Biomedical Engineering Reference
In-Depth Information
way to assess nanotoxicity should be established before the omnipresence of nanoparticles. Not
only the interactions of nanoparticles with biological systems and natural ecosystems, but also the
interactions between nanoparticles and other common compounds in the human body should be
estimated during toxic studies.
Toxicogenomics is a combination of toxicology and genomics or other high-throughput molecu-
lar profiling technologies to integrate changes in gene, protein, and metabolite expressions related to
chemical toxicity. It investigates the adverse effects of environmental and pharmaceutical chemicals
on human health and the environment. The components of toxicogenomics include microarray,
proteomics, metabolomics, and cytomics (Waters et al., 2003). Compared to traditional toxicity
evaluation systems, the information obtained and analyzed by toxicogenomics can be more dis-
criminating, predictive, and sensitive. Thus, toxicogenomics has a huge potential in improving risk
assessments and hazard screenings.
The focus of this chapter is on current nanotoxicological aspects on
in silico
,
in vitro
, and
in vivo
studies via toxicogenomic approaches.
10.2 NANOTOXICOLOGY
Nanotoxicology is a new branch of toxicology focusing on the adverse health effects specifically
caused by nanomaterials. The study of nanotoxicology aims at learning the physicochemical proper-
ties of nanomaterials, its routes of exposure, absorption, distribution, metabolism, excretion (ADME),
molecular determinants, genotoxic and immunogenic potential, and safety regulation (Figure 10.1).
The physicochemical properties of nanoparticles include their size, chemical composition,
surface structure, solubility, shape, and aggregation. A tiny change in any of these can lead to
unique biological effects. People can be exposed to engineered nanomaterials by direct substance
exchanges with the environment, such as the skin, respiratory tract, and gastrointestinal tract, or by
administration as drug vectors. Nanoparticles, due to their unique physicochemical characteristics,
Size/shape
Chemical composition
Solubility
Surface structure
Aggregation
Skin
Respiratory tract
Gastrointestinal
tract
Academia
Industry
Governmental agencies
Physicochemical
properties
Routes of
exposure
Safety regulation
Absorption
Distribution
Metabolism
Excretion
Nanotoxicology
ADME
characteristics
Immunogenic potential
Molecular
determinants
Inflammation
ROS generation
Oxidative stress
Genotoxicity
Cytokine production
Chromosomal fragmentation
DNA strand breakages
Point mutations
Oxidative DNA adducts
Gene expression changes
FIGURE 10.1
The area of nanotoxicology research.
