ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- All Subjects: chemical engineering
- Creators: Acharya, Abhinav
Description
Cellular models have been the backbone of models for drug therapeutics, discovery, or diagnostics, and for modeling a tumor microenvironment to understand the proliferation, migration, invasion, dormancy, angiogenesis, Conventional two-dimensional (2D) cell culture models are used because of the cost-effectiveness compared to animal models. But these models fail to mimic the cellular phenotype of a three-dimensional (3D) microenvironment. As a result, it is important to develop a 3D model that predicts cellular behaviors and their interaction with neighboring cells and extracellular matrix (ECM) in a more realistic setting. Various 3D cell culture methods have been employed to generate spheroids, in vitro, but most of these platforms face drawbacks such as spheroid size heterogeneity, low yield, use of specialized instruments etc. The hydrogel platform mentioned here was able to solve all the previous problems and can create a novel 3D tumor microenvironment. This thesis is focused on developing an in-vitro 3D model which can modulate the tumor microenvironment consisting of cancer cells and macrophages and how the Amikagel platform modulated the macrophage phenotype is discussed in detail here. This platform can be an ideal platform for macrophage phenotype modulation.
ContributorsChowdhury, Trishita (Author) / Rege, Kaushal (Thesis advisor) / Acharya, Abhinav (Committee member) / Khalifehzadeh, Layla (Committee member) / Arizona State University (Publisher)
Created2023
Description
Abnormally low or high blood iron levels are common health conditions worldwide and can seriously affect an individual’s overall well-being. A low-cost point-of-care technology that measures blood iron markers with a goal of both preventing and treating iron-related disorders represents a significant advancement in medical care delivery systems. Methods: A novel assay equipped with an accurate, storable, and robust dry sensor strip, as well as a smartphone mount and (iPhone) app is used to measure total iron in human serum. The sensor strip has a vertical flow design and is based on an optimized chemical reaction. The reaction strips iron ions from blood-transport proteins, reduces Fe(III) to Fe(II), and chelates Fe(II) with ferene, with the change indicated by a blue color on the strip. The smartphone mount is robust and controls the light source of the color reading App, which is calibrated to obtain output iron concentration results. The real serum samples are then used to assess iron concentrations from the new assay and validated through intra-laboratory and inter-laboratory experiments. The intra-laboratory validation uses an optimized iron detection assay with multi-well plate spectrophotometry. The inter-laboratory validation method is performed in a commercial testing facility (LabCorp). Results: The novel assay with the dry sensor strip and smartphone mount, and App is seen to be sensitive to iron detection with a dynamic range of 50 - 300 µg/dL, sensitivity of 0.00049 µg/dL, coefficient of variation (CV) of 10.5%, and an estimated detection limit of ~15 µg/dL These analytical specifications are useful for predicting iron deficiency and overloads. The optimized reference method has a sensitivity of 0.00093 µg/dL and CV of 2.2%. The correlation of serum iron concentrations (N=20) between the optimized reference method and the novel assay renders a slope of 0.95, and a regression coefficient of 0.98, suggesting that the new assay is accurate. Lastly, a spectrophotometric study of the iron detection reaction kinetics is seen to reveal the reaction order for iron and chelating agent. Conclusion: The new assay is able to provide accurate results in intra- and inter- laboratory validations and has promising features of both mobility and low-cost.
ContributorsSerhan, Michael (Author) / Forzani, Erica (Thesis advisor) / Raupp, Gregory (Committee member) / Acharya, Abhinav (Committee member) / Hu, Tony (Committee member) / Smith, Barbara (Committee member) / Arizona State University (Publisher)
Created2020
Description
Crystalline polymeric materials play an increasingly important role in daily life.Understanding and controlling the development of crystallinity is integral to improving the
performance of crystalline polymers in packaging, drug delivery, water treatment, gas
separations, and many other industries. Herein, fluorescence and Raman spectroscopy have
been applied for the first time to study the crystallinity of polymers, including traditional
semicrystalline thermoplastics and covalent organic frameworks (COFs; an emerging class
of crystalline polymers with highly ordered pore structures). On one hand, by incorporating
a fluorescent dye segment into a semicrystalline polymer matrix, it is feasible to accurately
monitor its crystallization and melting. The flexibility of dye incorporation allows for new
fundamental insights into polymer crystallization in the bulk and at/near interfaces that
may otherwise be out of reach for established techniques like differential scanning
calorimetry (DSC). On the other hand, Raman spectroscopy has been identified as a
technique sensitive to the crystallinity of COFs and applied alongside well-established
characterization techniques (X-ray diffraction and N2 adsorption) to monitor the
crystallization of COFs during synthesis. This has enabled careful control of COF
crystallinity during solvothermal synthesis for improved application in the field of drug
delivery. The monitoring of COF crystallinity has been extended to more complex film
geometries produced by interfacial polymerization. The high molecular sieving potential
of COFs remains out of reach in part due to a lack of understanding of the interplay between
crystallinity, crystallite orientation, and filtration performance. A careful study of these
relationships is suggested for future work to provide key insight toward applying COFs as
molecular sieving materials in water treatment and other separation applications.
ContributorsNile, Richard Gabriel (Author) / Jin, Kailong (Thesis advisor) / Lin, Jerry (Committee member) / Acharya, Abhinav (Committee member) / Seo, S. Eileen (Committee member) / Chen, Xiangfan (Committee member) / Arizona State University (Publisher)
Created2024