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Chemical Engineering

Iowa State University

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Articles 1 - 30 of 254

Full-Text Articles in Biomedical Engineering and Bioengineering

Analyzing Drug Release Kinetics From Water-Soluble Polymers, Sean M. Kelly, Arun K. Upadhyay, Akash Mitra, Balaji Narasimhan Feb 2019

Analyzing Drug Release Kinetics From Water-Soluble Polymers, Sean M. Kelly, Arun K. Upadhyay, Akash Mitra, Balaji Narasimhan

Chemical and Biological Engineering Publications

The ability to develop predictive mathematical models of therapeutic release from pharmaceutical formulations has enormous potential to enhance our understanding of such systems and improve the controlled release of the payload. The current work describes the development and testing of a one-dimensional model of drug transport from amorphous, swelling/dissolving polymers. Model parameters such as the diffusivities of water and drug, the initial loading of the drug, the polymer dissolution rate, drug-polymer interactions, and the tablet thickness were varied, demonstrating the ability to tune the release to be controlled by either drug diffusion or polymer chain disentanglement. In addition, predictions ...


Degradation And Remodeling Of Epitaxially Grown Collagen Fibrils, Juan Wang, Anuraag Boddupalli, Joseph Koelbl, Dong Hyun Nam, Xin Ge, Kaitlin M. Bratlie, Ian C. Schneider Feb 2019

Degradation And Remodeling Of Epitaxially Grown Collagen Fibrils, Juan Wang, Anuraag Boddupalli, Joseph Koelbl, Dong Hyun Nam, Xin Ge, Kaitlin M. Bratlie, Ian C. Schneider

Materials Science and Engineering Publications

Introduction: The extracellular matrix (ECM) in the tumor microenvironment contains high densities of collagen that are highly aligned, resulting in directional migration called contact guidance that facilitates efficient migration out of the tumor. Cancer cells can remodel the ECM through traction force controlled by myosin contractility or proteolytic activity controlled by matrix metalloproteinase (MMP) activity, leading to either enhanced or diminished contact guidance.

Methods: Recently, we have leveraged the ability of mica to epitaxially grow aligned collagen fibrils in order to assess contact guidance. In this article, we probe the mechanisms of remodeling of aligned collagen fibrils on mica by ...


Development Of Gelatin And Graphene-Based Nerve Regeneration Conduits Using 3d Printing Strategies For Electrical Transdifferentiation Of Mesenchymal Stem Cells, Metin Uz, Maxsam Donta, Meryem Mededovic, Donald S. Sakaguchi, Surya Mallapragada Feb 2019

Development Of Gelatin And Graphene-Based Nerve Regeneration Conduits Using 3d Printing Strategies For Electrical Transdifferentiation Of Mesenchymal Stem Cells, Metin Uz, Maxsam Donta, Meryem Mededovic, Donald S. Sakaguchi, Surya Mallapragada

Chemical and Biological Engineering Publications

In this study, gelatin and graphene-based nerve regeneration conduits/scaffolds possessing tailored 3D microstructures and mechanical properties were fabricated using 3D printing. The effect of 3D conduit microstructure and mechanical properties along with the applied electrical stimuli on mesenchymal stem cell (MSCs) behavior and transdifferentiation into Schwann cell (SC)-like phenotypes were investigated. The results indicated that the gelatin conduits/scaffolds had favorable 3D microstructural and mechanical properties for MSC attachment and growth. Immunocytochemistry results demonstrated that the application of electrical stimuli through the conductive graphene within the gelatin-based 3D microstructure had a profound effect on the differentiation of MSCs ...


Interleukin-1 Alpha Increases Anti-Tumor Efficacy Of Cetuximab In Head And Neck Squamous Cell Carcinoma, Madelyn Espinosa-Cotton, Samuel N. Rodman Iii, Kathleen A. Ross, Isaac J. Jensen, Kenley Sangodeyi-Miller, Ayana J. Mclaren, Rachel A. Dahl, Katherine N. Gibson-Corley, Adam T. Koch, Yang-Xin Fu, Vladimir P. Badovinac, Douglas Laux, Balaji Narasimhan, Andrean L. Simons Jan 2019

Interleukin-1 Alpha Increases Anti-Tumor Efficacy Of Cetuximab In Head And Neck Squamous Cell Carcinoma, Madelyn Espinosa-Cotton, Samuel N. Rodman Iii, Kathleen A. Ross, Isaac J. Jensen, Kenley Sangodeyi-Miller, Ayana J. Mclaren, Rachel A. Dahl, Katherine N. Gibson-Corley, Adam T. Koch, Yang-Xin Fu, Vladimir P. Badovinac, Douglas Laux, Balaji Narasimhan, Andrean L. Simons

Chemical and Biological Engineering Publications

Background: Despite the high prevalence of epidermal growth factor receptor (EGFR) overexpression in head and neck squamous cell carcinomas (HNSCCs), incorporation of the EGFR inhibitor cetuximab into the clinical management of HNSCC has not led to significant changes in long-term survival outcomes. Therefore, the identification of novel therapeutic approaches to enhance the clinical efficacy of cetuximab could lead to improved long-term survival for HNSCC patients. Our previous work suggests that EGFR inhibition activates the interleukin-1 (IL-1) pathway via tumor release of IL-1 alpha (IL-1α), although the clinical implications of activating this pathway are unclear in the context of cetuximab therapy ...


How Crosslinking Mechanisms Of Methacrylated Gellan Gum Hydrogels Alter Macrophage Phenotype, Zhuqing Li, Kaitlin M. Bratlie Dec 2018

How Crosslinking Mechanisms Of Methacrylated Gellan Gum Hydrogels Alter Macrophage Phenotype, Zhuqing Li, Kaitlin M. Bratlie

Materials Science and Engineering Publications

In tissue engineering scaffolds, macrophages play a critical role in determining the host response to implanted biomaterials. Macrophage phenotype is dynamic throughout the host response, and a balance of phenotypes is essential for timely progression from injury to proper wound healing. Therefore, it is important to predict how materials will modulate the response of macrophages. In this study, we investigated the effect of methacrylated gellan gum hydrogels on macrophage phenotype and proliferation with the ultimate goal of improving rational design of biomedical implants. Naïve, along with classically and alternatively activated RAW 264.7 macrophages were seeded on methacrylated gellan gum ...


Treatment Of Neurodegenerative Disorders Through The Blood-Brain Barrier Using Nanocarriers, Nitya Poovaiah, Zahra Davoudi, Haisheng Peng, Benjamin Schlichtmann, Surya K. Mallapragada, Balaji Narasimhan, Qun Wang Aug 2018

Treatment Of Neurodegenerative Disorders Through The Blood-Brain Barrier Using Nanocarriers, Nitya Poovaiah, Zahra Davoudi, Haisheng Peng, Benjamin Schlichtmann, Surya K. Mallapragada, Balaji Narasimhan, Qun Wang

Chemical and Biological Engineering Publications

Neurodegenerative diseases refer to disorders of the central nervous system (CNS) that are caused by neuronal degradations, dysfunctions, or death. Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease (APHD) are regarded as the three major neurodegenerative diseases. There is a vast body of literature on the causes and treatments of these neurodegenerative diseases. However, the main obstacle in developing an effective treatment strategy is the permeability of the treatment components to the blood-brain barrier (BBB). Several strategies have been developed to improve this obstruction. For example, nanomaterials facilitate drug delivery to the BBB due to their size. They ...


Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie Jun 2018

Chemically Modified Gellan Gum Hydrogels With Tunable Properties For Use As Tissue Engineering Scaffolds, Zihao Xu, Zhuqing Li, Shan Jiang, Kaitlin M. Bratlie

Chemical and Biological Engineering Publications

Gellan gum is a naturally occurring polymer that can cross-link in the presence of divalent cations to form biocompatible hydrogels. However, physically cross-linked gellan gum hydrogels lose their stability under physiological conditions, thus restricting the applications of these hydrogels in vivo. To improve the mechanical strength of the gels, we incorporated methacrylate into the gellan gum and chemically cross-linked the hydrogel through three polymerization methods: step growth through thiol–ene photoclick chemistry, chain-growth via photopolymerization, and mixed model in which both mechanisms were employed. Methacrylation was confirmed and quantified by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared ...


Modeling Of Reaction-Diffusion Transport Into A Core-Shell Geometry, Clarence C. King, Amelia Ann Brown, Irmak Sargin, Kaitlin M. Bratlie, S. P. Beckman Jan 2018

Modeling Of Reaction-Diffusion Transport Into A Core-Shell Geometry, Clarence C. King, Amelia Ann Brown, Irmak Sargin, Kaitlin M. Bratlie, S. P. Beckman

Materials Science and Engineering Publications

Fickian diffusion into a core-shell geometry is modeled. The interior core mimics pancreatic Langerhan islets and the exterior shell acts as inert protection. The consumption of oxygen diffusing into the cells is approximated using Michaelis-Menten kinetics. The problem is transformed to dimensionless units and solved numerically. Two regimes are identified, one that is diffusion limited and the other consumption limited. A regression is fit that describes the concentration at the center of the cells as a function of the relevant physical parameters. It is determined that, in a cell culture environment, the cells will remain viable as long as the ...


Collagen Organization Deposited By Fibroblasts Encapsulated In Ph Responsive Methacrylated Alginate Hydrogels, Anuraag Boddupalli, Kaitlin M. Bratlie Jan 2018

Collagen Organization Deposited By Fibroblasts Encapsulated In Ph Responsive Methacrylated Alginate Hydrogels, Anuraag Boddupalli, Kaitlin M. Bratlie

Materials Science and Engineering Publications

The pH of dermal wounds shifts from neutral during the inflammatory phase to slightly basic in the tissue remodeling phase. Stage specific wound treatment can be developed using environmentally responsive alginate hydrogels. The chemistry of these networks dictates swelling behavior. Here, we fabricated alginate hydrogels using chain growth, step growth, and combined mixed mode gelation methods to crosslink methacrylated alginate (ALGMA) and gain control over swelling responses. Methacrylation of the alginate network was confirmed through NMR spectroscopy. Strontium cations were introduced to fabricate stiffer, dually crosslinked hydrogels. Dual crosslinking significantly decreased the swelling response over the pH range of 3 ...


Escherichia Coli Attachment To Model Particulates: The Effects Of Bacterial Cell Characteristics And Particulate Properties, Xiao Liang, Chunyu Liao, Michelle L. Soupir, Laura R. Jarboe, Michael L. Thompson, Philip M. Dixon Sep 2017

Escherichia Coli Attachment To Model Particulates: The Effects Of Bacterial Cell Characteristics And Particulate Properties, Xiao Liang, Chunyu Liao, Michelle L. Soupir, Laura R. Jarboe, Michael L. Thompson, Philip M. Dixon

Chemical and Biological Engineering Publications

E. coli bacteria move in streams freely in a planktonic state or attached to suspended particulates. Attachment is a dynamic process, and the fraction of attached microorganisms is thought to be affected by both bacterial characteristics and particulate properties. In this study, we investigated how the properties of cell surfaces and stream particulates influence attachment. Attachment assays were conducted for 77 E. coli strains and three model particulates (ferrihydrite, Ca-montmorillonite, or corn stover) under environmentally relevant conditions. Surface area, particle size distribution, and total carbon content were determined for each type of particulate. Among the three particulates, attachment fractions to ...


Influence Of Lysine-Based Biomaterials On Fibroblast To Myofibroblast Differentiation, Catherine Le Denmat Apr 2017

Influence Of Lysine-Based Biomaterials On Fibroblast To Myofibroblast Differentiation, Catherine Le Denmat

Honors Projects and Posters

Fibrous encapsulation occurs as a result of implantation of devices such as pacemakers, artificial breast implants, and microencapsulated islet cells used in type 1 diabetes treatment. The foreign body response (FBR) is responsible for the development of a fibrous capsule, which is often detrimental to the function of the implanted device and therefore affected patients. One event leading to fibrous capsule formation is contraction of collagen by myofibroblasts. The objective of this project was to significantly reduce the thickness of the fibrous capsule by limiting fibroblast to myofibroblast differentiation. It was hypothesized that using lysine-based biomaterials with amidine-like functional group ...


Hemolysis As A Rapid Screening Technique For Assessing The Toxicity Of Native Surfactin And A Genetically Engineered Derivative, William J. Colonna, Mustafa E. Marti, John A. Nyman, Chris Green, Charles Glatz Mar 2017

Hemolysis As A Rapid Screening Technique For Assessing The Toxicity Of Native Surfactin And A Genetically Engineered Derivative, William J. Colonna, Mustafa E. Marti, John A. Nyman, Chris Green, Charles Glatz

Chemical and Biological Engineering Publications

If biosurfactants are to achieve their promise in environmental oil-spill remediation, their toxicity to marine life must be assessed. A killifish larvae assay is commonly used as a measure of toxicity but is difficult and nonlinear in response. Red blood cell (RBC) hemolysis has also been the basis for assays of some surfactant levels. Here we present a modified sheep RBC suspension assay and compare its response to that of the fish assay for surfactin and its genetically modified variant fatty-acyl-glutamate (FA-Glu). This is the first report of hemolytic activity as a property of FA-Glu. The method's potential for ...


Improving Escherichia Coli Membrane Integrity And Fatty Acid Production By Expression Tuning Of Fadl And Ompf, Zaigao Tan, William Black, Jong Moon Yoon, Jacqueline V. Shanks, Laura R. Jarboe Feb 2017

Improving Escherichia Coli Membrane Integrity And Fatty Acid Production By Expression Tuning Of Fadl And Ompf, Zaigao Tan, William Black, Jong Moon Yoon, Jacqueline V. Shanks, Laura R. Jarboe

Chemical and Biological Engineering Publications

Background

Construction of microbial biocatalysts for the production of biorenewables at economically viable yields and titers is frequently hampered by product toxicity. Membrane damage is often deemed as the principal mechanism of this toxicity, particularly in regards to decreased membrane integrity. Previous studies have attempted to engineer the membrane with the goal of increasing membrane integrity. However, most of these works focused on engineering of phospholipids and efforts to identify membrane proteins that can be targeted to improve fatty acid production have been unsuccessful.

Results

Here we show that deletion of outer membrane protein ompF significantly increased membrane integrity, fatty ...


Anticancer Drugs, Le Zhao, Zengyi Shao, Jacqueline V. Shanks Jan 2017

Anticancer Drugs, Le Zhao, Zengyi Shao, Jacqueline V. Shanks

Chemical and Biological Engineering Publications

Plant‐derived anticancer drugs play a large role in anticancer pharmaceuticals. Through reviewing the four major types of plant anticancer drugs, namely vinca alkaloids, taxane diterpenoids, podophyllotoxin lignans, and camptothecin quinoline alkaloids, this article illustrates the development process, current status, existing challenges, and future perspective of the plant anticancer drug production. Moreover, this review explains how various biotechnologies, from the mature elicitation strategy to the “omics” techniques that are still undergoing development, can be applied to address the challenges in improving the production of the plant‐sourced anticancer drugs.


Recovery And Utilization Of Lignin Monomers As Part Of The Biorefinery Approach, Kirsten M. Davis, Marjorie Rover, Robert C. Brown, Xianglan Bai, Zhiyou Wen, Laura R. Jarboe Oct 2016

Recovery And Utilization Of Lignin Monomers As Part Of The Biorefinery Approach, Kirsten M. Davis, Marjorie Rover, Robert C. Brown, Xianglan Bai, Zhiyou Wen, Laura R. Jarboe

Chemical and Biological Engineering Publications

Lignin is a substantial component of lignocellulosic biomass but is under-utilized relative to the cellulose and hemicellulose components. Historically, lignin has been burned as a source of process heat, but this heat is usually in excess of the process energy demands. Current models indicate that development of an economically competitive biorefinery system requires adding value to lignin beyond process heat. This addition of value, also known as lignin valorization, requires economically viable processes for separating the lignin from the other biomass components, depolymerizing the lignin into monomeric subunits, and then upgrading these monomers to a value-added product. The fact that ...


The Development Of A Virtual Sensor In Glucose Monitoring For Non-Insulin Dependent People, Sophia Masters, Sarah Jacobson Apr 2016

The Development Of A Virtual Sensor In Glucose Monitoring For Non-Insulin Dependent People, Sophia Masters, Sarah Jacobson

Honors Projects and Posters

The project involves an Android application that acts as a continuous-time monitor of glucose levels for people with Type II diabetes. Our objective was to get information from a glucose lancet meter to automatically upload via Bluetooth into the application. This allows a person to easily monitor their insulin levels without manually inputting glucose levels into the application. The glucose meter used was a ForaCare Test N’ Go system. To aid in the Bluetooth process, we were granted open access to the glucose meter from Fora Care. The process involved using the programming language of Java in the Android software ...


High Throughput Studies Of Cell Migration In 3d Microtissues Fabricated By A Droplet Microfluidic Chip, Xiangchen Che, Jacob A. M. Nuhn, Ian C. Schneider, Long Que Jan 2016

High Throughput Studies Of Cell Migration In 3d Microtissues Fabricated By A Droplet Microfluidic Chip, Xiangchen Che, Jacob A. M. Nuhn, Ian C. Schneider, Long Que

Chemical and Biological Engineering Publications

Arrayed three-dimensional (3D) micro-sized tissues with encapsulated cells (microtissues) have been fabricated by a droplet microfluidic chip. The extracellular matrix (ECM) is a polymerized collagen network. One or multiple breast cancer cells were embedded within the microtissues, which were stored in arrayed microchambers on the same chip without ECM droplet shrinkage over 48 h. The migration trajectory of the cells was recorded by optical microscopy. The migration speed was calculated in the range of 3–6 µm/h. Interestingly, cells in devices filled with a continuous collagen network migrated faster than those where only droplets were arrayed in the chambers ...


Polymeric Adjuvants For Vaccine Delivery, Tiffany Lam Dec 2015

Polymeric Adjuvants For Vaccine Delivery, Tiffany Lam

Honors Projects and Posters

This research has investigated the use of pentablock copolymers and polyanhydride nanoparticles in combination to form a hydrogel matrix giving controlled and sustained release of model protein ovalbumin (OVA) for vaccine delivery applications. To investigate the influence of hydrogel composition on release of OVA, the weight percent of polyvinyl alcohol (PVA), form of OVA, and molecular weight of pentablock copolymer were varied. The weight percent of PVA was tested for 20% and 30%. Molecular weight of the pentablock copolymer was also varied giving a low molecular weight or high molecular weight copolymer. Lastly, OVA was incorporated into hydrogels either in ...


Epitaxially Grown Collagen Fibrils Reveal Diversity In Contact Guidance Behavior Among Cancer Cells, Juan Wang, Joseph W. Petefish, Andrew C. Hillier, Ian C. Schneider Jan 2015

Epitaxially Grown Collagen Fibrils Reveal Diversity In Contact Guidance Behavior Among Cancer Cells, Juan Wang, Joseph W. Petefish, Andrew C. Hillier, Ian C. Schneider

Chemical and Biological Engineering Publications

Invasion of cancer cells into the surrounding tissue is an important step during cancer progression and is driven by cell migration. Cell migration can be random, but often it is directed by various cues such as aligned fibers composed of extracellular matrix (ECM), a process called contact guidance. During contact guidance, aligned fibers bias migration along the long axis of the fibers. These aligned fibers of ECM are commonly composed of type I collagen, an abundant structural protein around tumors. In this paper, we epitaxially grew several different patterns of organized type I collagen on mica and compared the morphology ...


Hemagglutinin-Based Polyanhydride Nanovaccines Against H5n1 Influenza Elicit Protective Virus Neutralizing Titers And Cell-Mediated Immunity, Kathleen Alaine Ross, Hyelee Park Loyd, Wuwei Wu, Lucas Mark Huntimer, Shaheen Ahmed, Anthony Sambol, Scott Broderick, Zachary Flickinger, Krishna Rajan, Tatiana Bronich, Surya K. Mallapragada, Michael J. Wannemuehler, Susan Long Carpenter, Balaji Narasimhan Jan 2015

Hemagglutinin-Based Polyanhydride Nanovaccines Against H5n1 Influenza Elicit Protective Virus Neutralizing Titers And Cell-Mediated Immunity, Kathleen Alaine Ross, Hyelee Park Loyd, Wuwei Wu, Lucas Mark Huntimer, Shaheen Ahmed, Anthony Sambol, Scott Broderick, Zachary Flickinger, Krishna Rajan, Tatiana Bronich, Surya K. Mallapragada, Michael J. Wannemuehler, Susan Long Carpenter, Balaji Narasimhan

Chemical and Biological Engineering Publications

H5N1 avian influenza is a significant global concern with the potential to become the next pandemic threat. Recombinant subunit vaccines are an attractive alternative for pandemic vaccines compared to traditional vaccine technologies. In particular, polyanhydride nanoparticles encapsulating subunit proteins have been shown to enhance humoral and cell-mediated immunity and provide protection upon lethal challenge. In this work, a recombinant H5 hemagglutinin trimer (H53) was produced and encapsulated into polyanhydride nanoparticles. The studies performed indicated that the recombinant H53 antigen was a robust immunogen. Immunizing mice with H53 encapsulated into polyanhydride nanoparticles induced high neutralizing antibody titers and enhanced CD4+ T ...


Responsive Pentablock Copolymers For Sirna Delivery, Surya K. Mallapragada, Metin Uz, Sacide Alsoy Altinkaya Jan 2015

Responsive Pentablock Copolymers For Sirna Delivery, Surya K. Mallapragada, Metin Uz, Sacide Alsoy Altinkaya

Chemical and Biological Engineering Publications

In this study, temperature and pH responsive cationic and amphiphilic pentablock copolymers, which consist of the temperature responsive triblock Pluronic F127 sandwiched between pH responsive PDEAEM (poly(2-diethylaminoethyl methacrylate)) end blocks, were used for the first time in the development of polyplex and gold nanoparticle (AuNP) based multicomponent siRNA delivery systems (MCSs). Copolymers in both systems protected siRNA from external effects, provided cell entry and endosomal escape. The thermoreversible micellization of the hydrophobic PPO block facilitated the cellular entry while the PDEAEM blocks enhanced the endosomal escape through protonated tertiary amine groups by pH buffering. The synergistic advantages of the ...


Cellular Contractility And Extracellular Matrix Stiffness Regulate Matrix Metalloproteinase Activity In Pancreatic Cancer Cells, Amanda Haage, Ian C. Schneider Aug 2014

Cellular Contractility And Extracellular Matrix Stiffness Regulate Matrix Metalloproteinase Activity In Pancreatic Cancer Cells, Amanda Haage, Ian C. Schneider

Chemical and Biological Engineering Publications

The pathogenesis of cancer is often driven by local invasion and metastasis. Recently, mechanical properties of the tumor microenvironment have been identified as potent regulators of invasion and metastasis, while matrix metalloproteinases (MMPs) are classically known as significant enhancers of cancer cell migration and invasion. Here we have been able to sensitively measure MMP activity changes in response to specific extracellular matrix (ECM) environments and cell contractility states. A pancreatic cancer cell line, Panc-1 cells, up-regulate MMP activities between 3- and 10- fold with increased cell contractility. Conversely, they down-regulate MMP activities when contractility is blocked to levels seen with ...


Characterization Of Sheared Colloidal Aggregation Using Langevin Dynamics Simulation, Sergiy Markutsya, Rodney O. Fox, Shankar Subramaniam Jun 2014

Characterization Of Sheared Colloidal Aggregation Using Langevin Dynamics Simulation, Sergiy Markutsya, Rodney O. Fox, Shankar Subramaniam

Chemical and Biological Engineering Publications

Aggregation of colloidal particles under shear is studied in model systems using a Langevin dynamics model with an improved interparticle interaction potential. In the absence of shear, aggregates that form are characterized by compact structure at small scales and ramified structure at larger scales. This confirms the structural crossover mechanism previously suggested by Sorensen and coworkers, that colloidal aggregation occurs due to monomer addition at small scales and due to cluster-cluster aggregation at large scales. The fractal dimension of nonsheared aggregates is scale-dependent. Smaller aggregates have a higher fractal dimension than larger ones, but the radius of gyration where this ...


The Number Of Lines A Cell Contacts And Cell Contractility Drive The Efficiency Of Contact Guidance, Nicholas R. Romsey, Yue Hou, Laura L. Rodriguez, Ian C. Schneider Mar 2014

The Number Of Lines A Cell Contacts And Cell Contractility Drive The Efficiency Of Contact Guidance, Nicholas R. Romsey, Yue Hou, Laura L. Rodriguez, Ian C. Schneider

Chemical and Biological Engineering Publications

Cell migration is an important biological function that impacts many physiological and pathological processes. Often migration is directed along various densities of aligned fibers of collagen, a process called contact guidance. However, cells adhere to other components in the extracellular matrix, possibly affecting migrational behavior. Additionally, changes in intracellular contractility are well known to affect random migration, but its effect on contact guidance is less known. This study examines differences in directed migration in response to variations in the spacing of collagen, non-specific background adhesion strength and myosin II-mediated contractility. Collagen was microcontact printed onto glass substrates and timelapse live-cell ...


Angle-Tunable Enhanced Infrared Reflection Absorption Spectroscopy Via Grating-Coupled Surface Plasmon Resonance, Joseph W. Petefish, Andrew C. Hillier Jan 2014

Angle-Tunable Enhanced Infrared Reflection Absorption Spectroscopy Via Grating-Coupled Surface Plasmon Resonance, Joseph W. Petefish, Andrew C. Hillier

Chemical and Biological Engineering Publications

Surface enhanced infrared absorption (SEIRA) spectroscopy is an attractive method for increasing the prominence of vibrational modes in infrared spectroscopy. To date, the majority of reports associated with SEIRA utilize localized surface plasmon resonance from metal nanoparticles to enhance electromagnetic fields in the region of analytes. Limited work has been performed using propagating surface plasmons as a method for SEIRA excitation. In this report, we demonstrate angle-tunable enhancement of vibrational stretching modes associated with a thin poly(methyl methacrylate) (PMMA) film that is coupled to a silver-coated diffraction grating. Gratings are fabricated using laser interference lithography to achieve precise surface ...


Collagen Attachment To The Substrate Controls Cell Clustering Through Migration, Yue Hou, Laura L. Rodriguez, Juan Wang, Ian C. Schneider Jan 2014

Collagen Attachment To The Substrate Controls Cell Clustering Through Migration, Yue Hou, Laura L. Rodriguez, Juan Wang, Ian C. Schneider

Chemical and Biological Engineering Publications

Cell clustering and scattering play important roles in cancer progression and tissue engineering. While the extracellular matrix (ECM) is known to control cell clustering, much of the quantitative work has focused on the analysis of clustering between cells with strong cell-cell junctions. Much less is known about how the ECM regulates cells with weak cell-cell contact. Clustering characteristics were quantified in rat adenocarcinoma cells, which form clusters on physically adsorbed collagen substrates, but not on covalently attached collagen substrates. Covalently attaching collagen inhibited desorption of collagen from the surface. While changes in proliferation rate could not explain differences seen in ...


Nucleation Of Iron Oxide Nanoparticles Mediated By Mms6 Protein In Situ, Sanjay Kashyap, Taylor J. Woehl, Xunpei Liu, Surya K. Mallapragada, Tanya Prozorov Jan 2014

Nucleation Of Iron Oxide Nanoparticles Mediated By Mms6 Protein In Situ, Sanjay Kashyap, Taylor J. Woehl, Xunpei Liu, Surya K. Mallapragada, Tanya Prozorov

Chemical and Biological Engineering Publications

Biomineralization proteins are widely used as templating agents in biomimetic synthesis of a variety of organic-inorganic nanostructures. However, the role of the protein in controlling the nucleation and growth of biomimetic particles is not well understood, because the mechanism of the bioinspired reaction is often deduced from ex situ analysis of the resultant nanoscale mineral phase. Here we report the direct visualization of biomimetic iron oxide nanoparticle nucleation mediated by an acidic bacterial recombinant protein, Mms6, during an in situ reaction induced by the controlled addition of sodium hydroxide to solution-phase Mms6 protein micelles incubated with ferric chloride. Using in ...


A Systems Approach To Designing Next Generation Vaccines: Combining α-Galactose Modified Antigens With Nanoparticle Platforms, Yashdeep Phanse, Brenda Rocio Carrillo-Conde, Amanda Ellen Ramer-Tait, Scott Broderick, Chang Sun Kong, Krishna Rajan, Ramon Flick, Robert B. Mandell, Balaji Narasimhan, Michael J. Wannemuehler Jan 2014

A Systems Approach To Designing Next Generation Vaccines: Combining α-Galactose Modified Antigens With Nanoparticle Platforms, Yashdeep Phanse, Brenda Rocio Carrillo-Conde, Amanda Ellen Ramer-Tait, Scott Broderick, Chang Sun Kong, Krishna Rajan, Ramon Flick, Robert B. Mandell, Balaji Narasimhan, Michael J. Wannemuehler

Chemical and Biological Engineering Publications

Innovative vaccine platforms are needed to develop effective countermeasures against emerging and re-emerging diseases. These platforms should direct antigen internalization by antigen presenting cells and promote immunogenic responses. This work describes an innovative systems approach combining two novel platforms, αGalactose (αGal)-modification of antigens and amphiphilic polyanhydride nanoparticles as vaccine delivery vehicles, to rationally design vaccine formulations. Regimens comprising soluble αGal-modified antigen and nanoparticle-encapsulated unmodified antigen induced a high titer, high avidity antibody response with broader epitope recognition of antigenic peptides than other regimen. Proliferation of antigen-specific CD4 + T cells was also enhanced compared to a traditional ...


Development Of A Combined Catalyst And Sorbent For The Water Gas Shift Reaction, Meng Kong, Karl O. Albrecht, Brent H. Shanks, Thomas D. Wheelock Jan 2014

Development Of A Combined Catalyst And Sorbent For The Water Gas Shift Reaction, Meng Kong, Karl O. Albrecht, Brent H. Shanks, Thomas D. Wheelock

Chemical and Biological Engineering Publications

A combined catalyst and sorbent was developed for reacting CO with steam to produce H2 in a single reaction stage at 600 °C by employing the water gas shift (WGS) reaction. The combined material was in the form of spherical pellets where each pellet consisted of a CaO core for absorbing byproduct CO2 surrounded by a porous shell of Al2O 3 which supported a Ni catalyst. The best results were achieved by incorporating 5 wt % limestone in the shell material to suppress coking. By employing the best core-in-shell pellets and supplying a 3:1 mol ratio ...


The Influence Of Alkali And Alkaline Earth Metals And The Role Of Acid Pretreatments In Production Of Sugars From Switchgrass Based On Solvent Liquefaction, Xianglan Bai, Robert C. Brown, Jie Fu, Brent H. Shanks, Matthew Kieffer Jan 2014

The Influence Of Alkali And Alkaline Earth Metals And The Role Of Acid Pretreatments In Production Of Sugars From Switchgrass Based On Solvent Liquefaction, Xianglan Bai, Robert C. Brown, Jie Fu, Brent H. Shanks, Matthew Kieffer

Chemical and Biological Engineering Publications

This study investigated the influence of alkali and alkaline earth metals (AAEM) and the role of acid pretreatments in the production of sugars during solvent liquefaction of lignocellulosic biomass using 1,4-dioxane and water as solvents. The present study found that removal of AAEM by acid washing/water rinsing did not enhance sugar production during solvent liquefaction of pretreated switchgrass nearly to the extent observed for fast pyrolysis nor did it inhibit lignin decomposition, suggesting that AAEM play less of a role in determining product yields in solvent liquefaction. On the other hand, acid infusion greatly enhanced the yields of ...