Digital Commons Network^™

Effects Of Subnormothermic Regulated Hepatic Reperfusion On Mitochondrial And Transcriptomic Profiles In A Porcine Model, Joohyun Kim, Michael A Zimmerman, Woo Young Shin, Brent T Boettcher, Ju-Seog Lee, Jong-In Park, Muhammed Ali, Meiying Yang, Jyotsna Mishra, Catherine E Hagen, Joseph E Mcgraw, Angela Mathison, Harvey J Woehlck, Gwen Lomberk, Amadou K S Camara, Raul A Urrutia, David F Stowe, Johnny C Hong

Faculty, Staff and Student Publications

OBJECTIVE: We sought to investigate the biological effects of pre-reperfusion treatments of the liver after warm and cold ischemic injuries in a porcine donation after circulatory death model.

SUMMARY OF BACKGROUND DATA: Donation after circulatory death represents a severe form of liver ischemia and reperfusion injury that has a profound impact on graft function after liver transplantation.

METHODS: Twenty donor pig livers underwent 60 minutes of in situ warm ischemia after circulatory arrest and 120 minutes of cold static preservation prior to simulated transplantation using an ex vivo perfusion machine. Four reperfusion treatments were compared: Control-Normothermic (N), Control- Subnormothermic (S), …

Profiling Human Pathogenic Repeat Expansion Regions By Synergistic And Multi-Level Impacts On Molecular Connections, Cong Fan, Ken Chen, Yukai Wang, Edward V Ball, Peter D Stenson, Matthew Mort, Albino Bacolla, Hildegard Kehrer-Sawatzki, John A Tainer, David N Cooper, Huiying Zhao

Faculty, Staff and Student Publications

Whilst DNA repeat expansions cause numerous heritable human disorders, their origins and underlying pathological mechanisms are often unclear. We collated a dataset comprising 224 human repeat expansions encompassing 203 different genes, and performed a systematic analysis with respect to key topological features at the DNA, RNA and protein levels. Comparison with controls without known pathogenicity and genomic regions lacking repeats, allowed the construction of the first tool to discriminate repeat regions harboring pathogenic repeat expansions (DPREx). At the DNA level, pathogenic repeat expansions exhibited stronger signals for DNA regulatory factors (e.g. H3K4me3, transcription factor-binding sites) in exons, promoters, 5'UTRs and …

Fucosylation Of Hla-Drb1 Regulates Cd4+ T Cell-Mediated Anti-Melanoma Immunity And Enhances Immunotherapy Efficacy, Daniel K Lester, Chase Burton, Alycia Gardner, Patrick Innamarato, Krithika Kodumudi, Qian Liu, Emma Adhikari, Qianqian Ming, Daniel B Williamson, Dennie T Frederick, Tatyana Sharova, Michael G White, Joseph Markowitz, Biwei Cao, Jonathan Nguyen, Joseph Johnson, Matthew Beatty, Andrea Mockabee-Macias, Matthew Mercurio, Gregory Watson, Pei-Ling Chen, Susan Mccarthy, Carlos Moransegura, Jane Messina, Kerry L Thomas, Lancia Darville, Victoria Izumi, John M Koomen, Shari A Pilon-Thomas, Brian Ruffell, Vincent C Luca, Robert S Haltiwanger, Xuefeng Wang, Jennifer A Wargo, Genevieve M Boland, Eric K Lau

Faculty, Staff and Student Publications

Immunotherapy efficacy is limited in melanoma, and combinations of immunotherapies with other modalities have yielded limited improvements but also adverse events requiring cessation of treatment. In addition to ineffective patient stratification, efficacy is impaired by paucity of intratumoral immune cells (itICs); thus, effective strategies to safely increase itICs are needed. We report that dietary administration of l-fucose induces fucosylation and cell surface enrichment of the major histocompatibility complex (MHC)-II protein HLA-DRB1 in melanoma cells, triggering CD4+ T cell-mediated increases in itICs and anti-tumor immunity, enhancing immune checkpoint blockade responses. Melanoma fucosylation and fucosylated HLA-DRB1 associate with intratumoral T cell abundance …

A 24-Month Updated Analysis Of The Comparative Effectiveness Of Zuma-5 (Axi-Cel) Vs Scholar-5 External Control In Relapsed/Refractory Follicular Lymphoma, M Lia Palomba, Paola Ghione, Anik R Patel, Myrna Nahas, Sara Beygi, Anthony J Hatswell, Steve Kanters, Eve H Limbrick-Oldfield, Sally W Wade, Markqayne D Ray, Jessica Owen, Sattva S Neelapu, John Gribben, John Radford, Sabela Bobillo

Faculty, Staff and Student Publications

Background: In the ZUMA-5 trial (Clinical trials identification: NCT03105336), axicabtagene ciloleucel (axi-cel; a chimeric antigen receptor T-cell therapy) demonstrated high rates of durable response in relapsed/refractory (r/r) follicular lymphoma (FL) patients and clear superiority relative to the SCHOLAR-5 external control cohort. We update this comparison using the ZUMA-5 24-month data.

Research design and methods: The SCHOLAR-5 cohort is comprised of r/r FL patients who initiated ≥3rd line of therapy after July 2014 and meeting ZUMA-5 eligibility criteria. Groups were balanced for patient characteristics through propensity scoring on prespecified prognostic factors using standardized mortality ratio (SMR) weighting. The overall response …

Erratum: "Aapm Task Group Report 303 Endorsed By The Abs: Mri Implementation In Hdr Brachytherapy-Considerations From Simulation To Treatment", Joann Prisciandaro, Jacqueline Esthappan Zoberi, Gil'ad Cohen, Yusung Kim, Perry Johnson, Eric Paulson, William Song, Ken-Pin Hwang, Beth Erickson, Sushil Beriwal, Christian Kirisits, Firas Mourtada

Faculty, Staff and Student Publications

No abstract provided.

Energy Intake At The Intersection Of The Clock And Ageing, Kristin Eckel-Mahan

Faculty, Staff and Student Publications

Calorie restriction and timed dietary intake are two approaches known to increase lifespan or delay age-associated diseases. New studies reveal the importance of the ‘how much’ and ‘when’ of dietary intake in ageing modulation and collectively demonstrate how protection of the internal clock by diet can delay the ageing process.

A Complete Methyl-Lysine Binding Aromatic Cage Constructed By Two Domains Of Phf2, John R Horton, Jujun Zhou, Qin Chen, Xing Zhang, Mark T Bedford, Xiaodong Cheng

Faculty, Staff and Student Publications

The N-terminal half of PHF2 harbors both a plant homeodomain (PHD) and a Jumonji domain. The PHD recognizes both histone H3 trimethylated at lysine 4 and methylated nonhistone proteins including vaccinia-related kinase 1 (VRK1). The Jumonji domain erases the repressive dimethylation mark from histone H3 lysine 9 (H3K9me2) at select promoters. The N-terminal amino acid sequences of H3 (AR2TK4) and VRK1 (PR2VK4) bear an arginine at position 2 and lysine at position 4. Here, we show that the PHF2 N-terminal half binds to H3 and VRK1 peptides containing K4me3, with dissociation constants (KD values) of 160 nM and 42 nM, …

Adverse Pregnancy Outcomes And Long Term Risk Of Ischemic Heart Disease In Mothers: National Cohort And Co-Sibling Study, Casey Crump, Jan Sundquist, Mary Ann Mclaughlin, Siobhan M Dolan, Usha Govindarajulu, Weiva Sieh, Kristina Sundquist

Faculty, Staff and Student Publications

OBJECTIVE: To examine the associations between five major adverse pregnancy outcomes and long term risks of ischemic heart disease in mothers.

DESIGN: National cohort study.

SETTING: Sweden.

PARTICIPANTS: All 2 195 266 women with a first singleton delivery in Sweden during 1973-2015.

MAIN OUTCOME MEASURES: The main outcome measure was incidence of ischemic heart disease from delivery to 2018, identified from nationwide inpatient and outpatient diagnoses. Cox regression was used to calculate hazard ratios for ischemic heart disease associated with preterm delivery, small for gestational age, pre-eclampsia, other hypertensive disorders of pregnancy, and gestational diabetes, adjusting for other adverse pregnancy …

Spatiotemporal View Of Malignant Histogenesis And Macroevolution Via Formation Of Polyploid Giant Cancer Cells, Xiaoran Li, Yanping Zhong, Xudong Zhang, Anil K Sood, Jinsong Liu

Faculty, Staff and Student Publications

To understand how malignant tumors develop, we tracked cell membrane, nuclear membrane, spindle, and cell cycle dynamics in polyploid giant cancer cells (PGCCs) during the formation of high-grade serous carcinoma organoids using long-term time-lapse imaging. Single cells underwent traditional mitosis to generate tissue with uniform nuclear size, while others formed PGCCs via asymmetric mitosis, endoreplication, multipolar endomitosis, nuclear fusion, and karyokinesis without cytokinesis. PGCCs underwent restitution multipolar endomitosis, nuclear fragmentation, and micronuclei formation to increase nuclear contents and heterogeneity. At the cellular level, the development of PGCCs was associated with forming transient intracellular cells, termed fecundity cells. The fecundity cells …

The Ra-Be-Real Multinational, Prospective, Observational Study In Patients With Rheumatoid Arthritis Receiving Baricitinib, Targeted Synthetic, Or Biologic Disease-Modifying Therapies: A 6-Month Interim Analysis, Rieke Alten, Gerd R Burmester, Marco Matucci-Cerinic, Jean-Hugues Salmon, Pedro Lopez-Romero, Walid Fakhouri, Inmaculada De La Torre, Liliana Zaremba-Pechmann, Thorsten Holzkämper, Bruno Fautrel

Faculty, Staff and Student Publications

INTRODUCTION: RA-BE-REAL has the overall aim of defining a profile of patients with rheumatoid arthritis (RA) starting baricitinib or any other targeted synthetic (ts) or any biologic (b) disease-modifying antirheumatic drug (DMARD) for the first time, and the primary objective of estimating time until discontinuation from any cause (excluding sustained response) of the initial treatment.

METHODS: RA-BE-REAL is an ongoing, prospective, observational, 36-month study in patients with RA initiating treatment with baricitinib (cohort A) or any other tsDMARD or any bDMARD (cohort B) for the first time. The primary objective is to assess the time until treatment discontinuation from any …

Phase Ii Trial Of Weekly Erlotinib Dosing To Reduce Duodenal Polyp Burden Associated With Familial Adenomatous Polyposis, N Jewel Samadder, Nathan Foster, Ryan P Mcmurray, Carol A Burke, Elena Stoffel, Priyanka Kanth, Rohit Das, Marcia Cruz-Correa, E Vilar, Gautam Mankaney, Navtej Buttar, Selvi Thirumurthi, Danielle K Turgeon, Michael Sossenheimer, Michelle Westover, Ellen Richmond, Asad Umar, Gary Della'zanna, Luz M Rodriguez, Eva Szabo, David Zahrieh, Paul J Limburg

Faculty, Staff and Student Publications

Importance: Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal adenomas and cancer. Combination sulindac and erlotinib was previously shown to reduce duodenal polyp burden but was associated with a relatively high adverse event (AE) rate.

Objective: To evaluate if a once weekly dosing schedule for erlotinib intervention improves the AE profile, while still providing efficacy with respect to reduced polyp burden, in participants with FAP.

Design, setting and participants: Single-arm trial, enrolling 46 participants with FAP, conducted from October 2017 to September 2019 in eight academic cancer centres.

Exposures: Participants self-administered 350 mg of erlotinib …

Vip152 Is A Selective Cdk9 Inhibitor With Pre-Clinical In Vitro And In Vivo Efficacy In Chronic Lymphocytic Leukemia, Steven Sher, Ethan Whipp, Janek Walker, Pu Zhang, Larry Beaver, Katie Williams, Shelley Orwick, Janani Ravikrishnan, Brandi Walker, Elizabeth Perry, Charles Gregory, Matthew Purcell, Alexander Pan, Pearlly Yan, Lapo Alinari, Amy J Johnson, Melanie M Frigault, Joy M Greer, Ahmed Hamdy, Raquel Izumi, Xiaokui Mo, Deepa Sampath, Jennifer Woyach, James Blachly, John C Byrd, Rosa Lapalombella

Faculty, Staff and Student Publications

Chronic lymphocytic leukemia (CLL) is effectively treated with targeted therapies including Bruton tyrosine kinase inhibitors and BCL2 antagonists. When these become ineffective, treatment options are limited. Positive transcription elongation factor complex (P-TEFb), a heterodimeric protein complex composed of cyclin dependent kinase 9 (CDK9) and cyclin T1, functions to regulate short half-life transcripts by phosphorylation of RNA Polymerase II (POLII). These transcripts are frequently dysregulated in hematologic malignancies; however, therapies targeting inhibition of P-TEFb have not yet achieved approval for cancer treatment. VIP152 kinome profiling revealed CDK9 as the main enzyme inhibited at 100 nM, with over a 10-fold increase in …

Updated Virophage Taxonomy And Distinction From Polinton-Like Viruses, Simon Roux, Matthias G. Fischer, Thomas Hackl, Laura A. Katz, Frederik Schulz, Natalya Yutin

Biological Sciences: Faculty Publications

Virophages are small dsDNA viruses that hijack the machinery of giant viruses during the co-infection of a protist (i.e., microeukaryotic) host and represent an exceptional case of “hyperparasitism” in the viral world. While only a handful of virophages have been isolated, a vast diversity of virophage-like sequences have been uncovered from diverse metagenomes. Their wide ecological distribution, idiosyncratic infection and replication strategy, ability to integrate into protist and giant virus genomes and potential role in antiviral defense have made virophages a topic of broad interest. However, one limitation for further studies is the lack of clarity regarding the nomenclature and …

Stressors, Coping Strategies, And Achievement During Teaching Practicum In A Nigerian Public University, Mensah Prince Osiesi, Udukhomose Suleiman Omokhabi, Sunday Ade Adeniran, Oluwayemisi Damilola Akomolafe, Oluwatoyin Tolu Obateru, Chigozie Celestina Oke, Adenike Lucia Aruleba

Higher Learning Research Communications

Objectives: This study assessed pre-service teacher stressors, coping strategies, and achievement during teaching practicum in a Nigerian public university.

Method: The study adopted the quantitative case study approach. The population consisted of all 300-level students in the faculty of education in the university who had completed their teaching practicum for the first semester of the 2020–2021 academic session. The quota sampling technique was used in selecting a sample of 130 pre-service teachers. We analysed data using multiple regression.

Results: Findings revealed the stressors and coping strategies, controlling for gender, did not significantly predict achievement in the teaching practicum. Several coping …

Recruitment In Acute Stroke Trials: Challenges And Potential Solutions, Joseph P Broderick, Yasmin N Aziz, Opeolu M Adeoye, James C Grotta, Andrew M Naidech, Andrew D Barreto, Colin P Derdeyn, Heidi J Sucharew, Jordan J Elm, Pooja Khatri

Faculty, Staff and Student Publications

Randomized clinical trials of acute stroke have led to major advances in acute stroke therapy over the past decade. Despite these successes, recruitment in acute trials is often difficult. We outline challenges in recruitment for acute stroke trials and present potential solutions, which can increase the speed and decrease the cost of identifying new treatments for acute stroke. One of the largest opportunities to increase the speed of enrollment and make trials more generalizable is expansion of inclusion criteria whose impact on expected recruitment can be assessed by epidemiologic and registry databases. Another barrier to recruitment besides the number of …

Cellular Factors That Shape The Activity Or Function Of Nitric Oxide-Stimulated Soluble Guanylyl Cyclase, Iraida Sharina, Emil Martin

Faculty, Staff and Student Publications

NO-stimulated guanylyl cyclase (SGC) is a hemoprotein that plays key roles in various physiological functions. SGC is a typical enzyme-linked receptor that combines the functions of a sensor for NO gas and cGMP generator. SGC possesses exclusive selectivity for NO and exhibits a very fast binding of NO, which allows it to function as a sensitive NO receptor. This review describes the effect of various cellular factors, such as additional NO, cell thiols, cell-derived small molecules and proteins on the function of SGC as cellular NO receptor. Due to its vital physiological function SGC is an important drug target. An …

Origin And Evolution Of Marsupial-Specific Imprinting Clusters Through Lineage-Specific Gene Duplications And Acquisition Of Promoter Differential Methylation, Wenqi Cao, Kory C. Douglas, Paul B. Samollow, John Vandeberg, Xu Wang, Andrew G. Clark

School of Medicine Publications

Genomic imprinting is a parent-of-origin-specific expression phenomenon that plays fundamental roles in many biological processes. In animals, imprinting is only observed in therian mammals, with ∼200 imprinted genes known in humans and mice. The imprinting pattern in marsupials has been minimally investigated by examining orthologs to known eutherian imprinted genes. To identify marsupial-specific imprinting in an unbiased way, we performed RNA-seq studies on samples of fetal brain and placenta from the reciprocal cross progeny of two laboratory opossum stocks. We inferred allele-specific expression for >3,000 expressed genes and discovered/validated 13 imprinted genes, including three previously known imprinted genes, Igf2r, Peg10, …

Network Analysis Examining Intrahospital Traffic Of Patients With Traumatic Hip Fracture, Elizabeth A. Secor, David Hamilton, Cecile D'Huyvetter, Kristin Salottolo, David Bar-Or

GME Publications

Introduction: Increased intrahospital traffic (IHT) is associated with adverse events and infections in hospitalized patients. Network science has been used to study patient flow in hospitals but not specifically for patients with traumatic injuries.

Methods: This retrospective analysis included 103 patients with traumatic hip fractures admitted to a level I trauma center between April 2021 and September 2021. Associations with IHTs (moves within the hospital) were analyzed using R (4.1.2) as a weighted directed graph.

Results: The median (interquartile range) number of moves was 8 (7–9). The network consisted of 16 distinct units and showed mild disassortativity (−0.35), similar to …

Titan Success: Faculty Behind The Scenes, February, Thorpe Center

Publications from the Associate Deans

No abstract provided.

Overexpression Of Both Human Sodium Iodide Symporter (Nis) And Brg1-Bromodomain Synergistically Enhances Radioiodine Sensitivity By Stabilizing P53 Through Npm1 Expression, J Na, C-H Lee, J-K Chung, H Youn

Peninsula Medical School

Improved therapeutic strategies are required to minimize side effects associated with radioiodine gene therapy to avoid unnecessary damage to normal cells and radiation-induced secondary malignancies. We previously reported that codon-optimized sodium iodide symporter (oNIS) enhances absorption of I-131 and that the brahma-associated gene 1 bromodomain (BRG1-BRD) causes inefficient DNA damage repair after high-energy X-ray therapy. To increase the therapeutic effect without applying excessive radiation, we considered the combination of oNIS and BRG1-BRD as gene therapy for the most effective radioiodine treatment. The antitumor effect of I-131 with oNIS or oNIS+BRD expression was examined by tumor xenograft models along with functional …

Phenomics Enables Measurement Of Complex Responses Of Developing Animals To Global Environmental Drivers, Oliver Tills, Luke A. Holmes, Elliot Quinn, Tony Everett, Manuela Truebano, John I. Spicer

School of Biological and Marine Sciences

Phenomics offers technological advances for high-dimensional phenotyping, facilitating rapid, high-throughput assessment of physiological performance and has proven invaluable in global research challenges including drug discovery and food security. However, this rapidly growing discipline has remained largely inaccessible to the increasingly urgent challenge of assessing organismal functional sensitivity to global change drivers. Here, we investigate the response of an ecologically important marine invertebrate to multiple environmental drivers using Energy Proxy Traits (EPTs), a new approach for measuring complex phenotypes captured on video as a spectrum of energy levels across different temporal frequencies in fluctuating pixel values. We imaged three developmental stages …

Transeuntis Mundi, A Nomadic Artistic Practice, Cândida Luiza Borges Da Silva

School of Law, Humanities and Social Sciences Theses

In this practice-led Ph.D. research, I investigate how an artistic practice can respond to the migration phenomena performed by human beings across the planet over millennia ¬– what I refer to as the millennial global human journey. Based on the idea of mobility, I chose to frame this research in the articulation of concepts deriving from the prefix trans: transculture, transhumance and transmediality. This research contributes to studies in art composition by developing the processes and concept of transmedial composition, mainly contributing to the field of New Media Art. This investigation resulted in the work Transeuntis Mundi (TM) Project – …

Fibroblast-Generated Extracellular Matrix Guides Anastomosis During Wound Healing In An Engineered Lymphatic Skin Flap, Alvis Chiu, Wenkai Jia, Yumeng Sun, Jeremy Goldman, Feng Zhao

Michigan Tech Publications, Part 1

A healthy lymphatic system is required to return excess interstitial fluid back to the venous circulation. However, up to 49% of breast cancer survivors eventually develop breast cancer-related lymphedema due to lymphatic injuries from lymph node dissections or biopsies performed to treat cancer. While early-stage lymphedema can be ameliorated by manual lymph drainage, no cure exists for late-stage lymphedema when lymph vessels become completely dysfunctional. A viable late-stage treatment is the autotransplantation of functional lymphatic vessels. Here we report on a novel engineered lymphatic flap that may eventually replace the skin flaps used in vascularized lymph vessel transfers. The engineered …

Editorial: Green Chemistry Biocatalysis, Barry J. Ryan, Gary T. Henehan, Bekir E. Eser, Ning Li, Zheng Guo, Gemma K. Kinsella

Articles

Editorial on the Research Topic: Green chemistry biocatalysis

Lightweight And Non-Invasive User Authentication On Earables, Changshuo Hu, Xiao Ma, Dong Ma, Ting Dang

Research Collection School Of Computing and Information Systems

The widespread adoption of wireless earbuds has advanced the developments in earable-based sensing in various domains like entertainment, human-computer interaction, and health monitoring. Recently, researchers have shown an increased interest in user authentication using earables. Despite the successes witnessed in acoustic probing and speech based authentication systems, this paper proposed a lightweight and non-invasive ambient sound based user authentication scheme. It employs the difference between the in-ear and out-ear sounds to estimate the individual-specific occluded ear canal transfer function (OECTF). Specifically, the {out-ear, in-ear} scaling factors at different frequency bands are captured via linear regression and treated as the OECTF …

Clinical Epigenomic Explanation Of The Epidemiology Of Cannabinoid Genotoxicity Manifesting As Transgenerational Teratogenesis, Cancerogenesis And Aging Acceleration, Albert Stuart Reece, Gary Kenneth Hulse

Research outputs 2022 to 2026

As global interest in the therapeutic potential of cannabis and its’ derivatives for the management of selected diseases increases, it is increasingly imperative that the toxic profile of cannabinoids be thoroughly understood in order to correctly assess the balance between the therapeutic risks and benefits. Modern studies across a number of jurisdictions, including Canada, Australia, the US and Europe have confirmed that some of the most worrying and severe historical reports of both congenital anomalies and cancer induction following cannabis exposure actually underestimate the multisystem thousand megabase-scale transgenerational genetic damage. These findings from teratogenic and carcinogenic literature are supported by …

Biostimulation Of Petroleum-Contaminated Soil Using Organic And Inorganic Amendments, Ogochukwu A. Udume, Gideon O. Abu, Herbert O. Stanley, Ijeoma F. Vincent-Akpu, Yusuf Momoh, Michael O. Eze

Chemistry Faculty Research & Creative Works

The most common approaches for the in-situ bioremediation of contaminated sites worldwide are bioaugmentation and bio stimulation. Bio stimulation has often proved more effective for chronically contaminated sites. This study examined the effectiveness of optimized water hyacinth compost in comparison with other organic and inorganic amendments for the remediation of crude oil-polluted soils. Water hyacinth was found to be rich in nutrients necessary to stimulate microbial growth and activity. an organic geochemical analysis revealed that all amendments in this study increased total petroleum hydrocarbon (TPH) biodegradation by ≥75% within 56 days, with the greatest biodegradation (93%) occurring in sterilized soil …

Curcumin Release From Biomaterials For Enhanced Tissue Regeneration Following Injury Or Disease, Adelle E. Hamilton, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Curcumin, a bioactive phenol derived from turmeric, is an antioxidant, anti-inflammatory, and antibacterial molecule. Although curcumin exhibits beneficial effects in its innate form, it is highly hydrophobic, which leads to poor water solubility and, consequently, low bioavailability. The lack of bioavailability limits curcumin's effectiveness as a treatment and restricts its use in clinical applications. Furthermore, to achieve beneficial, clinically relevant results, high doses of curcumin are required for systemic administration. Many researchers have utilized biomaterial carriers, including electrospun fibers, nanoparticles, hydrogels, and composite scaffolds, to overcome curcumin's principle therapeutic limitation of low bioavailability. By using biomaterials to deliver curcumin directly …

Mathematical Modeling Of Microscale Biology: Ion Pairing, Spatially Varying Permittivity, And Born Energy In Glycosaminoglycan Brushes, William J. Ceely, Marina Chugunova, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Biological macromolecules including nucleic acids, proteins, and glycosaminoglycans are typically anionic and can span domains of up to hundreds of nanometers and even micron length scales. The structures exist in crowded environments that are dominated by multivalent electrostatic interactions that can be modeled using mean-field continuum approaches that represent underlying molecular nanoscale biophysics. We develop such models for glycosaminoglycan brushes using steady state modified Poisson-Boltzmann models that incorporate important ion-specific (Hofmeister) effects. The results quantify how electroneutrality is attained through ion electrophoresis, spatially varying permittivity hydration forces, and ion-specific pairing. Brush-salt interfacial profiles of the electrostatic potential as well as …

Salt Doping Of Hyaluronic Acid Glycopolymer Biocondensates, James D. Sterling, Lu Fu, Kenisha Pudun, Shenda Baker, Megan Lord, Henry E. Riggs

Business and Information Technology Faculty Research & Creative Works

Biocondensates are largely studied with regard to intracellular components, while recognition of the formation of extracellular biocondensates are emerging, such as for cell surface heparan sulfate binding with basic fibroblast growth factor. This study analyzed the formation of biocondensates in vitro between the ubiquitous extracellular component, hyaluronan an anionic glycosaminoglycan, and cationic derivitized polyglucosamines known to bind to mucosal interfaces. The effect of molecular weight and net charge ratio was studied using a combination of microscopy, turbidity, laser diffraction particle sizing and zeta potential measurements. These analyses revealed that molecular weight affected the ability to form biocondensates while the surface …