PhD, University of Cincinnati, 2021, Pharmacy: Pharmaceutical Sciences

Many sulfate-free and amino acid-based surfactant systems for personal care formulations do not respond to salt thickening with sodium chloride as readily as traditional sulfate-based formulations. This thesis focuses on alternative thickening mechanisms for a model amino acid-based surfactant, sodium lauroyl sarcosinate (SLSar). Rheology, diffusing wave spectroscopy, potentiometric titration, cross-polarized microscopy, zeta potential and cryo-TEM were used to obtain zero-shear viscosity and analyze the structure-rheology relationship. We focused on using pH adjustment as the main thickening mechanism while incorporating various types of additives. There were three main additives that we studied: zwitterionic surfactant, cationic ions/surfactant and nonionic cosurfactants. For the model formulation investigated here, thickening through partial neutralization of the titrable surfactant by lowering pH and the addition of nonionic surfactants to control the micelle breakage kinetics were most successful in providing robust thickening mechanisms. Chapter 3-6 were submitted for publication. The content of this dissertation is based on the following publications: 1.

Committee: Gerald Kasting Ph.D. (Committee Chair); Kavssery Ananthapadmanabhan ENG.SC.D. (Committee Member); Peter Koenig Ph.D. (Committee Member); Harshita Kumari Ph.D. (Committee Member); Michael Weaver Ph.D. (Committee Member) Subjects: Chemical Engineering; Pharmaceuticals

Master of Science, Miami University, 2020, Chemical, Paper and Biomedical Engineering

Protein-surfactant interactions have been studied due to the numerous applications in different industries including hygienic products, cosmetics, pharmaceuticals, and food products. Single surfactant and mixed surfactant systems with protein are of interest to assess the changes in structure and function of protein. Using several different methods to analyze changes in protein structure, surfactant critical micelle concentration (CMC), and protein-bound surfactant, we can understand the interactions between the surfactant and protein molecules. In this study, two different types of surfactants sodium dodecyl sulfate (SDS) and lauryldimethylamine oxide (LDAO) are analyzed to understand their impact on the protein β-lactoglobulin (βLG). The impact of mixtures of the two surfactants on βLG was also explored. SDS has a significant impact on the structure of βLG at low concentrations. In contrast, higher concentrations of LDAO are required to impact the structure of βLG. The mixtures of the two surfactants with the protein showed minimal changes in surfactant aggregation concentration compared to the mixed surfactant solution with no protein. The mixed surfactant system with protein also required a higher concentration of surfactant to impact the protein structure.

Committee: Jason Berberich (Advisor); Justin Saul (Committee Member); Jason Boock (Committee Member); Neil Danielson (Committee Member) Subjects: Analytical Chemistry; Biochemistry; Chemical Engineering

MS, University of Cincinnati, 2018, Pharmacy: Pharmaceutical Sciences

It is established that the cleansing properties and irritation potential of surfactants can be managed with the addition of other surfactants or polymers. However, the mechanism of the surfactant-induced irritation is not fully understood. In 2003, the Blankschtein group used 14C-radiolabelling assay and dynamic light scattering (DLS) to study the penetration of sodium dodecyl sulfate (SDS) and a system of SDS with polyethylene glycol (PEG) through porcine skin. They concluded that the micelles and monomers contributed to skin irritation and the irritation potential of a surfactant was dependent on the size of the assembly body (this is referred to as the “Blankschtein Hypothesis” within this body of work). Herein, we use combined small-angle neutron scattering (SANS), DLS, and proton nuclear magnetic resonance (1H-NMR) spectroscopy to investigate the shape, size, and solution dynamics of the surfactant systems to further elaborate the “Blankschtein Hypothesis”. The results revealed that shape and inter-micellar interactions, in addition to size, serve as important factors in determining surfactant skin penetration. The validity of the Blankschtein Hypothesis was furthered explored by adding a clinical component to the study. Part of Nicole McCardy's MS thesis work was to determine if pre-clinical assays, including 14C-radiolabeled skin penetration assay and DLS, could be used to predict the clinical results observed with human subjects. A model was built to predict the harshness of mixed surfactant and surfactant-polymer composition on human skin, as measured by corneometry and visual dryness scores in a five-day forearm controlled application test (FCAT). A similar method was applied to another set of formulations, simplified to contain only one anionic surfactant. All of the surfactants in this set were structurally similar, differing only slightly in chain lengths and functional groups. The pre-clinical assays in this study were correlated with clinical resu (open full item for complete abstract)

Committee: Harshita Kumari Ph.D. (Committee Chair); Gerald Kasting Ph.D. (Committee Member); Michael Weaver Ph.D. (Committee Member) Subjects: Pharmaceuticals

Master of Science (MS), Wright State University, 2015, Pharmacology and Toxicology

The “surfactant” produced by type II pneumonocytes is deficient in term and preterm infants born and diagnosed with Respiratory Distress Syndrome (RDS). Corticosteroids such as dexamethasone or betamethasone are clinically used as the primary line of treatment to stimulate the production of surfactant. The steroidal hormone, progesterone appears to play a role in the fetal lung development and also appears to increase the expression of inflammatory markers in both term and preterm infants. However, the impact of progesterone on surfactant production remains unknown. Like progesterone, the tocolytic drug terbutaline has also been implicated in phosphatidylcholine production in the pneumonocytes of the human lung. Interestingly, recent reports indicate that leptin, a hormone mainly produced by adipocytes may increase surfactant production in-vitro. However, other authors could not reproduce those results. This study was designed to analyze the long-term effect of progesterone, terbutaline and leptin on surfactant production in-vitro, either alone or in combination with betamethasone as a positive control. As a model, we used the human lung cell line NCI-H441. The production and processing of Surfactant Protein-B (SP-B), in this cell line is almost identical to explant cultures of fetal lung and cultured type II cells. Biochemical, immunochemical and molecular approaches, including thin layer chromatography (TLC) and RealTime-PCR were followed to determine the pharmacological role of progesterone, terbutaline and leptin on surfactant production. Our experiments indicate that betamethasone increased lipid secretion and surfactant-B production at 24 hours. Likewise, progesterone and terbutaline, increased lipid secretion and surfactant production when analyzed by immunocytochemistry. Betamethasone also increased surfactant production when added to these tocolytics. RealTime PCR also showed a similar increase in surfactant-B mRNA. The results suggest that progesterone in (open full item for complete abstract)

Committee: David R Cool Ph.D. (Advisor); Mauricio Di Fulvio Ph.D. (Committee Member); Nadja Grobe Ph.D. (Committee Member) Subjects: Developmental Biology; Obstetrics; Pharmacology

PhD, University of Cincinnati, 2024, Engineering and Applied Science: Materials Science

The dispersion process of dispersants across different media—whether solid, liquid, or gaseous—follows a common mechanism rooted in collision-based dynamics, namely the collision-based dispersion mechanism. This paper aims to provide an in-depth analysis of the dispersion process through the lens of this fundamental mechanism. Ultra small-angle X-ray scattering (USAXS) techniques have been used to quantify nano-scale filler dispersion through the virial coefficient. The impact of processing oil, such as AO and PO, on carbon black nanofiller dispersion in PBD (BR38 and BR54) has been quantified and characterized by the linear relationship between the complex viscosity, η, and the second virial coefficient, B2*. The third order polynomial function has been used to quantify the relationship between the complex viscosity and the third Virial Coefficient, B3*. The structure of processing oils has been studied by using Fourier transform Infrared spectroscopy (FTIR) and CHN elemental analysis technology. The solubility parameter, δ, of the different components has been calculated by using the group contribution method. Δ δ for PO/carbon black, and PO/BR was 2.83 (J/cm^(3))^(1/2), and 0.85 (J/cm^(3))^(1/2), respectively. Similarly, Δ δ, for AO/carbon black, and AO/BR was 1.12 (J/cm^(3))^(1/2), and 0.86 (J/cm^(3))^(1/2) respectively, indicating that both oils have a similar affinity for polybutadiene, the aromatic oil is marginally more compatible with carbon black. The dispersion of Carbon black in PBD/SBR blends immiscible three-body system has been analyzed qualitatively and quantitatively by using USAXS and DSC. In this study, the copper phthalocyanine pigment particles, PB 15:3, are successfully encapsulated by an efficient dispersant, Modified TritonTM X-100, in the polar medium. Further stabilization through steric hindrance or Coulomb-repulsion forces of the encapsulation has successfully proceeded with the presence of a photoinitiator through free radical polymeriza (open full item for complete abstract)

Committee: Gregory Beaucage Ph.D. (Committee Chair); Kabir Rishi Ph.D. (Committee Member); Vesselin Shanov Ph.D. (Committee Member); Benjamin Yavitt Ph.D. (Committee Member) Subjects: Materials Science

Master of Science, University of Akron, 2024, Polymer Science

Dumbbell- and bola-shaped surfactants are commonly expected to self-assemble into vesicles with condensed hydrophobic domains due to the dominant hydrophobic interaction. Meanwhile, macroions are expected to self-assemble into porous blackberry structure due to counterion-mediated interaction. Which structure will be formed by dumbbell-shaped macroions and what is the main driving force? It is reasonable to assume that the study on dumbbell-shaped macroions can help people have further understanding of vesicles, blackberry structure, and counterion-mediated interaction. Moreover, the unique permeability of blackberry structure may provide some reference significance in biology research on ion transport. In this work, a series of dumbbell-shaped fullerene macroions (AC60-C6H4-AC60, AC60-PEGn-AC60, n denotes the number of repeat units) are applied as a model system to studied the features of assemblies formed by dumbbell-shaped macroions. We examined the assemblies of these macroions and found that they assemble into hollow, spherical structures and the main driving force is counterion-mediated interaction. Besides, the length and hydrophobicity of organic linker were found as significant factors that can affect the size of assemblies.

Committee: Tianbo Liu (Advisor); Nita Sahai (Committee Member) Subjects: Chemistry

Master of Science, University of Toledo, 2023, Chemical Engineering

Multilayer plastics (MLPs) have become one of the most common food packaging materials. By combining multiple polymer types with distinct advantageous properties (e.g., water, light, or oxygen barrier properties), they extend the product shelf life while using less material. Yet, MLPs are challenging to recycle because their layers are difficult to separate, and this difficulty now presents a formidable sustainability challenge. To this end, we have developed new tie-layer materials through the complex coacervation (i.e., self-assembly) between the cationic polyelectrolyte, polyallylamine (PAH) and unsaturated, anionic fatty acids (either oleic acid or linoleic acid). Akin to the liquifying effects of double bonds in cis-unsaturated fats, the double bonds in these fatty acid tails imparted the otherwise-flaky PAH/surfactant complex precipitates with either moldable semisolid or liquid (coacervate) properties. These coacervates were prepared in two different solvents (water and ethanol) and were capable of (1) adhering two dissimilar plastic layers, (2) dissociating during recycling, thus enabling facile separation of MLP layers for further processing, and (3) as a bonus, serving as oxygen scavengers. These complexes exhibited tunable rheological properties, which ranged from viscous liquids (when solvated in ethanol) to putty-like semisolids (when formed in water) and coincided with solvent-dependent changes in their microstructure, where replacing water with ethanol led to a disruption of their lamellar order. Moreover, when prepared as low-viscosity dispersions of submicron coacervate droplets suspended in ethanol, these coacervates could be easily spread onto plastic substrates and (on partial drying) formed adhesive films that could bond dissimilar plastic layers, such as polyethylene terephthalate (PET), low-density polyethylene (LDPE), and ethylene vinyl alcohol (EVOH), with fewer defects and higher adhesion strengths than those achieved by spreading macro (open full item for complete abstract)

Committee: Yakov Lapitsky (Committee Chair); Maria Coleman (Committee Member); Joseph Lawrence (Committee Co-Chair) Subjects: Chemical Engineering; Chemistry; Packaging

MS, University of Cincinnati, 2022, Engineering and Applied Science: Chemical Engineering

Conductive polymers are an amazing class of materials with unique electrical and optical properties for polymeric systems. The difficulties of processing conductive polymers is an obstacle to realizing their full potential, motivating novel solutions to increase their solubility, miscibility and stability. In this work, we demonstrate an approach to prepare conductive polymer shells using a lipid conjugated precursor. This is done by leveraging the self-assembly of lipid molecules into vesicular shapes and utilizing the lipid conjugate as an anchor for a surface bound polymer shell to form. We describe the preparation of the conductive polymer precursor, Py-DMPE, demonstrate the polypyrrole coated vesicle spheres. We also detail the preparation of the n-substituted pyrrole upon which this conjugate is based, along with additional substituted polypyrrole products, namely; poly(Py-DSPE) and poly(Py-DCC).

Committee: Jonathan Nickels Ph.D. (Committee Member); Jude Iroh Ph.D. (Committee Member); Gregory Beaucage Ph.D. (Committee Member) Subjects: Chemical Engineering

Master of Science, Miami University, 2021, Chemistry and Biochemistry

We have coated a typical C18 column with the inexpensive zwitterionic synthetic surfactant, cocamidopropyl betaine (CAPB), in order to generate a mixed mode reversed phase weak ion exchange column with a capacity of 0.29 mmoles. The addition of 8.8 x 10-4 M CAPB to the totally aqueous mobile phase ensured stability of the surfactant on the column and permitted separation of the four component sulfonamide mixture with micellar liquid chromatography (MLC) in under 11 min with baseline separation for all components. Comparatively, with a dilute H2SO4 mobile phase the sulfonamide mixture reached excessive run times of an hour on the bare C18 chains. A five component short chain carboxylic acid mixture was used to examine the ion exchange character of the column in pH environments of 2.3 and 4.6. Three phase MLC equilibrium experiments were also performed in these pH environments with the two sulfa drug and carboxylic acid mixtures to determine partition coefficients. Finally, two high molecular weight anionic compounds, polystyrene sulfonates, were characterized by MLC with CAPB and variable pH mobile phases; the optimal pH was determined to be 2.95. A totally aqueous mobile phase without CAPB was not suitable for profiling these polymers.

Committee: Neil Danielson (Advisor); Ellen Yezierski (Committee Chair); Andrea Kravats (Committee Member); David Tierney (Committee Member) Subjects: Analytical Chemistry; Chemistry

Doctor of Philosophy (PhD), Ohio University, 2021, Chemical Engineering (Engineering and Technology)

Surfactant molecules are widely used in the oil and gas industry as corrosion inhibitors. These inhibitor molecules are known to self-assemble in various morphologies at the metal-water interfaces. Despite their wide usage in the oil and gas industry for corrosion mitigation purposes, the selection of corrosion inhibitors is still mostly based on trial-and-error experimentation, and the mechanisms by which these molecules retard corrosion are still poorly understood. This dissertation focuses on the study of the adsorption and self-assembly of surfactant molecules of different chemistry and geometry via classical molecular dynamics of a coarse-grained model. From this research, the following key findings are made: (a) Hydrophobic interactions between surfactant tails play an important role in their adsorption and self-assembly on surfaces; (b) The morphology of the adsorbed surfactant film is dictated by the molecular geometry; (c) Entrainment of oil in surfactant films improves film integrity and hydrophobicity; (d) A theoretical model was developed that is able to predict adsorbed morphologies given geometry of surfactant molecules and their strength of interactions with the surface. It has been shown, via coarse-grained simulations, that this theoretical model is quantitatively accurate in predicting the adsorbed configurations for both linear-shaped surfactants as well as asymmetrically shaped surfactant molecules; (e) Lateral hydrophobic interactions can help surfactant molecules adsorb onto a heterogeneous surface where part of the surface has no interactions with surfactant molecules.

Committee: Sumit Sharma (Advisor); Srdjan Nesic (Committee Member); David Young (Committee Member); David Drabold (Committee Member); Katherine Cimatu (Committee Member) Subjects: Chemical Engineering; Materials Science

MS, University of Cincinnati, 2021, Engineering and Applied Science: Environmental Engineering

VOC emissions from industries have increasingly been difficult to treat in the recent years due to the hydrophobicity nature of the compounds utilized in manufacturing and treatment. Although physiochemical, thermo and catalytic oxidation processes have been successfully implemented in treating VOCs, a cost and energy efficient alternative is required. Biofiltration has proven to be an effectual treatment technology in biodegrading hydrophilic and hydrophobic VOCs. However, the degradation of hydrophobic VOCs has been a challenge due to their low gas-liquid phase mass transfer rate. In this thesis, a literature review is presented on the best strategies available to incorporate in a biofiltration system to degrade hydrophobic and recalcitrant VOCs effectively. Employing a biosurfactant in a fungal biocatalyst to increase the solubility and bioavailability of the hydrophobic VOCs have had successful results with high percentage of removal efficiency. For this study, biodegradation of 2-Ethyl-1-Hexanol, a highly hydrophobic VOC emitted from the paint booth of an automobile industry was studied. Increasing concentrations of 2-EH, mimicking that of an industry, were employed in a Biotrickling Filter seeded with filamentous fungi and surfactin. The biofiltration system was supplied with continuous flow of nutrients, maintained at pH 4. The effect of the increasing loading rates on the BTF performance, reaction rate kinetics, COD consumption, nitrogen utilization and carbon mass balance were observed and recorded. The removal efficiency of 2-EH with increasing loading rates ranging from 3.98 g/(m3.hr) to 47.69 g/(m3.hr) were between 95% to 98%, one of the highest recorded percentages for a hydrophobic VOC treatment in published studies.

Committee: George Sorial Ph.D. (Committee Chair); Margaret Kupferle Ph.D. (Committee Member); Drew McAvoy Ph.D. (Committee Member); Bineyam Mezgebe Ph.D. (Committee Member) Subjects: Environmental Engineering

Master of Science in Chemical Engineering, Cleveland State University, 2021, Washkewicz College of Engineering

Boron nitride nanotubes (BNNTs) have promising optical, mechanical, and thermal properties which make them one of the most promising material candidates for fabricating protective and multifunctional fibers with remarkable thermal and chemical stabilities, electrically insulating, and ultraviolet radiation shielding capabilities. Here, we have demonstrated an effective method to produce stable dispersions of BNNTs coated by surfactants and fabricate continuous BNNTs and polyvinyl alcohol (PVA) composite fibers via a wet-spinning approach. BNNTs/polymer composite fibers were spun by combining SDC-coated BNNT dispersions with aqueous solutions of PVA and coagulating the resulting mixtures in the flow of a solvent, such as methanol (MeOH), ethanol (EtOH), and MeOH/acetone cosolvent. We examined the effects of various parameters, such as pristine versus purified BNNT material, the concentrations of BNNTs and PVA, and the specific coagulation solvent, on the overall mechanical properties of the composite fibers. Specifically, we compared the tensile strength, Young's modulus, and toughness of neat PVA and BNNT/PVA composite fibers containing either pristine or purified BNNTs. Our results indicate that increasing the BNNT content, in composite fibers with 5 mass% PVA and spun in EtOH, to 0.1 mass % increases the tensile strength and Young's modulus by 140% and 520%, respectively, for pristine BNNTs and by 200% and 543% for purified BNNTs compared to neat PVA fiber. Reducing the PVA concentration, for the same composite fibers, to 2.5 mass % improves the tensile strength and Young's modulus by 308% and 1179%, respectively, compared to neat PVA fiber. Fibers formed in MeOH/acetone exhibited higher toughness, but lower strength, compared to fibers formed in MeOH and EtOH which showed relatively similar average mechanical properties. Combined, our results provided insights into the structure-processing-property relationships of BNNT/polymer fibers and the vast potent (open full item for complete abstract)

Committee: Geyou Ao (Committee Chair); Orhan Talu (Committee Member); Shawn Ryan (Committee Member) Subjects: Nanoscience; Nanotechnology; Polymers

Master of Science, University of Toledo, 2021, Mechanical Engineering

Abstract: This study presents the changes in phase behavior of lipid bilayer in the presence of ethanol and surfactant. Lipid bilayer or biological phospholipid bilayer forms a barrier around all cells providing them structural stability. Self-assemblies of lipids of liposomes comprising of lipid bilayer can be used as model membranes to study the binding and internalization of various therapeutics, diagnostics, and other agents. It is hypothesized that studying the interaction of alcohols and surfactants can predict the efficacy of alcohol vs surfactant against lipid membrane. This can help to compare the ability of alcohol and surfactant to disrupt the lipid membrane of microbial cells that could lead to their death. This study is focused on the investigation of changes in size and zeta potential of zwitterionic liposomes in the presence of alcohol and surfactant using Dynamic light scattering (DLS). Observations in changes in zeta potential are attributed to the electrostatic binding between the lipid head group and alcohol or surfactants. Differential scanning calorimetry (DSC) was used to study the phase transitions in lipid bilayer due to the binding of alcohol and surfactant, and their thermodynamic parameters. Furthermore, annealing studies performed on DSC, comprising of subsequent heating and cooling cycles led to insights on phase separation and lipid bilayer disruption. Additionally, Isothermal titration calorimetry (ITC) was used to study the kinetic binding properties. It was found that surfactant was more effective in disrupting the lipid bilayer. The findings of this work can be used to design effective surfactant-based cleaners against microbes.

Committee: Anju Gupta Dr. (Committee Chair); Mohamed Hefzy Dr. (Committee Member); Thehazhnan Ponnaiyan Dr. (Committee Member) Subjects: Biophysics; Engineering; Nanotechnology

Doctor of Philosophy (PhD), Ohio University, 2021, Chemistry and Biochemistry (Arts and Sciences)

Surfactants are extensively used as corrosion inhibitors to mitigate the internal corrosion of oil and gas pipelines. Surfactants are amphiphilic, consisting of both polar headgroup and nonpolar tail group. The arrangement of headgroup and tail group governs the adsorption as well as the inhibition process. In this dissertation, we explore the conformation of the short alkyl chain length and the nature of the headgroup of surfactants that affects on the ordering of interfacial water molecules. Quaternary ammonium compound (Quat) with five different chain lengths were synthesized via Quaternization of primary amine with Bromo alkane. Imidazolines with five different chain lengths were synthesized from fatty acid or aldehyde and amine. Aqueous solutions of Quat at different ionic strengths were studied by surface and interface selective sum frequency generation spectroscopy technique at the air-liquid interface. We found that Quat solutions containing 0%, 1%, and 10% NaCl salt showed no clear trend for the number of gauche defect as a function of ionic strength. In general, the longer chain surfactants were found to have more ordered interfacial water molecules compared to the shorter ones at the air-liquid interface. The SFG results were correlated with the surface tension measurements and pH values. As a continuation, the self-assembly of surfactant was also studied in-situ at the liquid-metal interface by SFG spectroscopy. A self-assembled monolayer at liquid-metal interface is vital for corrosion, catalysis, and electrochemical reactions. We probed the adsorption and self-assembly of Quats at the liquid-metal interface by SFG spectroscopy without applying any external potential. This provides direct evidence of the effect of alkyl chain length of surfactants in the conformational changes of an adsorbed monolayer on the liquid-metal interface. We found that longer chain surfactant forms highly ordered monolayer due to the strong tail-tail interaction. On the other (open full item for complete abstract)

Committee: Katherine Cimatu Dr. (Advisor); Jixin Chen Dr. (Committee Member); Micheal Held Dr. (Committee Member); John Staser Dr. (Committee Member) Subjects: Chemistry; Physical Chemistry; Physics

Doctor of Philosophy, Miami University, 2019, Chemistry and Biochemistry

Reversed-phase liquid chromatography (RPLC) is by far the most important separation technique in analytical chemistry. It is an essential separation technique that has been extensively used in science and industry fields. However, this technique has some drawbacks such as the harmful environmental impact due to the thousands of gallons of toxic organic solvents used as a mobile phase, which usually end up as waste. An RPLC developed method used methanol and acetonitrile as organic solvents and compared the efficiency and selectivity of these solvents using the same C18 column to separate terephthalic acid (TPA) and eight of its contaminants. Methanol showed a different selectivity and faster separation than acetonitrile. The developed method was successfully used to analyze two different industrial samples. Using surfactants in the RPLC mobile phase (MP) has many advantages such as decreasing the environmental impact, lower cost, higher efficiency in separating structural isomers, and, most importantly, the ability to inject samples directly with minimal treatment. Tween 20 was used for what we believe is the first time to dynamically coat a C18 column, which was used to separate TPA impurities. The developed method is simple, fast, green and showed excellent coated column stability. The analysis took only 19 minutes to achieve baseline separation. This method was successfully applied to measure TPA contaminants in industrial samples. There is little published literature reporting the use of ultra-high performance micellar liquid chromatography (MLC); it seems the surfactants Tween 20 and Tween 40 have never been used in this mode as mobile phase components. Cinnamic acid derivatives are well known for their antioxidant properties, and they are present in food, beverages, pharmaceuticals, and supplements. A comparison study included separation of nine cinnamic acids (CA) derivatives using Tween 20 and Tween 40 in the ultra-high-performance MLC mode. In general, th (open full item for complete abstract)

Committee: Neil Danielson (Advisor); Andre Sommer (Committee Chair); Benjamin Gung (Committee Member); Ellen Yezierski (Committee Member) Subjects: Analytical Chemistry; Chemistry

PhD, University of Cincinnati, 2019, Medicine: Molecular and Developmental Biology

Alveolar type 2 epithelial (AT2) cells in the distal lung are multifaceted cells that serve as alveolar progenitors, source of pulmonary surfactant and modulators of innate immunity. Given the multitude of functions performed by AT2 cells, it was postulated in the 1970s that irreversible damage to AT2 cells was the basis for several chronic and/or degenerative lung diseases including pulmonary fibrosis; studies performed in this dissertation provide experimental evidence in support of this hypothesis. Studies in chapter 2 focus to a knock-in mouse model of a disease-associated mutation in the AT2 cell-restricted Surfactant Protein C (Sftpc). Adult mutant mice demonstrated reduction in AT2 cell numbers, and consequently, impaired lung regeneration. Postnatal AT2 cell expansion was impeded in mutant mice which was associated with activation of cell stress responses resulting from increased synthesis of mutant proprotein (proSP-C). Collectively, the data provide support for the hypothesis that AT2 cells at the onset of postnatal alveologenesis are exquisitely vulnerable to stressors; disruption of postnatal AT2 cell-homeostasis results in a permanent loss of AT2 cells in adult mice. Misfolded proSP-C resulting from specific mutations in Sftpc is cleared by the ubiquitin-proteasome system (UPS); studies performed in chapter 3 focus to understanding the role of the UPS in maintenance of AT2 cell-homeostasis. Knock-out of a proteasome subunit in AT2 cells resulted in impairment of UPS activity, accumulation of polyubiquitinated substrates and rapid AT2 cell-death. Adult mice developed significant surfactant deficiency leading to lethal acute respiratory distress syndrome secondary to AT2 cell depletion. Collectively, the data demonstrated a high dependence of AT2 cells on UPS activity and provided support for the hypothesis that severity of lung disease is directly related to the rate and frequency of AT2 cell-loss. Overall studies performed in this dissertation using AT2 (open full item for complete abstract)

Committee: Timothy Weaver Ph.D. (Committee Chair); Michael Borchers Ph.D. (Committee Member); James Bridges Ph.D. (Committee Member); Vladimir Kalinichenko M.D. Ph.D. (Committee Member); Takahisa Nakamura Ph.D. (Committee Member); Kathryn Wikenheiser-Brokamp M.D. Ph.D. (Committee Member) Subjects: Cellular Biology

Master of Science, Miami University, 2019, Chemical, Paper and Biomedical Engineering

Light Duty Liquid (LDL) detergents are a mixture of surfactants in water, better known as dishwashing detergents, hand soap and general household products. The foamability of LDL detergent is an important metric when consumers are cleaning a surface. This study seeks to determine the effect of protein as foam booster on foamability. This study also seeks to study the location of protein in the emulsion and foam in varying LDL detergent and oil concentrations. The addition of protein acts as a foam booster to LDL detergent with olive oil in hardwater. These emulsion and foams made up of protein, LDL detergent and olive oil were separated and imaged by confocal microscopy and quantified by size exclusion high pressure liquid chromatography. Methods to remove oil from the emulsion and foam were developed for protein quantification. At low LDL detergent concentrations, the protein can be seen adsorbed to the oil-water interface. At high LDL detergent concentration, the protein is dispersed in the bulk fluid. The point at which the protein was no longer at the interface correlated well with the CMC of LDL detergent as calculated by surface tension and a pyrene assay.

Committee: Jason Berberich Dr. (Advisor); Andrew Jones Dr. (Committee Member); Justin Saul Dr. (Committee Member) Subjects: Chemical Engineering; Chemistry; Polymers

MS, University of Cincinnati, 2019, Medicine: Molecular Genetics, Biochemistry, and Microbiology

GPR116 is an orphan adhesion GPCR (aGPCR) expressed primarily in alveolar type II (ATII) lung epithelial cells. Although the mechanism in unknown, GPR116 has been identified to regulate surfactant secretion and reabsorption through a Gaq effector protein. Being an orphan receptor, no known ligand has been identified for GPR116. However, a peptide coded from the Stachel sequence contained in the GAIN domain, specific to aGPCRs, can be used to activate the full-length receptor. Previous studies have linked GPR116 activation with an increase in Rho family GTPase activity and ultimately an increase in cytoskeletal structures in various cell types. While not well characterized, a similar increase in cortical F-actin has been observed following GPR116 activation in ATII cells as well. We hypothesize that the suppression of surfactant secretion mediated by GPR116 is a direct result of an increase in RhoA signaling leading to cortical F-actin stabilization.

Committee: James Bridges Ph.D. (Committee Chair); Rhett Kovall Ph.D. (Committee Member); William Miller Ph.D. (Committee Member) Subjects: Molecular Biology

Master of Science in Polymer Engineering, University of Akron, 2019, Polymer Engineering

This study focuses on fabrication and use of aerogel coatings on macroporous fabrics for the purpose of filtration of airborne nanometric particles. Filtering airborne particles is an important aspect due to their hazardous effects on human health. In this work, syndiotactic polystyrene (sPS) and polyimide (PI) aerogels were coated via a dip coating process on polyester woven fabric substrates and the resultant materials were evaluated to determine their effectiveness on air filtration. In addition, syndiotactic polystyrene aerogel monoliths were modified with triblock copolymer surfactants and the effects of the morphology on permeability and filtration efficiency were studied. In the first part of this study, thin films of syndiotactic polystyrene and polyimide aerogel were cast on fibrous substrates by a dip coating process. The results showed that syndiotactic polystyrene would be more suitable for the dip coating process. However, a reflection into fundamentals of dip coating process showed an imminent technical issue.. In sol-gel dip coating, the final step in producing a film is the evaporation of the solvent to leave the solid materials behind. This presents a serious challenge, as solvent evaporation from the gels destroys the pores in resultant aerogels. To correct this, an additional step was used in which the coated substrate was held in excess heated solvent vapor as the solution turned into a gel. In the second part of this study, syndiotactic polystyrene aerogel monoliths were modified by the addition of triblock copolymer surfactants during the synthesis step. Specifically, F108 and F127 Pluronic®, surfactants were dissolved in sPS solution in tetrahydrofuran before allowing sPS to gel. Monoliths modified with F108 surfactant were found to have unfavorable surface structure due to poor dispersion of the surfactant. The aerogels with F127 surfactant showed improved porous structures particularly at the surface where a fibrous structure was obse (open full item for complete abstract)

Committee: Sadhan Jana Dr. (Advisor); Kevin Cavicchi Dr. (Committee Chair); Erol Sancaktar Dr. (Committee Member) Subjects: Polymers

PhD, University of Cincinnati, 2019, Pharmacy: Pharmaceutical Sciences/Biopharmaceutics

Rinse-off products are designed to cleanse the skin and hair of dirt, sweat, and oils, and then be rinsed away with water. Anionic surfactants, which are often used in rinse-off products due to their excellent foaming and lather characteristics, bind to and denature skin proteins as well as intercalate into and extract skin lipids. Repeated use leads to skin dryness and irritation over time. Although a number of theories have been proposed, the exact mechanisms of surfactant penetration into human skin remain unknown. The purpose of this research was to elucidate these mechanisms in single and mixed anionic surfactant systems. These understandings will lead to strategies which can be used to mitigate skin dryness and irritation from repeated use of commercial rinse-off products, thereby improving consumer experience and streamlining product research and development.

Committee: Gerald Kasting Ph.D. (Committee Chair); Kavssery Ananthapadmanabhan (Committee Member); Thomas Beck Ph.D. (Committee Member); Harshita Kumari (Committee Member); Kevin Li Ph.D. (Committee Member); Peng Zhang Ph.D. (Committee Member) Subjects: Individual and Family Studies; Pharmaceuticals; Web Studies