Engineering Commons^™

Elucidating Mammalian Cellular Responses To The Uptake Of Nanoparticles (Nps), Pathogens, And Lipoproteins: Similarities And Differences, Monireh Asoudeh

Doctoral Dissertations

Soft poly-ethylene-glycol (PEG)-based soft nanoparticles (NPs) including cylindrical (CNPs) micelles, spherical (SNPs) micelles, and lipid bilayer vesicles (LNPs) are thought to be treated as foreign objects by mammalian phagocytes. If this hypothesis is true, NPs should trigger a proinflammatory, autophagic phenotype that is similar to the one seen when macrophages phagocytose pathogens or when macrophage surface expressed proteins bind pathogen surface factors such as lipopolysaccharide (LPS). Here, we show that macrophage responses to the above NPs are almost completely unique from those triggered by group A streptococcus (GAS) pathogens (JRS4 cells) and LPS. Instead, macrophages treat these soft NPs more …

Optics Of Two-Dimensional Materials Used As Substrates For Nanoparticle-Based Devices, Reagan Newman

Chancellor’s Honors Program Projects

No abstract provided.

Crafting Nanostructured Neural Interfaces With Hydrogel Particles, Emily Ann Morin

Doctoral Dissertations

Central nervous system neural device functionality hinges on effective communication with surrounding neurons. This depends on both the permissiveness of the device material to promote neuron integration and the ability of the device to avoid a chronic inflammatory response. Here, a facile approach has been developed exploring the multiple functionalities of hydrogel particles to provide cues to impart neural integration for such materials. Three distinct, yet interconnected tasks were undertaken: investigating hydrogel particle-modified substrate neuron integration and central nervous system inflammatory response, investigating guided hydrogel particle adsorption, and investigating hydrogel particles as local reservoirs for counteracting adverse effects from oxidative …

Elucidating The Effects Of Metabolic State On Nanoparticle Distribution In Mice And In Vitro Uptake, Kevin James Quigley

Doctoral Dissertations

Since almost 70% of the U.S. population over 20 years old is overweight and 30% is obese, with much of the western world following suit, many patients that will potentially be administered circulating nanoparticles designed to localize to tumors and avoid non-target areas will have significant amounts of white adipose tissue (WAT), enlarged livers, and additional metabolic complications such as type 2 diabetes. However, studies on nanoparticle biodistribution and efficacy take place almost without exception in lean rodents with healthy metabolic states. In this work, I determined the biodistribution of model nanoparticles – neutral filomicelles and polystyrene spheres both carrying …

Symbiotic Plasmonic Nanomaterials: Synthesis And Properties, Abhinav Malasi

Doctoral Dissertations

Metal particles of the dimensions of the order of 1 to 100's of nanometers show unique properties that are not clearly evident in their bulk state. These nanoparticles are highly reactive and sensitive to the changes in the vicinity of the particle surface and hence find applications in the field of sensing of chemical and biological agents, catalysis, energy harvesting, data storage and many more. By synthesizing bimetallic nanoparticles, a single nanoparticle can show multifunctional characteristics. The focus of this thesis is to detail the synthesis and understand the properties of bimetallic nanomaterial systems that show interesting optical, chemical, and …

Magnetism Of Magnetite Nanoparticles As Determined By Mössbauer Spectroscopy, Hien-Yoong Hah

Masters Theses

Fe₃O₄ [Magnetite] nanoparticles have magnetism that differs greatly from their bulk counterparts. Whereas bulk Fe₃O₄ is a ferrimagnet, single-domain Fe₃O₄ nanoparticles have been found to be superparamagnetic. This allows for increased magnetization of the nanoparticles compared to the bulk when in a magnetic field. For most paramagnets, magnetization requires applied fields of a few Tesla at low temperatures. This is achievable through the application of superconducting magnets. In superparamagnets, the high susceptibility of the particles allows magnetization through a Nd-Fe-B permanent magnet at room temperature. This is caused by an increased …

Processing, Structure, And Properties Of Nanoparticle Reinforced Nonwoven Sandwich Composites, Josh Griffith Fogle

Doctoral Dissertations

Shockwaves produced from ballistic impacts and improvised explosive devices are capable of causing severe internal trauma to soldiers. Current antiballistic materials give adequate protection to soldiers from high velocity impacts, however they are insufficient at absorbing and dissipating shockwave energy generated by these impacts and explosive blasts. The goal of this research was to develop shockwave absorbing protective materials which can be used as liners in conjunction with current antiballistic materials by reinforcing thermoplastic polyurethane nonwovens with high modulus nanoparticles

To determine the appropriate TPU for the application, a series of TPUs of shore hardness ranging from 60D to 85A …

Green Manufacturing Of Nanoparticles For Biomedical Applications, Sijia Yi

Doctoral Dissertations

The vast majority of nanomaterials are chemically synthesized, a costly process, that is environmentally risky, and the produced nanoparticles are potentially toxic to patients. Nature-based nanomaterials, however, are proving to be much more biocompatible with lower environmental toxicity. Even though a variety of natural nanomaterials have been designed, fabrication technologies for the desired natural nanoparticles with reproducible quality, high productivity and low cost remain a challenge. My objective has been to establish strategies for the isolation, purification and characterization of nanoparticles using a production system based on green tea and fungus (Arthrobotrys oligospora) and also to develop new …

Localized Surface Plasmon Resonance With The Use Of Silver And Titanium Oxide Nanostructures, Charles Wei-Shing Chin

Masters Theses

Light scattering and surface Plasmon calculations were done on a variety of novel geometries using the DDSCAT software package, which simulates the scattering of objects using the discrete dipole approximation method. Calculations were done on core shell nanoparticles consisting of a silver shell and a TiO₂ core in order to determine changes in the extinction spectrum and the near field patterns. Several geometries were tested, including spheres, cylinders, and hexagons, each of varying size and number. It was determined that when geometries were coupled together, there was significant near field enhancement where the geometries were in contact. This enhancement …

Optimizing The Performance Of A Glass-Ceramic Storage Phosphor As An Imaging Plate For Medical Use, Manh Vu

Masters Theses

Europium-doped-fluorochlorozirconate glass ceramics, known as ZBLAN, were produced in a glove box which has a controlled environment of argon gas. For imaging applications BaCl₂ is used instead of BaF₂. Their properties after different thermal processing and different amounts of europium-doping were investigated. After annealing the ZBLAN glass, BaCl₂ nanoparticles are precipitated in the glass matrix. These glass ceramic storage phosphors are strong candidates for replacing traditional x-ray screen film system and commercial storage phosphors such as Agfa MD-30.

Differential scanning calorimetry (DSC) was used to determine the crystallization temperature of the hexagonal phase of BaCl_{2 …}

Label-Free Mapping Of Near-Field Transport Properties Of Micro/Nano-Fluidic Phenomena Using Surface Plasmon Resonance (Spr) Reflectance Imaging, Iltai Kim

Doctoral Dissertations

My doctoral research has focused on the development of surface plasmon resonance (SPR) reflectance imaging technique to detect near-field transport properties such as concentration, temperature, and salinity in micro/nano fluidic phenomena in label-free, real-time, and full-field manner. A label-free visualization technique based on surface plasmon resonance (SPR) reflectance sensing is presented for real-time and full-field mapping of microscale concentration and temperature fields. The key idea is that the SPR reflectance sensitivity varies with the refractive index of the near-wall region of the test mixture fluid. The Fresnel equation, based on Kretschmann’s theory, correlates the SPR reflectance with the refractive index …