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Full-Text Articles in Biomedical Engineering and Bioengineering

Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim Oct 2019

Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim

Tool Data

S1805 positive photoresist has been deposited on single crystalline Si wafers using a Suss MicroTec Alta Spray. The influence of flow rate, nozzle speed, pitch and number of passes on the thickness of the photoresist was studied. Results show that the thickness of S1805 is linearly proportional to the flow rate and number of passes, and inversely proportional to the nozzle speed and pitch.


Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson Sep 2019

Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson

Protocols and Reports

The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.


Fibrinogen, Factor Xiii And Fibronectin: A Biophysical And Kinetic Characterization Of Their Interactions, Frank Fabian Jun 2019

Fibrinogen, Factor Xiii And Fibronectin: A Biophysical And Kinetic Characterization Of Their Interactions, Frank Fabian

Chemical & Biomolecular Engineering Theses, Dissertations, & Student Research

The development of recombinant-based liquid fibrin tissue sealants having enhanced hemostatic and wound healing properties will involve understanding as yet not well characterized interactions between fibrinogen, fibrin (Fbn) factor XIII, thrombin and fibronectin. We study these phenomena in the context of comparing plasma derived fibrinogen to recombinant fibrinogen (rFI) produced in the milk of transgenic cows. An abundance of purified γγ and γγ’ FI subspecies enables detailed study of γγ or γγ’ biomonomer and their respective Fbn biopolymer formation as having different substrate behaviors of activated plasma derived factor XIII (pFXIIIa2b2). High pressure size exclusion (HPSEC) and ...


Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu May 2019

Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper presents a systematic method to analyse the stability of systems with single delay in which the coefficient polynomials of the characteristic equation depend on the delay. Such systems often arise in, for example, life science and engineering systems. A method to analyze such systems was presented by Beretta and Kuang in a 2002 paper, but with some very restrictive assumptions. This work extends their results to the general case with the exception of some degenerate cases. It is found that a much richer behavior is possible when the restrictive assumptions are removed. The interval of interest for the ...


Generation Of Silver Nanoparticle Pharmacokinetic Profiles In A Lung Model, Rachel Galaska Apr 2019

Generation Of Silver Nanoparticle Pharmacokinetic Profiles In A Lung Model, Rachel Galaska

Honors Theses

Nanomaterial technologies are becoming increasingly prevalent in consumer and industrial applications, including drug delivery, energy harvesting, environmental applications, and medicine due to their unique physiochemical properties. As nanomaterial use increases, so too does human exposure. This has made it progressively more important to understand the toxicological effects of nanomaterials and their interactions with the human body. Silver nanoparticles (AgNPs) are one of the most commonly used nanomaterials due to their antibacterial properties. As inhalation is one of the most common exposure routes, understanding the toxicity of these AgNPs on lung tissue was studied. Using A549 cells for a lung tissue ...


Effect Of Activated Carbon On The Performance Of A Solar Thermal Adsorptive Refrigerator (Star) Using Activated Carbon-Ethanol, Joshua Romo Apr 2019

Effect Of Activated Carbon On The Performance Of A Solar Thermal Adsorptive Refrigerator (Star) Using Activated Carbon-Ethanol, Joshua Romo

Honors Theses

The Solar Thermal Adsorptive Refrigerator (STAR) project at the University of Dayton seeks to bridge sustainability and the need for reliable refrigeration in developing communities. Cost-effective construction, operation, and maintenance as well as the use of a sustainable adsorption pair, activated carbon-ethanol, give STAR great potential in the realm of humanitarian engineering. This project explores the effect of using two activated carbon brands, 8x16 and CocoPlus, on the cyclic performance of the STAR system. Although both brands have similar specifications given by the manufacturer, one (8x16) inhibited successful performance while the other (CocoPlus) enabled it. This project highlights both the ...


Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two fluorocarbon Gases Chf3 And Cf4, Meiyue Zhang, Pat Watson Mar 2019

Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two fluorocarbon Gases Chf3 And Cf4, Meiyue Zhang, Pat Watson

Protocols and Reports

Two reactive ion etching (RIE) processes were studied to show the relative etch selectivity between SiO2 and Si using two fluorocarbon gases, CF4 and CHF3. Results show that CHF3 gives better selectivity (16:1) over CF4 (1.2 :1). On the other hand, the etch rate of SiO2 of CF4 is approximately 52.8 nm/min, faster than CHF3 (32.4 nm/min).


Analyzing Drug Release Kinetics From Water-Soluble Polymers, Sean M. Kelly, Arun K. Upadhyay, Akash Mitra, Balaji Narasimhan Feb 2019

Analyzing Drug Release Kinetics From Water-Soluble Polymers, Sean M. Kelly, Arun K. Upadhyay, Akash Mitra, Balaji Narasimhan

Chemical and Biological Engineering Publications

The ability to develop predictive mathematical models of therapeutic release from pharmaceutical formulations has enormous potential to enhance our understanding of such systems and improve the controlled release of the payload. The current work describes the development and testing of a one-dimensional model of drug transport from amorphous, swelling/dissolving polymers. Model parameters such as the diffusivities of water and drug, the initial loading of the drug, the polymer dissolution rate, drug-polymer interactions, and the tablet thickness were varied, demonstrating the ability to tune the release to be controlled by either drug diffusion or polymer chain disentanglement. In addition, predictions ...


Degradation And Remodeling Of Epitaxially Grown Collagen Fibrils, Juan Wang, Anuraag Boddupalli, Joseph Koelbl, Dong Hyun Nam, Xin Ge, Kaitlin M. Bratlie, Ian C. Schneider Feb 2019

Degradation And Remodeling Of Epitaxially Grown Collagen Fibrils, Juan Wang, Anuraag Boddupalli, Joseph Koelbl, Dong Hyun Nam, Xin Ge, Kaitlin M. Bratlie, Ian C. Schneider

Materials Science and Engineering Publications

Introduction: The extracellular matrix (ECM) in the tumor microenvironment contains high densities of collagen that are highly aligned, resulting in directional migration called contact guidance that facilitates efficient migration out of the tumor. Cancer cells can remodel the ECM through traction force controlled by myosin contractility or proteolytic activity controlled by matrix metalloproteinase (MMP) activity, leading to either enhanced or diminished contact guidance.

Methods: Recently, we have leveraged the ability of mica to epitaxially grow aligned collagen fibrils in order to assess contact guidance. In this article, we probe the mechanisms of remodeling of aligned collagen fibrils on mica by ...


Development Of Gelatin And Graphene-Based Nerve Regeneration Conduits Using 3d Printing Strategies For Electrical Transdifferentiation Of Mesenchymal Stem Cells, Metin Uz, Maxsam Donta, Meryem Mededovic, Donald S. Sakaguchi, Surya Mallapragada Feb 2019

Development Of Gelatin And Graphene-Based Nerve Regeneration Conduits Using 3d Printing Strategies For Electrical Transdifferentiation Of Mesenchymal Stem Cells, Metin Uz, Maxsam Donta, Meryem Mededovic, Donald S. Sakaguchi, Surya Mallapragada

Chemical and Biological Engineering Publications

In this study, gelatin and graphene-based nerve regeneration conduits/scaffolds possessing tailored 3D microstructures and mechanical properties were fabricated using 3D printing. The effect of 3D conduit microstructure and mechanical properties along with the applied electrical stimuli on mesenchymal stem cell (MSCs) behavior and transdifferentiation into Schwann cell (SC)-like phenotypes were investigated. The results indicated that the gelatin conduits/scaffolds had favorable 3D microstructural and mechanical properties for MSC attachment and growth. Immunocytochemistry results demonstrated that the application of electrical stimuli through the conductive graphene within the gelatin-based 3D microstructure had a profound effect on the differentiation of MSCs ...


Coatings On Mammalian Cells: Interfacing Cells With Their Environment, Kara A. Davis, Pei-Jung Wu, Calvin F. Cahall, Cong Li, Anuhya Gottipati, Brad J. Berron Jan 2019

Coatings On Mammalian Cells: Interfacing Cells With Their Environment, Kara A. Davis, Pei-Jung Wu, Calvin F. Cahall, Cong Li, Anuhya Gottipati, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

The research community is intent on harnessing increasingly complex biological building blocks. At present, cells represent a highly functional component for integration into higher order systems. In this review, we discuss the current application space for cellular coating technologies and emphasize the relationship between the target application and coating design. We also discuss how the cell and the coating interact in common analytical techniques, and where caution must be exercised in the interpretation of results. Finally, we look ahead at emerging application areas that are ideal for innovation in cellular coatings. In all, cellular coatings leverage the machinery unique to ...


The Endocytotic Fate Of A Mesoporous Silica Nanoparticle Supported Lipid Bylayer Crispr Delivery Vehicle, Angelea Maestas-Olguin Jan 2019

The Endocytotic Fate Of A Mesoporous Silica Nanoparticle Supported Lipid Bylayer Crispr Delivery Vehicle, Angelea Maestas-Olguin

2019 Award Winners

No abstract provided.


Performance Enhancement Of Human Motion Based Piezoelectric Energy Harvesters, Iman Izadgoshasb Jan 2019

Performance Enhancement Of Human Motion Based Piezoelectric Energy Harvesters, Iman Izadgoshasb

Theses

Harvesting electricity from human motions using piezoelectric materials is attracting the attention of many researchers in recent years. These harvesters can potentially power portable electronic devices without the need of external power sources.

The aim of this thesis was to improve the efficiency of piezoelectric energy harvesting from human motions. To achieve this, optimising orientation of piezoelectric cantilever beam investigated; the new mechanism consisting of double pendulum system was studied and finally the new shape design of cantilever was proposed to generate multi resonance peaks. These achievements may help to improve the efficiency of piezoelectric energy harvesters in the future.


Interleukin-1 Alpha Increases Anti-Tumor Efficacy Of Cetuximab In Head And Neck Squamous Cell Carcinoma, Madelyn Espinosa-Cotton, Samuel N. Rodman Iii, Kathleen A. Ross, Isaac J. Jensen, Kenley Sangodeyi-Miller, Ayana J. Mclaren, Rachel A. Dahl, Katherine N. Gibson-Corley, Adam T. Koch, Yang-Xin Fu, Vladimir P. Badovinac, Douglas Laux, Balaji Narasimhan, Andrean L. Simons Jan 2019

Interleukin-1 Alpha Increases Anti-Tumor Efficacy Of Cetuximab In Head And Neck Squamous Cell Carcinoma, Madelyn Espinosa-Cotton, Samuel N. Rodman Iii, Kathleen A. Ross, Isaac J. Jensen, Kenley Sangodeyi-Miller, Ayana J. Mclaren, Rachel A. Dahl, Katherine N. Gibson-Corley, Adam T. Koch, Yang-Xin Fu, Vladimir P. Badovinac, Douglas Laux, Balaji Narasimhan, Andrean L. Simons

Chemical and Biological Engineering Publications

Background: Despite the high prevalence of epidermal growth factor receptor (EGFR) overexpression in head and neck squamous cell carcinomas (HNSCCs), incorporation of the EGFR inhibitor cetuximab into the clinical management of HNSCC has not led to significant changes in long-term survival outcomes. Therefore, the identification of novel therapeutic approaches to enhance the clinical efficacy of cetuximab could lead to improved long-term survival for HNSCC patients. Our previous work suggests that EGFR inhibition activates the interleukin-1 (IL-1) pathway via tumor release of IL-1 alpha (IL-1α), although the clinical implications of activating this pathway are unclear in the context of cetuximab therapy ...


Comparative Kinetic Modeling Of Growth And Molecular Hydrogen Overproduction By Engineered Strains Of Thermotoga Maritima , Raghuveer Singh, Rahul Tevatia, Derrick White, Yasar Demirel, Paul H. Blum Jan 2019

Comparative Kinetic Modeling Of Growth And Molecular Hydrogen Overproduction By Engineered Strains Of Thermotoga Maritima , Raghuveer Singh, Rahul Tevatia, Derrick White, Yasar Demirel, Paul H. Blum

Chemical and Biomolecular Engineering -- All Faculty Papers

Thermotoga maritima is an anaerobic hyperthermophilic bacterium known for its high amounts of hydrogen (H2) production. In the current study, the kinetic modeling was applied on the engineered strains of T. maritima that surpassed the natural H2 production limit. The study generated a kinetic model explaining H2 overproduction and predicted a continuous fermentation system. A Leudking-Piret equation-based model predicted that H2 production by Tma200 (0.217 mol-H2 g–1-biomass) and Tma100 (0.147 mol-H2 g–1-biomass) were higher than wild type (0.096 mol-H2 g–1 -biomass) with reduced rates of ...


How Crosslinking Mechanisms Of Methacrylated Gellan Gum Hydrogels Alter Macrophage Phenotype, Zhuqing Li, Kaitlin M. Bratlie Dec 2018

How Crosslinking Mechanisms Of Methacrylated Gellan Gum Hydrogels Alter Macrophage Phenotype, Zhuqing Li, Kaitlin M. Bratlie

Materials Science and Engineering Publications

In tissue engineering scaffolds, macrophages play a critical role in determining the host response to implanted biomaterials. Macrophage phenotype is dynamic throughout the host response, and a balance of phenotypes is essential for timely progression from injury to proper wound healing. Therefore, it is important to predict how materials will modulate the response of macrophages. In this study, we investigated the effect of methacrylated gellan gum hydrogels on macrophage phenotype and proliferation with the ultimate goal of improving rational design of biomedical implants. Naïve, along with classically and alternatively activated RAW 264.7 macrophages were seeded on methacrylated gellan gum ...


Treatment Of Neurodegenerative Disorders Through The Blood-Brain Barrier Using Nanocarriers, Nitya Poovaiah, Zahra Davoudi, Haisheng Peng, Benjamin Schlichtmann, Surya K. Mallapragada, Balaji Narasimhan, Qun Wang Aug 2018

Treatment Of Neurodegenerative Disorders Through The Blood-Brain Barrier Using Nanocarriers, Nitya Poovaiah, Zahra Davoudi, Haisheng Peng, Benjamin Schlichtmann, Surya K. Mallapragada, Balaji Narasimhan, Qun Wang

Chemical and Biological Engineering Publications

Neurodegenerative diseases refer to disorders of the central nervous system (CNS) that are caused by neuronal degradations, dysfunctions, or death. Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease (APHD) are regarded as the three major neurodegenerative diseases. There is a vast body of literature on the causes and treatments of these neurodegenerative diseases. However, the main obstacle in developing an effective treatment strategy is the permeability of the treatment components to the blood-brain barrier (BBB). Several strategies have been developed to improve this obstruction. For example, nanomaterials facilitate drug delivery to the BBB due to their size. They ...


Uncoupling Fermentative Synthesis Of Molecular Hydrogen From Biomass Formation In Thermotoga Maritima, Raghuveer Singh, Derrick White, Yaşar Demirel, Robert Kelley, Kenneth Noll, Paul H. Blum Aug 2018

Uncoupling Fermentative Synthesis Of Molecular Hydrogen From Biomass Formation In Thermotoga Maritima, Raghuveer Singh, Derrick White, Yaşar Demirel, Robert Kelley, Kenneth Noll, Paul H. Blum

Chemical and Biomolecular Engineering -- All Faculty Papers

When carbohydrates are fermented by the hyperthermophilic anaerobe Thermotoga maritima, molecular hydrogen (H2) is formed in strict proportion to substrate availability. Excretion of the organic acids acetate and lactate provide an additional sink for removal of excess reductant. However, mechanisms controlling energy management of these metabolic pathways are largely unexplored. To investigate this topic, transient gene inactivation was used to block lactate production as a strategy to produce spontaneous mutant cell lines that overproduced H2 through mutation of unpredicted genetic targets. Single-crossover homologous chromosomal recombination was used to disrupt lactate dehydrogenase (encoded by ldh) with a truncated ldh ...


Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie Jun 2018

Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie

Chemical and Biological Engineering Publications

Gellan gum is a naturally occurring polymer that can cross-link in the presence of divalent cations to form biocompatible hydrogels. However, physically cross-linked gellan gum hydrogels lose their stability under physiological conditions, thus restricting the applications of these hydrogels in vivo. To improve the mechanical strength of the gels, we incorporated methacrylate into the gellan gum and chemically cross-linked the hydrogel through three polymerization methods: step growth through thiol–ene photoclick chemistry, chain-growth via photopolymerization, and mixed model in which both mechanisms were employed. Methacrylation was confirmed and quantified by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared ...


Comparison Of Eosin And Fluorescein Conjugates For The Photoinitiation Of Cell-Compatible Polymer Coatings, Jacob L. Lilly, Anuhya Gottipati, Calvin F. Cahall, Mohamed Agoub, Brad J. Berron Jan 2018

Comparison Of Eosin And Fluorescein Conjugates For The Photoinitiation Of Cell-Compatible Polymer Coatings, Jacob L. Lilly, Anuhya Gottipati, Calvin F. Cahall, Mohamed Agoub, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more ...


Modeling Of Reaction-Diffusion Transport Into A Core-Shell Geometry, Clarence C. King, Amelia Ann Brown, Irmak Sargin, Kaitlin M. Bratlie, S. P. Beckman Jan 2018

Modeling Of Reaction-Diffusion Transport Into A Core-Shell Geometry, Clarence C. King, Amelia Ann Brown, Irmak Sargin, Kaitlin M. Bratlie, S. P. Beckman

Materials Science and Engineering Publications

Fickian diffusion into a core-shell geometry is modeled. The interior core mimics pancreatic Langerhan islets and the exterior shell acts as inert protection. The consumption of oxygen diffusing into the cells is approximated using Michaelis-Menten kinetics. The problem is transformed to dimensionless units and solved numerically. Two regimes are identified, one that is diffusion limited and the other consumption limited. A regression is fit that describes the concentration at the center of the cells as a function of the relevant physical parameters. It is determined that, in a cell culture environment, the cells will remain viable as long as the ...


Collagen Organization Deposited By Fibroblasts Encapsulated In Ph Responsive Methacrylated Alginate Hydrogels, Anuraag Boddupalli, Kaitlin M. Bratlie Jan 2018

Collagen Organization Deposited By Fibroblasts Encapsulated In Ph Responsive Methacrylated Alginate Hydrogels, Anuraag Boddupalli, Kaitlin M. Bratlie

Materials Science and Engineering Publications

The pH of dermal wounds shifts from neutral during the inflammatory phase to slightly basic in the tissue remodeling phase. Stage specific wound treatment can be developed using environmentally responsive alginate hydrogels. The chemistry of these networks dictates swelling behavior. Here, we fabricated alginate hydrogels using chain growth, step growth, and combined mixed mode gelation methods to crosslink methacrylated alginate (ALGMA) and gain control over swelling responses. Methacrylation of the alginate network was confirmed through NMR spectroscopy. Strontium cations were introduced to fabricate stiffer, dually crosslinked hydrogels. Dual crosslinking significantly decreased the swelling response over the pH range of 3 ...


Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard Dec 2017

Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard

Center for Applied Energy Research Faculty Publications

Commercial scale production of biofuels from lignocellulosic feed stocks has been hampered by the resistance of plant cell walls to enzymatic conversion, primarily owing to lignin. This study investigated whether DypB, the lignin-degrading peroxidase from Rodococcus jostii, depolymerizes lignin and reduces recalcitrance in transgenic tobacco (Nicotiana benthamiana). The protein was targeted to the cytosol or the ER using ER-targeting and retention signal peptides. For each construct, five independent transgenic lines were characterized phenotypically and genotypically. Our findings reveal that expression of DypB in the cytosol and ER does not affect plant development. ER-targeting increased protein accumulation, and extracts from transgenic ...


Tuning Properties Of Poly(Ethylene Glycol)-Block-Poly(Simvastatin) Copolymers Synthesized Via Triazabicyclodecene, Theodora A. Asafo-Adjei, Thomas D. Dziubla, David A. Puleo Oct 2017

Tuning Properties Of Poly(Ethylene Glycol)-Block-Poly(Simvastatin) Copolymers Synthesized Via Triazabicyclodecene, Theodora A. Asafo-Adjei, Thomas D. Dziubla, David A. Puleo

Biomedical Engineering Faculty Publications

Simvastatin was polymerized into copolymers to better control drug loading and release for therapeutic delivery. When using the conventional stannous octoate catalyst in ring-opening polymerization (ROP), reaction temperatures ≥ 200 °C were required, which promoted uncontrollable and undesirable side reactions. Triazabicyclodecene (TBD), a highly reactive guanidine base organocatalyst, was used as an alternative to polymerize simvastatin. Polymerization was achieved at 150 °C using 5 kDa methyl-terminated poly(ethylene glycol) (mPEG) as the initiator. ROP reactions with 2 kDa or 550 Da mPEG initiators were also successful using TBD at 150 °C instead of stannous octoate, which required a higher reaction temperature ...


Escherichia Coli Attachment To Model Particulates: The Effects Of Bacterial Cell Characteristics And Particulate Properties, Xiao Liang, Chunyu Liao, Michelle L. Soupir, Laura R. Jarboe, Michael L. Thompson, Philip M. Dixon Sep 2017

Escherichia Coli Attachment To Model Particulates: The Effects Of Bacterial Cell Characteristics And Particulate Properties, Xiao Liang, Chunyu Liao, Michelle L. Soupir, Laura R. Jarboe, Michael L. Thompson, Philip M. Dixon

Chemical and Biological Engineering Publications

E. coli bacteria move in streams freely in a planktonic state or attached to suspended particulates. Attachment is a dynamic process, and the fraction of attached microorganisms is thought to be affected by both bacterial characteristics and particulate properties. In this study, we investigated how the properties of cell surfaces and stream particulates influence attachment. Attachment assays were conducted for 77 E. coli strains and three model particulates (ferrihydrite, Ca-montmorillonite, or corn stover) under environmentally relevant conditions. Surface area, particle size distribution, and total carbon content were determined for each type of particulate. Among the three particulates, attachment fractions to ...


Inkjet Printing Of Ag Nanoparticles Using Dimatix Inkjet Printer, No 2, Ming Yuan Chuang May 2017

Inkjet Printing Of Ag Nanoparticles Using Dimatix Inkjet Printer, No 2, Ming Yuan Chuang

Protocols and Reports

This report describes the rheological analysisof the present Ag nanoparticle ink, and confirms that it is suitable for the piezoelectric drop-on-demand printing for both of 1 pL and 10 pL cartridges. The satellite drops and the splashing on the substrate are also discussed for optimization of the nozzle temperature and the jetting voltage. The minimum horizontal and vertical line widths are shown to be 30 and 40 µm, respectively, but the average minimum single line width is estimated to be ~50 µm. The non-uniform width lines are suggested to arise from the bulge instability. Furthermore, it is indicated that the ...


Genetic Code Expansion In Biochemical Investigations And Biomedical Applications, Nanxi Wang Apr 2017

Genetic Code Expansion In Biochemical Investigations And Biomedical Applications, Nanxi Wang

Student Research Projects, Dissertations, and Theses - Chemistry Department

Genetic code expansion provides a powerful tool for site-specific incorporation of unnatural amino acids (unAAs) with novel biochemical and physiological properties into proteins in live cells and organisms. To achieve this, a nonsense codon suppression system, which consists of an orthogonal aminoacyl-tRNA synthetase (aaRS) and tRNA pair that specifically decodes a nonsense codon (e.g., amber codon and quadruplet codon) with an unAA but do not “cross talk” with their endogenous counterparts, was established. This Ph.D. thesis presents our efforts on evolution and application of nonsense codon suppression systems for biochemical and biomedical investigations.

In Chapter 1, a brief ...


Hemolysis As A Rapid Screening Technique For Assessing The Toxicity Of Native Surfactin And A Genetically Engineered Derivative, William J. Colonna, Mustafa E. Marti, John A. Nyman, Chris Green, Charles Glatz Mar 2017

Hemolysis As A Rapid Screening Technique For Assessing The Toxicity Of Native Surfactin And A Genetically Engineered Derivative, William J. Colonna, Mustafa E. Marti, John A. Nyman, Chris Green, Charles Glatz

Chemical and Biological Engineering Publications

If biosurfactants are to achieve their promise in environmental oil-spill remediation, their toxicity to marine life must be assessed. A killifish larvae assay is commonly used as a measure of toxicity but is difficult and nonlinear in response. Red blood cell (RBC) hemolysis has also been the basis for assays of some surfactant levels. Here we present a modified sheep RBC suspension assay and compare its response to that of the fish assay for surfactin and its genetically modified variant fatty-acyl-glutamate (FA-Glu). This is the first report of hemolytic activity as a property of FA-Glu. The method's potential for ...


Toxicity Evaluation Of Magnetic Hyperthermia Induced By Remote Actuation Of Magnetic Nanoparticles In 3d Micrometastasic Tumor Tissue Analogs For Triple Negative Breast Cancer, Nathanael A. Stocke, Pallavi Sethi, Amar Jyoti, Ryan Chan, Susanne M. Arnold, J. Zach Hilt, Meenakshi Upreti Mar 2017

Toxicity Evaluation Of Magnetic Hyperthermia Induced By Remote Actuation Of Magnetic Nanoparticles In 3d Micrometastasic Tumor Tissue Analogs For Triple Negative Breast Cancer, Nathanael A. Stocke, Pallavi Sethi, Amar Jyoti, Ryan Chan, Susanne M. Arnold, J. Zach Hilt, Meenakshi Upreti

Chemical and Materials Engineering Faculty Publications

Magnetic hyperthermia as a treatment modality is acquiring increased recognition for loco-regional therapy of primary and metastatic lung malignancies by pulmonary delivery of magnetic nanoparticles (MNP). The unique characteristic of magnetic nanoparticles to induce localized hyperthermia in the presence of an alternating magnetic field (AMF) allows for preferential killing of cells at the tumor site. In this study we demonstrate the effect of hyperthermia induced by low and high dose of MNP under the influence of an AMF using 3D tumor tissue analogs (TTA) representing the micrometastatic, perfusion independent stage of triple negative breast cancer (TNBC) that infiltrates the lungs ...


Improving Escherichia Coli Membrane Integrity And Fatty Acid Production By Expression Tuning Of Fadl And Ompf, Zaigao Tan, William Black, Jong Moon Yoon, Jacqueline V. Shanks, Laura R. Jarboe Feb 2017

Improving Escherichia Coli Membrane Integrity And Fatty Acid Production By Expression Tuning Of Fadl And Ompf, Zaigao Tan, William Black, Jong Moon Yoon, Jacqueline V. Shanks, Laura R. Jarboe

Chemical and Biological Engineering Publications

Background

Construction of microbial biocatalysts for the production of biorenewables at economically viable yields and titers is frequently hampered by product toxicity. Membrane damage is often deemed as the principal mechanism of this toxicity, particularly in regards to decreased membrane integrity. Previous studies have attempted to engineer the membrane with the goal of increasing membrane integrity. However, most of these works focused on engineering of phospholipids and efforts to identify membrane proteins that can be targeted to improve fatty acid production have been unsuccessful.

Results

Here we show that deletion of outer membrane protein ompF significantly increased membrane integrity, fatty ...