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Biomedical Engineering and Bioengineering Commons

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Articles 1 - 9 of 9

Full-Text Articles in Biomedical Engineering and Bioengineering

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 ...


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 ...


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 ...


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 ...


Genome Sequence Of The Psychrophilic Deep-Sea Bacterium Moritella Marina Mp-1 (Atcc 15381), Kumar Babu Kautharapu, Laura R. Jarboe Nov 2012

Genome Sequence Of The Psychrophilic Deep-Sea Bacterium Moritella Marina Mp-1 (Atcc 15381), Kumar Babu Kautharapu, Laura R. Jarboe

Chemical and Biological Engineering Publications

Moritella marina MP-1 is a bacterial species known for its production of docosahexaenoic acid. We present the draft genome sequence of the type strainMoritella marina MP-1 (ATCC 15381), having 4,636,778 bp with a G+C content of 40.5% and consisting of 83 contigs.


Mixed-Surface, Lipid-Tethered Quantum Dots For Targeting Cells And Tissues, Yanjie Zhang, Amanda Haage, Elizabeth M. Whitley, Ian C. Schneider, Aaron R. Clapp Jun 2012

Mixed-Surface, Lipid-Tethered Quantum Dots For Targeting Cells And Tissues, Yanjie Zhang, Amanda Haage, Elizabeth M. Whitley, Ian C. Schneider, Aaron R. Clapp

Chemical and Biological Engineering Publications

Quantum dots (QDs), with their variable luminescent properties, are rapidly transcending traditional labeling techniques in biological imaging and hold vast potential for biosensing applications. An obstacle in any biosensor development is targeted specificity. Here we report a facile procedure for creating QDs targeted to the cell membrane with the goal of cell-surface protease biosensing. This procedure generates water-soluble QDs with variable coverage of lipid functional groups. The resulting hydrophobicity is quantitatively controlled by the molar ratio of lipids per QD. Appropriate tuning of the hydrophobicity ensures solubility in common aqueous cell culture media and while providing affinity to the lipid ...


Reconstructing Genome-Wide Regulatory Network Of E. Coli Using Transcriptome Data And Predicted Transcription Factor Activities, Yao Fu, Laura R. Jarboe, Julie A. Dickerson Jun 2011

Reconstructing Genome-Wide Regulatory Network Of E. Coli Using Transcriptome Data And Predicted Transcription Factor Activities, Yao Fu, Laura R. Jarboe, Julie A. Dickerson

Chemical and Biological Engineering Publications

Background: Gene regulatory networks play essential roles in living organisms to control growth, keep internal metabolism running and respond to external environmental changes. Understanding the connections and the activity levels of regulators is important for the research of gene regulatory networks. While relevance score based algorithms that reconstruct gene regulatory networks from transcriptome data can infer genome-wide gene regulatory networks, they are unfortunately prone to false positive results. Transcription factor activities (TFAs) quantitatively reflect the ability of the transcription factor to regulate target genes. However, classic relevance score based gene regulatory network reconstruction algorithms use models do not include the ...


Myosin Ii Activity Regulates Vinculin Recruitment To Focal Adhesions Through Fak-Mediated Paxillin Phosphorylation, Ana M. Pasapera, Ian C. Schneider, Erin Rericha, David D. Schlaepfer, Clare M. Waterman Jan 2010

Myosin Ii Activity Regulates Vinculin Recruitment To Focal Adhesions Through Fak-Mediated Paxillin Phosphorylation, Ana M. Pasapera, Ian C. Schneider, Erin Rericha, David D. Schlaepfer, Clare M. Waterman

Chemical and Biological Engineering Publications

Focal adhesions (FAs) are mechanosensitive adhesion and signaling complexes that grow and change composition in response to myosin II-mediated cytoskeletal tension in a process known as FA maturation. To understand tension-mediated FA maturation, we sought to identify proteins that are recruited to FAs in a myosin II-dependent manner and to examine the mechanism for their myosin II-sensitive FA association. We find that FA recruitment of both the cytoskeletal adapter protein vinculin and the tyrosine kinase FA kinase (FAK) are myosin II and extracellular matrix (ECM) stiffness dependent. Myosin II activity promotes FAK/Src-mediated phosphorylation of paxillin on tyrosines 31 and ...


Epidermal Growth Factor-Induced Contraction Regulates Paxillin Phosphorylation To Temporally Separate Traction Generation From De-Adhesion, Ian C. Schneider, Cristen K. Hays, Clare M. Waterman Jul 2009

Epidermal Growth Factor-Induced Contraction Regulates Paxillin Phosphorylation To Temporally Separate Traction Generation From De-Adhesion, Ian C. Schneider, Cristen K. Hays, Clare M. Waterman

Chemical and Biological Engineering Publications

Directed cell migration is mediated by cycles of protrusion, adhesion, traction generation on the extracellular matrix and retraction. However, how the events after protrusion are timed, and what dictates their temporal order is completely unknown. We used acute epidermal growth factor (EGF) stimulation of epidermal keratinocytes to initiate the cell migration cycle to study the mechanism of the timing of adhesion, traction generation, and de-adhesion. Using microscopic and biochemical assays, we surprisingly found that at ∼2 min after EGF stimulation protrusion, activation of myosin-II, traction generation, adhesion assembly, and paxillin phosphorylation occurred nearly simultaneously, followed by a 10-min delay during ...