Digital Commons Network^™

Encapsulation Of Inorganic Nanoparticles By Anionic Emulsion Polymerization Of Diethyl Methylene Malonate For Developing Hybrid Microparticles With Tailorable Composition, Peter J. Beltramo, Et. Al.

Chemical Engineering Faculty Publication Series

Colloidal particle self-assembly into higher-ordered structures has been of great interest due to the promise of creating metamaterials with novel macroscopic properties. The physicochemical properties of these metamaterials can be tailored to achieve composites with tunable functionalities, either by controlling the assembly morphology and/or chemistry of the colloidal building blocks. This work describes a strategy of developing microparticles with a hybrid configuration that have an inorganic and an organic part. The inorganic part comprises functional nanoparticles, which are embedded within an organic polymer particle composed of diethyl methylene malonate polymer [p(DEMM)] prepared using anionic emulsion polymerization. DEMM polymerization is initiated …

Genetic Circuits For Feedback Control Of Gamma-Aminobutyric Acid Biosynthesis In Probiotic Escherichia Coli Nissle 1917, Matthew Lebovich, Marcos A. Lora, Jared Gracia-David, Lauren Andrews

Chemical Engineering Faculty Publication Series

Engineered microorganisms such as the probiotic strain Escherichia coli Nissle 1917 (EcN) offer a strategy to sense and modulate the concentration of metabolites or therapeutics in the gastrointestinal tract. Here, we present an approach to regulate the production of the depression-associated metabolite gamma-aminobutyric acid (GABA) in EcN using genetic circuits that implement negative feedback. We engineered EcN to produce GABA by overexpressing glutamate decarboxylase and applied an intracellular GABA biosensor to identify growth conditions that improve GABA biosynthesis. We next employed characterized genetically encoded NOT gates to construct genetic circuits with layered feedback to control the rate of GABA biosynthesis …

Self-Assembling Polypeptides In Complex Coacervation, Arvind Sathyavageeswaran, Júlia Bonesso Sabadini, Sarah L. Perry

Chemical Engineering Faculty Publication Series

No abstract provided.

Intracellular Salmonella Delivery Of An Exogenous Immunization Antigen Refocuses Cd8 T Cells Against Cancer Cells, Eliminates Pancreatic Tumors And Forms Antitumor Immunity, Vishnu Raman, Lars M. Howell, Shoshana M. K. Bloom, Christopher L. Hall, Victoria E. Wetherby, Lisa M. Minter, Ashish A. Kulkarni, Neil S. Forbes

Chemical Engineering Faculty Publication Series

Introduction: Immunotherapies have shown great promise, but are not effective for all tumors types and are effective in less than 3% of patients with pancreatic ductal adenocarcinomas (PDAC). To make an immune treatment that is effective for more cancer patients and those with PDAC specifically, we genetically engineered Salmonella to deliver exogenous antigens directly into the cytoplasm of tumor cells. We hypothesized that intracellular delivery of an exogenous immunization antigen would activate antigen-specific CD8 T cells and reduce tumors in immunized mice.

Methods: To test this hypothesis, we administered intracellular delivering (ID) Salmonella that deliver ovalbumin as a model antigen …

Challenges And Opportunities Modeling The Dynamic Tumor Matrisome, Shelly R. Peyton, Manu O. Platt, Edna Cukierman

Chemical Engineering Faculty Publication Series

We need novel strategies to target the complexity of cancer and, particularly, of metastatic disease. As an example of this complexity, certain tissues are particularly hospitable environments for metastases, whereas others do not contain fertile microenvironments to support cancer cell growth. Continuing evidence that the extracellular matrix (ECM) of tissues is one of a host of factors necessary to support cancer cell growth at both primary and secondary tissue sites is emerging. Research on cancer metastasis has largely been focused on the molecular adaptations of tumor cells in various cytokine and growth factor environments on 2-dimensional tissue culture polystyrene plates. …

Design Rules For Sequestration Of Viruses Into Polypeptide Complex Coacervates, Pratik U. Joshi, Claire Decker, Xianci Zeng, Arvind Sathyavageeswaran, Sarah L. Perry, Caryn L. Heidt

Chemical Engineering Faculty Publication Series

Encapsulation is a strategy that has been used to facilitate the delivery and increase the stability of proteins and viruses. Here, we investigate the encapsulation of viruses via complex coacervation, which is a liquid–liquid phase separation resulting from the complexation of oppositely charged polymers. In particular, we utilized polypeptide-based coacervates and explored the effects of peptide chemistry, chain length, charge patterning, and hydrophobicity to better understand the effects of the coacervating polypeptides on virus incorporation. Our study utilized two nonenveloped viruses, porcine parvovirus (PPV) and human rhinovirus (HRV). PPV has a higher charge density than HRV, and they both appear …

Polymer-Based Microfluidic Device For On-Chip Counter-Diffusive Crystallization And In Situ X-Ray Crystallography At Room Temperature, Sarthak Saha, Can Özden, Alfred Samkutty, Silvia Russi, Aina Cohen, Margaret M. Stratton, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Proteins are long chains of amino acid residues that perform a myriad of functions in living organisms, including enzymatic reactions, signalling, and maintaining structural integrity. Protein function is determined directly by the protein structure. X-ray crystallography is the primary technique for determining the 3D structure of proteins, and facilitates understanding the effects of protein structure on function. The first step towards structure determination is crystallizing the protein of interest. We have developed a centrifugally-actuated microfluidic device that incorporates the fluid handling and metering necessary for protein crystallization. Liquid handling takes advantage of surface forces to control fluid flow and enable …

Cavitation Induced Fracture Of Intact Brain Tissue, Carey E. Dougan, Zhaoqiang Song, Hongo Fu, Alfred J. Crosby, Shengqiang Cai, Shelly Peyton

Chemical Engineering Faculty Publication Series

Nonpenetrating traumatic brain injuries (TBI) are linked to cavitation. The structural organization of the brain makes it particularly susceptible to tears and fractures from these cavitation events, but limitations in existing characterization methods make it difficult to understand the relationship between fracture and cavitation in this tissue. More broadly, fracture energy is an important, yet often overlooked, mechanical property of all soft tissues. We combined needle-induced cavitation (NIC) with hydraulic fracture models to induce and quantify fracture in intact brains at precise locations. We report here the first measurements of the fracture energy of intact brain tissue that range from …

A Poly(Ethylene Glycol) Three-Dimensional Bone Marrow Hydrogel, Lauren E. Jansen, Hyuna Kim, Christopher L. Hall, Thomas P. Mccarthy, Michael J. Lee, Shelly R. Peyton

Chemical Engineering Faculty Publication Series

Three-dimensional (3D) hydrogels made from synthetic polymers have emerged as in vitro cell culture platforms capable of representing the extracellular geometry, modulus, and water content of tissues in a tunable fashion. Hydrogels made from these otherwise non-bioactive polymers can be decorated with short peptides derived from proteins naturally found in tissues to support cell viability and direct phenotype. We identified two key limitations that limit the ability of this class of materials to recapitulate real tissue. First, these environments typically display between 1 and 3 bioactive peptides, which vastly underrepresents the diversity of proteins found in the extracellular matrix …

Materials-Driven Approaches To Understand Extrinsic Drug Resistance In Cancer, Pritchard Justin, Michael Lee, Shelly Peyton

Chemical Engineering Faculty Publication Series

Metastatic cancer has a poor prognosis, because it is broadly disseminated and associated with both intrinsic and acquired drug resistance. Critical unmet needs in effectively killing drug resistant cancer cells include overcoming the drug desensitization characteristics of some metastatic cancers/lesions, and tailoring therapeutic regimens to both the tumor microenvironment and the genetic profiles of the resident cancer cells. Bioengineers and materials scientists are developing technologies to determine how metastatic sites exclude therapies, and how extracellular factors (including cells, proteins, metabolites, extracellular matrix, and abiotic factors) at metastatic sites significantly affect drug pharmacodynamics. Two looming challenges are determining which feature, or …

Linear Viscoelasticity And Time—Alcohol Superposition Of Chitosan/Hyaluronic Acid Complex Coacervates, Juanfeng Sun, Jessica D. Schiffman, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Complex coacervation is an associative liquid−liquid phase separation phenomenon resulting from the complexation of oppositely charged macroions. While it is well-known that the phase behavior and rheological character of the resulting coacervates can vary as a function of the identity of the various species present (i.e., macroions, salt, and solution conditions), the effect of solvent quality has been rarely studied. Here, the effect of adding small amounts of either methanol or ethanol to complex coacervates of the natural polymers chitosan and hyaluronic acid is described. The effect of cosolvent addition on the phase behavior and linear viscoelasticity of the resulting …

Genetic Mutations Associated With Hormone-Positive Breast Cancer In A Small Cohort Of Ethiopian Women, Alyssa D. Schwartz, Afua Adusei, Solomon Tsegaye, Christopher A. Moskaluk, Sallie S. Schneider, Manu O. Platt, Daniel Seifu, Shelly R. Peyton, Courtney C. Babbitt

Chemical Engineering Faculty Publication Series

In Ethiopia, a breast cancer diagnosis is associated with a prognosis significantly worse than that of Europe and the US. Further, patients presenting with breast cancer in Ethiopia are far younger, on average, and patients are typically diagnosed at very late stages, relative to breast cancer patients of European descent. Emerging data suggest that a large proportion of Ethiopian patients have hormone-positive (ER⁺) breast cancer. This is surprising given 1) that patients have late-stage breast cancer at the time of diagnosis, 2) that African Americans with breast cancer frequently have triple negative breast cancer (TNBC), and 3) these …

One Versus Many: Polymicrobial Communities And The Cystic Fibrosis Airway, Fabrice Jean-Pierre, Arsh Vyas, Thomas H. Hampton, Michael A. Henson, George A. O'Toole

Chemical Engineering Faculty Publication Series

Culture-independent studies have revealed that chronic lung infections in persons with cystic fibrosis (pwCF) are rarely limited to one microbial species. Interactions among bacterial members of these polymicrobial communities in the airways of pwCF have been reported to modulate clinically relevant phenotypes. Furthermore, it is clear that a single polymicrobial community in the context of CF airway infections cannot explain the diversity of clinical outcomes. While large 16S rRNA gene- based studies have allowed us to gain insight into the microbial composition and predicted functional capacities of communities found in the CF lung, here we argue that in silico approaches …

Computational Modeling Of The Gut Microbiota Reveals Putative Metabolic Mechanisms Of Recurrent Clostridioides Difficile Infection, Michael A. Henson

Chemical Engineering Faculty Publication Series

Author summary Clostridioides difficile is an opportunistic human pathogen responsible for acute and sometimes chronic infections of the colon. Elderly individuals who are immunocompromised, frequently hospitalized and antibiotic recipients are particular susceptible to C. difficile infection (CDI). Approximately 30% of CDI patients will suffer at least one episode of reinfection, commonly termed recurrence. The objective of the current study was to utilize computational metabolic modeling to investigate the hypothesis that recurrent infections are related to the composition of the gut bacterial community within each patient. Our modeling results suggest that patients who have high abundances of the bacterial family Enterobacteriaceae …

Interrogation Of The Perturbed Gut Microbiota In Gouty Arthritis Patients Through In Silico Metabolic Modeling, Michael A. Henson

Chemical Engineering Faculty Publication Series

Recent studies have shown perturbed gut microbiota associated with gouty arthritis, a metabolic disease characterized by an imbalance between uric acid production and excretion. To mechanistically investigate altered microbiota metabolism associated with gout disease, 16S rRNA gene amplicon sequence data from stool samples of gout patients and healthy controls were computationally analyzed through bacterial community metabolic models. Patient-specific community models constructed with the metagenomics modeling pipeline, mgPipe, were used to perform k-means clustering of samples according to their metabolic capabilities. The clustering analysis generated statistically significant partitioning of samples into a Bacteroides-dominated, high gout cluster and a Faecalibacterium-elevated, …

Trabecular Bone Organoid Model For Studying The Regulation Of Localized Bone Remodeling, Yongkuk Park, Eugene Cheong, Jun-Goo Kwak, Ryan Carpenter, Jae-Hyuk Shim, Jungwoo Lee

Chemical Engineering Faculty Publication Series

Trabecular bone maintains physiological homeostasis and consistent structure and mass through repeated cycles of bone remodeling by means of tightly localized regulation. The molecular and cellular processes that regulate localized bone remodeling are poorly understood because of a lack of relevant experimental models. A tissue-engineered model is described here that reproduces bone tissue complexity and bone remodeling processes with high fidelity and control. An osteoid-inspired biomaterial-demineralized bone paper-directs osteoblasts to deposit structural mineralized bone tissue and subsequently acquire the resting-state bone lining cell phenotype. These cells activate and shift their secretory profile to induce osteoclastogenesis in response to chemical stimulation. …

Pseudomonas Aeruginosa Reverse Diauxie Is A Multidimensionl, Optimized, Resource Utilization Strategy, S. Lee Mcgill, Yeni Yung, Kristopher A. Hunt, Michael A. Henson, Luke Hanley, Ross P. Carlson

Chemical Engineering Faculty Publication Series

Pseudomonas aeruginosa is a globally-distributed bacterium often found in medical infections. The opportunistic pathogen uses a different, carbon catabolite repression (CCR) strategy than many, model microorganisms. It does not utilize a classic diauxie phenotype, nor does it follow common systems biology assumptions including preferential consumption of glucose with an ‘overflow’ metabolism. Despite these contradictions, P. aeruginosa is competitive in many, disparate environments underscoring knowledge gaps in microbial ecology and systems biology. Physiological, omics, and in silico analyses were used to quantify the P. aeruginosa CCR strategy known as ‘reverse diauxie’. An ecological basis of reverse diauxie was identified using a …

Encapsulating Bacteria In Alginate-Based Electrospun Nanofibers, Emily Diep, Jessica D. Schiffman

Chemical Engineering Faculty Publication Series

Encapsulation technologies are imperative for the safe delivery of live bacteria into the gut where they regulate bodily functions and human health. In this study, we develop alginate-based nanofibers that could potentially serve as a biocompatible, edible probiotic delivery system. By systematically exploring the ratio of three components, the biopolymer alginate (SA), the carrier polymer poly(ethylene oxide) (PEO), and the FDA approved surfactant polysorbate 80 (PS80), the surface tension and conductivity of the precursor solutions were optimized to electrospin bead-free fibers with an average diameter of 167 ± 23 nm. Next, the optimized precursor solution (2.8/1.2/3 wt% of SA/PEO/PS80) was …

Complex Coacervation Of Polymerized Ionic Liquids In Non-Acqueous Solvents, Minjung Lee, Sarah L. Perry, Ryan C. Hayward

Chemical Engineering Faculty Publication Series

Oppositely charged polymerized ionic liquids (PILs) were used to form complex coacervates in two different organic solvents, 2,2,2-trifluoroethanol (TFE) and hexafluoro-2-propanol (HFIP), and the corresponding phase diagrams were constructed using UV–vis, NMR, and turbidity experiments. While previous studies on complex coacervates have focused almost exclusively on aqueous environments, the use of PILs in the current work enabled studies in solvents with substantially lower dielectric constants (27.0 for TFE, 16.7 for HFIP). The critical salt concentration required to induce complete miscibility was roughly 2-fold larger in HFIP compared with TFE, and two different PIL complexes, solidlike precipitates and liquidlike coacervates, were …

Intracellular Delivery Of Protein Drugs With An Autonomously Lysing Bacterial System Reduces Tumor Growth And Metastases, Vishnu Raman, Nele Van Dessel, Christopher L. Hall, Victoria E. Wetherby, Samantha A. Whitney, Emily L. Kolewe, Shoshana M. K. Bloom, Abhinav Sharma, Jeanne A. Hardy, Mathieu Bollen, Aleyde Van Eynde, Neil S. Forbes

Chemical Engineering Faculty Publication Series

Critical cancer pathways often cannot be targeted because of limited efficiency crossing cell membranes. Here we report the development of a Salmonella-based intracellular delivery system to address this challenge. We engineer genetic circuits that (1) activate the regulator flhDC to drive invasion and (2) induce lysis to release proteins into tumor cells. Released protein drugs diffuse from Salmonella containing vacuoles into the cellular cytoplasm where they interact with their therapeutic targets. Control of invasion with flhDC increases delivery over 500 times. The autonomous triggering of lysis after invasion makes the platform self-limiting and prevents drug release in healthy organs. Bacterial …

Strain Effects On The Diffusion Properties Of Near-Surface Self-Interstitial Atoms And Adatoms In Tungsten, Bochuan Sun, Dimitrios Maroudas, Brian D. Wirth, Enrique Martínez

Chemical Engineering Faculty Publication Series

Tungsten (W) is a candidate for the plasma-facing components and divertor in future fusion applications. The material will be subject to a large particle influx (mainly helium and hydrogenic species) that will form bubbles. As bubbles grow, they compress the material, adding to thermal stresses, and eject self-interstitial atoms (SIAs-isolated or in clusters) to release internal pressure. These SIAs diffuse towards the surface in large stress/strain fields and on the surface are thought to act as precursors for nanotendril formation (also known as fuzz) that develops on the material surface modifying its morphology. In this work we analyze the effect …

100th Anniversary Of Macromolecular Science Viewpoint: Opportunities In The Physics Of Sequence-Defined Polymers, Sarah L. Perry, Charles E. Sing

Chemical Engineering Faculty Publication Series

Polymer science has been driven by ever-increasing molecular complexity, as polymer synthesis expands an already-vast palette of chemical and architectural parameter space. Copolymers represent a key example, where simple homopolymers have given rise to random, alternating, gradient, and block copolymers. Polymer physics has provided the insight needed to explore this monomer sequence parameter space. The future of polymer science, however, must contend with further increases in monomer precision, as this class of macromolecules moves ever closer to the sequence-monodisperse polymers that are the workhorses of biology. The advent of sequence-defined polymers gives rise to opportunities for material design, with increasing …

Effect Of Polymer Chemistry On The Linear Viscoelasticity Of Complex Coacervates, Yalin Liu, Cristiam F. Santa Chalarca, R. Nicholas Carmean, Rebecca A. Olson, Jason Madinya, Brent S. Sumerlin, Charles E. Sing, Todd Emrick, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Complex coacervates can form through the electrostatic complexation of oppositely charged polymers. The material properties of the resulting coacervates can change based on the polymer chemistry and the complex interplay between electrostatic interactions and water structure, controlled by salt. We examined the effect of varying the polymer backbone chemistry using methacryloyl- and acryloyl-based complex coacervates over a range of polymer chain lengths and salt conditions. We simultaneously quantified the coacervate phase behavior and the linear viscoelasticity of the resulting coacervates to understand the interplay between polymer chain length, backbone chemistry, polymer concentration, and salt concentration. Time-salt superposition analysis was used …

Emerging Concepts And Tools In Cell Mechanomemory, Tanmay Lele, Amy Brock, Shelly Peyton

Chemical Engineering Faculty Publication Series

Studying a cell’s ability to sense and respond to mechanical cues has emerged as a field unto itself over the last several decades, and this research area is now populated by engineers and biologists alike. As just one example of this cell mechanosensing, fibroblasts on soft substrates have slower growth rates, smaller spread areas, lower traction forces, and slower migration speeds compared to cells on stiff substrates. This phenomenon is not unique to fibroblasts, as these behaviors, and others, on soft substrates has been shown across a variety of cell types, and reproduced in many different labs. Thus far, the …

Vascularized Biomaterials To Study Cancer Metastasis, Katherine Bittner, Juan Jimenez, Shelly Peyton

Chemical Engineering Faculty Publication Series

Cancer metastasis, the spread of cancer cells to distant organs, is responsible for 90 percent of cancer-related deaths. Cancer cells need to enter and exit circulation in order to form metastases, and the vasculature and endothelial cells are key regulators of this process. While vascularized 3D in vitrosystems have been developed, few have been used to study cancer, and many lack key features of vessels that are necessary to study metastasis. This review will focus on current methods of vascularizing biomaterials for the study of cancer, and three main factors that regulate intravasation and extravasation: endothelial cell heterogeneity, hemodynamics, …

Protein Encapsulation Using Complex Coacervates: What Nature Has To Teach Us, Whitney C. Blocher Mctigue, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Protein encapsulation is a growing area of interest, particularly in the fields of food science and medicine. The sequestration of protein cargoes is achieved using a variety of methods, each with benefits and drawbacks. One of the most significant challenges associated with protein encapsulation is achieving high loading while maintaining protein viability. This difficulty is exacerbated because many encapsulant systems require the use of organic solvents. By contrast, nature has optimized strategies to compartmentalize and protect proteins inside the cell—a purely aqueous environment. Although the mechanisms whereby aspects of the cytosol is able to stabilize proteins are unknown, the crowded …

Control Of Astrocyte Quiescence And Activation In A Synthetic Brain Hydrogel, Sualyneth Galarza, Alfred J. Crosby, Changhui Pak, Shelly Peyton

Chemical Engineering Faculty Publication Series

Bioengineers have designed numerous instructive brain extracellular matrix (ECM) environments with tailored and tunable protein composition and biomechanical properties in vitro to study astrocyte reactivity during trauma and inflammation. However, a major limitation of both protein-based and model microenvironments is that astrocytes within fail to retain their characteristic stellate morphology and quiescent state without becoming activated under “normal” culture conditions. Here we introduce a synthetic hydrogel, that for the first time demonstrates maintenance of astrocyte quiescence and activation on demand. With this synthetic brain hydrogel, we show the brain-specific integrin-binding and matrix metalloprotease (MMP)-degradable domains of proteins control astrocyte star-shaped …

Recent Advances In Encapsulation, Protection, And Oral Delivery Of Bioactive Proteins And Peptides Using Colloidal Systems, Sarah L. Perry, David Julian Mcclements

Chemical Engineering Faculty Publication Series

There are many areas in medicine and industry where it would be advantageous to orally deliver bioactive proteins and peptides (BPPs), including ACE inhibitors, antimicrobials, antioxidants, hormones, enzymes, and vaccines. A major challenge in this area is that many BPPs degrade during storage of the product or during passage through the human gut, thereby losing their activity. Moreover, many BPPs have undesirable taste profiles (such as bitterness or astringency), which makes them unpleasant to consume. These challenges can often be overcome by encapsulating them within colloidal particles that protect them from any adverse conditions in their environment, but then release …

Recent Progress In The Science Of Complex Coacervation, Charles E. Sing, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Complex coacervation is an associative, liquid–liquid phase separation that can occur in solutions of oppositely-charged macromolecular species, such as proteins, polymers, and colloids. This process results in a coacervate phase, which is a dense mix of the oppositely-charged components, and a supernatant phase, which is primarily devoid of these same species. First observed almost a century ago, coacervates have since found relevance in a wide range of applications; they are used in personal care and food products, cutting edge biotechnology, and as a motif for materials design and self-assembly. There has recently been a renaissance in our understanding of this …

Incorporation Of Proteins Into Complex Coacervates, Whitney C. Blocher Mctigue, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Complex coacervates have found a renewed interest in the past few decades in various fields such as food and personal care products, membraneless cellular compartments, the origin of life, and, most notably, as a mode of transport and stabilization of drugs. Here, we describe general methods for characterizing the phase behavior of complex coacervates and quantifying the incorporation of proteins into these phase separated materials.