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Biomedical Engineering and Bioengineering Commons

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Full-Text Articles in Biomedical Engineering and Bioengineering

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 ...


Direct Expression Of Active Human Tissue Inhibitors Of Metalloproteinases By Periplasmic Secretion In Escherichia Coli, Ki Baek Lee, Dong Hyun Nam, Jacob A. M. Nuhn, Juan Wang, Ian C. Schneider, Xin Ge Apr 2017

Direct Expression Of Active Human Tissue Inhibitors Of Metalloproteinases By Periplasmic Secretion In Escherichia Coli, Ki Baek Lee, Dong Hyun Nam, Jacob A. M. Nuhn, Juan Wang, Ian C. Schneider, Xin Ge

Chemical and Biological Engineering Publications

Background

As regulators of multifunctional metalloproteinases including MMP, ADAM and ADAMTS families, tissue inhibitors of metalloproteinases (TIMPs) play a pivotal role in extracellular matrix remodeling, which is involved in a wide variety of physiological processes. Since abnormal metalloproteinase activities are related to numerous diseases such as arthritis, cancer, atherosclerosis, and neurological disorders, TIMPs and their engineered mutants hold therapeutic potential and thus have been extensively studied. Traditional productions of functional TIMPs and their N-terminal inhibitory domains (N-TIMPs) rely on costly and time-consuming insect and mammalian cell systems, or tedious and inefficient refolding from denatured inclusion bodies. The later process is ...


Myosin Phosphorylation On Stress Fibers Predicts Contact Guidance Behavior Across Diverse Breast Cancer Cells, Juan Wang, Ian C. Schneider Mar 2017

Myosin Phosphorylation On Stress Fibers Predicts Contact Guidance Behavior Across Diverse Breast Cancer Cells, Juan Wang, Ian C. Schneider

Chemical and Biological Engineering Publications

During cancer progression the extracellular matrix is remodeled, forming aligned collagen fibers that proceed radially from the tumor, resulting in invasion. We have recently shown that different invasive breast cancer cells respond to epitaxially grown, aligned collagen fibrils differently. This article develops insight into why these cells differ in their contact guidance fidelity. Small changes in contractility or adhesion dramatically alter directional persistence on aligned collagen fibrils, while migration speed remains constant. The directionality of highly contractile and adhesive MDA-MB-231 cells can be diminished by inhibiting Rho kinase or β1 integrin binding. Inversely, the directionality of less contractile and adhesive ...


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.


Smart Materials For Nerve Regeneration And Neural Tissue Engineering, Surya K. Mallapragada, Metin Uz Jan 2017

Smart Materials For Nerve Regeneration And Neural Tissue Engineering, Surya K. Mallapragada, Metin Uz

Chemical and Biological Engineering Publications

Stimuli-responsive smart-biomaterial-based approaches have been identified as a promising tool for nerve regeneration and neural tissue engineering. Understanding the stimuli-responsive behavior of the smart materials, along with the fundamentals of cellular interactions, is the key to future strategies for neural tissue engineering. Advances in the development and application of smart biomaterials and 3-D scaffold fabrication techniques as well as cellular reprogramming and transdifferentiation technologies make it possible to combine stem cells, cellular engineering, drug/gene delivery systems, nanotechnology and biomaterial-based therapies to develop experimental and clinical strategies for neural tissue engineering. The application of smart biomaterials in these technologies is ...