Metal-polymer nanocomposites consisting of gold nanorods and temperature-responsive hydrogel nanoparticulates were investigated for use in externally-controlled drug delivery systems. Several different thermo-responsive hydrogels including poly(N-isopropyl acrylamide) (PNIPAAm) and poly(N-isopropryl acrylamide-co-acrylic acid) (P(NIPAAm-co-AA)) nanoparticles were synthesized for these nanocomposites using an aqueous dispersion polymerization method. In addition, nanoparticles of interpenetrating polymer networks (IPN) composed of poly(acrylamide) (PAAm) and poly(acrylic acid) (PAA) were synthesized using a water-in-oil emulsion polymerization. Temperature-responsive equilibrium swelling behavior of nanoparticles with varying crosslinking densities was characterized using dynamic light scattering. IPN systems exhibited a positive swelling response upon heating while PNIPAAm and copolymer systems collapsed upon increase in temperature above the transition point. Nanoparticles were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) which demonstrated shape and morphology of polymer particles. Gold-polymer nanocomposites were formed by grafting gold nanorods to the surface of the polymer nanoparticles. Amine-functionalized gold nanorods were coupled to polymers using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (Sulfo-NHS) to activate carboxyl groups on the surface of the polymer nanoparticles. TEM confirmed successful formation of the metal-polymer nanocomposites. Loading and release of a model therapeutic were done to assess the potential use of the polymer component of the nanocomposite for drug delivery. Fluorescein, a model for chemotherapeutics, was loaded into P(NIPAAm-co-AA) polymer nanoparticulates. Loading of the compound was shown to be a function of crosslinking density in the polymer network. Maximum loading was achieved using nanoparticles synthesized with a 10 mol% crosslinker feed ratio with entrapment efficiencies of 80.0 % and loading capacities of 12.0 %. Cytotoxicity studies were performed using a NIH/3T3 mouse fibroblast cell model. Cell viabilities in presence of P(NIPAAm-co-AA) nanoparticles were comparable to (not statistically different than) controls at concentrations up to 4 mg/ml. Similarly, gold-polymer composite concentrations up to 0.5 mg/ml caused limited cell death. / text

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Traditional radiation therapy is limited by the radiotoxic effects on surrounding healthy tissues. This project investigated the use of a gold nanoparticle (AuNP) conjugated to a cell-penetrating peptide (CPP) to increase tumour cell death during radiotherapy by maximizing the cellular import of the gold nanoparticles. ~8300 octaarginine CPPs were coupled per 30 nm AuNP through poly(ethylene glycol) spacers (AuNP-PEG-CPP). The CPPs enhanced the internalization of the AuNPs into three human breast cancer cell lines by a factor >2 as compared to untargeted AuNPs. Cells were treated with AuNP-PEG-CPP for 24 hours, prior to radiotherapy and their long-term proliferation was assessed in clonogenic assays. The increased internalization of AuNPs by the CPPs resulted in greater cell death following exposure to 300 kVp radiotherapy, by a dose enhancement factors between 1.3 and 2.1 depending on the cell line. These findings illustrate the potential of using AuNP-CPPs to enhance radiotherapy in patients.

Traditional radiation therapy is limited by the radiotoxic effects on surrounding healthy tissues. This project investigated the use of a gold nanoparticle (AuNP) conjugated to a cell-penetrating peptide (CPP) to increase tumour cell death during radiotherapy by maximizing the cellular import of the gold nanoparticles. ~8300 octaarginine CPPs were coupled per 30 nm AuNP through poly(ethylene glycol) spacers (AuNP-PEG-CPP). The CPPs enhanced the internalization of the AuNPs into three human breast cancer cell lines by a factor >2 as compared to untargeted AuNPs. Cells were treated with AuNP-PEG-CPP for 24 hours, prior to radiotherapy and their long-term proliferation was assessed in clonogenic assays. The increased internalization of AuNPs by the CPPs resulted in greater cell death following exposure to 300 kVp radiotherapy, by a dose enhancement factors between 1.3 and 2.1 depending on the cell line. These findings illustrate the potential of using AuNP-CPPs to enhance radiotherapy in patients.

Small particles of gold (< 100 nm) have attracted great interest among researchers due to the unique combination of their physicochemical properties. Among various research areas catalysis and bio-nanotechnology represent the largest areas of growth for gold nanoparticle research. Catalysts play a crucial role in the life of the modern society. More than 85 % of all chemical processes are catalytic, and this number is increasing every year. There is a constant demand to develop more efficient and durable catalysts in order to address increasing energy demands and environmental requirements. The first part of the thesis is focused on the study of catalytic activity of supported gold and mixed-metal catalysts, derived from atomically precise phosphine-stabilised gold and mixed-metal clusters in the liquid-phase oxidation of cyclohexene and one-pot synthesis of imines. Various characterisation techniques (TEM, diffuse-reflectance UV-vis, XPS, etc.) as well as kinetic studies were used in order to establish the optimal structure of gold catalysts. The effect of catalytic support, nature of hetero-metal atom for mixed metal-systems and type of catalyst pre-treatment were also examined. Gold nanoparticles are actively studied in various biomedical applications as they are offering new approaches to the detection and treatment of life-threatening diseases, such as cancer. The second part of this work discusses our preliminary investigations of biological activity of gold nanoparticles, stabilised with cancer-targeting molecules. In particular, the cytotoxicity of gold nanoparticles was studied using 11 different cancer and normal cell types. Gold uptake and particle localisation inside the cells were also investigated.

The development of sustainable, environmentally benign oxidation processes of organic compounds is an important task for chemical industry. This challenge can be addressed by designing catalysts that enable the utilisation of molecular oxygen as an oxidant. The work in this thesis is focused on the development of heterogeneous catalysts for the selective aerobic oxidation of various organic compounds. The first part of the thesis (Chapters 3 and 4) covers the study of bifunctional gold catalysts for the solvent-free aerobic oxidation of cyclohexene, with a particular focus on tuning the selectivity of the catalyst. Various characterisation techniques (such as TEM, diffuse-reflectance UV-Vis spectroscopy, XPS), catalytic experiments and kinetic studies were used to investigate the nature of catalyst functionality and establish the optimal structure of a gold catalyst. The second part of the thesis (Chapter 5) covers the study of the photocatalytic activity of hydrous ruthenium oxide deposited on TiO₂ in the aerobic oxidation of amines to nitriles under irradiation with visible light. The effect of the wavelength of the utilised light, applicability of the Sun as light source and water as a solvent were investigated. High catalytic activity of ruthenium-based catalyst was demonstrated for various benzylic and aliphatic amines. Various mechanistic studies were performed, based on which the mechanism of photocatalysis was suggested.

Cold weather masonry construction is a major concern for contractors as they either have to implement heating practices for laying and curing masonry systems or postpone the construction to warmer periods. This can lead to loss of productivity rate and delays in construction schedules with associated extra costs. This thesis explores a novel approach for mitigating the adverse effects of cold weather on masonry construction in early fall periods through the application of nano-alumina (NA) and nano-silica (NS) in mortar joints. The assessment criteria were based on the fresh properties, hardened properties and microstructural features of mortar mixtures and mechanical behaviour of concrete masonry prisms at early and later ages. Various test results show that NS can be successfully used to minimize the adverse effects of cold temperature on mortar joints by speeding up the hydration of cement, shortening the setting time, and increasing the strength up to 72 h.

Polyoxometalates (POMs) are a class of transition-metal oxide clusters with significant applications in material science as well as in the biomedical field. Recently, it has been reported that POMs exhibit antitumor activity. POMs containing molybdenum (Mo), tungsten (W), and vanadium (V) with oxygen are three types of POMs with different structural features introduced by our lab as a novel inorganic chemotherapeutic agent for cancer treatment. In this study, Vanadium polyoxometalate (V-POM), which exhibited highest cytotoxicity in 5 different cancer cell lines in in vitro experiment, will be incorporated with Gelatin type B through polymer modification in hopes of prolonging circulation time and avoiding undesired toxicity. The stability, cellular uptake, and cytotoxicity of the V6-POM/Gelatin nanoparticles will be investigated in vitro. The reported study indicates the feasibility of using V6-POM/gelatin nanoparicles for anticancer applications.

Nanoparticles may affect secondary pollutants such as copper. Layer Double Hydroxides (LDH) are synthetically produced nanoparticles that adsorb copper via cation exchange. Pretreatment of copper test solutions with LDH nanoparticles followed by filtration removal of LDH nanoparticles demonstrated the smallest LDH aggregates removed the most copper toxicity. This was due to increased surface area for cation exchange relative to larger particle aggregates. Co-exposure tests of copper chloride and clay were run to determine if smaller clay particles increased copper uptake by D. magna. Coexposure treatments had lower LC50 values compared to the filtration tests, likely as a result of additive toxicity. LDH nanoclays do reduce copper toxicity in Daphnia magna and may serve as a remediation tool.

While research on the environmental impacts of engineered nanoparticles (ENPs) is growing, the potential for them to be chemically transformed in the atmosphere has been largely ignored. The overall objective of this work was to assess the atmospheric transformation of carbonaceous nanoparticles (CNPs). The research focuses on C₆₀ fullerene because it is an important member of the carbonaceous nanoparticle (CNP) family and is used in a wide variety of applications. The first specific objective was to review the potential of atmospheric transformations to alter the environmental impacts of CNPs. We described atmospheric processes that were likely to physically or chemically alter aerosolized CNPs and demonstrated their relevance to CNP behavior and toxicity in the aqueous and terrestrial environment. In order to investigate the transformations of CNP aerosols under controlled conditions, we developed an aerosolization technique that produces nano-scale aerosols without using solvents, which can alter the surface chemistry of the aerosols. We demonstrated the technique with carbonaceous (C₆₀) and metal oxide (TiO₂, CeO₂) nanoparticle powders. All resulting aerosols exhibited unimodal size distributions and mode particle diameters below 100 nm. We used the new aerosolization technique to investigate the reaction between aerosolized C₆₀ and atmospherically realistic levels of ozone (O₃) in terms of reaction products, reaction rate, and oxidative stress potential. We identified C₆₀O, C₆₀O2, and C₆₀O3 as products of the C₆₀-O3 reaction. We demonstrated that the oxidative stress potential of C₆₀ may be enhanced by exposure to O3. We found the pseudo-first order reaction rate to be 9 x 10⁻⁶ to 2 x 10⁻⁵ s⁻¹, which is several orders of magnitude lower than the rate for several PAH species under comparable conditions. This research has demonstrated that a thorough understanding of atmospheric chemistry of ENPs is critical for accurate prediction of their environmental impacts. It has also enabled future research in that vein by developing a novel technique to produce nanoscale aerosols from nanoparticle powders. Results of this research will help guide the formulation of appropriate environmental policy concerning the regulation of ENPs. / Ph. D.