Protein Sequence-Structure-Function Relationship: Testing Ke-50 Modification On Recombinant Green Fluorescent Protein (Acgfp), Anna E. Burkey

Williams Honors College, Honors Research Projects

Protein modification shows promise for improving the effectiveness of protein therapy, including the use of Interferon-beta-1b for the treatment of multiple sclerosis. The addition of a chain of 50 lysine and glutamic acid residues (also called a KE50 modification) was tested on green fluorescent protein (AcGFP) to determine its effect on the bioactivity of the protein. Standard transformation protocol was used to grow the normal and modified proteins in E.Coli, and the bioactivity of the protein was measured using quantum yield and extinction coefficients to determine the reduction in brightness from the native form to the modified form. The …

Bio-Inspired Structural Colors Produced Via Self-Assembly Of Synthetic Melanin Nanoparticles, Ming Xiao, Yiwen Li, Michael C. Allen, Dimitri D. Deheyn, Xiujun Yue, Jiuzhou Zhao, Nathan C. Gianneschi, Matthew D. Shawkey, Ali Dhinojwala

Polymer Science Faculty Research

Structural colors arising from interactions of light with submicron scale periodic structures have been found in many species across all taxa, serving multiple biological functions including sexual signaling, camouflage, and aposematism. Directly inspired by the extensive use of self-assembled melanosomes to produce colors in avian feathers, we set out to synthesize and assemble polydopamine-based synthetic melanin nanoparticles in an effort to fabricate colored films. We have quantitatively demonstrated that synthetic melanin nanoparticles have a high refractive index and broad absorption spanning across the UV–visible range, similar to natural melanins. Utilizing a thin-film interference model, we demonstrated the coloration mechanism of …

Effects Of Magnetic Nanoparticles And External Magnetostatic Field On The Bulk Heterojunction Polymer Solar Cells, Kai Wang, Chao Yi, Chang Liu, Xiaowen Hu, Steven Chuang, Xiong Gong

Polymer Science Faculty Research

The price of energy to separate tightly bound electron-hole pair (or charge-transfer state) and extract freely movable charges from low-mobility materials represents fundamental losses for many low-cost photovoltaic devices. In bulk heterojunction (BHJ) polymer solar cells (PSCs), approximately 50% of the total efficiency lost among all energy loss pathways is due to the photogenerated charge carrier recombination within PSCs and low charge carrier mobility of disordered organic materials. To address these issues, we introduce magnetic nanoparticles (MNPs) and orientate these MNPS within BHJ composite by an external magnetostatic field. Over 50% enhanced efficiency was observed from BHJ PSCs incorporated with …

A Versatile Microparticle-Based Immunoaggregation Assay For Macromolecular Biomarker Detection And Quantification, Haiyan Wu, Yu Han, George G. Chase, Qiong Tang, Chen-Jung Lee, Bin Cao, Jiang Zhe, Gang Cheng

Mechanical Engineering Faculty Research

The rapid, sensitive and low-cost detection of macromolecular biomarkers is critical in clinical diagnostics, environmental monitoring, research, etc. Conventional assay methods usually require bulky, expensive and designated instruments and relative long assay time. For hospitals and laboratories that lack immediate access to analytical instruments, fast and low-cost assay methods for the detection of macromolecular biomarkers are urgently needed. In this work, we developed a versatile microparticle (MP)-based immunoaggregation method for the detection and quantification of macromolecular biomarkers. Antibodies (Abs) were firstly conjugated to MP through streptavidin-biotin interaction; the addition of macromolecular biomarkers caused the aggregation of Ab-MPs, which were subsequently …

Synthesis, Characterization And Anti-Proliferative Activity Of An Imidazolium Salt And Its Silver Carbene Complex: Utilization Of Picolyl And Quinolylmethyl Substituents, Cari E. Molnar

Williams Honors College, Honors Research Projects

The imidazolium salt (IS) and silver carbene complex (SCC) studied in this report are 3-(pyridin-2-ylmethyl)-1-(quinolin-2-ylmethyl)imidazolium chloride (1) and 3-(pyridin-2-ylmethyl)-1-(quinolin-2-ylmethyl)imidazole – silver acetate complex (2). It was anticipated that the anti-proliferative activity of 1 and 2 would be similar to other characterized ISs while having increased solubility. The SCC (2) was synthesized in order to simulate the ligand-metal coordination similar to that of cisplatin.

The success of the synthetic processes of 1 and 2 were determined by ¹H NMR (300 MHz) spectroscopy. In addition, 1 was also characterized by ¹H NMR (500 MHz) …

Predicting Key Residues Relevant To Hiapp Fibril Stability Using Permuted Residue Minimal Distance Pairs Of Riapp And Hiapp Dimers, Zak Kohler

Williams Honors College, Honors Research Projects

In order to discover the most significant residues involved in hIAPP fibril formation, Replica Exchange Molecular Dynamics (REMD) trajectories of both fibril forming hIAPP dimers and non-fibril-forming rIAPP dimers were analyzed. An import heuristic for this is the minimum distance between the peptides. To gain a greater resolution than the standard center of mass distance or 1-1, 2-2, etc.\ residue distances, every permutation of residue distance between molecules of the dimer was measured ranked. It was found that while the rIAPP had a single favored contact, (26 10), hIAPP appeared to have a network of at least three significant contacts: …

Effect Of Nanofiber Morphology On Pvdf Air Filter Performance, Andrew W. Marton

Williams Honors College, Honors Research Projects

Poly(vinylidene fluoride) (PVDF) can be formed into small nanofibers by electrospinning that are useful for a variety of applications. Air filters produced with PVDF are known to capture ionic particles with high efficiency. Existing studies have focused on the effects of electrospinning conditions on nanofiber morphology. In this study fibers were generated with varying morphologies. Air filters were then made from each sample and then characterized by TSI. Air filters were found to have increased resistances relative to their capture efficiencies according to particle diameter. Capture efficiencies did not correlate strongly with particle diameter, and the presence of beads in …

Filtration Of Aerosolized Oils With Layered Filter Media And Drainage Channels, Corey A. Boldon

Williams Honors College, Honors Research Projects

The purpose of this experiment is to compare the efficiency of four different filter media with two different drainage channel materials when filtering out aerosolized oil. The filter media include 2 micron stainless steel fibers, 6.5 micron stainless steel fibers, 2 micron woven glass fibers, and 6 micron woven glass fibers. The drainage channel materials are 500 micron Teflon (PTFE) and nylon mesh.

One major application that this research is targeted towards is air compressors. Air compressors use lubricating oil to minimize wear and corrosion. During operation some of this lubricating oil is aerosolized into the outgoing air stream. Inhalation …

Iso: Understanding Elective International Certification, Lauren R. Kukwa

Williams Honors College, Honors Research Projects

The purpose of this paper is to investigate elective certification specifically as it pertains to the Process Engineering II capstone project assigned at the University of Akron in the Spring Semester of 2015. The standards for certification are those needed to obtain certification in International Organization for Standardization’s 9000:2005 Quality Management standard. The ethics of a Chemical Engineering position as it pertains to the project will also be presented and similarities between elective certification and the American Institute of Chemical Engineers Code of Ethics will be noted.

Optimization Of Polydopamine Coatings, Helen C. Terrill Ms.

Williams Honors College, Honors Research Projects

Polydopamine coatings were fabricated onto the surfaces of glass slides, silicon wafers, and Teflon pieces. A method to change surface properties was optimized, providing a new way of using substrates by means of make-over surface properties. The technology has a wide range of potential approaches including high performance coatings and biomedical surfaces. The experiments can be conducted with various types of surface modifications to make surfaces hydrophilic, hydrophobic, conductive, or magnetic. The changes of film thickness and surface energy as functions of incubation time were quantified by means of ellipsometry, profilometry, and contact angle measurements. The use of primer polydopamine …

Evaluation Of The Signature Molecular Descriptor With Blosum62 And An All-Atom Description For Use In Sequence Alignment Of Proteins, Lindsay M. Aichinger

Williams Honors College, Honors Research Projects

This Honors Project focused on a few aspects of this topic. The second is comparing the molecular signature kernels to three of the BLOSUM matrices (30, 62, and 90) to test the accuracy of the mathematical model. The kernel matrix was manipulated in order to improve the relationship by focusing on side groups and also by changing how the structure was represented in the matrix by increasing the initial height distance from the central atom (Height 1 and Height 2 included).

There were multiple design constraints for this project. The first was the comparison with the BLOSUM matrices (30, 62, …

Developing A Colorimetric Membrane Sensor To Detect Trihalomethanes In Water Samples Utilizing The Fujiwara Reaction, Max D. Duckworth

Williams Honors College, Honors Research Projects

This work focused on creating a colorimetric sensor to detect trihalomethanes (THMs) at concentrations near the level of environmental regulations from the environmental protection agency (EPA). This work utlized the fujiwara reaction as well as a hydrophobic electrospun polyprolylene membrane to produce a sensitive colorimetric reaction. A calibration curve was produced which was able to predict the concentration of a bromoroform solution in the range of 8-250 ppb with a confidence of 97.7 % using the intensity of the color change as a quantitative measure.

Polymer Interactions With Nucleic Acids Under Various Physiological Conditions, Matthew S. Obrzut

Williams Honors College, Honors Research Projects

The goal of this project is to improve our understanding of nucleic acid interactions with cationic polymers with the theory that the polymers could protect the nucleic acids from degradation caused by biological enzymes. We seek to understand what the limitations of the cationic polymers are which, in this case, is mainly polymer-DNA compatibility. This experiment utilized peptide-dextran hybrid polymers with differing functionalizations to condense anionic nucleic acids into nanometer-sized polyplexes. Techniques of dynamic light scattering and zeta-potential were utilized to determine the particle sizes and surface charges of polyplexes.

In this experiment, dextran with a molecular weight of 20 …

Nylon-6 Fabric Nanocomposite Resistance Temperature Detectors - Effects Of Oxidant, Mwcnt, And Nylon-6 Concentration, Rebecca Howdyshell

Williams Honors College, Honors Research Projects

Abstract

The purpose of this honors project is to construct and test temperature detectors, which can be used for the advancement of exercise devices, prosthetic sockets, or medical applications. Resistance Temperature Detectors (RTDs) are an effective way to measure temperature due to the dependence of the RTD material’s resistance on temperature. The focus of this project was to develop an RTD for prosthetic socket or exercise applications, where the RTD is in close contact with the skin of the user. Generally, RTDs are constructed from platinum, copper, or nickel. However, metal RTDs have a tendency to be large and rigid, …

Electrospinning Of S-B-S Triblock And S-I-S Triblock Copolymers For Use In Fuel Filtration, Kevin Houser

Williams Honors College, Honors Research Projects

The following research project looked into the potential of using nanofibers of syrene-isoprene-styrene triblock copolymer produced through the electrospinning process for the filtration of water out of fuel as well as a comparison of styrene-isoprene-styrene triblock to the styrene-butadiene-styrene triblock nanofibers produced at equivalent operating parameters. Based on the work completed, it is concluded that the styrene-isoprene-styrene triblock is not suitable for use in filtration with the current electrospinning conditions. On average, the styrene-isoprene-styrene triblock produced nanofibers of lower average diameter and lower standard deviation in diameter when compared to styene-butadiene-styrene triblock.

Formation Of Polymer Micro-Tubes, Daniel Peters

Williams Honors College, Honors Research Projects

Abstract

Current demand for organs is greater than the supply of donated organs, which means that a new method of obtaining replacement organs needs to be found. The objective of the research is to evaluate the use of thermo-triggered self-rolling polymer tubes that can be used for scaffolds in tissue engineering. Additionally, the research also includes a method for forming polymer tubes through the removal of a sugar fiber, coated with a thin film of polymer, by dissolving it in deionized water. For the first approach, the effect of the aqueous environment and temperature on a polymer bilayer was observed …

Determining The Critical Micelle Concentration Of Polymer Matrix For Drug Delivery Purposes, Katie Emmert

Williams Honors College, Honors Research Projects

Targeted oral release systems have been a large topic within drug delivery systems. There are several benefits to an oral delivery including patient convenience and lower chance of infection. The colon specifically has been researched as the release media. The colon is an ideal location for a release because the pH is stable with high levels of microorganisms. Like any type of drug delivery research, there are several hurdles to overcome. In order for a drug to be released in the colon, the drug must survive the stomach and be biocompatible. This biocompatibility and pH sensitivity was created using a …

The Impact Of Shrinkage Reducing Admixtures On The Corrosion Of Steel Rebar In Concrete, Carlee C. Mccowin, Donald P. Visco Jr.

Williams Honors College, Honors Research Projects

Chemical admixtures are prepared in modern concrete to control certain performance properties, such as strength, setting-time, and workability. In this research, the corrosion inhibition properties of various shrinkage reducing admixtures in a synthetic concrete pore solution are examined. These compounds can inhibit or promote corrosion of the carbon steel rebar in concrete structures. The corrosive effects were tested by modeling the environment of concrete in a cathodic cell with a similar pH (12-13). Each shrinkage-reducing admixture (SRA) was compared to a standard reference cell. Tafel curves were used to determine the corrosion current and potential.

New Multiphase Reactor Design Using Electrospun Nanofibers, Victoria Smith

Williams Honors College, Honors Research Projects

No abstract provided.

Biosurfactants In Electrospinning, Jonathan Russell

Williams Honors College, Honors Research Projects

Surfactants are useful in electrospinning to help improve the fiber morphology. Crocin is a naturally occurring biosurfactant from saffron that is highly soluble in water. By electrospinning a biocompatible polymer, such as polyethylene oxide (PEO) and Crocin, one can improve the fiber morphology. A systematic study of PEO was conducted by varying the voltage, flow rate, and gap distance. The viscosity of the solution was determined using a viscometer and the surface tension was determined using the pendant drop method. Fiber morphology was examined using SEM and fiber diameters were determined using ImageJ to measure the fibers in the SEM …

Temperature Control Of An Emulsion Polymerization Process, Evan M. Arnold

Williams Honors College, Honors Research Projects

The project premise was to create a new temperature control scheme for an emulsion polymerization process at the pilot scale with intentions of implementing the system into a production facility in the near future. The data was collected using electronic instrumentation at a current emulsion polymerization pilot plant facility in real-time and saved in a Microsoft Excel format. The control scheme was based on three parameters: the rate of change, temperature dead band around the set point to determine heating or cooling, and a jacket fluid clamp temperature. After research and experimentation on actual emulsion polymerization batches it was determined …

3d Differentiation Of Neural Stem Cells In Macroporous Photopolymerizable Hydrogel Scaffolds, Nic Leipzig

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Neural stem/progenitor cells (NSPCs) are the stem cell of the adult central nervous system (CNS). These cells are able to differentiate into the major cell types found in the CNS (neurons, oligodendrocytes, astrocytes), thus NSPCs are the mechanism by which the adult CNS could potentially regenerate after injury or disorder. Microenviromental factors are critical for guiding NSPC differentiation and are thus important for neural tissue engineering. In this study, D-mannitol crystals were mixed with photocrosslinkable methacrylamide chitosan (MAC) as a porogen to enhance pore size during hydrogel formation. D-mannitol was admixed to MAC at 5, 10 and 20 wt% D-mannitol …

Fabrication And Degradation Of Electrospun Scaffolds From L-Tyrosine Based Polyurethane Blends For Tissue Engineering Applications, Lingyun Liu

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

It is important to control the degradation rate of a tissue-engineered scaffold so that the scaffold will degrade in an appropriate matching rate as the tissue cells grow in. A set of potential tissue engineering scaffolds with controllable rates of degradation were fabricated from blends of two biocompatible, biodegradable L-tyrosine-based polyurethanes (PEG1000-HDI-DTH and PCL1250-HDI-DTH) using the electrospinning process. The scaffolds were characterized by mat morphology, fiber diameter, diameter distribution, pore size, and hydrolytic degradation behavior. The majority of the scaffolds, despite having radically different chemical compositions, possessed no statistical difference with pore sizes and fiber diameters. The degradation pattern observed …

Did Mineral Surface Chemistry And Toxicity Contribute To Evolution Of Microbial Extracellular Polymeric Substances?, Jie Xu, Jay M. Campbell, Nianli Zhang, William J. Hickey, Nita Sahai

College of Polymer Science and Polymer Engineering

Modern ecological niches are teeming with an astonishing diversity of microbial life in biofilms closely associated with mineral surfaces, which highlights the remarkable success of microorganisms in conquering the challenges and capitalizing on the benefits presented by the mineral-water interface. Biofilm formation capability likely evolved on early Earth because biofilms provide crucial cell survival functions. The potential toxicity of mineral surfaces toward cells and the complexities of the mineral-water-cell interface in determining the toxicity mechanisms, however, have not been fully appreciated. Here, we report a previously unrecognized role for extracellular polymeric substances (EPS), which form biofilms in shielding cells against …

Clay Minerals For Nanocomposites And Biotechnology: Surface Modification, Dynamics And Responses To Stimuli, Hendrik Heinz

College of Polymer Science and Polymer Engineering

Clay minerals find a wide range of application in composites, paints, drilling liquids, cosmetics, and medicine. This article reviews chemical and physical properties of natural and organically modified clay minerals to understand the nanometre-scale structure, surface characteristics, and application in functional materials. The relation between fundamental properties and materials design is emphasized and illustrated by examples. The discussion comprises the following: an overview; surface structure and cation density; solubility and solubility reversal by surface modification; the degree of covalent and ionic bonding represented by atomic charges; the distribution of metal substitution sites; measurements and simulations of interfacial properties at the …

Temperature Dependent Droplet Impact Dynamics On Flat And Textured Surfaces, Azar Alizadeh, Vaibhav Bahadur, Sheng Zhong, Wen Shang, Ri Li, James Ruud, Masako Yamada, Liehui Ge, Ali Dhinojwala, Manohar Sohal

College of Polymer Science and Polymer Engineering

Droplet impact dynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling, and heat transfer. We study impact dynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Droplet retraction shows very strong temperature dependence especially on hydrophilic surfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures combined with an increased work of adhesion can explain the decreased retraction. The present findings serve as a starting …

Polymorphic Structures Of Alzheimer's Beta-Amyloid Globulomers, Jie Zheng

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Misfolding and self-assembly of Amyloid-β (Aβ) peptides into amyloid fibrils is pathologically linked to the development of Alzheimer's disease. Polymorphic Aβ structures derived from monomers to intermediate oligomers, protofilaments, and mature fibrils have been often observed in solution. Some aggregates are on-pathway species to amyloid fibrils, while the others are off-pathway species that do not evolve into amyloid fibrils. Both on-pathway and off-pathway species could be biologically relevant species. But, the lack of atomic-level structural information for these Aβ species leads to the difficulty in the understanding of their biological roles in amyloid toxicity and amyloid formation.

Hemocompatibility Of Silicon-Based Substrates For Biomedical Implant Applications, Lingyan Liu

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Silicon membranes with highly uniform nanopore sizes fabricated using microelectromechanical systems (MEMS) technology allow for the development of miniaturized implants such as those needed for renal replacement therapies. However, the blood compatibility of silicon has thus far been an unresolved issue in the use of these substrates in implantable biomedical devices. We report the results of hemocompatibility studies using bare silicon, polysilicon, and modified silicon substrates. The surface modifications tested have been shown to reduce protein and/or platelet adhesion, thus potentially improving biocompatibility of silicon. Hemocompatibility was evaluated under four categories—coagulation (thrombin–antithrombin complex, TAT generation), complement activation (complement protein, C3a …

Surface Hydration: Principles And Applications Toward Low-Fouling/Nonfouling Biomaterials, Lingyan Liu, Jie Zheng

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Surface resistance to nonspecific protein adsorption, cell/bacterial adhesion, and biofilm formation is critical for the development and performance of biomedical and analytical devices. Significant needs and efforts have been made in the development of biocompatible and bioactive materials for antifouling surfaces, but much of the work retains an empirical flavor due to the complexity of experiments and the lack of robust theoretical models. In this review, two major classes of nonfouling materials (i.e. hydrophilic and zwitterionic materials) and associated basic nonfouling mechanisms and practical examples are discussed. Highly hydrated chemical groups with optimized physical properties of the surface, along with …

Effect Of Surface Freezing On Meniscus Relaxation In Side Chain Comb Polymers, Shishir Prasad, Zhang Jiang, Michael Sprung, Sunil K. Sinha, Ali Dhinojwala

College of Polymer Science and Polymer Engineering

We have observed a sharp slowing down of the relaxation of the liquid meniscus for polydn-alkyl acrylate) at temperatures where there are no abrupt changes in bulk viscosity or surface tension. This slowing down is due to the formation of a surface-ordered monolayer above the bulk melting temperatures. X-ray photon correlation spectroscopy measurements reveal that the surface capillary fluctuations are also significantly slower due to the formation of the ordered monolayer for film thicknesses comparable to that of the precursor films. The slowing down of the precursor film dynamics is responsible for slower meniscus relaxation below the surface ordering transition …