Biomedical Engineering and Bioengineering Commons^™

Consistent And Reproducible Cultures Of Large-Scale 3d Mammary Epithelial Structures Using An Accessible Bioprinting Platform, John A. Reid, Peter M. Mollica, Robert D. Bruno, Patrick C. Sachs

Medical Diagnostics & Translational Sciences Faculty Publications

Background: Standard three-dimensional (3D) in vitro culture techniques, such as those used for mammary epithelial cells, rely on random distribution of cells within hydrogels. Although these systems offer advantages over traditional 2D models, limitations persist owing to the lack of control over cellular placement within the hydrogel. This results in experimental inconsistencies and random organoid morphology. Robust, high-throughput experimentation requires greater standardization of 3D epithelial culture techniques.

Methods: Here, we detail the use of a 3D bioprinting platform as an investigative tool to control the 3D formation of organoids through the "self-assembly" of human mammary epithelial cells. Experimental bioprinting procedures …

Preparation And Characterization Of Functionalized Heparin-Loaded Poly-Ɛ-Caprolactone Fibrous Mats To Prevent Infection With Human Papillomaviruses, Daniela Gonzalez, Jorge Ragusa, Peter C. Angeletti, Gustavo F. Larsen

Department of Chemical and Biomolecular Engineering: Faculty Publications

In this study, heparin-loaded poly-ε-caprolactone (PCL) fibrous mats were prepared and characterized based on their physical, cytotoxic, thermal, and biological properties. The main objective of the work described here was to test the hypothesis that incorporation of heparin into a PCL carrier could serve as bio-compatible material capable of inhibiting Human Papillomavirus (HPV) infection. The idea of firmly anchoring heparin to capture soluble virus, vs. a slow heparin release to inhibit a virus in solution was tested. Thus, one material was produced via conventional heparin matrix encapsulation and electrohydrodynamic fiber processing in one step. A second type of material was …

The Oscillatory Shear Index: Quantifications For Valve Tissue Engineering And A Novel Interpretation For Calcification, Alex Williams

FIU Electronic Theses and Dissertations

Heart valve tissue engineering (HVTE) stands as a potential intervention that could reduce the prevalence of congenital heart valve disease in juvenile patients. Prior studies in our laboratory have utilized mechanobiological testing to quantify the forces involved in the development of heart valve tissue, utilizing a Flow-Stretch-Flexure (FSF) bioreactor to condition bone marrow stem cells (BMSCs)-derived valve tissue. Simulations have demonstrated that certain sets of flow conditions can introduce specific levels of oscillatory shear stress (OSS)-induced stimuli, augmenting the growth of engineered valves as well as influencing collagen formation, extracellular matrix (ECM) composition and gene expression. The computational findings discussed …

Distribution And Localization Of Novel Iodine Nanoparticles In The Human Glioma 1242 Growing In The Brains Of Mice, Benjamin Billings

Honors Scholar Theses

Observing and designing the in vivo distribution and localization of therapeutic nanoparticles is an essential aspect of developing and understanding novel nanoparticle- based medical treatments. This study investigates novel PEGylated Iodine-based nanoparticles (INPs), an alternate composition to the more widely researched gold nanoparticles (AuNPs), which may help avoid adverse effects associated with AuNPs, such as potential toxicity and skin discoloration, when used in similar applications. Determining the localization of the novel INPs within murine brains containing human glioma U-1242MG cells is critical in assisting the development of radiation dose enhancement therapy for this aggressive cancer. Radiation dose enhancement utilizes the …

Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell …

Comparison Of Eosin And Fluorescein Conjugates For The Photoinitiation Of Cell-Compatible Polymer Coatings, Jacob L. Lilly, Anuhya Gottipati, Calvin F. Cahall, Mohamed Agoub, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more …

Multiple Factors Drive Variation Of Forest Root Biomass In Southwestern China, Hao Zhang, Kelin Wang, Zhaoxia Zeng, Zhigang Zou, Yanfang Xu, Fuping Zeng

Nebraska Center for Biotechnology: Faculty and Staff Publications

The roots linking the above-ground organs and soil are key components for estimating net primary productivity and carbon sequestration of forests. The patterns and drivers of root biomass in forest have not been examined well at the regional scale, especially for the widely distributed forest ecosystems in southwestern China. We attempted to determine the spatial patterns of root biomass (RB, Mg/ha), annual increment root biomass (AIRB, Mg/ha/year), ratio of root and above-ground (RRA), and the relative contributions of abiotic and biotic factors that drive the variation of root biomass. Forest biomass and multiple factors (climate, soil, forest types, and stand …

Non-Targeted Colonization By The Endomycorrhizal Fungus, Serendipita Vermifera, In Three Weeds Typically Co-Occurring With Switchgrass, Prasun Ray, Yingqing Guo, Jaydeep Kolape

Nebraska Center for Biotechnology: Faculty and Staff Publications

Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830) is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted …

Developing Vascular Graft From Adipose-Derived Stem Cells, Ashley C. Apil

Research Opportunities for Engineering Undergraduates (ROEU) Program 2017-18

This project aims to differentiate adipose-derived stem cells into fibroblasts through the addition of platelet-derived growth factor (PDGF) into the culture media. Differentiation protocol will be optimized, then successful differentiation will be verified through PCR analysis. The ASC-fibroblasts will then be seeded into a ring construct as outlined by the protocol by Lam et al. The ring constructs will be tensile tested and analyzed through histology to characterize their strength and cellularity.

Preparation For The Study Of Gene Expression Aboard The International Space Station, Amber Paturzo

STAR Program Research Presentations

WetLab-2 performs quantitative polymerase chain reaction (qPCR) aboard the micro-gravity environment of the International Space Station in order to research how the stress of micro-gravity affects an organism’s RNA production and gene expression. This on-station qPCR allows researchers to gather information earlier and thereby allow them to modify experiments in a matter of hours rather than wait until the next flight opportunity. After a successful validation flight on SpaceX-8 and follow-up investigation on SpaceX-9, system components must now be adjusted for a new type of biological sample. Specifically, the WetLab-2 facility includes a commercial qPCR instrument (RNA SmartCycler), a sample …

Characterization Of Electroactive Nanofibers For Nerve Regeneration, Jean-Yves Azar

Research Opportunities for Engineering Undergraduates (ROEU) Program 2017-18

In the event of peripheral nerve injury, loss of function may occur as the result of a severed nerve. Hollow nerve gap conduits are used to provide a protected environment for nerves to reconnect and regain function, although therapies for nerve gaps larger than 3 cm lack a stable environment for nerves to reconnect. Development of a nerve guide conduit filler has been proposed to mimic the cell’s microenvironment. This would lead to increased functional regeneration. We are aiming to create a biomaterial to act as a filler for the hollow nerve gap conduits to promote functional regeneration of the …

Targeting Ovarian Cancer And Endothelium With An Allosteric Ptp4a3 Phosphatase Inhibitor, Kelley E. Mcqueeney, Joseph M. Salamoun, James C. Burnett, Nektarios Barabutis, Paula Pekic, Sophie L. Lewandowski, Danielle C. Llaneza, Robert Cornelison, Yunpeng Bai, Zhong-Yin Zhang, John D. Catravas

Bioelectrics Publications

Overexpression of protein tyrosine phosphatase PTP4A oncoproteins is common in many human cancers and is associated with poor patient prognosis and survival. We observed elevated levels of PTP4A3 phosphatase in 79% of human ovarian tumor samples, with significant overexpression in tumor endothelium and pericytes. Furthermore, PTP4A phosphatases appear to regulate several key malignant processes, such as invasion, migration, and angiogenesis, suggesting a pivotal regulatory role in cancer and endothelial signaling pathways. While phosphatases are attractive therapeutic targets, they have been poorly investigated because of a lack of potent and selective chemical probes. In this study, we disclose that a potent, …

Efficient One‑Step Fusion Pcr Based On Dual‑Asymmetric Primers And Two‑Step Annealing, Yilan Liu, Jinjin Chen, Anders Thygesen

Department of Chemical and Biomolecular Engineering: Faculty Publications

Gene splicing by fusion PCR is a versatile and widely used methodology, especially in synthetic biology. We here describe a rapid method for splicing two fragments by one-round fusion PCR with a dual-asymmetric primers and two-step annealing (ODT) method. During the process, the asymmetric intermediate fragments were generated in the early stage. Thereafter, they were hybridized in the subsequent cycles to serve as template for the target full-length product. The process parameters such as primer ratio, elongation temperature and cycle numbers were optimized. In addition, the fusion products produced with this method were successfully applied in seamless genome editing. The …

Diversity And Functional Evolution Of Terpene Synthases In Dictyostelid Social Amoebae, Xinlu Chen, Tobias G. Kollner, Gad Shaulsky, Qidong Jia, Jeroen S. Dickschat, Jonathan Gershenzon, Feng Chen

Nebraska Center for Biotechnology: Faculty and Staff Publications

Dictyostelids, or social amoebae, have a unique life style in forming multicellular fruiting bodies from unicellular amoeboids upon starvation. Recently, dictyostelids were found to contain terpene synthase (TPS) genes, a gene type of secondary metabolism previously known to occur only in plants, fungi and bacteria. Here we report an evolutionary functional study of dictyostelid TPS genes. The number of TPS genes in six species of dictyostelids examined ranges from 1 to 19; and the model species Dictyostelium purpureum contains 12 genes. Using in vitro enzyme assays, the 12 TPS genes from D. purpureum were shown to encode functional enzymes with …

A Purification And In Vitro Activity Assay For A (P)Ppgpp Synthetase From Clostridium Difficile, Astha Pokhrel, Asia Poudel, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

Kinase and pyrophosphokinase enzymes transfer the gamma phosphate or the beta-gamma pyrophosphate moiety from nucleotide triphosphate precursors to substrates to create phosphorylated products. The use of γ-³²-P labeled NTP precursors allows simultaneous monitoring of substrate utilization and product formation by radiography. Thin layer chromatography (TLC) on cellulose plates allows rapid separation and sensitive quantification of substrate and product. We present a method for utilizing the thin-layer chromatography to assay the pyrophosphokinase activity of a purified (p)ppGpp synthetase. This method has previously been used to characterize the activity of cyclic nucleotide and dinucleotide synthetases and is broadly suitable for …

Wild-Type P53 Enhances Endothelial Barrier Function By Mediating Rac1 Signalling And Rhoa Inhibition, Nektarios Barabutis, Christiana Dimitropoulou, Betsy Gregory, John D. Catravas

Bioelectrics Publications

Inflammation is the major cause of endothelial barrier hyper-permeability, associated with acute lung injury and acute respiratory distress syndrome. This study reports that p53 "orchestrates" the defence of vascular endothelium against LPS, by mediating the opposing actions of Rac1 and RhoA in pulmonary tissues. Human lung microvascular endothelial cells treated with HSP90 inhibitors activated both Rac1- and P21-activated kinase, which is an essential element of vascular barrier function. 17AAG increased the phosphorylation of both LIMK and cofilin, in contrast to LPS which counteracted those effects. Mouse lung microvascular endothelial cells exposed to LPS exhibited decreased expression of phospho-cofilin. 17AAG treatment …

Alteration Of Metabolite Profiling By Cold Atmospheric Plasma Treatment In Human Myeloma Cells, Dehui Xu, Yujing Xu, Ning Ning, Qingjie Cui, Zhijie Liu, Xiaohua Wang, Dingxin Liu, Hailan Chen, Michael G. Kong

Bioelectrics Publications

BACKGROUND: Despite new progress of chemotherapy in multiple myeloma (MM) clinical treatment, MM is still a refractory disease and new technology is needed to improve the outcomes and prolong the survival. Cold atmospheric plasma is a rapidly developed technology in recent years, which has been widely applied in biomedicine. Although plasma could efficiently inactivate various tumor cells, the effects of plasma on tumor cell metabolism have not been studied yet.

METHODS: In this study, we investigated the metabolite profiling of He plasma treatment on myeloma tumor cells by gas-chromatography time-of-flight (GC-TOF) mass-spectrometry. Meanwhile, by bioinformatic analysis such as GO and …