Matching Items (6)
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- All Subjects: Materials
- All Subjects: Virus-like Particles
- Creators: Department of Physics
- Status: Published
Description
Dry and steam NanoBonding™ are conceived and researched to bond Si-based surfaces, via nucleation and growth of a two-dimensional SiOxHy or hydrated SiOxHy interphase connecting surfaces at the nanoscale across macroscopic domains. The motivation is to create strong, long lasting, hermetically bonded sensors with their electronics for the development of an artificial pancreas and to bond solar cells to glass panels for robust photovoltaic technology. The first step in NanoBonding™ is to synthesize smooth surfaces with 20 nm wide atomic terraces via a precursor phase, ß-cSiO2 on Si(100) and oxygen-deficient SiOx on the silica using the Herbots-Atluri process and Entrepix’s spin etching. Smooth precursor phases act as geometric and chemical template to nucleate and grow macroscopic contacting domains where cross bridging occurs via arrays of molecular strands in the hydrated SiOxHy interphase. Steam pressurization is found to catalyze NanoBonding™ consistently, eliminating the need for direct mechanical compression that limits the size and shape of wafers to be bonded in turn, reducing the cost of processing. Total surface energy measurements via 3 Liquids Contact Angle Analysis (3L CAA) enables accurate quantitative analysis of the total surface energy and each of its components. 3L CAA at each step in the process shows that surface energy drops to 42.4 ± 0.6 mJ/m2 from 57.5 ± 1.4 mJ/m2 after the Herbots-Atluri clean of an “As Received” wafer. 3L CAA after steam pressurization Nanobonding™ shows almost complete elimination from 13.8 mJ/m2 ± 1.0 to 0.002 ±- 0.0002 mJ/m2 in the contribution of acceptors to the total free surface energy, and an increase from 0.2 ± .03 to 23.8± 1.6 mJ/m2 in the contribution of donors. This is consistent with an increase in hydroxylation of the ß-cSiO2 surface as a consistent precursor phase for cross-bridging. This research optimizes the use of glycerin, water, and α-bromo-naphtalene in the use of 3L CAA to effectively quantify the components of total free surface energy which helps to better understand the most consistent method for NanoBonding™.
ContributorsBennett-Kennett, Ross Buchanan (Author) / Culbertson, Robert (Thesis director) / Herbots, Nicole (Committee member) / Foy, Joseph (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor) / Department of Physics (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2013-05
Description
Dengue virus infects millions of people every year. Yet there is still no vaccine available to prevent it. Here we use a neutralizing epitope determinant on the dengue envelope (E) protein as an immunogen to be vectored by a measles virus (MV) vaccine. However the domain III (DIII) of the dengue 2 E protein is too small to be immunogenic by itself. In order for it to be displayed on a larger particle, it was inserted into the amino terminus of small hepatitis B surface antigen (HBsAg, S) coding sequence. To generate the recombinant MV vector and verify the efficiency of this concept, a reverse genetics system was used where the MV vectors express one or two additional transcription units to direct the assembly of hybrid HBsAg particles. Two types of recombinant measles virus were produced: pB(+)MVvac2(DIII-S,S)P and pB(+)MVvac2(DIII-S)N. Virus recovered from pB(+)MVvac2(DIII-S,S)P was viable. An ELISA assay was performed to demonstrate the expression and secretion of HBsAg. Supernatant from MVvac2(DIII-S,S)P infected cells confirmed that hybrid HBsAg-domain III particles with a density similar to traditional HBsAg particles were released. Characteristics of the subviral particle have been analyzed for the successful incorporation of domain III. The replication fitness of the recombinant MV was evaluated using multi-step growth kinetics and showed reduced replication fitness when compared to the parental strain MVvac2. This demonstrates that viral replication is hindered by the addition of the two inserts into MV genome. Further analysis of MVvac2(DIII-S)N is needed to justify immune response studies in a small animal model using both of the generated recombinant vectors.
ContributorsHarahap, Indira Saridewi (Author) / Reyes del Valle, Jorge (Thesis director) / Hogue, Brenda (Committee member) / Misra, Rajeev (Committee member) / Barrett, The Honors College (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
The HIV-1 pandemic continues to cause millions of new infections and AIDS-related deaths each year, and a majority of these occur in regions of the world with limited access to antiretroviral therapy. Therefore, an HIV-1 vaccine is still desperately needed. The most successful HIV-1 clinical trial to date used a non-replicating canarypox viral vector and protein boosting, yet its modest efficacy left room for improvement. Efforts to derive novel vectors which can be both safe and immunogenic, have spawned a new era of live, viral vectors. One such vaccinia virus vector, NYVAC-KC, was specifically designed to replicate in humans and had several immune modulators deleted to improve immunogenicity and reduce pathogenicity. Two NYVAC-KC vectors were generated: one expressing the Gag capsid, and one with deconstructed-gp41 (dgp41), which contains an important neutralizing antibody target, the membrane proximal external region (MPER). These vectors were combined with HIV-1 Gag/dgp41 virus-like particles (VLPs) produced in the tobacco-relative Nicotiana benthamiana. Different plant expression vectors were compared in an effort to improve yield. A Geminivirus-based vector was shown to increase the amount of MPER present in VLPs, thus potentially enhancing immunogenicity. Furthermore, these VLPs were shown to interact with the innate immune system through Toll-like receptor (TLR) signaling, which activated antigen presenting cells to induce a Th2-biased response in a TLR-dependent manner. Furthermore, expression of Gag and dgp41 in NYVAC-KC vectors resulted in activation of antiviral signaling pathways reliant on TBK1/IRF3, which necessitated the use of higher doses in mice to match the immunogenicity of wild-type viral vectors. VLPs and NYVAC-KC vectors were tested in mice, ultimately showing that the best antibody and Gag-specific T cell responses were generated when both components were administered simultaneously. Thus, plant-produced VLPs and poxvirus vectors represent a highly immunogenic HIV-1 vaccine candidate that warrants further study.
ContributorsMeador, Lydia Rebecca (Author) / Mor, Tsafrir S (Thesis advisor) / Jacobs, Bertram L (Thesis advisor) / Blattman, Joseph N (Committee member) / Mason, Hugh S (Committee member) / Arizona State University (Publisher)
Created2016
Description
In this project, we aim to fabricate PIN structure-like diodes for radiation detectors using Boron Nitride (BN). This fabrication is done by performing lithography and metal deposition processes on a Cubic Boron Nitride (cBN) of around 200 nm in thickness layer on top of a boron doped diamond substrate. The main goal is to create the most efficient and affordable alpha particle—and ideally neutron—detector in a radiation setting. Thus, making more accessible radiation detectors that can be more easily produced and disposed of, as well as minimizing the size of conventional detectors.
ContributorsGutierrez, Eric (Author) / Nemanich, Robert (Thesis director) / Zaniewski, Anna (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor)
Created2023-05
Description
In this project we are analyzing the diamond-titanium interface as it applies to diamond-based diode devices, including alpha particle, proton, and neutron detectors. This is done through the fabrication of an O-terminated B-doped diamond sample with a 20 Å Ti / 10 Å Pt overlayer which was then annealed and examined via X-ray photoelectron spectroscopy (XPS). It was discovered that after annealing the sample at temperatures ranging from 400 C - 900 C that TiC was not formed at any point during this experiment. Possible reasons for this include a lack of sufficient titanium in order to form TiC and over oxygenating the diamond surface before the metal was deposited.
ContributorsJohnson, Holly (Author) / Zaniewski, Anna (Thesis director) / Nemanich, Robert (Committee member) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Plant-made virus-like particles (VLPs), composed of HIV-1 Gag and deconstructed gp41 proteins, have been shown to be safe and immunogenic in mice. Here, we report the successful production of HIV-1 Gag/dgp41 VLPs in Nicotiana benthamiana, using an enhanced geminivirus-based expression vector. This novel vector results in unique expression kinetics, with peak protein accumulation and minimal necrosis achieved on day 4 post-infiltration. In comparing various purification strategies, it was determined that a 20% ammonium sulfate precipitation is an effective and efficient method for removing plant proteins and purifying the recombinant VLPs of interest. If further purification is required, this may be achieved through ultracentrifugation. VLPs are a useful platform for a variety of biomedical applications and developing the technology to efficiently produce VLPs in the plant expression system is of critical importance.
ContributorsFleming, Claire (Author) / Mor, Tsafrir (Thesis director) / Mason, Hugh (Committee member) / Kamzina, Aigerim (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor) / School of Life Sciences (Contributor)
Created2022-05