Matching Items (6)
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- All Subjects: Nanoparticles
- Creators: Chemical Engineering Program
Scaled Formulations of Succinate based Polymeric particles for Eventual Testing in Clinical Settings
Description
With an estimated 19.3 million cases and nearly 10 million deaths from cancer in a year worldwide, immunotherapies, which stimulate the immune system so that it can attack and kill cancer cells, are of interest. Tumors are produced from the uncontrolled and rapid proliferation of cells in the body. Cancer cells rely heavily on glutamine for proliferation due to its contribution of nitrogen for nucleotides and amino acids. Glutamine enters the tricarboxylic acid (TCA) cycle as α-ketoglutarate via glutaminolysis, in which glutamine is converted into glutamate by the enzyme glutaminase (GLS). Cancer cell proliferation may be limited by using glutaminase inhibitor CB-839. However, immune cells also rely on these metabolic pathways. Thus, a method for restarting the metabolic pathways in the presence of inhibitors is attractive. Succinate, a key metabolite in the TCA cycle, has been shown to stimulate the immune system despite the presence of metabolic inhibitors, such as CB-839. A delivery method of succinate is through microparticles (MPs) or nanoparticles (NPs) which may be coated in polyethylene glycol (PEG) for improved hydrophilicity. Polyethylene glycol succinate (PEGS) MPs were generated and tested in vivo and were shown to reduce tumor growth and prolong mouse survival. With the success in stimulating the immune system with MPs, NPs were investigated for an improved immune response due to their smaller size. These PES NPs were generated in this study. For clinical settings, it is necessary to scale-up the production of particles. Two methods of scale-up were proposed: (1) a combination of multiple small batches into a mixed batch, and (2) a singular, big batch. Size and release properties were compared to a small batch of PES NPs, and it was concluded that the big batch more closely resembled the small batch compared to the mixed batch. Thus, it was concluded that batch-to-batch variability plays a larger role than volume changes when scaling-up. In clinical settings, it is recommended to produce the particles in a big batch rather than a mixed batch.
ContributorsSundem, Alison (Author) / Acharya, Abhinav (Thesis director) / Inamdar, Sahil (Committee member) / Barrett, The Honors College (Contributor) / School of Molecular Sciences (Contributor) / Chemical Engineering Program (Contributor)
Created2023-05
Description
Polymer-nanoparticle composites (PNCs) show improved chemical and physical properties compared to pure polymers. However, nanoparticles dispersed in a polymer matrix tend to aggregate due to strong interparticle interactions. Electrospun nanofibers impregnated with nanoparticles have shown improved dispersion of nanoparticles. Currently, there are few models for quantifying dispersion in a PNC, and none for electrospun PNC fibers. A simulation model was developed to quantify the effects of nanoparticle volume loading and fiber to particle diameter ratios on the dispersion in a nanofiber. The dispersion was characterized using the interparticle distance along the fiber. Distributions of the interparticle distance were fit to Weibull distributions and a two-parameter empirical equation for the mean and standard deviation was found. A dispersion factor was defined to quantify the dispersion along the polymer fiber. This model serves as a standard for comparison for future experimental studies through its comparability with microscopy techniques, and as way to quantify and predict dispersion in polymer-nanoparticle electrospinning systems with a single performance metric.
ContributorsBalzer, Christopher James (Author) / Mu, Bin (Thesis director) / Armstrong, Mitchell (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
One of the grand challenges of engineering is to provide access to clean water because it is predicted that by 2025 more than two thirds of the world’s population will face severe water shortages. To combat this global issue, our lab focuses on creating a novel composite membrane to recover potable water from waste. For use as the water-selective component in this membrane design Linde Type A zeolites were synthesized for optimal size without the use of a template. Current template-free synthesis of zeolite LTA produces particles that are too large for our application therefore the particle size was reduced in this study to reduce fouling of the membrane while also investigating the nanoparticle synthesis mechanisms. The time and temperature of the reaction and the aging of the precursor gel were systematically modified and observed to determine the optimal conditions for producing the particles. Scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray analysis were used for characterization. Sub-micron sized particles were synthesized at 2 weeks aging time at -8°C with an average size of 0.6 micrometers, a size suitable for our membrane. There is a limit to the posterity and uniformity of particles produced from modifying the reaction time and temperature. All results follow general crystallization theory. Longer aging produced smaller particles, consistent with nucleation theory. Spinodal decomposition is predicted to affect nucleation clustering during aging due to the temperature scheme. Efforts will be made to shorten the effective aging time and these particles will eventually be incorporated into our mixed matrix osmosis membrane.
ContributorsKing, Julia Ann (Author) / Lind, Mary Laura (Thesis director) / Durgun, Pinar Cay (Committee member) / Chemical Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Proteins play a central role to human body and biological activities. As powerful tools for protein detections, many surface plasmon resonance based techniques have been developed to enhance the sensitivity. However, sensitivity is not the only final goal. As a biosensor, four things really matter: sensitivity, specificity, resolution (temporal/spatial) and throughput.
This dissertation presents several works on developing novel plasmonic based techniques for protein detections on the last two aspects to extend the application field. A fast electrochemically controlled plasmonic detection technique is first developed with the capability of monitoring electrochemical signal with nanosecond response time. The study reveals that the conformational gating of electron transfer in a redox protein (cytochrome c) takes place over a broad range of time scales (sub-µs to ms). The second platform integrates ultra-low volume piezoelectric liquid dispensing and plasmonic imaging detection to monitor different protein binding processes simultaneously with low sample cost. Experiment demonstrates the system can observe binding kinetics in 10×10 microarray of 6 nL droplet, with variations of kinetic rate constants among spots less than ±5%. A focused plasmonic imaging system with bi-cell algorithm is also proposed for spatial resolution enhancement. The two operation modes, scanning mode and focus mode, can be applied for different purposes. Measurement of bacterial aggregation demonstrates the higher spatial resolution. Detections of polystyrene beads binding and 50 nm gold nanoparticles oscillation show a high signal to noise ratio of the system.
The real properties of protein rely on its dynamic personalities. The above works shed light upon fast and high throughput detection of protein kinetics, and enable more applications for plasmonic imaging techniques. It is anticipated that such methods will help to invoke a new surge to unveil the mysteries of biological activities and chemical process.
This dissertation presents several works on developing novel plasmonic based techniques for protein detections on the last two aspects to extend the application field. A fast electrochemically controlled plasmonic detection technique is first developed with the capability of monitoring electrochemical signal with nanosecond response time. The study reveals that the conformational gating of electron transfer in a redox protein (cytochrome c) takes place over a broad range of time scales (sub-µs to ms). The second platform integrates ultra-low volume piezoelectric liquid dispensing and plasmonic imaging detection to monitor different protein binding processes simultaneously with low sample cost. Experiment demonstrates the system can observe binding kinetics in 10×10 microarray of 6 nL droplet, with variations of kinetic rate constants among spots less than ±5%. A focused plasmonic imaging system with bi-cell algorithm is also proposed for spatial resolution enhancement. The two operation modes, scanning mode and focus mode, can be applied for different purposes. Measurement of bacterial aggregation demonstrates the higher spatial resolution. Detections of polystyrene beads binding and 50 nm gold nanoparticles oscillation show a high signal to noise ratio of the system.
The real properties of protein rely on its dynamic personalities. The above works shed light upon fast and high throughput detection of protein kinetics, and enable more applications for plasmonic imaging techniques. It is anticipated that such methods will help to invoke a new surge to unveil the mysteries of biological activities and chemical process.
ContributorsWang, Yan (Author) / Tao, Nongjian (Thesis advisor) / Chae, Junseok (Committee member) / Goryll, Michael (Committee member) / Wang, Shaopeng (Committee member) / Arizona State University (Publisher)
Created2018
Description
Gold nanoparticles are valuable for their distinct properties and nanotechnology applications. Because their properties are controlled in part by nanoparticle size, manipulation of synthesis method is vital, since the chosen synthesis method has a significant effect on nanoparticle size. By aiding mediating synthesis with proteins, unique nanoparticle structures can form, which open new possibilities for potential applications. Furthermore, protein-mediated synthesis favors conditions that are more environmentally and biologically friendly than traditional synthesis methods. Thus far, gold particles have been synthesized through mediation with jack bean urease (JBU) and para mercaptobenzoic acid (p-MBA). Nanoparticles synthesized with JBU were 80-90nm diameter in size, while those mediated by p-MBA were revealed by TEM to have a size between 1-3 nm, which was consistent with the expectation based on the black-red color of solution. Future trials will feature replacement of p-MBA by amino acids of similar structure, followed by peptides containing similarly structured amino acids.
ContributorsHathorn, Gregory Michael (Author) / Nannenga, Brent (Thesis director) / Green, Matthew (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The overall goal of this project is to use metallic nanoparticles to develop a thin, ductile amorphous film at room temperature. Currently bulk metallic glasses are mainly formed via quenching, which requires very high cooling rates to achieve an amorphous molecular structure. These formations often fail in a brittle manner. The advantages of using a bottom-up approach with amorphous nanoparticles at ambient conditions is that the ductility of the metal can be improved, and the process will be less energy intensive. The nanoparticles used are iron precursors with ATMP and DTPMP ligand stabilizers and dispersed in methanol. Three forms of experimentation were applied over the course of this project. The first was a simple, preliminary data collection approach where the particles were dispersed onto a glass slide and left to dry under various conditions. The second method was hypersonic particle deposition, which accelerated the particles to high speeds and bombarded onto a glass or silicon substrate. The third method used Langmuir-Blodgett concepts and equipment to make a film. Qualitative analyses were used to determine the efficacy of each approach, including SEM imaging. In the end, none of the approaches proved successful. The first approach showed inconsistencies in the film formation and aggregation of the particles. The results from the hypersonic particle deposition technique showed that not enough particles were deposited to make a consistent film, and many of the particles that were able to be deposited were aggregated. The Langmuir-Blodgett method showed potential, but aggregation of the particles and uneven film formation were challenges here as well. Although there are ways the three discussed experimental approaches could be optimized, the next best step is to try completely new approaches, such as convective assembly and 3D printing to form the ideal nanoparticle film.
ContributorsKline, Katelyn Ann (Author) / Lind, Mary Laura (Thesis director) / Cay, Pinar (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12