Cells Commons^™

Balancing Regeneration And Resistance: Targeting Dclk1 To Mitigate Gastrointestinal Radiation Injury And Oncogenesis, Landon L. Moore, Jerry Jaboin, Milton L. Brown, Courtney W. Houchen

Department of Medicine Faculty Publications

Ionizing radiation (IR) poses a dual challenge in medicine; while essential for cancer therapy, it inflicts collateral damage to normal tissues, particularly the gastrointestinal (GI) tract. High-dose IR triggers acute radiation syndrome (ARS), characterized by crypt stem cell depletion, mucosal barrier disruption, inflammation, and potential progression to fibrosis and secondary malignancy. Emerging evidence identifies the epithelial kinase doublecortin-like kinase 1 (DCLK1)—highly expressed in GI tuft cells and cancer stem-like cells—as a master regulator of post-IR responses. DCLK1 integrates DNA repair (via p53/ATM), and survival signaling (via NF-κB, TGF-β, and MAPK) to promote epithelial regeneration, yet these same mechanisms contribute to …

A Linear Presentation Of Cutaneous Rosai Dorfman Disease, Emily Sheetz, Ryan C. Saal, Molly K. Smith, Rachel Chikowski Byrd

Department of Medicine Faculty Publications

[Case description] A 53-year-old female with type II diabetes and hypertension presented to the dermatology clinic with a 3-month history of an asymptomatic linear eruption along the right knee that extended distally along the shin. Initial biopsy showed an atypical lymphohistiocytic infiltrate (Fig 1), which was found to be polyclonal. At her 3-month follow up visit, the eruption demonstrated significant clinical progression with numerous indurated papules and papulonodules, some of which were tender, along the right knee and pretibial surface (Fig 2). No improvement was noted with topical triamcinolone prescribed at her initial visit.

The Pre-Polarization And Concentration Of Cells Near Micro-Electrodes Using Ac Electric Fields Enhances The Electrical Cell Lysis In A Sessile Drop, Kishor Kaphle, Dharmakeerthi Nawarathna

Electrical & Computer Engineering Faculty Publications

Cell lysis is the starting step of many biomedical assays. Electric field-based cell lysis is widely used in many applications, including point-of-care (POC) applications, because it provides an easy one-step solution. Many electric field-based lysis methods utilize micro-electrodes to apply short electric pulses across cells. Unfortunately, these cell lysis devices produce relatively low cell lysis efficiency as electric fields do not reach a significant portion of cells in the sample. Additionally, the utility of syringe pumps for flow cells in and out of the microfluidics channel causes cell loss and low throughput cell lysis. To address these critical issues, we …

Development Of 2d Microfluidics Surface With Low-Frequency Electric Fields For Cell Separation Applications, Madushan Wickramasinghe, Dharmakeerthi Nawarathna

Electrical & Computer Engineering Faculty Publications

Cell separation techniques are widely used in many biomedical and clinical applications for the development of screening, diagnosis and therapeutic tests. Current 3D microfluidics-based cell separation methods have limited applications in part due to low throughput and technical complexity. To address these critical needs, we have developed a 2D microfluidics surface which is the miniaturized version of a 3D microfluids cell separation device. Using low-frequency electric fields (1–10 Vpp and 1 kHz–20 MHz), we have first studied dielectrophoresis, AC electro-osmosis and capillary flow within a sessile drop, and finally utilized the results to develop the 2D cell separation surface. Our …

The Role Of Tgf-Beta Superfamily Members In Immune Homeostasis And Disease, Natalie Eva Nieuwenhuizen, Ioannis Eleftherianos, Piotr Jan Kraj, Maria Semitekolou

Biological Sciences Faculty Publications

[Introduction] The Transforming Growth Factor beta (TGF-beta) superfamily, encompassing molecules such as TGFs, activins, Bone Morphogenetic Proteins (BMPs), Growth/Differentiation Factor (GDFs) and Nodals, represents the largest family of growth and differentiation factors, playing crucial roles in developmental and physiological processes across animal species (1). These molecules are integral to tissue homeostasis and cell fate determination. Among them, TGF-beta is particularly noted for its regulatory influence on immune responses and tissue fibrosis (2, 3). Recent research has expanded our understanding of the immune functions of other superfamily members, including activin A and BMPs (4). These molecules signal through receptor complexes composed …

Dengue Virus Modulates Critical Cell Cycle Regulatory Proteins In Human Megakaryocyte Cells, Swarnendu Basak, Shovan Dutta, Supreet Khanal, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Suppression of human megakaryocytes by dengue virus (DENV) infection significantly reduces the platelet count that eventually leads to thrombocytopenia, severe dengue and death. To understand DENV interactions with megakaryocytes, we investigated the cell cycle in leukemic human megakaryocytic in vitro cell line (MEG-01 cells). Megakaryocytes are known for complex endomitotic cell cycle leading to their polyploidy state. Our study shows that DENV uses these polyploid cells for its replication. Understanding the modulation of DENV-mediated cell cycle regulation in megakaryocytes is therefore highly important. We show that DENV2 (serotype 2) infection significantly modulates cell cycle signaling. Our protein profile microarray data …

Enhancing Bone Regeneration Using Kaempferol As An Osteoprotective Compound: Signaling Mechanisms, Delivery Strategies, And Potential Applications, Mojdeh Salehi Namini, Sanam Mohandesnezhad, Sadaf Mohandesnezhad, Vahid Mansouri, Lobat Tayebi, Nima Beheshtizadeh

Electrical & Computer Engineering Faculty Publications

Various plants, including fruits, vegetables, and spices, contain kaempferol, a bioflavonoid compound with diverse medicinal effects, such as antioxidant, antibacterial, and anti-inflammatory characteristics. Furthermore, this compound exhibits multiple health-promoting properties, including osteoprotection and osteogenesis, primarily by modulating various cell-signaling pathways. This review aims to illustrate the medical advantages of kaempferol and its role in regulating bone metabolism through cell signaling mechanisms. Numerous studies have demonstrated the bone-protective properties of kaempferol and its encapsulated form. Further research is needed to clarify the optimal dosages, toxicity, safety, and other potential mechanisms of action. This review demonstrates that several signaling pathways, including nuclear …

Protein Marker-Dependent Drug Discovery Targeting Breast Cancer Stem Cells, Ashley V. Huang, Yali Kong, Kan Wang, Milton L. Brown, David Mu

Department of Biomedical and Translational Sciences Faculty Publications

Breast cancer is one of the most common cancers globally. Unfortunately, many patients with breast cancer develop resistance to chemotherapy and tumor recurrence, which is primarily driven by breast cancer stem cells (BCSCs). BCSCs behave like stem cells and can self-renew and differentiate into mature tumor cells, enabling the cancer to regrow and metastasize. Key markers like CD44 and aldehyde dehydrogenase-1 (ALDH1), along with pathways like Wingless-related integration site (Wnt), Notch, and Hedgehog, are critical to regulating this stem-like behavior of BCSCs and, thus, are being investigated as targets for various new therapies. This review summarizes marker-dependent strategies for targeting …

Nanosecond Pulsed Electric Fields Increase Antibiotic Susceptibility In Methicillin-Resistant Staphylococcus Aureus, Alexandra E. Chittams-Miles, Areej Malik, Erin B. Purcell, Claudia Muratori

Bioelectrics Publications

Staphylococcus aureus is the leading cause of skin and soft-tissue infections (SSTIs). SSTIs caused by bacteria resistant to antimicrobials, such as methicillin-resistant S. aureus (MRSA), are increasing in incidence and have led to higher rates of hospitalization. In this study, we measured MRSA inactivation by nanosecond pulsed electric fields (nsPEF), a promising new cell ablation technology. Our results show that treatment with 120 pulses of 600 ns duration (28 kV/cm, 1 Hz), caused modest inactivation, indicating cellular damage. We anticipated that the perturbation created by nsPEF could increase antibiotic efficacy if nsPEF were applied as a co-treatment. To test this …

Dihydroethidium-Derived Fluorescence In Electrically Stressed Cells Indicates Intracellular Microenvironment Modifications Independent Of Ros, Esin B. Sözer, Iurii Semenov, P. Thomas Vernier

Bioelectrics Publications

Intracellular reactive oxygen species (ROS) generation is widely suggested as a trigger for biological consequences of electric field exposures, such as those in electroporation applications. ROS are linked with membrane barrier function degradation, genetic damage, and complex events like immunological cell death. Dihydroethidium (DHE) is commonly used to monitor ROS in cells. DHE is linked to intracellular ROS by a primary oxidation product, Ethidium (Eth⁺), that shows increased fluorescence upon binding to polynucleotides. We observed changes in DHE-derived fluorescence in Chinese hamster ovary (CHO) cells post 300-ns electric pulse exposures, comparing them to tert-butyl-hydroperoxide (t-BHP) induced oxidative stress. …

Synergistic Effects Of Nanosecond Pulsed Plasma And Electric Field On Inactivation Of Pancreatic Cancer Cells In Vitro, Edwin A. Oshin, Zobia Minhas, Ruben M. L. Colunga Biancatelli, John D. Catravas, Richard Heller, Siqi Guo, Chunqi Jiang

Bioelectrics Publications

Nanosecond pulsed atmospheric pressure plasma jets (ns-APPJs) produce reactive plasma species, including charged particles and reactive oxygen and nitrogen species (RONS), which can induce oxidative stress in biological cells. Nanosecond pulsed electric field (nsPEF) has also been found to cause permeabilization of cell membranes and induce apoptosis or cell death. Combining the treatment of ns-APPJ and nsPEF may enhance the effectiveness of cancer cell inactivation with only moderate doses of both treatments. Employing ns-APPJ powered by 9 kV, 200 ns pulses at 2 kHz and 60-nsPEF of 50 kV/cm at 1 Hz, the synergistic effects on pancreatic cancer cells (Pan02) …

Dynamics Of Cell Membrane Lesions And Adaptive Conductance Under The Electrical Stress, Mantas Silkunas, Olga N. Pakhomova, Giedre Silkuniene, Andrei G. Pakhomov

Bioelectrics Publications

Exceeding physiological limits of the cell membrane potential compromises structural integrity, enabling the passage of normally impermeant solutes and disrupting cell function. Electropermeabilization has been studied extensively at the cellular scale, but not at the individual membrane lesion level. We employed fast total internal reflection fluorescence (TIRF) imaging of Ca(2+) entry transients to discern individual lesions in a hyperpolarized cell membrane and characterize their focality, thresholds, electrical conductance, and the lifecycle. A diffuse and momentary membrane permeabilization without a distinct pore formation was observed already at a -100 mV threshold. Polarizing down to -200 mV created focal pores with a …

Synthesis And Structure-Activity Relationship Of Boronic Acid Bioisosteres Of Combretastatin A-4 As Anticancer Agents, Yali Kong, Michael C. Edler, Ernest Hamel, Asa R. Britton-Jenkins, Omar Gillan, Susan L. Mooberry, David Mu, Milton L. Brown

Department of Biomedical and Translational Sciences Faculty Publications

The boronic acid group plays an important role in drug discovery. Following our discovery of a boronic acid analog of combretastatin A-4 (CA-4), a series of analogs featuring a boronic acid group on the C phenyl ring of CA-4 was synthesized and evaluated for cytotoxicity, as well as for their ability to inhibit tubulin polymerization, inhibit the binding of [³H]colchicine to tubulin and cause depolymerization of cellular microtubules. Modifications on the C ring of CA-4, either eliminating the methoxy group or replacing the C phenyl ring with a pyridine ring, resulted in a reduced potency for inhibiting tubulin polymerization, colchicine …

Gene Expression Of Tight Junctions In Foreskin Is Not Affected By Hiv Pre-Exposure Prophylaxis, Emily L. Webb, Stefan Petkov, Heejin Yun, Laura Else, Limakatso Lebina, Jennifer Serwanga, Azure-Dee A.P. Pillay, Thabiso B. Seiphetlo, Susan Mugaba, Patricia Namubiru, Geoffrey Odoch, Daniel Opoka, Andrew S. Ssemata, Pontiano Kaleebu, Saye Khoo, Neil Martinson, Julie Fox, Clive M. Gray, Carolina Herrera, Francesca Chiodi

Department of Obstetrics & Gynecology Faculty Publications

Introduction: Tight junctions (TJs) serve as permeability filters between the internal and external cellular environment. A large number of proteins have been identified to be localized at the TJs. Due to limitations in tissue collection, TJs in the male genital tract have been understudied.

Methods: We analysed the transcriptomics of 132 TJ genes in foreskin tissue of men requesting voluntary medical male circumcision (VMMC) and enrolled in the Combined HIV Adolescent Prevention Study (CHAPS) trial conducted in South Africa and Uganda (NCT03986970). The trial evaluated the dose requirements for event-driven HIV pre-exposure prophylaxis (PrEP) with emtricitabine-tenofovir (FTC-TDF) or emtricitabine-tenofovir alafenamide …

Predicting Radiation-Induced Immune Suppression In Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy, Jonathan Colen, Cam Nguyen, Seth W. Liyanage, Eric Aliotta, Joe Chen, Clayton Alonso, Kara Romano, Sean Peach, Timothy Showalter, Paul Read, James Larner, Krishni Wijesooriya

Data Science Faculty Publications

BACKGROUND: Stereotactic body radiation therapy (SBRT) is known to modulate the immune system and contribute to the generation of anti-tumor T cells and stimulate T cell infiltration into tumors. Radiation-induced immune suppression (RIIS) is a side effect of radiation therapy that can decrease immunological function by killing naive T cells as well as SBRT-induced newly created effector T cells, suppressing the immune response to tumors and increasing susceptibility to infections.

PURPOSE: RIIS varies substantially among patients and it is currently unclear what drives this variability. Models that can accurately predict RIIS in near real time based on treatment plan characteristics …

Enhancement Of Antitumor Effects Of Berberine Chloride With A Copper(Ii) Complex Against Human Triple Negative Breast Cancer: In Vitro Studies, Duaa R. Alajroush, Brittney F. Anderson, Janae A. Bruce, Christian I. Lartey, Dazonte A. Mathurin, Sean T. Washington, Tanaya S. Washington, Sidy Diawara, Sakariyau A. Waheed, Kaylin L. Thomas, Stephen J. Beebe, Alvin A. Holder

Chemistry & Biochemistry Faculty Publications

In this study, the copper(II) complex [Cu(chromoneTSC)Cl₂]•0.5H₂O•0.0625C₂H₅OH (where chromoneTSC = (E)-N-Ethyl-2-((4-oxo-4H-chromen-3-yl)methylene)-hydrazinecarbothioamide) was synthesized and characterized; then used to carry out in vitro studies in combination with berberine chloride (BBC). The ligand and complex were characterized by elemental analysis, FTIR and NMR (¹H and ¹³C) spectroscopy, and conductivity measurements. The cytotoxic effect was analyzed by using the CCK-8 viability assay in cancer MDA-MB-231 VIM RFP and non-cancer MCF-10A cell lines. The IC₅₀ values for the complex and BBC were 21.2 ± 1.6 and 48.3 ± 2.4 μM, respectively at 24 h incubation, while the IC₅₀ value of the combination treatment …

Synthetic Approaches Of Carbohydrate Based Self-Assembling Systems, Guijun Wang, Anji Chen, Pramod Aryal, Jonathan Bietsch

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based self-assembling systems are essential for the formation of advanced biocompatible materials via a bottom-up approach. The self-assembling of sugar-based small molecules has applications encompassing many research fields and has been studied extensively. In this focused review, we will discuss the synthetic approaches for carbohydrate-based self-assembling (SA) systems, the mechanisms of the assembly, as well as the main properties and applications. This review will mainly cover recent publications in the last four years from January 2020 to December 2023. We will essentially focus on small molecule self-assembly, excluding polymer-based systems, which include various derivatives of monosaccharides, disaccharides, and oligosaccharides. Glycolipids, …

Listeria Adhesion Protein Orchestrates Caveolae-Mediated Apical Junctional Remodeling Of Epithelial Barrier For Listeria Monocytogenes Translocation, Rishi Drolia, Donald B. Bryant, Shivendra Tenguria, Zuri A. Jules-Culver, Jessie Thind, Breanna Amelunke, Donqi Liu, Nicholas L. F. Gallina, Krishna K. Mishra, Manalee Samaddar, Manoj R. Sawale, Dharmendra K. Mishra, Abigail D. Cox, Arun K. Bhunia

Biological Sciences Faculty Publications

The cellular junctional architecture remodeling by Listeria adhesion protein-heat shock protein 60 (LAP-Hsp60) interaction for Listeria monocytogenes (Lm) passage through the epithelial barrier is incompletely understood. Here, using the gerbil model, permissive to internalin (Inl) A/B-mediated pathways like in humans, we demonstrate that Lm crosses the intestinal villi at 48 h post-infection. In contrast, the single isogenic (lap− or ΔinlA) or double (lap−ΔinlA) mutant strains show significant defects. LAP promotes Lm translocation via endocytosis of cell-cell junctional complex in enterocytes that do not display luminal E-cadherin. In comparison, InlA facilitates …

Nano-Pulse Treatment Overcomes The Immunosuppressive Tumor Microenvironment To Elicit In Situ Vaccination Protection Against Breast Cancer, Anthony Nanajian, Megan Scott, Niculina I. Burcus, Brittney L. Ruedlinger, Edwin A. Oshin, Stephen J. Beebe, Siqi Guo

Bioelectrics Publications

We previously reported that nano-pulse treatment (NPT), a pulsed power technology, resulted in 4T1-luc mammary tumor elimination and a strong in situ vaccination, thereby completely protecting tumor-free animals against a second live tumor challenge. The mechanism whereby NPT mounts effective antitumor immune responses in the 4T1 breast cancer predominantly immunosuppressive tumor microenvironment (TME) remains unanswered. In this study, orthotopic 4T1 mouse breast tumors were treated with NPT (100 ns, 50 kV/cm, 1000 pulses, 3 Hz). Blood, spleen, draining lymph nodes, and tumors were harvested at 4-h, 8-h, 1-day, 3-day, 7-day, and 3-month post-treatment intervals for the analysis of frequencies, death, …

Tailored Micromagnet Sorting Gate For Simultaneous Multiple Cell Screening In Portable Magnetophoretic Cell-On-Chip Platforms, Jonghwan Yoon, Yumin Kang, Hyeonseol Kim, Abbas Ali, Keonmok Kim, Sri Ramulu Torati, Mi-Young Im, Changyeop Jeon, Byeonghwa Lim, Cheolgi Kim

Center for Bioelectronics Publications

Conventional magnetophoresis techniques for manipulating biocarriers and cells predominantly rely on large-scale electromagnetic systems, which is a major obstacle to the development of portable and miniaturized cell-on-chip platforms. Herein, a novel magnetic engineering approach by tailoring a nanoscale notch on a disk micromagnet using two-step optical and thermal lithography is developed. Versatile manipulations are demonstrated, such as separation and trapping, of carriers and cells by mediating changes in the magnetic domain structure and discontinuous movement of magnetic energy wells around the circumferential edge of the micromagnet caused by a locally fabricated nano-notch in a low magnetic field system. The motion …

Identification And Characterization Of Two Novel Kcnh2 Mutations Contributing To Long Qt Syndrome, Anthony Owusu-Mensah, Jacqueline Treat, Joyce Bernardi, Ryan Pfeiffer, Robert Goodrow, Bright Tsevi, Victoria Lam, Michel Audette, Jonathan M. Cordeiro, Makarand Deo

Electrical & Computer Engineering Faculty Publications

We identified two different inherited mutations in KCNH2 gene, or human ether-a-go-go related gene (hERG), which are linked to Long QT Syndrome. The first mutation was in a 1-day-old infant, whereas the second was in a 14-year-old girl. The two KCNH2 mutations were transiently transfected into either human embryonic kidney (HEK) cells or human induced pluripotent stem-cell derived cardiomyocytes. We performed associated multiscale computer simulations to elucidate the arrhythmogenic potentials of the KCNH2 mutations. Genetic screening of the first and second index patients revealed a heterozygous missense mutation in KCNH2, resulting in an amino acid change (P632L) in the …

Exploring Angiotensin Ii And Oxidative Stress In Radiation-Induced Cataract Formation: Potential For Therapeutic Intervention, Vidya P. Kumar, Yali Kong, Riana Dolland, Sandra R. Brown, Kan Wang, Damian Dolland, David Mu, Milton L. Brown

Department of Biomedical and Translational Sciences Faculty Publications

Radiation-induced cataracts (RICs) represent a significant public health challenge, particularly impacting individuals exposed to ionizing radiation (IR) through medical treatments, occupational settings, and environmental factors. Effective therapeutic strategies require a deep understanding of the mechanisms underlying RIC formation (RICF). This study investigates the roles of angiotensin II (Ang II) and oxidative stress in RIC development, with a focus on their combined effects on lens transparency and cellular function. Key mechanisms include the generation of reactive oxygen species (ROS) and oxidative damage to lens proteins and lipids, as well as the impact of Ang II on inflammatory responses and cellular apoptosis. …

Sccad: Cluster Decomposition-Based Anomaly Detection For Rare Cell Identification In Single-Cell Expression Data, Yunpei Xu, Shaokai Wang, Qilong Feng, Jiazhi Xia, Yaohang Li, Hong-Dong Li, Jianxin Wang

Computer Science Faculty Publications

Single-cell RNA sequencing (scRNA-seq) technologies have become essential tools for characterizing cellular landscapes within complex tissues. Large-scale single-cell transcriptomics holds great potential for identifying rare cell types critical to the pathogenesis of diseases and biological processes. Existing methods for identifying rare cell types often rely on one-time clustering using partial or global gene expression. However, these rare cell types may be overlooked during the clustering phase, posing challenges for their accurate identification. In this paper, we propose a Cluster decomposition-based Anomaly Detection method (scCAD), which iteratively decomposes clusters based on the most differential signals in each cluster to effectively separate …

Control Of The Electroporation Efficiency Of Nanosecond Pulses By Swinging The Electric Field Vector Direction, Vitalii Kim, Iurii Semenov, Allen S. Kiester, Mark A. Keppler, Bennett L. Ibey, Joel N. Bixler, Ruben M. L. Colunga Biancatelli, Andrei G. Pakhomov

Bioelectrics Publications

Reversing the pulse polarity, i.e., changing the electric field direction by 180°, inhibits electroporation and electrostimulation by nanosecond electric pulses (nsEPs). This feature, known as “bipolar cancellation,” enables selective remote targeting with nsEPs and reduces the neuromuscular side effects of ablation therapies. We analyzed the biophysical mechanisms and measured how cancellation weakens and is replaced by facilitation when nsEPs are applied from different directions at angles from 0 to 180°. Monolayers of endothelial cells were electroporated by a train of five pulses (600 ns) or five paired pulses (600 + 600 ns) applied at 1 Hz or 833 kHz. Reversing …

Combined 3d Bioprinting And Tissue-Specific Ecm System Reveals The Influence Of Brain Matrix On Stem Cell Differentiation, Martina Zamponi, Peter A. Mollica, Yara Khodour, Julie S. Bjerring, Robert D. Bruno, Patrick C. Sachs

School of Medical Diagnostics & Translational Sciences Publications

We have previously shown that human and murine breast extracellular matrix (ECM) can significantly impact cellular behavior, including stem cell fate determination. It has been established that tissue-specific extracellular matrix from the central nervous system has the capacity to support neuronal survival. However, the characterization of its influence on stem cell differentiation and its adaptation to robust 3D culture models is underdeveloped. To address these issues, we combined our 3D bioprinter with hydrogels containing porcine brain extracellular matrix (BMX) to test the influence of the extracellular matrix on stem cell differentiation. Our 3D bioprinting system generated reproducible 3D neural structures …

Gene Expression Under Combined Hypoxia And Acidosis In Chondrosarcoma, Michael Stacey, Kostika Vangjeli, Christopher Osgood

Bioelectrics Publications

Chondrosarcomas are the second most common cause of bone cancer and are removed surgically with wide margins. On recurrence, they are resistant to chemo and radiation therapy and new treatment options are critically required. This tumor type produces hyaline cartilage, a cartilage normally formed under hypoxic and acidic environment due to lack of vasculature in cartilage. Paradoxically, chondrosarcomas arise in the well vascularized, oxygen rich environment of the bone. Hypoxia and acidosis are two stressors where the cellular effects are typically reported separately even though cells experience combined effects of hypoxia and acidosis. Given the mechanistic links between hypoxia and …

Interactions Of Carboxylated Nanodiamonds With Mouse Macrophages Cell Line And Primary Cells, Maisoun Bani-Hani, Stephen J. Beebe, Michael W. Stacey, Christopher Osgood

Bioelectrics Publications

Nanodiamonds (ND) have attracted significant interest for their use in several biomedical applications. These applications can be very useful if the safety and compatibility of ND are proven. We assessed the effects of ND (100 nm, Carboxylated) on primary macrophages and a macrophage-like cell line and found that these particles are not toxic to these cells at lower concentrations but may interfere with cell functions and differentiation. Internalization of ND by these cells in a time- and dose-dependent manner was mostly via phagocytosis and clathrin-dependent endocytosis and localized to the cytoplasm but not into the nucleus. No significant induction of …

Pulsed Electric Field Ablation Of Esophageal Malignancies And Mitigating Damage To Smooth Muscle: An In Vitro Study, Emily Gudvangen, Uma Mangalanathan, Iurii Semenov, Allen S. Kiester, Mark A. Keppler, Bennett L. Ibey, Joel N. Bixler, Andrei G. Pakhomov

Bioelectrics Publications

Cancer ablation therapies aim to be efficient while minimizing damage to healthy tissues. Nanosecond pulsed electric field (nsPEF) is a promising ablation modality because of its selectivity against certain cell types and reduced neuromuscular effects. We compared cell killing efficiency by PEF (100 pulses, 200 ns–10 µs duration, 10 Hz) in a panel of human esophageal cells (normal and pre-malignant epithelial and smooth muscle). Normal epithelial cells were less sensitive than the pre-malignant ones to unipolar PEF (15–20% higher LD50, p < 0.05). Smooth muscle cells (SMC) oriented randomly in the electric field were more sensitive, with 30–40% lower LD50 (p < 0.01). Trains of ten, 300-ns pulses at 10 kV/cm caused twofold weaker electroporative uptake of YO-PRO-1 dye in normal epithelial cells than in either pre-malignant cells or in SMC oriented perpendicularly to the field. Aligning SMC with the field reduced the dye uptake fourfold, along with a twofold reduction in Ca²⁺ transients. A 300-ns pulse induced a twofold smaller transmembrane potential in cells aligned with the field, making them …

Sound The (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide Pgpp, Areej Malik, Megan A. Hept, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been …

Integrating Shear Flow And Trypsin Treatment To Assess Cell Adhesion Strength, Antra Patel, Bhavana Bhavanam, Trevor Keenan, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

Cell adhesion is of fundamental importance in cell and tissue organization and for designing cell-laden constructs for tissue engineering. Prior methods to assess cell adhesion strength for strongly adherent cells using hydrodynamic shear flow either involved the use of specialized flow devices to generate high shear stress or used simpler implementations like larger height parallel plate chambers that enable multihour cell culture but generate low wall shear stress and are, hence, more applicable for weakly adherent cells. Here, we propose a shear flow assay for adhesion strength assessment of strongly adherent cells that employs off-the-shelf parallel plate chambers for shear …