Biochemical and Biomolecular Engineering Commons^™

Cationic Poly(Glucosamine)-Based Polymers Bind To Glycans With Varying Affinity Facilitating Transport Across The Glycocalyx Of Endothelial Cells, Claire Bridges, Lu Fu, Dan Wang, James D. Sterling, Susanna Liang, Shenda M. Baker, Jonathan Yeow, Megan S. Lord

Business and Information Technology Faculty Research & Creative Works

Natural polysaccharides, such as chitosan, offer promising avenues for drug delivery due to their cytocompatibility and ability to interact with cell surfaces. However, the endothelial glycocalyx, a glycan-rich extracellular matrix, presents a barrier that must be navigated for effective intracellular delivery. This study investigates how cationic poly(glucosamine)-based polymers, functionalized with guanidinium or ammonium groups, interact with key glycocalyx components including hyaluronan (HA) and heparan sulfate (HS). We demonstrate that these cationic polymers form tunable biomolecular condensates with glycans, with stronger binding observed for sulfated glycans, HS and heparin, than unsulfated HA. Derivatized chitosan polymers with varied cationic side chains exhibit …

The Interplay Between Endothelial Glycocalyx Maturity And Both The Toxicity And Intracellular Uptake Of Charged Nanoparticles, Claire A. Bridges, Lu Fu, Jonathan Yeow, Xiaojing Huang, Miriam Jackson, Rhiannon P. Kuchel, James D. Sterling, Shenda M. Baker, Megan S. Lord

Business and Information Technology Faculty Research & Creative Works

Nanoparticles are widely studied for delivering treatments to target tissues, but few have reached clinical use. Most nanoparticles encounter blood vessels on their way to target tissues. The inner surface of these vessels is lined with endothelial cells covered by a glycocalyx, an extracellular matrix rich in anionic glycans. The role of the glycocalyx in nanoparticle interactions is not well understood. Here, we demonstrate that endothelial cells need extended culture times to synthesize a mature glycocalyx. Our research shows that branched polyethyleneimine functionalized gold nanoparticles bind to endothelial cells expressing either a developing or mature glycocalyx, with the interaction involving …

The Interplay Between Endothelial Glycocalyx Maturity And Both The Toxicity And Intracellular Uptake Of Charged Nanoparticles, Claire A. Bridges, Lu D. Fu, Jonathan A. Yeow, Xiaojing D. Huang, Miriam D. Jackson, Rhiannon P. Kuchel, James D. Sterling, Shenda M. Baker, Megan S. Lord

Business and Information Technology Faculty Research & Creative Works

Nanoparticles are widely studied for delivering treatments to target tissues, but few have reached clinical use. Most nanoparticles encounter blood vessels on their way to target tissues. The inner surface of these vessels is lined with endothelial cells covered by a glycocalyx, an extracellular matrix rich in anionic glycans. The role of the glycocalyx in nanoparticle interactions is not well understood. Here, we demonstrate that endothelial cells need extended culture times to synthesize a mature glycocalyx. Our research shows that branched polyethyleneimine functionalized gold nanoparticles bind to endothelial cells expressing either a developing or mature glycocalyx, with the interaction involving …

Modeling Ion-Specific Effects In Polyelectrolyte Brushes: A Modified Poisson-Nernst-Planck Model, William J. Ceely, Marina Chugunova, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Polyelectrolyte brushes consist of a set of charged linear macromolecules, each tethered at one end to a surface. An example is the glycocalyx which refers to hair-like negatively charged sugar molecules that coat the outside membrane of all cells. We consider the transport and equilibrium distribution of ions and the resulting electrical potential when such a brush is immersed in a salt buffer containing monovalent cations (sodium and/or potassium). The Gouy-Chapman model for ion screening at a charged surface captures the effects of the Coulombic force that drives ion electrophoresis and diffusion but neglects non-Coulombic forces and ion pairing. By …

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 …

Greenhouse Tomatoes: Process Simulation, Juan Gabriel Marin Jr.

Graduate Theses and Dissertations

Growing population demand and challenges brought on by climate change have spurred the need for more resilient fruit and vegetable supply chains. One agricultural technology of significant interest is the use of greenhouses for food production. Greenhouses create a stable and adaptable environment for crops such as tomatoes to grow year-round. Fresh tomatoes are the second most consumed vegetable per capita in U.S. diets, currently averaging 20.7 pounds. The growing consumption of fresh tomatoes has been the result of increasing cultural diversity in the United States.

To meet the growing demand, Venlo-type greenhouses have been frequently used by growers. It …

Ion Pairing And Dielectric Decrement In Glycosaminoglycan Brushes, James D. Sterling, Wenjuan Jiang, Wesley M. Botello-Smith, Yun L. Luo

Business and Information Technology Faculty Research & Creative Works

Cell−surface polysaccharides are essential to many aspects of physiology, serving as a highly conserved evolutionary feature of life and as an important part of the innate immune system in mammals. Here, as simplified biophysical models of these sugar coatings, we present results of molecular dynamics simulations of hyaluronic acid and heparin brushes that show important effects of ion pairing, water dielectric decrease, and coion exclusion. As in prior studies of macromolecular crowding under physiologically relevant salt concentrations, our results show equilibria with electroneutrality attained through screening and pairing of brush anionic charges by monovalent cations at the atomistic detail. Most …

Systems, Apparatus And Method For Material Preparations And / Or Handling, Robert Doebler, Ali Nadim, James D. Sterling, Anna Hickerson, Barbara Erwin, Denice Woyski, Ryan P. Talbot, Bruce Irvine

Business and Information Technology Faculty Research & Creative Works

Oscillating angularly rotating a container containing a mate rial may cause the material to be separate. Denser or heavier material may unexpectedly tend to be collected relatively close to the axis of rotation, while less dense or light material may tend to collect relatively away from the axis of rotation. Oscillation along an arcuate path provides high lysing efficiency. Alternatively, a micromotor may drive an impeller removably received in a container. Lysing may be implemented in batch mode, flow - through stop or semi-batch mode, or flow - through continuous mode. Lysing particulate material may exceed material to be lysed …

Exploring Structure-Property Relationships Of Gags To Tailor Ecm-Mimicking Hydrogels, Ralf Zimmermann, Carsten Werner, James Sterling

Business and Information Technology Faculty Research & Creative Works

Glycosaminoglycans (GAGs) are a class of linear polysaccharides that are ubiquitous in the extracellular matrix (ECM) and on cell surfaces. Due to their key role in development, homeostasis, pathogenesis, and regeneration, GAGs are increasingly used in the design of ECM-mimicking hydrogels to stimulate tissue formation and regenerative processes via specifically orchestrated cell-instructive signals. These applications first and foremost build on the ability of GAGs to effectively bind, protect, and release morphogens. The specificity and strength of morphogen-GAG interactions are largely governed by the number and spatial distribution of negatively charged sulfate groups carried by GAGs. Herein, we summarize a mean-field …

Arrayed Lyser And Homogenizer Systems With Multiple Agitator Devices, Robert W. Doebler, Mark Brown, Tanya Ferguson, Bruce Irvine, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Systems and methods for the efficient agitation of tissue samples. A device may include a plurality of chambers that each receives samples therein. The plurality of chambers may be uniformly spaced with respect to a least one dimension, to form a one dimensional or two-dimensional array. Each of the chambers may include an opening and an agitator device in fluid contact with the sample disposed within the chamber. The agitator devices may include a micromotor which provides rotational motion to a shaft and an impeller fixed to the shaft such that the impeller and the shaft rotate together upon provision …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

A Continuum Model Of Mucosa With Glycan-Ion Pairing, James D. Sterling, Shenda M. Baker

Business and Information Technology Faculty Research & Creative Works

Advances in the study of glycosoaminoglycan biohydrogels, label-free electrokinetic analysis of soft-diffuse layers in contact with saline solutions, and elucidation of ion-specific behavior in many biochemical systems offer the opportunity to marry these principal features in a new mathematical model of the mucosal glycocalyx. The model is based on the electroquasistatic subset of Maxwell's equations in the form of the steady-state continuum Poisson–Boltzmann equation for electrostatics with explicit incorporation of pairwise binding of ions to fixed charged-groups in the hydrogel. The pairwise association is modeled using reversible bimolecular reactions via stoichiometric dissociation constants that represent the rule of matching water …

Materials Education And Research In Art And Design: A New Role For Libraries (Survey Stats), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Sheet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Booklet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Website), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Collection Creation And Administration: A New Role For Libraries (White Paper), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

The Problem/Opportunity: To define, identify, and guide design-based materials collections in academic settings and foster community among those with existing collections and/or those considering creating and supporting one.

Contents and topics:

1. What is a materials collection?
2. Why have a materials collection?
3. Acquisition strategies
4. Organizational approaches
5. Programming possibilities
6. Symposium summary
7. Resources

Systems And Devices For Isothermal Biochemical Reactions And / Or Analysis, Robert W. Doebler Ii, Christopher Cooney, Anna Hickerson, James D. Sterling, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

An isothermal reaction and analysis system may include a receiver to receive sample holders, a thermal control sub system to control a temperature of the receiver, an excitation Subsystem, a detection Subsystem and an analysis Subsystem. Excitation Sources and/or detectors are positioned to enhance data collection. Sample holders may include filters, selectively blocking and passing wavelengths or bands of electromagnetic radiation.

Temperature Control Device With A Flexible Temperature Control Surface, Phil D. Belgrader, Christopher G. Cooney, Robert D. Doebler, Anna D. Hickerson, Bruce D. Irvine, Ali D. Nadim, James D. Sterling, Reza Miraghale

Business and Information Technology Faculty Research & Creative Works

A device for controlling temperature in a reaction chamber is disclosed. The device comprises: a bladder assembly comprising a housing dimensioned to hold a reaction chamber disposed within an interior Volume of the housing; and a first temperature-control bladder disposed within the housing, the first temperature-control bladder is configured to receive a temperature-control fluid and comprises a flexible, heat conductive Surface that comes in contact with at least a portion of an exterior surface of the reaction chamber after receiving the temperature-control fluid. Also disclosed are a bladder thermal cycler, a temperature-control bladder assembly and methods for producing a thermal …

Continuous-Flow, Rapid Lysis Devices For Biodefense Nucleic Acid Diagnostic Systems, Robert W. Doebler, Barbara Erwin, Anna Hickerson, Bruce Irvine, Denice Woyski, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Two mechanical lysis devices have been developed as compact, robust components to provide rapid sample preparation for nucleic acid diagnostic systems. One such component, known as the Micro Bead-Beater™ (μBB™, BBTM, Claremont BioSolutions, Upland, CA), is a compact device that is capable of ultrarapid lysis (>90% lysis in 30 s) of micro volumes (< 80 μL) of Bacillus spores in a continuous-flow format or in a disposable single-tube format. The μBB is also capable of processing much larger volumes of solutions containing spores or vegetative cells using a continuous-flow mode. A second mechanical lysis device designed as a disposable component is the microfluidic bead blender, which uses a small electric motor to spin vanes within the bead-laden solution. DNA quantification results using dsDNA-binding fluorescence dyes and real-time PCR are presented, comparing the lysis of Bacillus subtilis spores using the μBB™ with other well-known lysis techniques. Nanoscale imaging results obtained using scanning electron microscopy and transmission electron microscopy on B. subtilis spores lyzed using the μBB™ are also presented. © 2009, Society for Laboratory Automation and Screening. All rights reserved.

Organizational Agility, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Ala Spotlight Series V.2, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Labevolution: What's The Next Mutation?, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Building Benchmarks, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Off And Running, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Moment Analysis Of Near-Equilibrium Binding Interactions During Electrophoresis, Yousef Daneshbod, James D. Sterling, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

The electrophoretic transport of three chemically reacting species, two of which can bind reversibly to form the third, is analyzed mathematically. The species are assumed to move horizontally through a long channel with different electrophoretic mobilities and diffusion coefficients. By considering small perturbations of the system about equilibrium or when one of the two binding species is much more abundant than the other, the governing advection-reaction- diffusion equations can be linearized and studied via the method of moments. The result is a set of coupled ordinary differential equations for the moments that can be solved analytically. Analysis of the long-time …

Electrowetting Droplet Microfluidics On A Single Planar Surface, Christopher G. Cooney, Chao Yi Chen, Michael R. Emerling, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Electrowetting refers to an electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on a surface. Most designs ground the droplet by either sandwiching the droplet with a grounding plate on top or by inserting a wire into the droplet. Washizu and others have developed systems capable of generating droplet motion without a top plate while allowing the droplet potential to float. In contrast to these designs, we demonstrate an electrowetting system in which the droplet can be electrically grounded from below using thin conductive lines on top of the dielectric layer. This alternative method of …

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Laboratory Automation Curriculum At Keck Graduate Institute, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

A novel curriculum in laboratory automation and high-throughput technologies has been developed at the Keck Graduate Institute (KGI) over the past five years as part of the professional master's degree program in applied life sciences. The goal of this curriculum has been four-fold: (1) motivate study by describing the need for automation through several example problems in combinatorial biological discovery, (2) provide elements of fundamental engineering science that are required for the development of the technologies and tools that enable automation, (3) provide opportunities for the students to see and use state-of-the-art instruments, learn about existing industry standards, and to …