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- Creators: Arizona State University
- Creators: Fox, Peter
Description
Bioparticles comprise a diverse amount of materials ubiquitously present in nature. From proteins to aerosolized biological debris, bioparticles have important roles spanning from regulating cellular functions to possibly influencing global climate. Understanding their structures, functions, and properties provides the necessary tools to expand our fundamental knowledge of biological systems and exploit them for useful applications. In order to contribute to this efforts, the work presented in this dissertation focuses on the study of electrokinetic properties of liposomes and novel applications of bioaerosol analysis. Using immobilized lipid vesicles under the influence of modest (less than 100 V/cm) electric fields, a novel strategy for bionanotubule fabrication with superior throughput and simplicity was developed. Fluorescence and bright field microscopy was used to describe the formation of these bilayer-bound cylindrical structures, which have been previously identified in nature (playing crucial roles in intercellular communication) and made synthetically by direct mechanical manipulation of membranes. In the biological context, the results of this work suggest that mechanical electrostatic interaction may play a role in the shape and function of individual biological membranes and networks of membrane-bound structures. A second project involving liposomes focused on membrane potential measurements in vesicles containing trans-membrane pH gradients. These types of gradients consist of differential charge states in the lipid bilayer leaflets, which have been shown to greatly influence the efficacy of drug targeting and the treatment of diseases such as cancer. Here, these systems are qualitatively and quantitatively assessed by using voltage-sensitive membrane dyes and fluorescence spectroscopy. Bioaerosol studies involved exploring the feasibility of a fingerprinting technology based on current understanding of cellular debris in aerosols and arguments regarding sampling, sensitivity, separations and detection schemes of these debris. Aerosolized particles of cellular material and proteins emitted by humans, animals and plants can be considered information-rich packets that carry biochemical information specific to the living organisms present in the collection settings. These materials could potentially be exploited for identification purposes. Preliminary studies evaluated protein concentration trends in both indoor and outdoor locations. Results indicated that concentrations correlate to certain conditions of the collection environment (e.g. extent of human presence), supporting the idea that bioaerosol fingerprinting is possible.
ContributorsCastillo Gutiérrez, Josemar Andreina (Author) / Hayes, Mark A. (Thesis advisor) / Herckes, Pierre (Committee member) / Ghrilanda, Giovanna (Committee member) / Arizona State University (Publisher)
Created2011
Description
In the United States, 12% of women are typically diagnosed with breast cancer, where 20-30% of these cases are identified as Triple Negative Breast Cancer (TNBC). In the state of Arizona, 810 deaths occur due to breast cancer and more than 4,600 cases are diagnosed every year (American Cancer Society). The lack of estrogen, progesterone, and HER2 receptors in TNBC makes discovery of targeted therapies further challenging. To tackle this issue, a novel multi-component drug vehicle is presented. Previously, we have shown that mitoxantrone, a DNA damaging drug, can sensitize TNBC cells to TRAIL, which is a protein that can selectively kill cancer cells. In this current study, we have formulated aminoglycoside-derived nanoparticles (liposomes) loaded with mitoxantrone, PARP inhibitors, for delivery to cancer cells. PARP inhibitors are helpful in preventing cancer cells from repairing their DNA following damage with other drugs (e.g. mitoxantrone). Various treatment liposome groups, consisting of lipid-containing polymers (lipopolymers) synthesized in our laboratory, were formulated and characterized for their size, surface charge, and stability. PARP inhibitors and treatment of cells for in-vitro and in-vivo experiments with these liposomes resulted in synergistic death of cancer cells. Finally, studies to evaluate the pre-clinical efficacy of these approaches using immuno-deficient mouse models of TNBC disease have been initiated.
ContributorsMuralikrishnan, Harini (Author) / Rege, Kaushal (Thesis advisor) / Holechek, Susan (Committee member) / Nannenga, Brent (Committee member) / Arizona State University (Publisher)
Created2018
Description
To mimic the membrane environment for the photosynthetic reaction center of the photoheterotrophic Heliobacterium modesticaldum, a proteoliposome system was developed using the lipids found in native membranes, as well as a lipid possessing a Ni(II)-NTA head group. The liposomes were also saturated with menaquinone-9 to provide further native conditions, given that menaquinone is active within the heliobacterial reaction center in some way. Purified heliobacterial reaction center was reconstituted into the liposomes and a recombinant cytochrome c553 was decorated onto the liposome surface. The native lipid-attachment sequence of cytochrome c553 was truncated and replaced with a hexahistidine tag. Thus, the membrane-anchoring observed in vivo was simulated through the histidine tag of the recombinant cytochrome binding to the Ni(II)-NTA lipid's head group. The kinetics of electron transfer in this system was measured and compared to native membranes using transient absorption spectroscopy. The preferential-orientation of reconstituted heliobacterial reaction center was also measured by monitoring the proteoliposome system's ability to reduce a soluble acceptor, flavodoxin, in both whole and detergent-solubilized proteoliposome conditions. These data demonstrate that this proteoliposome system is reliable, biomimetic, and efficient for selectively testing the function of the photosynthetic reaction center of Heliobacterium modesticaldum and its interactions with both donors and acceptors. The recombinant cytochrome c553 performs similarly to native cytochrome c553 in heliobacterial membranes. These data also support the hypothesis that the orientation of the reconstituted reaction center is inherently selective for its bacteriochlorophyll special pair directed to the outer-leaflet of the liposome.
ContributorsJohnson, William Alexander (Author) / Redding, Kevin E (Thesis advisor) / Van Horn, Wade D (Committee member) / Jones, Anne K (Committee member) / Arizona State University (Publisher)
Created2018
Description
The influence of climate variability and reclaimed wastewater on the water supply necessitates improved understanding of the treatability of trace and bulk organic matter. Dissolved organic matter (DOM) mobilized during extreme weather events and in treated wastewater includes natural organic matter (NOM), contaminants of emerging concern (CECs), and microbial extracellular polymeric substances (EPS). The goal of my dissertation was to quantify the impacts of extreme weather events on DOM in surface water and downstream treatment processes, and to improve membrane filtration efficiency and CECs oxidation efficiency during water reclamation with ozone. Surface water quality, air quality and hydrologic flow rate data were used to quantify changes in DOM and turbidity following dust storms, flooding, or runoff from wildfire burn areas in central Arizona. The subsequent impacts to treatment processes and public perception of water quality were also discussed. Findings showed a correlation between dust storm events and change in surface water turbidity (R2=0.6), attenuation of increased DOM through reservoir systems, a 30-40% increase in organic carbon and a 120-600% increase in turbidity following severe flooding, and differing impacts of upland and lowland wildfires. The use of ozone to reduce membrane fouling caused by vesicles (a subcomponent of EPS) and oxidize CECs through increased hydroxyl radical (HO●) production was investigated. An "ozone dose threshold" was observed above which addition of hydrogen peroxide increased HO● production; indicating the presence of ambient promoters in wastewater. Ozonation of CECs in secondary effluent over titanium dioxide or activated carbon did not increase radial production. Vesicles fouled ultrafiltration membranes faster (20 times greater flux decline) than polysaccharides, fatty acids, or NOM. Based upon the estimated carbon distribution of secondary effluent, vesicles could be responsible for 20-60% of fouling during ultrafiltration and may play a vital role in other environmental processes as well. Ozone reduced vesicle-caused membrane fouling that, in conjunction with the presence of ambient promoters, helps to explain why low ozone dosages improve membrane flux during full-scale water reclamation.
ContributorsBarry, Michelle (Author) / Barry, Michelle C (Thesis advisor) / Westerhoff, Paul (Committee member) / Fox, Peter (Committee member) / Halden, Rolf (Committee member) / Hristovski, Kiril (Committee member) / Arizona State University (Publisher)
Created2014
Description
Radioactive cesium (137Cs), released from nuclear power plants and nuclear accidental releases, is a problem due to difficulties regarding its removal. Efforts have been focused on removing cesium and the remediation of the contaminated environment. Traditional treatment techniques include Prussian blue and nano zero-valent ion (nZVI) and nano-Fe/Cu particles to remove Cs from water; however, they are not efficient at removing Cs when present at low concentrations of about 10 parts-per-billion (ppb), typical of concentrations found in the radioactive contaminated sites.
The objective of this study was to develop an innovative and simple method to remove Cs+ present at low concentrations by engineering a proteoliposome transporter composed of an uptake protein reconstituted into a liposome vesicle. To achieve this, the uptake protein, Kup, from E. coli, was isolated through protein extraction and purification procedures. The new and simple extraction methodology developed in this study was highly efficient and resulted in purified Kup at ~1 mg/mL. A new method was also developed to insert purified Kup protein into the bilayers of liposome vesicles. Finally, removal of CsCl (10 and 100 ppb) was demonstrated by spiking the constructed proteoliposome in lab-fortified water, followed by incubation and ultracentrifugation, and measuring Cs+ with inductively coupled plasma mass spectrometry (ICP-MS).
The ICP-MS results from testing water contaminated with 100 ppb CsCl, revealed that adding 0.1 – 8 mL of Kup proteoliposome resulted in 0.29 – 12.7% Cs removal. Addition of 0.1 – 2 mL of proteoliposome to water contaminated with 10 ppb CsCl resulted in 0.65 – 3.43% Cs removal. These removal efficiencies were greater than the control, liposome with no protein.
A linear relationship was observed between the amount of proteoliposome added to the contaminated water and removal percentage. Consequently, by adding more volumes of proteoliposome, removal can be simply improved. This suggests that with ~ 60-70 mL of proteoliposome, removal of about 90% can be achieved. The novel technique developed herein is a contribution to emerging technologies in the water and wastewater treatment industry.
The objective of this study was to develop an innovative and simple method to remove Cs+ present at low concentrations by engineering a proteoliposome transporter composed of an uptake protein reconstituted into a liposome vesicle. To achieve this, the uptake protein, Kup, from E. coli, was isolated through protein extraction and purification procedures. The new and simple extraction methodology developed in this study was highly efficient and resulted in purified Kup at ~1 mg/mL. A new method was also developed to insert purified Kup protein into the bilayers of liposome vesicles. Finally, removal of CsCl (10 and 100 ppb) was demonstrated by spiking the constructed proteoliposome in lab-fortified water, followed by incubation and ultracentrifugation, and measuring Cs+ with inductively coupled plasma mass spectrometry (ICP-MS).
The ICP-MS results from testing water contaminated with 100 ppb CsCl, revealed that adding 0.1 – 8 mL of Kup proteoliposome resulted in 0.29 – 12.7% Cs removal. Addition of 0.1 – 2 mL of proteoliposome to water contaminated with 10 ppb CsCl resulted in 0.65 – 3.43% Cs removal. These removal efficiencies were greater than the control, liposome with no protein.
A linear relationship was observed between the amount of proteoliposome added to the contaminated water and removal percentage. Consequently, by adding more volumes of proteoliposome, removal can be simply improved. This suggests that with ~ 60-70 mL of proteoliposome, removal of about 90% can be achieved. The novel technique developed herein is a contribution to emerging technologies in the water and wastewater treatment industry.
ContributorsHakim Elahi, Sepideh (Author) / Conroy-Ben, Otakuye (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2018