Oral Sessions

Session 1:

Associate Professor Elise Demeter

Assistant Dean Julie Goodliffe 

Assistant Professor Brittany Johnson 

Postdoctoral Researcher Paula Prieto Oliveira

Postdoctoral Fellow Tyler Adams

Session 2:

Professor Jordan Poler 

Professor Lufei Young

Assistant Professor Brittany Johnson 

Postdoctoral Researcher Ticiana Della Justina Farias

Microplastics are a major environmental concern, and wastewater treatment plants are key entry points for these pollutants into ecosystems. The treatment process usually involves primary and secondary stages. In primary treatment, solids settle and are removed. Afterwards, the lighter materials and wastewater depart and enter the secondary treatment chamber. In secondary treatment, biological processes are utilized to further purify the water and remove additional solids. These settled solids, known as biosolids, can be processed, and used as fertilizers for agricultural use. However, this reuse can lead to microplastic contamination in agricultural soils, posing risks to food safety. This research focuses on quantifying microplastics in treatment stages and finding removal strategies to prevent environmental contamination. It examines the size and concentration of microplastics in primary and secondary solids to assess removal efficiency in wastewater treatment. The study uses a thorough protocol for microplastic analysis, including wet peroxide digestion, density separation, and staining, with digital microscopy and the Fourier Transform Infrared (FTIR) spectrometry for identification and quantification. Initial findings show secondary sludge has more microplastics, with smaller particle sizes than primary solids. This suggests secondary clarifiers may accumulate more microplastics, highlighting the need for further study into treatment mechanisms. The disparity in concentrations between stages points to the need for targeted mitigation strategies in treatment facilities to reduce pollution. The research outcomes could impact environmental policies and management of wastewater treatment and biosolid use. A better understanding of microplastic behavior can improve mitigation efforts, protecting ecosystems and human health. 

Photodynamic therapy (PDT) is a non-invasive therapeutic technique widely used as a major local treatment for cancer. PDT relies upon three main components light, oxygen and a photosensitizer. PDT produces less side effects compared to chemo and radiotherapies. The photosensitizers used in PDT have a critical role in the efficiency of the treatment. Nevertheless, most of the photosensitizers are hydrophobic molecules like porphyrins, which have low solubility in aqueous media and high toxicity. To overcome this issue, nanoparticulate systems have been developed to enhance the bioavailability of photosensitizers. Herein, we present our results on the successful synthesis and characterization of porphyrin-based nanoparticles. We used the co-precipitation method to fabricate nanoparticles utilizing two commercially available photosensitizers tetraphenylporphyrin (TPP) and 5-(4-aminophenyl)-10, 15, 20-triphenylporphyrin (ATPP), and a novel porphyrin derivative containing polyhedral oligomeric silsesquioxane unit (POSS). All the nanoparticles are colloidally stable, as demonstrated by dynamic light scattering, and have a high content of porphyrin. The phototherapeutic performance of these porphyrin-based nanoparticles was evaluated in vitro using cervical (HeLa) and triple-negative cancer (MDA-MB-231) cell lines. The nanoparticles showed an improved phototherapeutic outcome, as demonstrated by the IC50 values in comparison with the parent porphyrins; most likely due to the dramatic increase in the solubility of the molecules after nanoparticle encapsulation. We envision that this is a promising alternative to overcome the lack of bioavailability for porphyrins, which is one of the main issues for their successful application to PDT. 

Pregnancy-related hypertensive disorders (PRHD) is a leading cause of maternal mortality among Black women. The development of gestational hypertension (GH) is a catalyst for more complex disorders such as preeclampsia and eclampsia. The attainment of higher education is noted as a protective factor to optimal health. However, higher education does not offer the same protection in Black women as it does for other groups of people. This research is designed to understand the association between education and the diagnosis of GH among Black women.  

US Live Birth Certificate data 2021 was used in the analysis of Black women in this study. The association between educational status and the development of GH was evaluated. Logistic regression was used in the analysis to determine if having a college degree increased the odds of women developing GH during pregnancy. Among the Black women (n= 463,446) who had a live birth in 2021, 50.15% of the women were between 18-29 years old, 9.38% developed GH, 44.8% had an associate degree or greater, and 60.7% were married. After adjustment for age, marital status, prenatal care timing, method of payment, birth attendants and birthplace, college educated Black women had a 5% increased odds of developing GH during pregnancy, compared to women who had not obtained a college degree. Interestingly, women between 30-34 years old also had an increased likelihood of 3.1% of being diagnosed with GH compared to women 25-29 years of age. Additionally, 24% increased odds of a GH diagnosis for women who had a certified midwife at delivery as the birth attendant compared to a MD. The findings determined that obtaining a college degree is associated with increased GH. Due to the progressive nature of such disorders, understanding factors that are associated with such conditions is helpful for mitigating more adverse pregnancy complications.  

Over 1.7 million people in the U.S. acquire healthcare associated infections (HAIs) annually, and the situation has been worsened during the COVID-19 pandemic. Evidence has shown that fomites, such as environmental surfaces and medical devices, play a critical role in the transmission of HAI. Our study systematically reviews findings from studies that provided quantitative evidence on the contact pattern and/or rank of high-touch surfaces (HTS). We systematically searched 4 major databases (PubMed, Web of Science, CINAHL and Cochrane Database) for articles published before June 30, 2023 following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (Registration No: CRD42023408483). Relevant search terms we used, including Fomites (eg. Bed Rails) AND Contact Pattern AND Healthcare Setting (e.g., Emergency Department OR ICU) AND HAI (eg Clostridiodes difficile). We also searched for relevant articles in the reference list. A total of 2,826 studies were screened across all four databases with 7 studies meeting the eligibility criteria. The fomite which was most frequently touched was the bed rail. Other most frequently ouched surfaces are supply carts, bed surfaces, patient files/notes, medication carts, bedside tables, and Intravenous pump. Common mutually touched fomites were bedside rail, patients’ body, patient notes, bedside table and hand washing faucet handles. Only 2 studies utilized a covert observational technique, the other 5 applied either direct observation or did not state explicitly. Conclusion Our study provides empirical data which is important for the prioritization in cleaning and disinfection practices, development of HAI prevention and control protocols, and the optimization of cleaning and disinfection resources. We suggest that more rigorous studies quantifying high-touch fomites, especially those including detailed contact duration, sequence and temporal variations, be conducted. 

Amine sensing is very crucial in various fields such as environmental monitoring, food safety, and biomedical applications due to the toxic effect of some amine compounds. Hydrogels possess high water content, biocompatibility, and tunable physical and chemical properties, which make them an ideal candidate for amine sensing. Sensing amine compounds with small molecular chromophores/fluorophores is a convenient method to easily detect the presence of toxic heavy metals, harmful chemicals, or gases. Sensing chemicals with low detection limits is important for applications like amine sensing for illicit drugs, fentanyl, which has a low LD50 making it lethal at small doses. The highly conjugated, electron-deficient TTz core promotes the TTz structure to be planar, rigid, and stable. Because the symmetric dipyridinium thiazolothiazole compounds (TTz’s) have two low potential single electron reductions, they can easily photo-oxidize various compounds, like amines and give a visible color change. This makes the TTz a strong candidate for sensing and photo-redox catalysis. Previous work with TTz’s in aqueous hydrogel devices showed high contrast color changes photochemically. In water or hydrogels, the two single electron reductions of the TTz can be visually seen, as it changes from yellow (TTz2+) to purple (TTz1+) to blue (TTz0). As different substituted amines have differing oxidation potentials, the TTz shows different colors (purple or blue) depending on the amine. Herein, we exhibit the use of dipyridinium thiazolothiazoles as photochemical sensors for amines with visible color changes and selective fluorescence quenching.  

Sepsis is one of the leading causes of intensive care unit (ICU) transfers and mortality in the inpatient setting due to delayed recognition and untimely management of sepsis symptoms on non-ICU medical-surgical floors. Educating nurses on units with the highest rates of sepsis mortality and ICU transfers is important to increase confidence and knowledge to promote early recognition of sepsis and implementation of initial management guidelines. The purpose of this project was to implement evidence-based education to prepare nurses to identify early warning signs of sepsis and clinical deterioration in medical-surgical patients. A two-group pre-/post-test design was utilized with a sample of 17 nurses in the non-ICU medical-surgical units within the medicine service line at the project site. After the interactive escape room educational event, a statistically significant improvement in confidence and increased knowledge was demonstrated. Mean knowledge scores increased from 77.4 (SD=13.7) pre-intervention to 82.4 (SD=14.3) post-intervention. Significant improvements were seen in self-reported knowledge and confidence in identifying sepsis patients (z=2.33, p=.02), knowing how and what to monitor in sepsis patients (z=2.714, p=.007), and knowing initial management of patients with sepsis (z=2.646, p=.008). Mean ICU transfers decreased from 13 (SD=1.0) pre-intervention to 8.67 (SD=3.51) post-intervention indicating the project units performed better than the comparison units. Implementing an innovative escape room education for non-ICU medical-surgical nurses is recommended to improve nurse knowledge and confidence in managing sepsis patients. By increasing nurse knowledge and confidence, earlier recognition of clinical signs of deterioration will assist with reducing ICU transfers related to clinical deterioration due to infections and sepsis. 

ancreatic cancer, the 3rd leading cause of cancer-related death in the USA, casts a formidable shadow on public health. Pancreatic ductal adenocarcinoma (PDAC) is the predominant subtype among all pancreatic malignancies originating from the body's exocrine compartment. The highly aggressive nature of PDAC impedes early diagnosis and treatment, yielding a 5-year survival rate of <10%. An urgent need arises for early PDAC detection and treatment. Current PDAC standards involve drug combinations (Gemcitabine + nab-paclitaxel or FOLFIRINOX) inducing significant toxic effects. A potential solution involves combining chemotherapies within a nanoplatform to enhance efficacy through drug synergy while mitigating toxicities. Mesoporous silica nanoparticles (MSNs) facilitate carrying multiple drugs due to their high surface area, high drug loading capacity, pore size and functionalization tunability, and biocompatibility. We synthesized an MSN platform loaded with cisplatin (cisPt) internally and gemcitabine (Gem) externally, creating Gem-cisPt-MSNs. This controlled drug release ensures tumor specificity, enhancing drug bioavailability at the target site and reducing systemic toxicity. Gem-cisPt-MSNs were meticulously designed with varying drug ratios (9-20% cisPt), (5%, 10%, and 19% gemcitabine). Characterization studies affirmed colloidal stability, positive Z-potential, and reproducibility. Additionally, we navigated CisPt and gemcitabine-resistant murine and human pancreatic cancer cell lines, attesting to clinical relevance. Cytotoxicity evaluations for Gem-cisPt-MSNs demonstrated overcoming gemcitabine-resistant mechanisms compared to their single-drug counterparts. Notably, the synergistic effect depended on the drug ratio, and the proposed nanoplatforms offers a promising avenue to address PDAC treatment challenges, particularly overcoming drug resistance in the current standard of care. 

The rate of antibiotic resistant bacteria (ARB) has dangerously increased limiting treatment options and increasing mortality. Antibacterial treatment can be improved by applying nanosized antimicrobial metals which are approximately 50 times smaller than the size of bacterium. These small metals are known as inorganic nanoparticles (NPs). Inorganic NPs such as iron oxide (IO) hold magnetic properties which aid in localization while gold (Au) and silver (Ag) binds to molecules (ligands) found within the bacteria and result in the bacteria’s death. To elaborate, Ag or Au holds a positive charge enforces its binding to ligands found within the bacteria containing electron pairs to donate. This will form a metal-ligand bond to favor a neutrally charged metal. This method can be exploited to load the IO NPs with the Au or Ag to form an antimicrobial magnetic NP. However, the chemical properties of these two metals are different due to their charge (Ag+ and Au3+), and the interaction of the metal-ligand can vary. The theory that can predict the metal-ligand interaction is known as the hard/soft acid/base (HSAB) theory. Therefore, we will test three different chemicals that will coat the surface of the IO NPs and mediate the binding of Ag or Au. These chemicals will hold either an amine, phosphonate, or thiol that act as ligands with varying affinities for the metals. We hypothesize that by using the HSAB theory, we can predict the efficiency of IO NPs coating with Au or Ag metals. The three different ligands will provide insight of the binding affinity of the two different metals resulting in optimal coating and antibacterial efficacy due to a higher loading of the antimicrobial metal. This research could lead to developing a simple and reproducible synthetic protocol to fabricate metal-coated IO NPs for biomedical applications. Additionally, we can attain a better understanding of the metal-ligand binding for both synthetic and biological applications. 

Chronic Ankle Instability is a condition characterized by instability and/or recurring ankle sprains lasting longer than 1-year. Balance deficits are a hallmark impairment of CAI. Monitoring balance in a clinical setting is crucial. The gold standard to assess balance is using an expensive force plate. The expense diminishes the utility of the instrument. The purpose of this study was to validate a low-cost crossline laser to assess balance in individuals with CAI. Participants classified as having CAI completed this study. Following consent, participants had a crossline laser fixed to the foot while standing in the center of a force plate with their involved limb maintained 10 seconds for 3 trials with both eyes-open and eyes-closed conditions. A camera was placed in front of the force plate to recording the laser while the force plate measured the center of pressure (COP) velocity. Pearson’s Correlation Coefficients and Simple Linear Regression were calculated measuring the relationship between the number of changes in the horizontal position of the laser and the COP velocity. Change in horizontal position of the laser was positively related to COP average velocity during the eyes-closed condition (r=0.63, p=0.007) However, no significant relationship between the variables during the eyes-open condition was found (r=0.22, p=0.33). Regression analysis showed eyes-closed condition laser horizontal position changes predicted 39% of the force plate COP velocity (F (1, 15) = 9.61 (p = 0.007); R2 = 0.39, p = 0.007). Our study found the number of changes in horizontal position of the laser can predict COP average velocity during eyes-closed single-limb balance. As such, clinicians may clinically utilize this tool as an affordable objective measure of balance assessment. Future research should analyze the relationship between the laser and the force plate combining more variables from the laser output with additional measures. 

In organisms with linear chromosomes, the chromosomes are shortened in each cell division due to flawed DNA replication. The ribonucleoprotein (RNP) telomerase adds caps of repetitive, non-coding DNA onto chromosomal ends to protect chromosomes from damage in repeated cell divisions. Telomerase is made of the telomerase RNA (TR), a set of instructions for making telomeres, and the telomerase reverse transcriptase (TERT), an enzyme for catalyzing the addition of telomeric repeats to the chromosome ends. When either the TR or TERT is missing or altered, telomerase activity and cell survival are jeopardized. This concept is the basis of our research: How does changing the structure of the TR alter the functionality of the telomerase RNP? While telomerase is not active in normal human cells, it is commonly active in cells with an unlimited capacity for dividing like cancer cells and some parasites. Trypanosoma brucei is the parasite that causes African sleeping sickness and requires constantly active telomerase to support the level of cell division for parasite survival. In the absence of active telomerase, the chromosomes shrink, the rate of cell division decreases, and the parasite dies. We cultured different mutant varieties of T. brucei, each lacking one TR structural domain. To understand the impact of individual domains on the TR structure, we used a method known as SHAPE-MaP to create models of the TR isolated from each domain deletion mutant. Next, we performed a functional study that used the telomerase RNP isolated from each domain deletion mutant to extend telomeric sequences from a primer. These TR domain deletion mutant parasites exhibited changes in the structure of the TR as well as the ability of the telomerase RNP to lengthen telomeres. These results suggest that discrete domains of the TR are crucial to maintaining normal telomerase activity in highly proliferative cells (such as T. brucei and cancer cells) and make them a potential therapeutic target.

Antibiotic resistance (AR) remains one of the top 10 public health threats facing humanity, responsible for 4.95 million deaths in 2019. With AR’s persistent rise, non-antibiotic strategies are being explored to achieve broad spectrum antibacterial activity. Nanoparticles such as silver nanoparticles (AgNP) are considered promising therapeutic alternatives to antibiotics due to their inherent antibacterial properties. The antibacterial property of these “nanobiotics” is linked to the release of silver ions (Ag+) that damages the bacterial cell membrane and associated proteins. The Ag+ release is a slow process taking up to days to achieve effective antibacterial levels. We previously demonstrated use of photodynamic inactivation to accelerate the release of Ag+ by conjugating protoporphyrin IX (PpIX) on AgNPs surface to obtain light responsive PpIX-AgNPs. The excitation of photosensitizer (PS or PpIX) under light irradiation provides a highly oxidizing environment for AgNPs that leads to enhanced Ag+ release. A single dose of irradiation of PpIX-AgNPs (in DPBS) leads to 2.5 times higher Ag+ release than AgNPs. In this study we explore the possibility maximizing the Ag+ ion release via multiple light excitations. We hypothesize that multiple irradiations of PpIX-AgNP can effectively convert AgNPs to Ag+ ions. ICP-OES was used to generate Ag+ kinetic release profiles post one, two and three rounds of light excitation. The release profiles were obtained for PpIX-AgNPs (0.15-2 ug/mL) in various realistic bacterial media i.e., tryptic soy broth (TSB), luria broth (LB) and nutrient broth (NB). Finally, the antibacterial activity of the PpIX-AgNPs under the multiple light irradiation conditions was evaluated in “MRSA” using colony count method. The antibacterial activity was evaluated in DPBS and NB media. The use of multiple irradiations resulted in enhanced antibacterial activity at lower concentrations in a shorter span.  

Fibrous nanomaterials, which consist of silica, titanium oxide, and carbon nanotubes, are known for inducing inflammatory reactions and toxic effects, limiting their usage in biomedical applications. Therefore, natural biopolymers such as RNA and DNA are used to develop “soft” biodegradable nanomaterials to steer away from unwanted immune responses. These nucleic acid nanofibers, when not introduced into cells, extracellularly, will aid in the regulation of blood coagulation within the blood plasma in a safe and effective manner. Nevertheless, when purposefully introducing these nanofibers into immune cells, the repercussions are yet to be revealed. In this study, RNA/DNA fibers, modified with DNA aptamers, function as a model to explore how structural characteristics influence cytokine response once delivered into immune cells. When looking at the relationship between the structure and activity of our fibers, we aim to advance our understanding of intracellularly delivered nucleic acid nanomaterials as adjuvants for vaccines and immunotherapies. The outcomes of this work have the potential to broaden the applications of these nanofibers in a controlled manner, potentially transforming the landscape of vaccine and immunotherapy advancements. 

A cell's ability to appropriately sense and counteract metabolic stressors is paramount to its survival. However, how cells sense and respond to changes in glucose is poorly understood on the molecular level. In the budding yeast Saccharomyces cerevisiae, Snf1 kinase (mammalian AMP-activated kinase homolog, AMPK) is the primary sensor of nutrient instability. Although previous studies suggested that molecular chaperones such as the yeast homolog of Hsp70, Ssa1, may bind Snf1 and promote its activity, the role that Hsp70 phosphorylation plays in this process has not been fully determined. Utilizing the yeast Hsp70 Chaperone Code, we screened 146 yeast strains expressing mutations in each of the Ssa1 phosphorylation sites (73 phospho-mutants, 73 phospho-mimics) for their ability to grow on media with alternative carbon sources such as glycerol, acetate, sucrose, and ethanol. Each carbon source's phenotypic fingerprint was created by mapping phospho-sites important for growth onto the yeast Hsp70 structure. While some phospho-site sensitivity between nutrient sources was observed, we also characterized sites uniquely important for each media. We are currently discerning the impact of Hsp70 phosphorylation sites on Snf1 stability, phosphorylation, localization, and kinase activity. This, along with proteomic experiments, will identify which of our indicated sites are dependent on the activity of Snf1. Taken together, our working model is that Snf1 and Ssa1 reciprocally regulate each other to allow correct maintenance of glucose signaling in yeast. Due to Hsp70 being highly evolutionarily conserved, we expect this discovery will likely also be applicable in mammalian cells. 

Excimer formation, where colliding molecules emit unique light upon excitation, presents both challenges and opportunities in organic fluorescent systems. Traditionally considered detrimental to photoluminescence efficiency (PLQY), recent studies on polyaromatic hydrocarbons have hinted at the potential for excimers to enhance PLQY through controlled formation and relaxation. However, this phenomenon remains unexplored in state-of-the-art materials like thiazolothiazole (TTz). Our research utilized TTz-based excimers in solution-processable films, to address three key questions: 1) Can excimer formation be conserved and controlled in films? 2) Can the excimers be modulated to yield enhanced PLQY? 3) Can these properties be used to fabricate a novel excimer-based optical device? Theoretical modeling and solution-based studies were used to establish the intrinsic molecular properties. Polymer-TTz films were then fabricated and studied using steady-state and time-resolved optical spectroscopic methods. We report a high level of control over excimer formation in films. Excimer formation and relaxation is a function of TTz concentration, polymer matrix, and film fabrication method. Excimer kinetics were regulated using UV light irradiation; and PLQY was found to be enhanced by over eight folds. We also report PLQY in excimer-based films as high as 61%. These properties were utilized to fabricate stimuli-responsive smart-optical devices which can be used for steganography, anti-counterfeiting, among other applications. This study will be crucial to envision excimer management in solution-processable films and will broaden the scope of utilizing organic fluorophores for a host of advanced applications.