Vivo
Toxicological Assessments
Embryonic zebrafish were obtained from an AB strain
of zebrafish (Danio rerio) reared in the Sinnhuber Aquatic
Research Laboratory (SARL) at OSU. Adults were kept at
standard laboratory conditions of 28°C on a 14h light/10h
dark photoperiod. Embryos collected from group spawns
were staged for experimental studies. To avoid barrier
effects posed by the chorion (egg membrane), embryos
staged at 6 hours post fertilization (hpf) were dechorionated
using pronase enzyme degradation.
To simulate dermal exposure, 8 hpf embryos were
continuously waterborne exposed at 28°C in individual
wells of a 96-well plate (N = 24 per treatment) until 120
hpf. Exposures were started at 8 hpf to ensure coverage of
gastrulation and organogenesis, the periods of development
most well conserved among vertebrates. For injection
exposures, 8 hpf embryos were arranged in agarose molds
and injected with 2 nl nanomaterial solution using a
picoliter injection system. As controls, samples were
injected with reverse osmosis water lacking nanoparticles.
After injection, embryos were transferred to fish water in
NSTI-Nanotech 2007, www.nsti.org, ISBN 1420061836 Vol. 2, 2007 667
wells of a 96-well plate and incubated at 28°C until 120
hpf.
4.2 Biodistribution Studies
Since distribution patterns were expected to depend on
the route of exposure, we employed three different modes
of administering FluoSphere® (40 ppm) and Qdots® (2
nM) to embryos. To simulate exposure by the dermal
route, embryos were continuously exposed from 8-96 hpf in
individual wells of a 96-well plate. Uptake via ingestion
(oral route) was evaluated in animals waterborne exposed
later in development (144-168 hpf) when the mouth is open
and functional, and dermal tissues are less permeable. The
third route of exposure we considered was injection.
Microinjections were performed at 8 hpf on embryos with
intact chorion. After injection, embryos were allowed to
mature to 96 hpf. For evaluations, embryos were
anesthetized with tricaine and mounted on a glass cover slip
in 3% methyl cellulose. Embryos were visualized using an
inverted Axiocam fluorescent microscope and photos
captured using Axiovert software.
5 EVALUATION OF BIOLOGICAL
RESPONSES
The principal characteristics that may be predictive of
nanoparticle-biological interactions have yet to be
identified. Embryonic zebrafish exposed to a variety of
nanomaterials were evaluated for mortality, morphological
malformations, behavioral abnormalities and developmental
progression.
5.1 Influence of Size and Surface
Functionalization
Our evaluations of exposure to graded concentrations of
fullerenes [C60, C70, and C60(OH)24] revealed that surface
functionalization had a greater effect on toxicity than size.
Exposure to C60 and C70 significantly increased mortality
and the incidence of pericardial edema and fin
malformations, while the response to C60(OH)24 exposure
was less pronounced even at concentrations an order of
magnitude higher.
Core size and surface functionalization both influenced
the toxicity of AuNPs. We found a strong dependence on
surface charge and a moderate influence of particle
diameter. Exposure to positively charged AuNPs resulted
in significantly higher toxicity than for negatively charged
particles, while neutral particles exhibited no toxicity.
AuNPs functionalized with TMAT caused a significant
increase in mortality at 10 parts per million (ppm) for 1.5
nm particles and 400 parts per billion (ppb) for 0.8 nm
particles. Exposure to MES-AuNPs did not result in
increased mortality at concentrations up to 250 ppm;
however, concentrations of 2 and 50 ppm did result in
increased incidence of morphological malformations at 1.5
and 0.8nm particles, respectively. Embryos exposed to 1.5
nm TMAT functionalized nanoparticles also displayed
increased incidences of malformations at 50ppm. Such
malformations were observed at a much lower
concentration (80 ppb) when the TMAT-AuNP size was
0.8nm.
5.2 Influence of Chemical Composition and
Route of Exposure
Of eleven metal oxide nanoparticulates tested,
approximately half were benign to embryonic zebrafish
after a 5-day continuous waterborne exposure at
concentrations ranging from 16 parts per billion (ppb) to
250 parts per million (ppm). Significant mortality was
observed at 50 ppm for Er2O3 and Sm2O3, and at 250 ppm
for Ho2O3 and Dy2O3. Significant morphological
malformations were induced by waterborne exposure to
Er2O3, Sm2O3 and Dy2O3 at concentrations of 10, 50 and
250 ppm, respectively. Exposure to Sm2O3 significantly
increased the incidence of jaw, heart, eye and snout
malformations at 50 ppm. Exposure to SiO2/Al2O resulted
in a significant incidence of jaw malformations at 250 ppm.
At 10 ppm, Er2O3 exposure elicited jaw malformations in
44% of embryos after 5 days. Exposure to 50 ppm Er2O3
significantly increased the incidence of jaw, heart, eye,
snout, trunk and body axis malformations. Dy2O3 exposure
significantly affected the jaw and eyes at 250 ppm.
Embryonic exposure to Y2O3 significantly increased the
incidence of jaw malformations at 10 ppm and the
incidence of jaw and heart malformations of embryos
exposed to 250 ppm.
Microinjections of metal oxide nanoparticle dispersions
were administered to embryonic zebrafish to test the effects
of exposure via an injection route. Morphological
malformations elicited by waterborne exposure to
nanoparticulate metal oxides were mimicked by injection
exposures for Sm2O3 (Figure 1) and Y2O3. No significant
morbidity or mortality was observed from any of the
nanoparticulate metal oxides when embryos were injected
with approximately 0.5 ng nanoparticles.
5.3 Biodistribution Evaluations
In vivo distributions were determined for embryonic
zebrafish exposed (waterborne, injection, oral) to
fluorescent FluoSphere® and Qdots® in order to evaluate
the influence of exposure route and surface
functionalization on uptake and biodistribution. A timeline
for uptake from waterborne exposures was determined for
FluoSphere® with carboxylated surface functionalization.
Waterborne FluoSpheres® were observed in external
epithelial tissues for the first 24 hours, in the vasculature by
72 hours and in the digestive tract by 144 hours.
Distribution after uptake appeared to be greater for Qdots®
than for FluoSpheres®, independent of the route of
NSTI-Nanotech 2007, www.nsti.org, ISBN 1420061836 Vol. 2, 2007
668
exposure (Figure 2). Uptake from a dermal route was
primarily limited to the epithelial layers and the yolk sac for
carboxylated FluoSpheres®, but distribution to the brain
region was achieved from waterborne exposure to Qdots®.
Microinjection route also shows differential uptake and
distribution. FluoSpheres® administered via the oral route
of exposure were retained within the gastrointestinal tract;
whereas, Qdots were readily taken up across the
gastrointestinal tract and distributed to the brain. A
comparison of carboxylate-modified Qdots® and
FluoSpheres® revealed a strong influence of chemical
composition on distribution independent of the surface
functional groups.
Immense data gaps and conflicting reports on
nanotoxicology currently prevent generalizing how
nanoparticle physicochemical properties relate to biological
activity and toxic potential. In vivo animal models, such as
the zebrafish, are needed to interpret the effects of
nanomaterial exposure in a whole animal context. Our
results show that size was not a determining factor for the
toxicity of carbon fullerenes or AuNPs. However, the size
differences we evaluated were relatively small and thus
limits our interpretation of the influence of size on
nanomaterial toxic potential. Surface functionalization
significantly affected toxicity of fullerenes and AuNPs yet
did not dictate the biodistribution of fluorescent
nanoparticles. Biodistribution was instead influenced by
chemical composition as well as route of exposure.
Chemical composition significantly influenced the toxicity
of nanoparticulate metal oxides but the influence of
exposure route was less pronounced, perhaps due to the
amount injected. Overall, our results indicate that the
zebrafish model is a powerful platform to help unravel
nanomaterial structure and biological response
relationships..
Waterborne Exposure Microinjection Exposure
Concentration
Sham
Injected
0 ppm 50 ppm 250 ppm
Percent With Effect
0
20
40
60
80
100 mortality
jaw
snout
eye
heart *
*
*
**
*
250ppm
Injected
Percent With Effect
0
20
40
60
80
100
*
*
**
ACB
Waterborne Exposure Microinjection Exposure
Concentration
Sham
Injected
0 ppm 50 ppm 250 ppm
Percent With Effect
0
20
40
60
80
100 mortality
jaw
snout
eye
heart *
*
*
**
*
250ppm
Injected
Percent With Effect
0
20
40
60
80
100
*
*
**
Waterborne Exposure Microinjection Exposure
Concentration
Sham
Injected
0 ppm 50 ppm 250 ppm
Percent With Effect
0
20
40
60
80
100 mortality
jaw
snout
eye
heart *
*
*
**
*
250ppm
Injected
Percent With Effect
0
20
40
60
80
100
*
*
**
ACB
Figure 1. Morbidity and mortality of embryonic
zebrafish (A) waterborne exposed to 50 or 250 ppm
samarium (III) oxide, (B) sham injected with 2 nl
water, and (C) microinjected with 2 nl of 250 ppm
(~0.5 ng) samarium (III) oxide. * indicates significant
difference from waterborne or microinjection control
groups using Fisher’s Exact test (p<0.05).
REFERENCES
[1] Ackermann, G. E.; Paw, B. H. Front Biosci, 2003,
8, d1227-53.
[2] Mathew, L. K.; Andreasen, E. A.; Tanguay, R. L.
Mol Pharmacol, 2006, 69, 257-65.
[3] Hill, A. J.; Teraoka, H.; Heideman, W.; Peterson,
R. E. Toxicol Sci, 2005, 86, 6-19.
[4] Brent, R. L. Birth Defects Research (Part B),
2004, 71, 303-320.
[5] Rubinstein, A. L. Curr Opin Drug Discov Devel,
2003, 6, 218-23.
6 CONCLUSIONS [6] Kimmel, C.; Ballard, W.; Kimmel, S.; Ullmann,
B.; Schilling, T. Developmental Dynamics, 1995,
203, 253-310.
Dermal
FluoSpheres®Quantum Dots®
Injection
Oral Dermal
FluoSpheres®Quantum Dots®
InjectionInjection
Oral Oral
[7] Bates, J. M.; Mittge, E.; Kuhlman, J.; Baden, K.
N.; Cheesman, S. E.; Guillemin, K. Dev Biol,
2006, 297, 374-386.
[8] Lein, P.; Silbergeld, E.; Locke, P.; Goldberg, A.
M. Environmental Toxicology and Pharmacology,
2005, 19, 735-744.
[9] (NRC), N. R. C. In Board on Environmental
Studies and Toxicology; NATIONAL ACADEMY
PRESS: Washington, DC, 2000, pp. 1-327.
[10] Nakamura, E.; Isobe, H. Accounts of Chemical
Research, 2003, 36, 807-815.
[11] Anderson, R.; Barron, A. R. Journal of American
Chemical Society, 2005, 127, 10458-10459.
[12] Woehrle, G. H.; Brown, L. O.; Hutchison, J. E. J
Am Chem Soc, 2005, 127, 2172-2183.
Figure 2. Biodistribution of FluoSpheres® and
Quantum Dots® administered via waterborne (dermal
and oral) or microinjection (injection) exposure.
[13] Cherukuri, P.; Bahilo, S.; Litovsky, S.; Weisman,
R. Journal of the American Chemical Society,
2004, 126, 15638-15639.
NSTI-Nanotech 2007, www.nsti.org, ISBN 1420061836 Vol. 2, 2007 669
... Novel toxicological methods need to look at realistic exposure levels during first-pass hazard identification studies to minimize the time and materials required for testing and rapidly identify materials of high concern (Oomen et al. 2014). The EZ Metric assay presented here utilizes developing zebrafish embryos (Danio rerio) as an integrated sensing and amplification system that is easy to evaluate non-invasively, providing the power of whole-animal investigations with the convenience of cell culture (Harper et al. 2008a; Usenko et al. 2007). Exposures are conducted in 96-well plates using intact organisms that have functional homeostatic feedback mechanisms and intercellular signaling (Harper et al. 2010, 2011; Truong et al. 2011).The endpoints evaluated in the EZ Metric assay require minimal equipment to assess and involve no experimental treatments such as dyes or other indicators that could alter the impacts of the nanomaterials (Harper et al. 2008a; Truong et al. 2011). ...
... Details of nanomaterial manufacturers and material composition are available in Online Resource 1, online at nbi.oregonstate .edu and in previous publications on selected materials (Harper et al. 2007, 2008a; Pryor et al. 2014; Usenko et al. 2007, 2008). ...
Article
Full-text available
The integration of rapid assays, large datasets, informatics, and modeling can overcome current barriers in understanding nanomaterial structure–toxicity relationships by providing a weight-of-the-evidence mechanism to generate hazard rankings for nanomaterials. Here, we present the use of a rapid, low-cost assay to perform screening-level toxicity evaluations of nanomaterials in vivo. Calculated EZ Metric scores, a combined measure of morbidity and mortality in developing embryonic zebrafish, were established at realistic exposure levels and used to develop a hazard ranking of diverse nanomaterial toxicity. Hazard ranking and clustering analysis of 68 diverse nanomaterials revealed distinct patterns of toxicity related to both the core composition and outermost surface chemistry of nanomaterials. The resulting clusters guided the development of a surface chemistry-based model of gold nanoparticle toxicity. Our findings suggest that risk assessments based on the size and core composition of nanomaterials alone may be wholly inappropriate, especially when considering complex engineered nanomaterials. Research should continue to focus on methodologies for determining nanomaterial hazard based on multiple sub-lethal responses following realistic, low-dose exposures, thus increasing the availability of quantitative measures of nanomaterial hazard to support the development of nanoparticle structure–activity relationships. Electronic supplementary material The online version of this article (doi:10.1007/s11051-015-3051-0) contains supplementary material, which is available to authorized users.
... The elemental composition (organic, inorganic or mixtures) of NPs is essential to understand their biological behavior, biodistribution and toxicity (Harper et al., 2007;Fubini et al., 2011). In fact, the elemental composition of NPs can be considered the main driver of toxicity for metal-bearing NPs. ...
Chapter
Over recent years, engineered nanoparticles (NPs) have been increasingly incorporated into many consumer products because they present novel physicochemical properties in comparison to their bulk counterparts. Metal-bearing NPs are used extensively and, among them, silver NPs (Ag NPs) have gained high commercial and scientific interest due to their unique optical, catalytical and antimicrobial properties. Applications of Ag NPs are increasing and so are concerns about their potential input into aquatic ecosystems and their environmental hazards. Due to their filter-feeding activity, mussels Mytilus spp. are sentinel species widely used in biomonitoring of environmental pollution and as suitable model organisms for characterizing the potential impact of NPs in marine environments. NPs are trapped by gills, the first organ vulnerable to particle interactions, and then directed to the digestive gland. NP accumulation, cellular fate and effects depend on their physicochemical characteristics. The application of biomarkers after waterborne exposure of mussels to Ag NPs revealed adverse effects such as destabilization of the lysosomal membrane in digestive cells, induction of antioxidant enzyme activities and lipid peroxidation in the digestive gland and gills, genotoxic effects in hemocytes as well as a concentration-dependent increase in malformed D-shell larvae, among others. Also, omic’s tools have identified molecular markers that can help to predict adverse outcome pathways from initiating events to higher level consequences. However, studies assessing the potential trophic transfer of Ag NPs remain scarce even though NPs may be prone to bioaccumulation and biomagnification along trophic chains. In this work we reviewed literature on the fate and toxicity of engineered NPs in aquatic organisms and discussed data showing that dietary exposure of marine mussels to Ag NPs at environmentally relevant concentrations caused deleterious effects at molecular, cellular and tissue levels, as well as on reproduction and offspring development. Proteomic and transcriptomic studies unveiled Ag NP responsive biological pathways, which were modulated by season, providing insights into the mechanisms of toxicity. Further, all the data were integrated in an adverse outcome pathway proposed for Ag NP impact in dietarily exposed mussels at different seasons.
... Target organs may include the gills, gut, liver and sometimes the brain. In embryos of zebra fish, [75] showed that biodistribution was influenced by chemical composition of NPs as well as route of exposure. Thus, FluoSpheres® administered via the oral route of exposure were retained within the gastrointestinal tract whereas Qdots® were readily taken up across the gastrointestinal tract and distributed to the brain. ...
Chapter
Nanosized materials have potential of practical application in a number of research fields, in industrial production, and in everyday life. However, at nanoscale level, many substances acquire new properties and therefore may become biologically very active. This has raised questions about the potential toxic effects of such mate- rials on living organisms due to either intentional or unintentional contact with them. Thus, biological toxicity of novel nanoparticles (NPs) is a key issue which has to be clarified before their full integration in everyday life. The critical analysis of the literature data in respect of the positive and negative effects of nanomaterials is given in this chapter. Moreover, the current approaches for the determination of the biological effects of these types of substances are presented. In this case, main attention is paid to characteristics of the approaches used by authors for the express estimation of the total toxicity with the application of bacteria, Daphnia, and plants with the express control of the level of natural bioluminescence and enhanced chemiluminescence, the energy of the seed germination, and the effi- ciency of the photosynthetic apparatus of growing plants according to the estima- tion of chlorophyll fluorescence by the special "Floratest" biosensor. In addition to that, simple and effective methods for the control of cytotoxicity and genotoxicity are described including application of the modern analytical approaches based on the principles of biosensorics. Using the above-mentioned methodical approaches, two aspects of biological effects of such nanomaterials as: (a) NPs ZnO, AgO, FeO, TiO2, and others and (b) their colloidal substances are considered. Namely, their (a) biocidal activity (NPs) and (b) improvement of the nutrition of plants on cal- careous soils (colloidal structures) are analyzed. A special attention is paid to the chemical and physical characteristics of the nanomaterials used by different spec- trometric approaches including atomic force microscopy and scanning electron microscopy methods.
... We found several important indicators of the 24 hpf mortality, including dosage concentration, shell composition, outermost surface functional groups, purity, core structure, and surface charge. These findings are consistent with the results of previous studies on nanomaterial toxicity using embryonic zebrafish.21,22,27,39,40 ...
Article
Full-text available
Predictive modeling of the biological effects of nanomaterials is critical for industry and policymakers to assess the potential hazards resulting from the application of engineered nanomaterials. We generated an experimental dataset on the toxic effects experienced by embryonic zebrafish due to exposure to nanomaterials. Several nanomaterials were studied, such as metal nanoparticles, dendrimer, metal oxide, and polymeric materials. The embryonic zebrafish metric (EZ Metric) was used as a screening-level measurement representative of adverse effects. Using the dataset, we developed a data mining approach to model the toxic endpoints and the overall biological impact of nanomaterials. Data mining techniques, such as numerical prediction, can assist analysts in developing risk assessment models for nanomaterials. We found several important attributes that contribute to the 24 hours post-fertilization (hpf) mortality, such as dosage concentration, shell composition, and surface charge. These findings concur with previous studies on nanomaterial toxicity using embryonic zebrafish. We conducted case studies on modeling the overall effect/impact of nanomaterials and the specific toxic endpoints such as mortality, delayed development, and morphological malformations. The results show that we can achieve high prediction accuracy for certain biological effects, such as 24 hpf mortality, 120 hpf mortality, and 120 hpf heart malformation. The results also show that the weighting scheme for individual biological effects has a significant influence on modeling the overall impact of nanomaterials. Sample prediction models can be found at http://neiminer.i-a-i.com/nei_models. The EZ Metric-based data mining approach has been shown to have predictive power. The results provide valuable insights into the modeling and understanding of nanomaterial exposure effects.
... 7,8,11 We have also identified some key attributes that determine nanomaterial disposition in whole animals, such as core composition and surface chemistry, as well as the route of exposure. 9,10 Data from our studies has been organized in a functional informatics system, the Nanomaterial-Biological Interactions Knowledgebase, 12 which will allow cross-species and crossplatform analysis in a metadata format. Furthermore, we have established collaborations across the nanobioinformatics community to facilitate the translation of data into knowledge and to broadly disseminate that information through a federated network in the future. ...
Article
Full-text available
Materials between 1 and 100nm in size behave differently than largermaterials ofthesamecomposition. Theyexhibitintriguing new properties that have the potential to radically improve hu- manhealth throughtargeteddrug delivery,bionicandprosthetic development, improved imaging and diagnostics systems, and novel therapeutics and regenerative medicines. According to the Project on Emerging Nanotechnologies,1 803 consumer prod- ucts already exploit nanoscale materials in merchandise rang- ing from cosmetics to children's plush toys. But amid the excite- ment surrounding the revolutionary potential of nanotechnol- ogy, such as electronics integrated into organisms featured in the 1970s television show 'The Six Million Dollar Man,' how do we ensure these new materials do not inadvertently harm or even destroy parts of our world? Several major challenges must be overcome to ensure the safety of new nanomaterials. First, studies on how and why nanoparticles interact with the environment and organisms are lacking. It is impossible to assess potential exposure risks with- out this information. Second, we do not currently have the tools to measure all nanomaterial characteristics that may be impor- tant. Moreover, we may not fully comprehend what we need to measure. Finally, with every element in the periodic table as fair game—and the countless ways in which materials can be mixed and matched—the sheer diversity of potential nanomaterials is mind-boggling.
... Toxicological data obtained from appropriately characterized AgNPs will at last yield a clear understanding of AgNP safety. Our group has developed a robust and rapid toxicity testing method in the embryonic zebrafish to define nanoparticle–biological interactions (NBI) [13, 14, 24]. The zebrafish is an established model for in vivo toxicity testing that helps identify molecular mechanisms, which can be extended for ecotoxicology [30]. ...
Article
Full-text available
The mechanism of action of silver nanoparticles (AgNPs) is unclear due to the particles' strong tendency to agglomerate. Preventing agglomeration could offer precise control of the physicochemical properties that drive biological response to AgNPs. In an attempt to control agglomeration, we exposed zebrafish embryos to AgNPs of 20 or 110 nm core size, and polypyrrolidone (PVP) or citrate surface coatings in media of varying ionic strength. AgNPs remained unagglomerated in 62.5 μM CaCl2 (CaCl2) and ultrapure water (UP), but not in standard zebrafish embryo medium (EM). Zebrafish embryos developed normally in the low ionic strength environments of CaCl2 and UP. Exposure of embryos to AgNPs suspended in UP and CaCl2 resulted in higher toxicity than suspensions in EM. 20 nm AgNPs were more toxic than 110 nm AgNPs, and the PVP coating was more toxic than the citrate coating at the same particle core size. The silver tissue burden correlated well with observed toxicity but only for those exposures where the AgNPs remained unagglomerated. Our results demonstrate that size- and surface coating-dependent toxicity is a result of AgNPs remaining unagglomerated, and thus a critical-design consideration for experiments to offer meaningful evaluations of AgNP toxicity.
Article
Full-text available
In the last few decades, the field of nanomedicine applied to cancer has revolutionized cancer treatment: several nanoformulations have already reached the market and are routinely being used in the clinical practice. In the case of genetic nanomedicines, i.e., designed to deliver gene therapies to cancer cells for therapeutic purposes, advances have been less impressive. This is because of the many barriers that limit the access of the therapeutic nucleic acids to their target site, and the lack of models that would allow for an improvement in the understanding of how nanocarriers can be tailored to overcome them. Zebrafish has important advantages as a model species for the study of anticancer therapies, and have a lot to offer regarding the rational development of efficient delivery of genetic nanomedicines, and hence increasing the chances of their successful translation. This review aims to provide an overview of the recent advances in the development of genetic anticancer nanomedicines, and of the zebrafish models that stand as promising tools to shed light on their mechanisms of action and overall potential in oncology.
Article
Full-text available
Over the past few years, nanoparticles and their role in drug delivery have been the centre of attraction as new drug delivery systems. Various forms of nanosystems have been designed, such as nanoclays, scaffolds and nanotubes, having numerous applications in areas such as drug loading, target cell uptake, bioassay and imaging. The present study discusses various types of nanoparticles, with special emphasis on ceramic nanocarriers. Ceramic materials have high mechanical strength, good body response and low or non-existing biodegradability. In this article, the various aspects concerning ceramic nanoparticles, such as their advantages over other systems, their cellular uptake and toxicity concerns are discussed in detail.
Article
The stability of citrate-capped silver nanoparticles (AgNPs) and the embryonic developmental toxicity were evaluated in the fish test water. Serious aggregation of AgNPs was observed in undiluted fish water (DM-100) in which high concentration of ionic salts exist. However, AgNPs were found to be stable for 7 days in DM-10, prepared by diluting the original fish water (DM-100) with deionized water to 10 %. The normal physiology of zebrafish embryos were evaluated in DM-10 to see if DM-10 can be used as a control vehicle for the embryonic fish toxicity test. As results, DM-10 without AgNPs did not induce any significant adverse effects on embryonic development of zebrafish determined by mortality, hatching, malformations and heart rate. When embryonic toxicity of AgNPs was tested in both DM-10 and in DM-100, AgNPs showed higher toxicity in DM-10 than in DM-100. This means that the big-sized aggregates of AgNPs were low toxic compared to the nano-sized AgNPs. AgNPs induced delayed hatching, decreased heart rate, pericardial edema, and embryo death. Accumulation of AgNPs in the embryo bodies was also observed. Based on this study, citrate-capped AgNPs are not aggregated in DM-10 and it can be used as a control vehicle in the toxicity test of fish embryonic development.
Article
Full-text available
To address the growing need for scientifically valid and humane alternatives to developmental neurotoxicity testing (DNT), we propose that basic research scientists in developmental neurobiology be brought together with mechanistic toxicologists and policy analysts to develop the science and policy for DNT alternatives that are based on evolutionarily conserved mechanisms of neurodevelopment. In this article we briefly review in vitro and other alternative models and present our rationale for proposing that resources be focused on adapting alternative simple organism systems for DNT. We recognize that alternatives to DNT will not completely replace a DNT paradigm that involves in vivo testing in mammals. However, we believe that alternatives will be of great value in prioritizing chemicals and in identifying mechanisms of developmental neurotoxicity, which in turn will be useful in refining and reducing in vivo mammalian tests for exposures most likely to be hazardous to the developing human nervous system.
  • G E Ackermann
  • B H Paw
Ackermann, G. E.; Paw, B. H. Front Biosci, 2003, 8, d1227-53.
  • L K Mathew
  • E A Andreasen
  • R L Tanguay
Mathew, L. K.; Andreasen, E. A.; Tanguay, R. L. Mol Pharmacol, 2006, 69, 257-65.
  • A J Hill
  • H Teraoka
  • W Heideman
  • R E Peterson
Hill, A. J.; Teraoka, H.; Heideman, W.; Peterson, R. E. Toxicol Sci, 2005, 86, 6-19.
  • R L Brent
Brent, R. L. Birth Defects Research (Part B), 2004, 71, 303-320.
  • A L Rubinstein
Rubinstein, A. L. Curr Opin Drug Discov Devel, 2003, 6, 218-23.
  • C Kimmel
  • W Ballard
  • S Kimmel
  • B Ullmann
  • T Schilling
Kimmel, C.; Ballard, W.; Kimmel, S.; Ullmann, B.; Schilling, T. Developmental Dynamics, 1995, 203, 253-310.
  • J M Bates
  • E Mittge
  • J Kuhlman
  • K N Baden
  • S E Cheesman
  • K Guillemin
Bates, J. M.; Mittge, E.; Kuhlman, J.; Baden, K. N.; Cheesman, S. E.; Guillemin, K. Dev Biol, 2006, 297, 374-386.
  • E Nakamura
  • H Isobe
Nakamura, E.; Isobe, H. Accounts of Chemical Research, 2003, 36, 807-815.
  • R Anderson
  • A R Barron
Anderson, R.; Barron, A. R. Journal of American Chemical Society, 2005, 127, 10458-10459.