Nanomaterials are defined as any material with at least one external dimension less than 100 nm. Recently, nanomaterials have become more common in medicine, technology, and engineering. One reason for their increased interest is due to nanomaterials having unique properties that allow them to interact effectively with biological systems. In terms of drug delivery, the lungs are a highly desirable site to administer therapeutic nanoparticles. Indeed, inflammatory diseases such as asthma and emphysema could potentially benefit from nanoparticle-mediated delivery. However, the lungs are also in constant contact with airborne particulate matter. Thus, harmful nanoparticles can enter the lungs and cause or even exacerbate inflammatory diseases. Our work focused on characterization of both therapeutic and potentially harmful nanoparticles in the lungs. We found that fluorescently-labeled nanoparticles were phagocytosed by macrophages and did not induce apoptosis or inflammation in the lungs, making them potentially useful as a therapeutic for inflammatory diseases. We also characterized a rare form of titanium-based particles called Magnéli phases, which have been shown to be produced via coal burning. We found that while these particles are non-inflammatory in the lungs of mice, they lead to apoptosis of macrophages as well as a change in gene expression associated with increased fibrosis. Ultimately, this was shown to lead to a decrease in lung function parameters and airway hyperresponsiveness, indicating increased lung stiffness after long-term nanoparticle exposure. Our data adds significant contributions to the field by assessing two nanoparticles with vastly different compositions in the lungs. Overall, we found that the unique properties of both particle types allows for interactions with cells and tissues. These interactions can have important outcomes on health, both in terms of disease treatment and exacerbation. / Ph. D. / Over the years, nanoparticles have become more common in medicine, technology, and engineering due to their unique properties. Many of these properties allow for increased interactions with biological materials. Organs such as the lungs are at increased risk of exposure because they naturally encounter microorganisms and airborne particles on a daily basis. However, the lungs are also a highly desirable site for drug delivery using nanoparticles, due to ease of access. Inflammatory diseases such as asthma and emphysema could potentially benefit from nanoparticle-mediated delivery. Additionally, harmful nanoparticles can enter the lungs and cause or even exacerbate these diseases. Unfortunately, there is a lack of knowledge pertaining to this subject. Our work focused on assessing the interactions of nanoparticles in the lungs. First, we looked at nanoparticles that could be used for drug delivery. We found that fluorescentlylabeled nanoparticles were taken up by phagocytic white blood cells called macrophages. Furthermore, these particles did not induce cell death or inflammation in the lungs. Therefore, we found that these particles could be useful for drug delivery in the lungs. Secondly, we investigated potentially harmful nanoparticles and their effects on the lungs. The titanium-based particles called Magnéli phases, have been shown to be produced through coal burning. We found that while these particles are non-inflammatory in the lungs, they do lead to programmed death of macrophages as well as the increase in genes associated with fibrosis. Ultimately these particles led to a decrease in lung function after long-term exposure.

Nanotechnology as a science is emerging rapidly. As materials are synthesized and utilized at the nanometer size scale, concerns of potential health and safety effects are arising. In an effort to elucidate the physicochemical characteristics of nanoparticles influential in toxicological studies, surface properties of metal oxide and carbonaceous nanoparticles were measured. These properties include zeta potential, dissolution and surface-bound chemical components. Subsequently, the role of these properties in oxidative stress was examined in vitro. This work identifies the influence that pH has on the zeta potential of nanoparticles. The zeta potential has the ability to alter colloidal stability, as the largest nanoparticle agglomerate is seen at or near the isoelectric point for each of the particles tested. Furthermore, it was observed that metal oxide nanoparticles which exhibit a charged surface at physiological pH, lead to decreased in vitro cellular viability as compared to those that were neutral. Thus, nanoparticle zeta potential may be an important factor to consider when attempting to predict nanoparticle toxicity. Real world exposure to nanoparticles is a mixture of various particulates and organics. Therefore, to simulate this particle mixture, iron oxide (Fe2O3) and engineered carbon black (ECB) were utilized in combination to identify potential synergistic reactions. Following in vitro exposure, both nanoparticle types are internalized into endosomes, where liberated Fe3+ reacts with hydroquinone moieties on the ECB surface yielding Fe2+. This bioavailable iron may then generate oxidative stress through intracellular pathways including the Fenton reaction. As oxidative stress is common in particulate toxicology, a comparison between the antioxidant defenses of epithelial (A549) and mesothelial (MeT-5A) cell lines was made. The A549 cell line exhibits alterations in the NRF2-KEAP1 transcription factor system and therefore retains high basal levels of phase II antioxidants. Both cell types were exposed to 33 nm silica where intracellular oxidant generation coupled with markers of oxidative stress were observed. While the MeT-5A cells exhibited a decrease in cell viability, the A549 cell line did not. Therefore, proper characterization of both material and biological systems prior to toxicity testing will help to further define the risks associated with the use of nanotechnology.

The use of nanoparticles in biomedical applications has greatly increased in recent years due to their unique properties, which allow them to supplement or even surpass the effectiveness of traditional treatments. Multiple types of nanoparticles are currently utilized or proposed for use in medicine, including gold, silver, and iron oxide. Each of these substances confer a unique set of benefits; gold has anti-inflammatory properties, silver is antibacterial, and iron oxide, in addition to being relatively inert, is useful is treating those with anemia. Unfortunately, many of the properties which make nanoparticles potentially useful for medical applications frequently contribute to their toxicity. While studies have been performed which examine the toxicity of nanoparticle therapeutics, virtually all have taken place in healthy conditions. This is not representative of the conditions in which these nanoparticles will be used, as treatments are, by definition, given to individuals who are somehow unhealthy. Additionally, a large and growing proportion of the population in the United States and worldwide suffer from a chronic disease, with some of the most common being obesity, high cholesterol, and metabolic syndrome. It is therefore important to consider these individuals in the development and testing of nanoparticle therapeutics. Specifically, these diseases alter the content of the circulation beyond the differences which exist solely due to individual variability. This may in turn may alter the biocorona, the term given to the coating of biomolecules which forms on the nanoparticle surface following exposure to a physiological environment. We hypothesized that individual variability and disease, specifically the common diseases obesity, high cholesterol, and metabolic syndrome, would alter the content of the biocorona, and that this would translate to differential nanoparticle toxicity.It was determined that both disease and individual variability caused distinct alterations in the biomolecular content of the biocorona. Further, these alterations were found to elicit distinct inflammatory responses when comparing between individuals or healthy to diseased conditions. These results have implications for the use of nanoparticles in biomedicine, as the variability observed within the biocoronain disease and between individuals may have a significant impact on the efficacy of the treatment,as well as any toxicological effects. It is therefore in the interest of public health to modify the process of developing, testing, and utilizing nanoparticle therapeutics such that the biocorona may work in conjunction with or regardless of differences in the biological milieu which exist as a result of individual variability or disease. By this, researchers 18ABSTRACTThe use of nanoparticles in biomedical applicationshas greatly increased in recent years due to their unique properties, which allow them to supplement or even surpass the effectiveness of traditional treatments. Multiple types of nanoparticles are currently utilized or proposed for use in medicine, including gold, silver, and iron oxide. Each of these substances confer a unique set of benefits; gold has anti-inflammatory properties, silver is antibacterial, and iron oxide, in addition to being relatively inert, is useful is treating those with anemia. Unfortunately, many of the properties which make nanoparticles potentially useful for medical applications frequently contribute to their toxicity. While studies have been performed which examine the toxicity of nanoparticle therapeutics, virtually all have taken place in healthy conditions. This is not representative of the conditions in which these nanoparticles will be used, as treatments are, by definition, given to individuals who are somehow unhealthy. Additionally, a large and growing proportion of the population in the United States and worldwide suffer from achronic disease, with some of the most common being obesity, high cholesterol, and metabolic syndrome. It is therefore important to consider these individuals in the development and testing of nanoparticletherapeutics. Specifically, these diseases alter the content of the circulationbeyond the differences which exist solely due to individual variability. This mayin turn may alter the biocorona, the term given to the coating of biomolecules whichforms on the nanoparticle surface following exposure toa physiologicalenvironment. We hypothesized that individual variability and disease, specifically the common diseases obesity, high cholesterol, and metabolic syndrome, would alter the content of the biocorona, and that this would translateto differential nanoparticle toxicity.It was determined that both disease and individual variability caused distinct alterations in the biomolecular content of the biocorona. Further, these alterations were foundto elicit distinct inflammatory responses when comparing between individuals or healthy to diseased conditions. These results have implications for the use of nanoparticles in biomedicine, as the variability observed within the biocoronain disease and between individuals may have a significant impact on the efficacy of the treatment,as well as any toxicological effects. It is therefore in the interest of public health to modify the process of developing, testing, and utilizing nanoparticle therapeutics such that the biocorona may work in conjunction with or regardless of differences in the biological milieu which exist as a result of individual variability or disease. By this, researchers.

A growing demand for information on the human health and environmental effects of materials produced using nanotechnology has led to a new area of investigation known as nanotoxicology. Research in this field has widespread implications in facilitating the medical applications of nanomaterials but also in addressing occupational and environmental toxicity concerns. Improving our understanding of these issues also has broad appeal in the stewardship of nanotechnology and its acceptance by the public. This work represents some of the early research in burgeoning field of nanotoxicology. Using a variety of in vivo and in vitro models, as well as cellular and molecular techniques I first studied a possible role for the novel cytokine endothelial monocyte activating polypeptide-II (EMAP-II) in acute lung inflammation in rats (Chapter 2). This work demonstrated a significant increase in total EMAP-II concentration in lipopolysaccharide inflamed lungs as early as 1h post-treatment (P<0.05). Increased numbers of monocytes and granulocytes were also observed in lungs treated with mature EMAP-II relative to control rats (P<0.05), and the recruitment of cells did not occur via upregulation of either Interleukin-1β or Macrophage inflammatory protein-2. I further studied whether mature EMAP-II can be induced in pulmonary nanotoxicity studies by exposure to rosette nanotubes (RNT) (Chapters 3-5). In the first in vivo experiments in mice on the RNT(1)-G0 (Chapter 3) I showed an acute inflammatory response at the 50 µg dose by 24h, but this response was resolving by 7d post-exposure as evidenced by a decreased number of cells in the bronchoalveolar lavage fluid (P<0.05) and from histological examination. The results of this study indicated that water soluble and metal-free rosette nanotubes can demonstrate a favorable acute pulmonary toxicity profile in mice. Subsequently, I studied the responses of the pulmonary epithelium using the human Calu-3 cell line (Chapter 4). This experiment indicated that RNT(2)-K1 neither reduces cell viability at 1 or 5 µg/ml doses nor does it induce a dose-dependent inflammatory cytokine response in pulmonary epithelial cells in vitro. My final experiment (Chapter 5) studied the human U937 pulmonary macrophage cell line since the macrophage is one of the key defense mechanisms to encounter RNT in the lung environment. The data indicate that this cell line lacks a robust inflammatory response upon exposure to RNT and that when RNT length is changed by altering the conditions of nanotube self-assembly, cytokine release into the supernatant is not affected profoundly. Although, EMAP-II is upregulated in a lipopolysaccharide model of lung inflammation, it does not serve as a good marker of RNT exposure. The data indicate that RNT have a favourable toxicity profile and these experiments provide a framework upon which rosette nanotubes can be investigated for a range of biomedical applications. Furthermore, in light of media and scientific reports of nanomaterials showing signs of toxicity, this work demonstrates that a biologically inspired nanostructure such as the RNT can be introduced to physiological environments without acute toxicity.

A growing demand for information on the human health and environmental effects of materials produced using nanotechnology has led to a new area of investigation known as nanotoxicology. Research in this field has widespread implications in facilitating the medical applications of nanomaterials but also in addressing occupational and environmental toxicity concerns. Improving our understanding of these issues also has broad appeal in the stewardship of nanotechnology and its acceptance by the public. This work represents some of the early research in burgeoning field of nanotoxicology. Using a variety of in vivo and in vitro models, as well as cellular and molecular techniques I first studied a possible role for the novel cytokine endothelial monocyte activating polypeptide-II (EMAP-II) in acute lung inflammation in rats (Chapter 2). This work demonstrated a significant increase in total EMAP-II concentration in lipopolysaccharide inflamed lungs as early as 1h post-treatment (P<0.05). Increased numbers of monocytes and granulocytes were also observed in lungs treated with mature EMAP-II relative to control rats (P<0.05), and the recruitment of cells did not occur via upregulation of either Interleukin-1β or Macrophage inflammatory protein-2. I further studied whether mature EMAP-II can be induced in pulmonary nanotoxicity studies by exposure to rosette nanotubes (RNT) (Chapters 3-5). In the first in vivo experiments in mice on the RNT(1)-G0 (Chapter 3) I showed an acute inflammatory response at the 50 µg dose by 24h, but this response was resolving by 7d post-exposure as evidenced by a decreased number of cells in the bronchoalveolar lavage fluid (P<0.05) and from histological examination. The results of this study indicated that water soluble and metal-free rosette nanotubes can demonstrate a favorable acute pulmonary toxicity profile in mice. Subsequently, I studied the responses of the pulmonary epithelium using the human Calu-3 cell line (Chapter 4). This experiment indicated that RNT(2)-K1 neither reduces cell viability at 1 or 5 µg/ml doses nor does it induce a dose-dependent inflammatory cytokine response in pulmonary epithelial cells in vitro. My final experiment (Chapter 5) studied the human U937 pulmonary macrophage cell line since the macrophage is one of the key defense mechanisms to encounter RNT in the lung environment. The data indicate that this cell line lacks a robust inflammatory response upon exposure to RNT and that when RNT length is changed by altering the conditions of nanotube self-assembly, cytokine release into the supernatant is not affected profoundly. Although, EMAP-II is upregulated in a lipopolysaccharide model of lung inflammation, it does not serve as a good marker of RNT exposure. The data indicate that RNT have a favourable toxicity profile and these experiments provide a framework upon which rosette nanotubes can be investigated for a range of biomedical applications. Furthermore, in light of media and scientific reports of nanomaterials showing signs of toxicity, this work demonstrates that a biologically inspired nanostructure such as the RNT can be introduced to physiological environments without acute toxicity.

The application of nanoparticles (NPs) in different technologies has led to tremendous advancement in those fields.  Moreover, there is growing interest in application of ultra-small NPs (USNPs) at 1-3 nm due to their distinct molecule like features. Parallel to these promises, there is a growing concern regarding their safety. The main goal of this thesis was to investigate the toxicity and underlying mechanisms following exposure to different metal and metal oxide NPs as well as USNPs. Their effects were studied on Saccharomyces cerevisiae, on hepatocytes and endothelial cells and finally in vivo on zebrafish embryos (Danio rerio). By selecting the rutile form of titanium dioxide (TiO2-USNPs) without intrinsic or intracellular reactive oxygen species (ROS) production, we could study biological impacts solely due to size and direct interaction with the cells. We showed that TiO2-USNPs were not cytotoxic but induced DNA damage. They had anti-angiogenic effects both in vitro and in vivo. Also, at high concentrations they caused complete mortality in zebrafish embryos exposed in water, while at lower concentrations induced delay in hatching. When injected they caused malformations. They specifically induced the differential overexpression of transcripts involved in lipid and cholesterol metabolism in endothelial cells. In hepatocytes they induced the overexpression of proteins in the electron transport chain and decreased lipids in lipid rafts. At 30 nm, TiO2-NPs, were also not cytotoxic but were genotoxic. They had no effects in vivo or on angiogenesis. However, they induced differential expression of transcripts involved in endoplasmic reticulum (ER) stress and heat shock response as well as cholesterol metabolism. This suggests a more toxic response in the cells compared to TiO2-USNPs.  Single walled carbon nanotubes (SWCNTs) despite having the highest oxidative activity among the NPs studied, were not severely cyto- or genotoxic but induced expression of transcripts involved in early ER stress response. Copper oxide (CuO-NPs) was the most toxic NPs studied due to both ion release and ROS production, affecting lipid metabolism of the cells. Silver (Ag-NPs) were also cytotoxic and caused the disruption of cellular components and lipids. ZnO-NPs were not cytotoxic, did not affect cellular lipids but they increased the size of vacuoles in yeast cells. Finally by using superparamagnetic iron oxide NPs (SPIONs) with different coatings, and using a mathematical model, a nano impact index (INI) was developed as a tool to enable the comparison of nanotoxicology data. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Accepted. Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript.</p>

Wastewater treatment plants (WwTP) act as the principle buffer between anthropogenic sources of Silver Nanoparticles (AgNPs) and environmental targets. AgNPs, given their effective anti-microbial properties, have the potential to negatively impact WwTP processes and organisms within the natural environment. A clear understanding of the fate and transport of AgNPs as they pass through WwTPs is crucial in evaluating AgNPs impacts for WwTP process, the natural environment and in the development of a comprehensive environmental risk assessment for AgNPs. The main aim of this thesis was to carry out an analysis on the fate, transport and transformation of AgNPs through WwTP relevant filtration medias in order to understand more about the toxicological implications for both WwTP processes and receiving environments. AgNPs were synthesised in-house, via an in-situ reduction method, which produced a homogeneous dispersion of nanoparticles of average particle diameter 9.98nm, with a standard deviation of 3.11nm. Column studies and adsorption isotherm experiments were conducted to investigate the fate and transport of silver nitrate, AgNPs and bulk silver across media beds of quartz sand and granulated activated carbon (GAC), both chosen for their relevance in wastewater treatment protocols. TEM imaging and EDS analysis was employed to characterise the AgNPs physically and elementally within the column influents and effluents. An original contribution made to the existing knowledge on AgNPs is that in contrast to bulk silver and silver nitrate, uncoated AgNPs were observed to be highly mobile through the quartz sand media. This high mobility was in contrast with the prior expectation that van der Waals forces of attraction between the positively charged AgNPs and the negative charge of the silica surfaces within the sand bed would lead to some measure of retention within the column matrix. The resulting high mobility of the AgNPs was attributed to particle surface contamination of boride ions originating from the reduction agent used during the synthesis process. This highlights (and reinforces) the importance of better understanding on the implications of the various methods of synthesis and use of capping agents for AgNPs characteristics and the impact this has on fate and transport. AgNPs were also noted to have been significantly altered after their passage through the quartz sand media, with up to 83% of the sample increasing in size, from 9.98nm to an average of 18.26nm and a maximum of 144nm. Particle size measurements were made using the measuring tool available in the GNU Image Manipulation Program (GIMP). This size increase was attributed to the formation of nano-alloy clusters with residual gold and iron compounds, naturally present within the sand bed. In the case of silver-gold alloy clusters, this is expected to exhibit positive implications for future environmental fates of the resulting AgNPs, where the presence of gold in alloy clusters has been observed to significantly deactivate AgNPs silver ion release. In contrast to the sand, it was observed that the GAC was an effective absorber of AgNPs. However, this was observed to be a size dependant relationship, where the GAC was not observed to be effective for adsorption of bulk silver at particle sizes of 300 – 800nm. In this thesis, in addition to the experimental work, a novel, low complexity technique was developed for the detection and quantification of AgNPs in laboratory aqueous solutions. This protocol utilises a laboratory bench top photometer and gave AgNPs concentration results that reliably and accurately reflected that of ICP-MS and ICP-OES results within a detection range of 0.01 and 20mg/L; where the correlation coefficient between the instrument absorbance response and ICP-MS/OES concentration (at 450nm) was R2 0.994.

Manufactured nanomaterials (MNMs) from the rapidly increasing number of consumer products that contain MNMs are being discharged into waste streams. Increasing evidence suggests that several classes of MNMs may accumulate in sludge derived from wastewater treatment and ultimately in soil following land application as biosolids. Little research has been conducted to evaluate the impact of MNMs on terrestrial ecosystems, despite the fact that land application of biosolids from wastewater treatment will be a major pathway for the introduction of MNMs to the environment. To begin addressing this knowledge gap, we have conducted a series of experiments designed to test how bioavailable MNMs are to terrestrial ecoreceptors when exposed through a variety of pathways. First, we used the model organisms Nicotiana tabacum L. cv Xanthi (tobacco) and Triticum aestivum (wheat) to investigate plant uptake of 10, 30 and 50 nm diameter gold (Au) MNMs coated with either tannate (T-MNMs) or citrate (C-MNMs). Both C-MNMs and T-MNMs of each size treatment bioaccumulated in tobacco, but no bioaccumulation of MNMs was observed for any treatment in wheat. In a second exposure, we investigated the potential for bioaccumulation of MNMs from contaminated plant surfaces by a terrestrial secondary consumer, tobacco hornworm (Manduca sexta). We found that hornworms bioaccumulate Au MNMs, but that the assimilation efficiency of bioaccumulation was low. Hornworms eliminate ingested Au MNMs rapidly from 0-24 h, but very slowly from 1 d to 7 d. Finally, we used the model organisms tobacco and tobacco hornworm to investigate the potential for trophic transfer of Au MNMs. Biomagnification of Au MNMs was observed in the hornworms. We have demonstrated that MNMs of a wide range of size and with different surface chemistries are bioavailable to plants, that MNMs resuspended by wind, rain, biota, and mechanical disturbance from soil onto plant surfaces are bioavailable to terrestrial consumers, and that trophic transfer and biomagnification of plant accumulated MNMs can occur. These results have important implications for risks associated with nanotechnology, including the potential for human exposure.

Nanoparticles (particles less than 100 nm in at least one dimension) exhibit chemical properties that differ from their bulk counterparts. Furthermore, they exhibit increased potential for systemic toxicities due to their deposition deep within pulmonary tissue upon inhalation. Thus, standard regulatory assays alone may not always be appropriate for evaluation of their full spectrum of toxicity. Systems biology (e.g., the study of molecular processes to describe a system as a whole) has emerged as a powerful platform proposed to provide insight in potential hazard, mode of action and human disease relevance. This work makes use of systems biology to characterize carbon black nanoparticle-induced toxicities in pulmonary and extra-pulmonary tissues (i.e., liver and heart) in mice over dose and time. This includes investigations of gene expression profiles, microRNA expression profiles, tissue-specific phenotypes and plasma proteins. The data are discussed in the context of potential use in human health risk assessment. In general, the work provides an example of how toxicogenomics can be used to support human health risk assessment.

Nanoparticles (particles less than 100 nm in at least one dimension) exhibit chemical properties that differ from their bulk counterparts. Furthermore, they exhibit increased potential for systemic toxicities due to their deposition deep within pulmonary tissue upon inhalation. Thus, standard regulatory assays alone may not always be appropriate for evaluation of their full spectrum of toxicity. Systems biology (e.g., the study of molecular processes to describe a system as a whole) has emerged as a powerful platform proposed to provide insight in potential hazard, mode of action and human disease relevance. This work makes use of systems biology to characterize carbon black nanoparticle-induced toxicities in pulmonary and extra-pulmonary tissues (i.e., liver and heart) in mice over dose and time. This includes investigations of gene expression profiles, microRNA expression profiles, tissue-specific phenotypes and plasma proteins. The data are discussed in the context of potential use in human health risk assessment. In general, the work provides an example of how toxicogenomics can be used to support human health risk assessment.