Dragonfly Larvae as Bioindicators of Mercury in Texas Waters

Type: Undergraduate
Author(s): Ely Raphael Biology Andrew Brinker Biology Matthew Chumchal Biology
Advisor(s): Matt Chumchal Biology
Location: Second Floor, Table 7, Position 3, 1:45-3:45

Mercury (Hg) is released into the environment by coal-fired power plants, artisanal gold mines, and other human activities. Aquatic bacteria then convert the inorganic mercury into a highly toxic compound called methyl mercury. The methyl mercury builds up through bioaccumulation and biomagnification causing consumption bans for several species of fish in Texas. Dragonfly larvae can be used as bioindicators for methyl mercury contamination in aquatic ecosystems. The carnivorous diet of larvae leads to the bioaccumulation of measurable amounts of methyl mercury. Fort Worth ISD students have been working with TCU on the USGS citizen science - “The Dragonfly Mercury Project”. Dragonfly larvae are collected by students using dipnets at the Fort Worth Nature Center and Refuge along with National Parks across the United States. The larvae are placed in Ziploc bags with a label indicating the family, total length, date and location. Students wore gloves and followed a strict protocol to avoid contamination of samples. The samples are frozen and shipped with dry ice to a USGS lab for analysis. We report the data collected during 2018, 2020, 2021 and 2022 at the Fort Worth Nature Center and Refuge. We sampled three different sites on the refuge, Lake Worth (n=62, x̄=20.5ppb), Lotus Marsh(n=62, x̄=61.4ppb), and West Pasture Pond(n=66, x̄=34.4ppb).

Exploring the effects of a comprehensive Mediterranean diet verses a typical American diet on peripheral inflammation and the expression of inflammation-related genes in the dorsal hippocampus

Type: Undergraduate
Author(s): Catherine Shoffner Biology Morgan Bertrand Biology Gary Boehm Psychology Michael Chumley Biology Paige Braden Kuhle Biology Vivienne Lacy Biology Caleb Pryor Biology Raleigh Robinson Biology Mary Skrabanek Biology
Advisor(s): Michael Chumley Biology
Location: Second Floor, Table 6, Position 3, 11:30-1:30

Exploring the effects of a comprehensive Mediterranean diet verses a typical American diet on peripheral inflammation and the expression of inflammation-related genes in the dorsal hippocampus
Catherine Shoffner, Mary Skrabanek, Raleigh Robinson, Caleb Pryor, Morgan Bertrand, Vivienne Lacy, Paige Braden Kuhle, Gary Boehm, Michael Chumley
Approximately 72% of Americans are overweight or obese, partially due to the consumption of a Western diet (WD). The highly-processed WD is composed of simple carbohydrates, sugars, and saturated fats. The WD has been identified as a risk factor for Alzheimer’s disease (AD) due to the elevated levels of pro-inflammatory cytokines following long-term diet consumption. In contrast to the WD, the Mediterranean diet (MD) is a plant-based, mostly unsaturated fat diet. Research has shown that it is crucial to consume a balanced omega-6 to omega-3 ratio of 1:1 or 2:1, like that in the MD, as elevated ratios found in the WD lead to increased inflammation.
Previous studies generally utilize an extremely high-fat Western rodent diet that does not resemble that of the typical American. Thus, our lab designed two novel macronutrient-matched diets that mimic typical American or Mediterranean diets. In the current study, we examined the effects of the typical American diet (TAD) versus the MD in relation to pro-inflammatory cytokine production in serum and gene expression in the dorsal hippocampus of C57BL/6J mice. Following six months of TAD or MD consumption, the mice were treated with one intraperitoneal injection of lipopolysaccharide (LPS) or saline 4 hours prior to euthanasia. In comparison to the MD, mice consuming the TAD had increased expression and levels of pro-inflammatory cytokines in the dorsal hippocampus and serum, respectively.

Assessment of Yolk Sac Depletion Within Inland Silverside and Sheepshead Minnow Larvae

Type: Undergraduate
Author(s): Colton Slabe Biology Dalton Allen Biology
Advisor(s): Marlo Jeffries Biology
Location: Third Floor, Table 10, Position 2, 11:30-1:30

In attempt to characterize the toxic effects of effluents discharged into surface waters, a previous study has shown crude oil contamination alters both mortality and hatching success among two model organisms: inland silversides and sheepshead minnows. Through toxicity testing it has become apparent that pollutants have the capacity to significantly alter growth and development of marine life. Specifically, it was found that exposure delayed the time of hatch or didn’t allow for hatch at all, and the unhatched embryos were less likely to survive. In addition, differences in both hatch and mortality were observed between the two organisms. Since the experimental conditions of the previous study were held constant for both groups the observed differences must be a result of a physiological difference, and a key distinction between the two species may lie in the differential use of the yolk sac. In the early stages of development marine organisms utilize the yolk sac as an internal source of energy prior to free feeding. It has been indicated that energy reserves and rate of depletions can differ between species. To determine the rate of yolk sac depletion in both inland silversides and sheepshead minnows, a total of 48 embryos per species were collected and raised to hatch. A subset of larvae at 24- to 96-hours post hatch were collected and the presence or absence of the yolk sac was determined. It was found that the yolk sac was depleted in 100% of the larvae 24-hours earlier for inland silversides as compared to sheepshead minnows. This observed difference shows a difference in the rates of energy reserve use and is indicative of a dissimilar response to external stressors, such as crude oil. These results may provide evidence of a mechanisms by which marine organisms experience differential hatch success and mortality when exposed to pollutants. Future research efforts might focus on the effect of yolk sac depletion as a key physiological distinction between species when outlining adverse effects of additional chemical exposures.

Determining if genetic markers associated with life history development of rainbow trout are shared across freshwater drainages

Type: Undergraduate
Author(s): Asher Smith Biology Bridey Brown Biology
Advisor(s): Matthew Hale Biology
Location: Second Floor, Table 3, Position 1, 1:45-3:45

Oncorhynchus mykiss, commonly known as rainbow trout, exhibit partial migratory behavior, in which some individuals in a population will opt to migrate, whereas others do not. Consequently, there are two ecotypes of O. mykiss: the non-migratory rainbow trout (also known as residents) and the migratory steelhead (also known as migrants). Previous evidence generated from our lab demonstrated that various loci in the rainbow trout genome segregate between resident rainbow trout and migrant steelhead trout in the Sashin creek system of Alaska. A unique feature of the Sashin system is that a series of waterfalls separate the lake and stream, thereby inhibiting gene flow between the lake between migratory stream individuals and resident lake individuals. However, it is still unknown whether these same genetic markers also segregate between behaviors in other freshwater systems. Therefore, the goal of my research project is to use DMAS-qPCR to genotype known migrant individuals and known resident individuals from Little Sheep Creek, Oregon. This population is geographically separated from the Sashin Creek watershed and differs from Sashin in that both life histories can and do interbreed. From this project, I will be able to deduce 1) if genetic markers associated with life history development are shared across freshwater drainages and 2) to test if there is evidence of assortative mating (i.e., residents mating with residents and migrants mating with migrants) within the Little Sheep Creek system which would suggest genetic differences between life histories.

Emergence Insect Biomass and Insect – Mediated Hg Flux from Six Ponds in NW Greenland

Type: Undergraduate
Author(s): Emma Sullivan Biology Aleah Appel Biology Benjamin Barst Biology Kurt Burnham Biology Reuben Heine Biology Ben Katzenmeyer Biology James Kennedy Biology Kevin Meyers Biology David Peebles Biology Sarah Scott Biology Benjamin Strang Biology Lance Viscioni Biology Kimberlee Whitmore Biology
Advisor(s): Mathew Chumchal Biology
Location: Basement, Table 13, Position 2, 1:45-3:45

Mercury (Hg) is a global contaminant produced primarily by anthropogenic activities (i.e. coal-fired power plants, artisanal gold-mining operations) and is found in all freshwater systems. Primary producers (e.g., algae) and aquatic organisms that consume algae (e.g., emerging aquatic insects) are exposed to mercury through their diet. As adults, these emerging insects leave freshwater systems to reproduce, transferring both energy and Hg from their aquatic environment to the adjacent terrestrial environment. We assessed the emergence biomass of aquatic insects and insect–mediated Hg flux from 6 ponds in Northwest Greenland from July 1-30, 2022. Emergence biomass ranged from 0.09 to 176.91 mg/m2/day and insect-mediated Hg flux ranged from 0.009 ng/m2/day to 23.67 ng/m2/day across all ponds for the sampling period. This study suggests that small pongs in the High Arctic are important sources of both energy and contaminants to food webs in surrounding terrestrial ecosystems.

Studying the Mode of Action of Novel Anti-Inflammatory Drugs

Type: Undergraduate
Author(s): Halley Tamene Biology
Advisor(s): Giridhar Akkaraju Biology
Location: Third Floor, Table 4, Position 1, 1:45-3:45

Alzheimer’s disease (AD) is ranked as the seventh leading cause of death in the US with over 6 million Americans currently diagnosed, and that number is projected to reach about 13 million by 2050. AD is currently believed to be caused by numerous factors ranging from genetics, lifestyle, and environmental conditions. The exact pathogenesis of AD remains uncertain, but the pathology of the disease includes the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles composed of the protein tau in the brain. These are two proteins are normally found in the brains of healthy individuals, but amyloid-beta peptides are often degraded under normal conditions, while tau plays a role in stabilizing our cell’s cytoskeletal structures. In Alzheimer’s however, these proteins are misfolded and accumulate, causing disruptions in cell signaling and neuronal death, therefore worsening the disease. Aβ plaques also activate microglial cells, which produce cytokines and induce inflammation. Cytokines are signaling molecules produced by immune cells that mediate inflammatory signaling. Activation of an inflammasome complex found in microglial cells, NLRP3, leads to the production of the cytokine IL-1β which has been implicated in Alzheimer’s due to its ability to induce and maintain this chronic cycle of inflammation, and possibly results in more amyloid-beta deposition. Our research looks into the mode of action of novel anti-inflammatory drugs and their potential to reduce inflammation at the level of the NLRP3 inflammasome as a mechanism to slow down the progression of AD.
 

Exploring the effects of a comprehensive Mediterranean diet verses a typical American diet on spatial memory and behavior in C57BL/6J mice

Type: Undergraduate
Author(s): Hatice Buse Uras Psychology Paige Braden Kuhle Psychology Taylor Ferguson Biology Logun Gunderson Psychology Vivienne Lacy Biology Sarah Grace White Psychology
Advisor(s): Michael Chumley Biology Gary Boehm Psychology
Location: Third Floor, Table 1, Position 2, 11:30-1:30

Alzheimer’s disease is the most common form of dementia and affects over 6 million Americans 65 and older. In the absence of a cure, addressing modifiable risk factors could potentially reduce the risk of AD development. There is an established relationship between diet and AD risk. For example, studies in rodents found that highly processed Western diets are associated with cognitive impairment and increased amyloid-beta in the hippocampus, a brain region critical for learning and memory. Conversely, plant-based diets like the Mediterranean diet (MD) have been shown to protect against cognitive impairment.

A key limitation in the scientific literature is that most animal studies have only examined the effects of extremely high-fat WD (providing over 40-60% kcal from fat), or a MD with only one or two key nutritional components. We aimed to fill a gap in the literature by designing a rodent diet that mimicked the typical American diet (TAD), rather than an exaggerated WD, and a macronutrient-matched MD. C57BL/6J mice were weaned onto one of the two diets at postnatal day 21. Following six months of diet, we conducted behavioral tests, including open field, elevated zero, and object-location memory task (OLMT). In comparison to the MD, mice consuming the TAD had decreased locomotor activity and exploratory behavior, increased anxiety-like behavior, and reduced spatial memory.

Mercury Concentrations in Northwest Greenland Seabird & Sea-duck Eggs

Type: Undergraduate
Author(s): Abi Welch Biology Kimberly Whitmore Biology
Advisor(s): Matt Chumchal Biology
Location: First Floor, Table 4, Position 1, 11:30-1:30

Mercury contamination is of increasing concern. As the earth’s temperature continues to rise, it is vital to study the trends of MeHg absorption. Continuing to gather MeHg absorption data in the Northwest part of Greenland will help to grow our understanding of MeHg trends in Arctic territories. This study will increase the amount of data collected on MeHg levels, allowing a more accurate comparison between MeHg level patterns and species behavior, breeding success, and death rates in Arctic bird species (Chastel et al., 2022). Understanding how MeHg contamination affects health and prosperity is critical, not only for the environment and animals but people as well, as these birds are often part of the native Greenlander diet (Hong et al. 2012; Johansen et al. 2004). Temporal monitoring is also highly beneficial for evaluating the efficacy of policies aiming to reduce anthropogenic Hg emissions (AMAP 2021).

'Fine-Tuning' Potential Alzheimer's Therapeutics through Pyridinophane Substitution

Type: Undergraduate
Author(s): Will Campa Chemistry & Biochemistry Sarah Dunn Chemistry & Biochemistry Christina Mantsorov Chemistry & Biochemistry Shrikant Nilewar Chemistry & Biochemistry Kristof Pota Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry
Location: Basement, Table 14, Position 1, 11:30-1:30

Pyridinophane molecules have recently been shown to have both antioxidant and pharmacological properties suitable for therapeutic applications targeting neurodegenerative diseases, including Alzheimer’s Disease. We have synthesized derivatives of this parent molecule with added moiety substitutions. These substitutions are designed to enhance the permeability and antioxidant activity beyond that of the parent molecule in the hopes of producing a molecule suitable for pharmacological testing in animal models. To establish a principle between moiety location on the parent molecule and its activity, we have placed 8-hydroxyquinoline, a moiety established in our lab to improve the antioxidant activity of parent molecules, in varying locations. The results presented here will detail our evaluation of the substitution of 8-hydroxyquinoline in varying locations and its impact on the molecule’s permeability and reactivity through a series of statistics, including a DPPH assay, determination of logBB, and the determination of chelating equilibrium quotients at varying pH (“log beta”).

An Investigation of Pyclen Metal Chelator Release on the Aggregation of Amyloid Beta

Type: Undergraduate
Author(s): Caroline Crittell Chemistry & Biochemistry
Advisor(s): Jeffrey Coffer Chemistry & Biochemistry
Location: First Floor, Table 2, Position 2, 1:45-3:45

Alzheimer’s Disease (AD) affects over 6.5 million Americans over the age of 65. Previous research links AD with Amyloid-Beta-40 (AB40) aggregation in the brain, which creates neurotoxic plaques, associated with AD. A potential mechanism in the treatment of AD is using therapeutics that will prevent the formation of these plaques, which is possible with Metal Chelation Therapy.
Metal ion chelation ideally stops metal ions from aiding in the aggregation of AB40. However, to deliver metal chelating agents to the brain, a drug-delivery mechanism is required that will be able to deliver this medicine across the Blood-Brain Barrier. Porous silica is a potential drug delivery material due to its small particle size, high loading capacity, surface tunability, and biocompatibility. Along with these characteristics, porous silica can create a “sustained” release of a given drug, allowing for a slow and steady release profile, reducing the risks of medication side effects.
This project seeks to establish the optimal loading capacities of a class of potential metal ion chelate therapeutic molecules known as pyclens into porous silica, each with different pyridyl moieties and chemical functionalities along the rim of the molecule. Encapsulation efficiencies measurements for these pyclen derivatives reveal loading percentages in the 10-19% range, varying by pyclen identity. Additionally, release studies monitored diffusion over time to find which pyclen molecule achieved “sustained” release. All loaded pyclen species were able to show sustained release after 20 minutes, both in the presence and absence of copper (II) ions. Turbidity assays with AB40 present showed that all pyclen species decreased protein aggregation in the presence of copper (relative to non-pyclen controls), showing that all pyclen species were able to successfully prevent the aggregation of AB40 in the presence of copper.
Release studies in a more authentic BBB model remain to be completed.

The effect of anionic surfactant on the fluorescence of polyvinyl pyrrolidone in water

Type: Undergraduate
Author(s): Ngan Dinh Chemistry & Biochemistry Shamberia Thomas Chemistry & Biochemistry
Advisor(s): Onofrio Annunziata Chemistry & Biochemistry
Location: Basement, Table 4, Position 1, 11:30-1:30

Polyvinyl pyrrolidone (PVP) is a nonionic synthetic polymer often employed in drug formulations. Due to its hydrophilicity, it is often found in aqueous solutions where it can act as a solubilizing agent for organic molecules with poor water solubility. Interestingly, PVP also exhibits fluorescence in water. Furthermore, PVP fluorescence intensity is known to decrease as the concentration of salt increases. This effect has been attributed to the affinity of inorganic anions to PVP chains. In this poster, we examine the effect of an anionic surfactant, sodium dodecyl sulfate (SDS), on PVP fluorescence. In contrast with inorganic anions, we found that PVP fluorescence intensity increases with SDS concentration. We attribute this effect to the binding of SDS anions to PVP chains. This hypothesis is supported by a crystallization assay showing that PVP suppresses formation of SDS crystals. Our experimental results indicate that PVP fluorescence could be used to determine concentration of other types of anionic surfactants in water. These include perfluoroalkyl substances (PFAS), which are relevant environmental chemistry.

Polyethylene Glycol as an LLPS Temperature Promoter for Protein Crystallization

Type: Undergraduate
Author(s): Joel Dougay Chemistry & Biochemistry Shamberia Thomas Chemistry & Biochemistry
Advisor(s): Onofrio Annunziata Chemistry & Biochemistry
Location: Second Floor, Table 8, Position 2, 1:45-3:45

Protein purification is a critical step in the downstream processing of protein. Although chromatography is the most employed technique for protein purification, novel strategies that reduce operational costs and increase the amount of purified protein are being developed. These strategies have the possibility to reduce the price of protein-based pharmaceutical and biotechnological products through the reduction of purification cost. Preparative protein crystallization is one such economically-sustainable alternative to chromatography, however protein crystallization is very slow and is difficult to implement in current protein purification protocols. In our lab, we explore the use of metastable liquid-liquid phase separation (LLPS) to enhance protein crystallization. LLPS is typically induced by cooling protein aqueous samples below a well-defined temperature, called the LLPS temperature. We have previously shown that cooling aqueous samples of lysozyme in the presence of NaCl (0.15 M) and HEPES (0.10 M, pH 7.4) below LLPS temperature reproducibly produces yields of lysozyme crystallization above 90%. However, this process requires sample cooling to relatively low temperatures
(below –10 °C). In this poster, we examine the use of polyethylene glycol (PEG) as an additive that increases LLPS temperature. Our experimental results show that PEG increases LLPS temperature without appreciably altering formation of lysozyme crystals. The effect of PEG concentration on LLPS temperature is explained by considering the mechanism of macromolecular crowding.

Dual genetic selection of synthetic riboswitches for TMAO as genetic and analytical tools

Type: Undergraduate
Author(s): Isabelle Galvan Chemistry & Biochemistry
Advisor(s): Youngha Ryu Chemistry & Biochemistry
Location: Basement, Table 6, Position 2, 1:45-3:45

The goal of this project is to develop synthetic riboswitches for trimethylamine N-oxide
(TMAO). TMAO has been shown to regulate various physiological processes involved in the
development of atherosclerosis. A riboswitch is a non-coding RNA molecule that specifically
binds to a ligand and thereby controls the expression of genes in the downstream. A synthetic
riboswitch for TMAO could be useful for regulating gene expression in response to TMAO and
detecting TMAO in complex biological samples such as urine and blood. The 17 nucleotides in
the aptamer domain of a naturally occurring glycine riboswitch were randomized to generate a
library containing billions of different variants. The library was placed in the upstream of the
cat-upp fusion gene for a series of dual genetic selections. The positive selection is done in the
presence of TMAO to identify functional riboswitches that make cells resistant to
chloramphenicol. The negative selection is performed in the presence of 5-fluorouracil to kill
the cells containing the riboswitch variants activated by any endogenous molecules. Once
identified by several rounds of dual genetic selections, the synthetic TMAO riboswitches will
be tested by colorimetric and fluorescence assays.

Isolating Chiral Nanoparticles from Paper: Templates for Chiral Semiconductor Nanoparticles

Type: Undergraduate
Author(s): Sarafina Gutterres Chemistry & Biochemistry
Advisor(s): Jeff Coffer Chemistry & Biochemistry
Location: Second Floor, Table 6, Position 2, 11:30-1:30

Chirality is a property of two molecules of the same composition to not be structurally superimposable on each other. Chiral structures are both common and essential throughout nature. Porous material can be used as templates for creating chirality. The use of cellulose as a template provides environmentally friendly alternatives for templating chirality onto materials such as silica. New research in this field includes using chiral silica templates for the synthesis of chiral perovskite films, a semiconductor material with bright light emission found in light sources like light emitting diodes (LEDs).

This project began by testing cellulose obtained from several different vendors to determine which product has the ideal properties for use in chiral films. An important aspect of cellulose product is its relative acidity/basicity (quantified in terms of pH), which can be regulated to control the degradation of cellulose into nanocrystals as well as the formation of chiral structures. Initially, the cellulose was acidified using sulfuric acid which causes aggregation and kinetic arrest within particles. A technique known as ion exchange chromatography is now being used in these experiments as the method of choice for acidifying cellulose samples.

The time allotted for cellulose nanocrystals to obtain chiral conformation is also an important aspect of creating chiral films. Initially, samples were not left to stand motionless and were immediately converted into silica films. Currently however, our procedure has been modified to allow the chiral cellulose nanocrystals at least seven days of sitting undisturbed before the addition of a silica precursor molecule, thereby facilitating the chiral product from the rest of the product mixture. Upon successful isolation of chiral cellulose-silica films, experiments will be initiated to template the formation of chiral light-emitting perovskite structures by infiltration.

First Year engagement - Chemistry Club

Type: Undergraduate
Author(s): Tatum Harvey Chemistry & Biochemistry Saba Anjum Biology Grace Bobo Chemistry & Biochemistry Jack Bonnell Chemistry & Biochemistry Braden Chadwick Biology Kathryn Collins Biology Caroline Crittell Chemistry & Biochemistry Delaney Davis Biology Audrey Dolt Biology Annie Downum Chemistry & Biochemistry Izzie Galvan Chemistry & Biochemistry Mark Sayegh Chemistry & Biochemistry Sam Shah Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry Heidi Conrad Chemistry & Biochemistry Julia Fry Chemistry & Biochemistry
Location: First Floor, Table 5, Position 2, 11:30-1:30

Texas Christian University’s Chemistry Club has always made a conscious effort to interest and include first year students through events and volunteering. This year’s project was focused on boosting numbers and cultivating a stronger community within the Chemistry and Biochemistry Department by specifically holding events to engage first year students. Events included the citrus social, periodic table of cupcakes, murder mystery play, tie dye event, and jeopardy night. This gave students a chance to get to know their peers better, to interact with a wide range of professors, and to gain knowledge about chemistry from outside the classroom. The success of these events has lead to record high attendance not only for the events but also for the Chemistry Club meetings held bi-weekly. The success of this initiative will ensure these and other events will be hosted for years to come, hopefully growing to the size where other schools can join and collaborate, further building a community within the field of chemistry and biochemistry.

Predicting pKas of flexible polybasic pyclen derivatives: A pKa challenge

Type: Undergraduate
Author(s): Tatum Harvey Chemistry & Biochemistry
Advisor(s): Benjamin Janesko Chemistry & Biochemistry Kayla Green Chemistry & Biochemistry
Location: Third Floor, Table 2, Position 1, 1:45-3:45

Predicting pKas is an outstanding challenge in computational chemistry. The Green group
at TCU is working to develop a library of pyclen derivatives that can successfully reduce oxidative
stress within the brain of people afflicted with neurodegenerative diseases1. Predicting the various
pKas of these flexible molecules, which are charged at neutral pH, challenges conventional
approaches to predicting pKas. For each pyclen derivative, we combine an extensive survey of
protonation site isomers, with conformational sampling using the CREST package2, DFT
calculations with continuum solvent models, followed by a linear fit to correct the solvent models
limitations for calculating energy of highly charged species. We can predict three to five measured
pKa values for each pyclen derivative with a RMSD of 0.9 pKa units, which is competitive with
the best-physics based method in the SAMPL6 blind challenge for the first pKa3. We are pushing
the boundaries of computational chemistry and its abilities to predict multiple pKas of flexible
molecules.

Models for the Next Generation of Drugs: Design, Synthesis, and Conformational Analysis of a 26-Atom Macrocycle

Type: Undergraduate
Author(s):
Advisor(s):
Location: First Floor, Table 4, Position 1, 1:45-3:45

To fight disease, pharmaceutical companies have historically prepared small molecules
designed to interfere with specific sites on proteins (enzymes) to prevent chemical reactions
from taking place. However, a second paradigm for interfering with proteins has gone largely
unexplored--blocking protein-protein interactions. To accomplish the latter, large molecules are
needed to bind to large areas on the protein target. However, large molecules present additional challenges. Typically, they are hard to synthesize, not orally available, and typically cannot cross cell membranes. Nature has designed large molecules like cyclosporin that should not work as drugs based on our current understanding. Despite its size, cyclosporin is orally available and can cross cell membranes. This research explores the design, synthesis, and conformational analysis of similar large ring-shaped molecules, so-called macrocycles. In this work, we are increasing the size of the ring-shaped molecule. By increasing the size of the ring-shaped molecule and varying the amino acid (in this case, valine), we are expanding the possible ways in which our macrocycle may interfere with protein-protein interactions. Here, a 26-atom macrocycle is reported. 1H NMR spectroscopy reveals a protonated molecule that is highly dynamic which has access to a beta-sheet conformation.

Implication of Steric Congestion on Sheet Formation: 26-Atom Macrocycles

Type: Undergraduate
Author(s): Lola Kouretas Chemistry & Biochemistry Luke Homfeldt Chemistry & Biochemistry Alex Menke Chemistry & Biochemistry
Advisor(s): Eric Simanek Chemistry & Biochemistry
Location: Second Floor, Table 1, Position 1, 1:45-3:45

Molecular engineering of larger macrocyclic compounds offers new avenues to disrupt protein-protein interfaces and potentially halt pathways that lead to neurodegenerative diseases, such as Alzheimer’s. The hallmark of Alzheimer’s disease involves the aggregation of so-called amyloid peptides that exhibit characteristic β-sheet structures. Thus, designing macrocycles that structurally/topologically mimic β-sheets should enhance the affinity of these macrocycles towards the amyloid aggregates and lead to rational design of more advanced scaffolds with superior structures. This will potentially present opportunities to interrogate protein-protein interactions, thus preventing amyloid plaque formation.

This work will describe the synthesis of structurally and functionally-diverse macrocyclic scaffolds containing leucine and isoleucine to understand the factors that contribute to β-sheet formation. Here, 26-atom macrocycles prepared in three steps will be described. Using a triazine core, a protected hydrazine group, and an amino acid constitute the base acid. In the second step the addition of an acetal of variable length forms the monomer. Acetals ranging from 2-4 carbons can be used to yield rings of 22-28 atoms. Previous work proves acetal length dictates morphology; three-carbon acetals demonstrate folded conformations and five-carbon acetals yield crinkled b-sheets. Four-carbon acetals yield the flattened b-sheets described here. Treatment with acid leads to dimerization in very high yields. Varying the amino acid choice can give way to synthesis of different homodimers and heterodimers.

These studies also address the optimization of the macrocyclization step. Early results indicate that a >300x reduction in the time of reaction (from 7 days to 30 min) might be realized. NMR spectroscopy provides confirmation of synthesis and 2D-NMR techniques offer opportunities to probe solution structure more efficiently.

Fabrication Process And Efficiency Analysis Of Organic Light-Emitting Diodes (OLEDs)

Type: Undergraduate
Author(s): Nhu Le Engineering
Advisor(s): Jeffery Coffer Chemistry & Biochemistry
Location: Second Floor, Table 1, Position 3, 1:45-3:45

Display technology is one of the industries of great significance, providing benefits for consumers with applications such as smartphones, televisions, and computer monitors. One of the current research topics in this industry of extensive interest is the development of new organic light-emitting diodes or OLEDs.

While such devices are common, fundamental challenges remain. Three pressing needs are: (1) longer device lifetimes, (2) lower fabrication costs, and (3) better control over emission color for ultrahigh definition displays and white-light lighting. Today, high-quality displays are built using high-vacuum deposition of molecular precursors, an expensive method unsuitable for ultra-large displays. Methods that rely on spin coating or printing of solutions of such precursors are far more economical, but present fabrication challenges of their own.

Our goal here is to improve device function and stability in OLEDs through simple solution-based routes with innovative fluorescent structures known as perovskites as building blocks. Ideally these new OLEDs will perform well at low voltage ranges and maintain good light emission intensity, as evaluated using techniques known as photoluminescence and electroluminescence spectroscopies.

In this research project, single-layer OLED and three-layer OLED devices are analyzed. Single-layer OLED devices consist of the substrate, anode, emissive layer, and cathode. Fluorine-doped Tin Oxide (FTO)/glass and Indium Tin Oxide (ITO)/plastic are the main substrates used, acting as anode. Ga-In eutectic, Silver Nanowire (AgNW), and Silver Epoxy are used as the interconnect / cathode layer to the emissive layer. To fabricate a three-layer OLED, the electron transport layer (ETL) is added between the cathode and emissive layer and a hole transport layer (HTL) added between emissive layer and anode, both to ideally improve energetics of electron/hole injection to the emissive layer. In our experiments, a species known as PEDOT:PSS is typically the hole transport layer and for the electron transport layer, we use ZnO or a mixture of ZnO and polyethylenimine.

The most success to date has been achieved with [Ru(bpy)3]2+ as the active emitting species in a thin polymer matrix referred to poly-vinylalcohol (PVA). Our current results show that the photoluminescence spectroscopy intensities were relatively high while the electroluminescence needs to be improved. The best result was recorded with the single-layer red OLED, which is made of FTO, [Ru(bpy)3]2+, and Ga-In eutectic. Visible light emission at low voltages from 3.5V-7V could be observed with the unaided eye under these conditions.

Bridging Theory and Practice Enhancing Drug Design Through Molecular Simulations and Solvent Stability Analysis

Type: Undergraduate
Author(s): Alejandro Munoz Chemistry & Biochemistry
Advisor(s): Benjamin Janesko Chemistry & Biochemistry
Location: Second Floor, Table 2, Position 3, 1:45-3:45

ARE GREEN ROUTES TO RED MOLECULES REAL? Sustainability and cost-effectiveness studies on the synthesis of high-value infrared emitting materials

Type: Undergraduate
Author(s): Hannah Sachs Chemistry & Biochemistry Harley Jacobs Chemistry & Biochemistry Daniel Ta Chemistry & Biochemistry
Advisor(s): Sergei Dzyuba Chemistry & Biochemistry
Location: Basement, Table 10, Position 1, 11:30-1:30

Typically, the costs associated with the synthesis, isolation, and purification of high value molecules/materials as well as environmental/health concerns related to the overall process are disregarded due to perceived profits that could be obtained from the use of the final products. However, as the scale of production of these materials increases, the need for more environmentally benign, sustainable, inexpensive, yet still facile and efficient processes increases exponentially.

Squaraine dyes are versatile, high-value fluorescent molecules, with a very broad and diverse range of applications due to their absorption and emission in the infrared spectral region. However, vast majority of literature syntheses of these dyes utilize toxic, volatile solvents. In this presentation, we will outline our current efforts on the use of green solvents, solvent-free and mechanochemical routes to various types of squaraine dyes. Furthermore, we will present sustainability and cost-effectiveness estimates as guiding tools for the future development of all around-efficient synthetic protocols for various types of squaraine dyes.

Beta-Sheet Mimics: A Step Towards Targeting Protein-Protein Interactions

Type: Undergraduate
Author(s): Brett Thorell Chemistry & Biochemistry Alex Menke Chemistry & Biochemistry
Advisor(s): Eric Simanek Chemistry & Biochemistry
Location: First Floor, Table 6, Position 1, 1:45-3:45

Small molecules are reliable and pervasive pharmaceuticals because critical drug characteristics are predictable including solubility and membrane permeability. In addition, small molecules are typically inexpensive to produce and their mechanisms of action subscribe to a common paradigm vis-à-vis blocking an enzyme active site. In contrast, nature employs elaborate machinery to make large molecules, oftentimes rings (or macrocycles). Drug companies avoid these because the rules for predicting behavior are under-explored and the paradigm used for action is different vis-à-vis blocking protein-protein interactions. Moreover, they are costly and laborious to make. To contribute to an understanding of drug design for large molecules, our group is preparing a series of large molecules (macrocycles). The lead adopts a beta-sheet conformation in the solid state, but its behavior in solution is unknown. Here, a second member of the class is described wherein alanine replaces glycine in the macrocycle to provide additional handles to study conformation and the effects that structure has on critical parameters. The 26-atom macrocycle is synthesized in a three-step process. The reaction of a triazine core, and the addition of BOC-hydrazine, alanine, and dimethylamine yields the first intermediate which undergoes elaboration with a 4-carbon acetal group using traditional peptide-coupling strategies (HBTU). Dimerization of the resulting monomer occurs in a 1:1 mixture of dichloromethane and trifluoroacetic acid. Reaction progress is followed by thin-layer chromatography and the identity of the products is confirmed by 1H and 13C NMR spectroscopy. Conformational analysis rests on 2-D 1H NMR spectroscopy. The molecule will also be subjected to analysis for solubility and membrane permeability. In the longer term, these beta-sheet mimics will be used to disrupt protein-protein interactions with an emphasis on the BRCA1-PALB2 interaction implicated in breast cancer.

INTEGRATED HYDROGEL-POROUS SILICON STRUCTURES FOR NON-INVASIVE BIOSENSING

Type: Undergraduate
Author(s): George Weimer Biology Alexa Frattini Chemistry & Biochemistry
Advisor(s): Jeffrey Coffer Chemistry & Biochemistry
Location: Basement, Table 5, Position 2, 11:30-1:30

Utilizing the supportive structure of hydrogels, the semiconducting character of porous silicon (pSi) membranes, and the biodegradability of both, a unique biosensor for the chemical analysis of health-relevant analytes can ideally be created.
Alginate-based hydrogels are water-infused, biodegradable polymer networks. These are particularly useful because of their environmental abundance, and their ability to interface well with human skin. These characteristics also make them an ideal medium for supporting pSi membranes and simultaneously assimilating them into a wide range of tissues.
Porous silicon (pSi), a highly porous form of the elemental semiconductor, is utilized to measure and conduct electrical signals throughout the hydrogel matrix. In diode form, these membranes exhibit measurable current values as a function of voltage, which can be used to detect bioelectrical stimuli such as the concentration of physiologically relevant ionic species (e.g. Na+, K+, and Ca2+).
Recent experiments center on integrating pSi membranes into various aqueous environments and hydrogels to test how variations in ion concentration affect the flow of electrical current as a function of applied voltage. pSi membranes are fashioned into diodes upon the attachment of 0.25 mm diameter copper wire using silver epoxy and annealing. An electrochemical cell is created by placing two pSi membranes parallel each other in an electrolyte composition. Current is measured as a function of applied voltage (typically from 0-5 V) for systems with differing NaCl concentration.
As expected, the magnitude of maximum current response is proportional to ion concentration present in the electrolyte, with an order of magnitude amplification or more of measured current for a given voltage upon immersion of the electrodes in an alginate hydrogel matrix relative to water alone.
This presentation will focus on initial diode fabrication protocols, as well as establishing limits of detection for simple ions species present in human sweat. More refined strategies are also envisioned, including the development of methods for stabilization of sensor performance along with miniaturization of the sensing platform itself.

Testing a Computation Workflow for Drug Design: pKa and logP from the SAMPL7 Blind Challenge

Type: Undergraduate
Author(s): Katherine Zabel Chemistry & Biochemistry
Advisor(s): Benjamin Janesko Chemistry & Biochemistry
Location: Third Floor, Table 4, Position 3, 1:45-3:45

Testing a Computational Workflow for Drug Design: pKa and logP from the SAMPL7 Blind Challenge
Katie Zabel
Advisor: Benjamin Janesko
Being able to produce accurate predictions of pKa for various molecules is an ongoing effort in computational chemistry. Drug companies and industries are constantly seeking accurate predictions of pKa and lipophilicity for molecules that are possible drug candidates. Accurate predictions of these values means that time, money, and effort won’t be wasted synthesizing molecules that aren’t going to be effective drugs. The Janesko group has developed a workflow that uses CREST for conformational analysis and (M11plus/def2TZVP/SMD) DFT calculations to identify a molecule’s pKa. The DFT calculations process and refine the relative energies of the stable conformations. The goal of this project is to benchmark the current workflow against the SAMPL7 challenge, which will test the workflow’s outperformance of the best quantum-mechanical methods from 2021. The SAMPL challenge is a competition that asks participants to predict the properties of molecules that have never been synthesized. These molecules will then be created in labs and their properties will be accurately tested. Comparison of the competitor's predicted properties to the true values measured will assess the accuracy of the competitor's predictions. If the prediction of pKa using the current workflow is accurate based off the benchmark against the SAMPL7 challenge, then the workflow could be entered into the next SAMPL Blind challenge.

Transparent Tuition: Finding your Financial Fit

Type: Undergraduate
Author(s): Paige Anderson Computer Science
Advisor(s): Michael Scherger Computer Science
Location: Second Floor, Table 3, Position 3, 1:45-3:45

During the college admissions process, students are presented with an overload of information from each school they are applying to and accepted by. A critical aspect for deciding on a school is the estimated Cost of Attendance (COA) and the financial aid package. Each school calculates their COA differently and thus offers a unique financial aid package. It is important for students to have a way of comparing and evaluating a school's cost with financial aid. While college counselors have developed excel sheets with algorithms that compare personalized cost with financial aid and scholarships, not all students are familiar with excel which may result in an inaccurate analysis. Transparent Tuition is a tool for students to accurately compare financial aid options from each university they are applying to. This project was developed using React.js and Spring Boot. These are two development libraries that will make Transparent Tuition scalable in the future. By creating a user-friendly web tool, students can better understand the school’s information and make a more educated decision when deciding on their university. Students will be able to connect with a college counselor to receive advice regarding their options when choosing a university. This will allow students to make an educated decision on their college based on both the short-term and long-term financial impact.