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Biomedical Engineering and Bioengineering Commons

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2015

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Full-Text Articles in Biomedical Engineering and Bioengineering

Combining Dynamic Stretch And Tunable Stiffness To Probe Cell Mechanobiology In Vitro, Angela Quinlan, Leslie Sierad, Andrew Capulli, Laura Firstenberg, Kristen Billiar Dec 2015

Combining Dynamic Stretch And Tunable Stiffness To Probe Cell Mechanobiology In Vitro, Angela Quinlan, Leslie Sierad, Andrew Capulli, Laura Firstenberg, Kristen Billiar

Kristen L. Billiar

Cells have the ability to actively sense their mechanical environment and respond to both substrate stiffness and stretch by altering their adhesion, proliferation, locomotion, morphology, and synthetic profile. In order to elucidate the interrelated effects of different mechanical stimuli on cell phenotype in vitro, we have developed a method for culturing mammalian cells in a two-dimensional environment at a wide range of combined levels of substrate stiffness and dynamic stretch. Polyacrylamide gels were covalently bonded to flexible silicone culture plates and coated with monomeric collagen for cell adhesion. Substrate stiffness was adjusted from relatively soft (G' = 0.3 kPa) to …


Fgf2-Induced Effects On Transcriptome Associated With Regeneration Competence In Adult Human Fibroblasts, Olga Kashpur, David Lapointe, Sakthikumar Ambady, Elizabeth Ryder, Tanja Dominko Dec 2015

Fgf2-Induced Effects On Transcriptome Associated With Regeneration Competence In Adult Human Fibroblasts, Olga Kashpur, David Lapointe, Sakthikumar Ambady, Elizabeth Ryder, Tanja Dominko

Sakthikumar Ambady

BACKGROUND: Adult human fibroblasts grown in low oxygen and with FGF2 supplementation have the capacity to tip the healing outcome of skeletal muscle injury - by favoring regeneration response in vivo over scar formation. Here, we compare the transcriptomes of control adult human dermal fibroblasts and induced regeneration-competent (iRC) fibroblasts to identify transcriptional changes that may be related to their regeneration competence. RESULTS: We identified a unique gene-expression profile that characterizes FGF2-induced iRC fibroblast phenotype. Significantly differentially expressed genes due to FGF2 treatment were identified and analyzed to determine overrepresented Gene Ontology terms. Genes belonging to extracellular matrix components, adhesion …


Getting To The Root Of Bacterial Hairs: What Is “S”?, Rebecca Gaddis, Samantha O'Conner, Evan Anderson, Terri Camesano, Nancy Burnham Dec 2015

Getting To The Root Of Bacterial Hairs: What Is “S”?, Rebecca Gaddis, Samantha O'Conner, Evan Anderson, Terri Camesano, Nancy Burnham

Nancy A. Burnham

An atomic force microscope (AFM) was used to measure the steric forces of lipopolysaccharides (LPS) on the biofilm-forming bacteria, Pseudomonas aeruginosa. It is well known that LPS play a vital role in biofilm formation. These forces were characterized with a modified version of the Alexander and de Gennes (AdG) model for polymers, which is a function of equilibrium brush length, L, probe radius, R, temperature, T, separation distance, D, and an indefinite density variable, s. This last parameter was originally distinguished by de Gennes as the root spacing or mesh spacing depending upon the type of polymer adhesion; however since …


A Case Study: Data Management In Biomedical Engineering, Glenn Gaudette, Donna Kafel Dec 2015

A Case Study: Data Management In Biomedical Engineering, Glenn Gaudette, Donna Kafel

Glenn R. Gaudette

In a biomedical engineering lab at Worcester Polytechnic Institute, co-author Dr. Glenn R. Gaudette and his research team are investigating the effects of stem cell therapy on the regeneration of function in damaged cardiac tissue in laboratory rats. Each instance of stem cell experimentation on a rat yields hundreds of data sets that must be carefully captured, documented and securely stored so that the data will be easily accessed and retrieved for papers, reports, further research, and validation of findings, while meeting NIH guidelines for data sharing. After a brief introduction to the bioengineering field and stem cell research, this …


Muscle Synergies Improve Estimation Of Knee Contact Forces During Walking, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd Dec 2015

Muscle Synergies Improve Estimation Of Knee Contact Forces During Walking, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd

Allison Kinney

This study investigates whether use of subject-specific muscle synergies can improve optimization predictions of muscle excitation patterns and knee contact forces during walking. Muscle synergies describe how a small number of neural commands generated by the nervous system can be linearly combined to produce the broad range of muscle electromyographic (EMG) signals measured experimentally. By quantifying the interdependence of individual EMG signals, muscle synergies provide dimensionality reduction for the neural control redundancy problem. Our hypothesis was that use of subjectspecific muscle synergies to limit muscle excitation patterns would improve prediction of muscle EMG patterns at the hip, knee, and ankle …


Muscle Synergy Constraints Improve Prediction Of Knee Contact Force During Gait, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd Dec 2015

Muscle Synergy Constraints Improve Prediction Of Knee Contact Force During Gait, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd

Allison Kinney

Knowledge of patient-specific muscle and joint contact forces during activities of daily living could improve the treatment of movement-related disorders (e.g., osteoarthritis, stroke, cerebral palsy, Parkinson’s disease). Unfortunately, it is currently impossible to measure these quantities directly under common clinical conditions, and calculation of these quantities using computer models is limited by the redundant nature of human neural control (i.e., more muscles than theoretically necessary to actuate the available degrees of freedom in the skeleton). Walking is a particularly important task to understand, since loss of mobility is associated with increased morbidity and decreased quality of life. Though numerous musculoskeletal …


Evaluation Of Different Optimal Control Problem Formulations For Solving The Muscle Redundancy Problem, Friedl De Groote, Allison Kinney, Anil Rao, Benjamin Fregly Dec 2015

Evaluation Of Different Optimal Control Problem Formulations For Solving The Muscle Redundancy Problem, Friedl De Groote, Allison Kinney, Anil Rao, Benjamin Fregly

Allison Kinney

This study evaluates several possible optimal control problem formulations for solving the muscle redundancy problem with the goal of identifying the most efficient and robust formulation. One novel formulation involves the introduction of additional controls that equal the time derivative of the states, resulting in very simple dynamic equations. The nonlinear equations describing muscle dynamics are then imposed as algebraic constraints in their implicit form, simplifying their evaluation. By comparing different problem formulations for computing muscle controls that can reproduce inverse dynamic joint torques during gait, we demonstrate the efficiency and robustness of the proposed novel formulation.


Synergies Controls Improve Prediction Of Knee Contact Forces And Muscle Excitations During Gait, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd Dec 2015

Synergies Controls Improve Prediction Of Knee Contact Forces And Muscle Excitations During Gait, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd

Allison Kinney

This study investigates whether use of muscle excitation controls constructed from subjectspecific muscle synergy information can improve optimization prediction of knee contact forces and muscle excitations during walking. Muscle synergies quantify how a large number of experimental muscle electromyographic (EMG) signals can be reconstructed by linearly mixing a much smaller number of neural commands generated by the nervous system. Our hypothesis was that controlling all muscle excitations with a small set of experimentally calculated neural commands would improve prediction of knee contact forces and leg muscle excitations compared to using independently controlled muscle excitations.


Comparison Of Material Properties And Microstructure Of Specimens Built Using The 3d Systems Vanguard Hs And Vanguard Hiq+Hs Sls Systems, T.J. Silverman, Allison Kinney, W. Yong, J.H. Koo Dec 2015

Comparison Of Material Properties And Microstructure Of Specimens Built Using The 3d Systems Vanguard Hs And Vanguard Hiq+Hs Sls Systems, T.J. Silverman, Allison Kinney, W. Yong, J.H. Koo

Allison Kinney

The HiQ upgrade to the 3D Systems Vanguard selective laser sintering (SLS) machine incorporates a revised thermal calibration system and new control software. The paper compares the tensile modulus, tensile strength, elongation at break, flexural modulus, Izod impact resistance and microstructure of two batteries of standard specimens built from recycled Duraform PA (Nylon 12). The first set is built on a Vanguard HS system and the second on the same system with the HiQ upgrade installed. The upgrade reduces user intervention, decreases total build time and improves surface finish. However, using the default processing parameters, tensile, flexure and impact properties …


Science Panel Discussion Presentation: "Data Management In Biomedical Engineering: Needs And Implementation", Glenn Gaudette Dec 2015

Science Panel Discussion Presentation: "Data Management In Biomedical Engineering: Needs And Implementation", Glenn Gaudette

Glenn R. Gaudette

Glenn Gaudette, PhD, is an Associate Professor, Department of Biomedical Engineering, Worcester Polytechnic Institute. He discussed data management in his research laboratory, which is focused on regenerating mechanical and electrophysiological function in hearts with cardiovascular disease.


Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang Sep 2015

Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang

Yi Pang

Mitochondria, vital organelles existing in almost all eukaryotic cells, play a crucial role in energy metabolism and apoptosis of aerobic organisms. In this work, we report two new flavone-based fluorescent probes, MC-Mito1 and MC-Mito2, for monitoring mitochondria in living cells. These two probes exhibit remarkably low toxicity, good cell permeability, and high specificity; these probes complement the existing library of mitochondrial imaging agents. The new dyes give nearly no background fluorescence, and their application does not require tedious postwashing after cell staining. The appreciable tolerance of MC-Mito2 encourages a broader range of biological applications for understanding the cell degeneration and …


Tailoring Material Properties Of Cardiac Matrix Hydrogels To Induce Endothelial Differentiation Of Human Mesenchymal Stem Cells, Megan Jeffords, Jinglei Wu, Michey Shah, Yi Hong, Ge Zhang Sep 2015

Tailoring Material Properties Of Cardiac Matrix Hydrogels To Induce Endothelial Differentiation Of Human Mesenchymal Stem Cells, Megan Jeffords, Jinglei Wu, Michey Shah, Yi Hong, Ge Zhang

Ge Zhang

Cardiac matrix hydrogel has shown great promise as an injectable biomaterial due to the possession of cardiac-specific extracellular matrix composition. A cardiac matrix hydrogel facilitating neovascularization will further improve its therapeutic outcomes in cardiac repair. In this study, we explored the feasibility of tailoring material properties of cardiac matrix hydrogels using a natural compound, genipin, to promote endothelial differentiation of stem cells. Our results demonstrated that the genipin cross-linking could increase the mechanical properties of the cardiac matrix hydrogel to a stiffness range promoting endothelial differentiation of human mesenchymal stem cells (hMSCs). It also decreased the swelling ratio and prolonged …


Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang Sep 2015

Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang

Ge Zhang

Mitochondria, vital organelles existing in almost all eukaryotic cells, play a crucial role in energy metabolism and apoptosis of aerobic organisms. In this work, we report two new flavone-based fluorescent probes, MC-Mito1 and MC-Mito2, for monitoring mitochondria in living cells. These two probes exhibit remarkably low toxicity, good cell permeability, and high specificity; these probes complement the existing library of mitochondrial imaging agents. The new dyes give nearly no background fluorescence, and their application does not require tedious postwashing after cell staining. The appreciable tolerance of MC-Mito2 encourages a broader range of biological applications for understanding the cell degeneration and …


De Novo Design Of Self-Assembled Hexapeptides As Β-Amyloid (Aβ) Peptide Inhibitors, Jie Zheng, Ge Zhang, Mingzhen Zhang, Qiuming Wang, Guizhao Liang, Mingzhen Zhang, Jun Zhao, Kunal Patel, Xiang Yu, Chao Zhao, Binrong Ding, Feimeng Zhou Sep 2015

De Novo Design Of Self-Assembled Hexapeptides As Β-Amyloid (Aβ) Peptide Inhibitors, Jie Zheng, Ge Zhang, Mingzhen Zhang, Qiuming Wang, Guizhao Liang, Mingzhen Zhang, Jun Zhao, Kunal Patel, Xiang Yu, Chao Zhao, Binrong Ding, Feimeng Zhou

Ge Zhang

The ability of peptides to construct specific secondary structures provides a useful function for biomaterial design that cannot be achieved with traditional organic molecules and polymers. Inhibition of amyloid formation is a promising therapeutic approach for the treatment of neurodegenerative diseases. Existing peptide-based inhibitors are mainly derived from original amyloid sequences, which have very limited sequence diversity and activity. It is highly desirable to explore other peptide-based inhibitors that are not directly derived from amyloid sequences. Here, we develop a hybrid high-throughput computational method to efficiently screen and design hexapeptide inhibitors against amyloid-β (Aβ) aggregation and toxicity from the first …


Magnetic Labeling Of Bm-Msc-Derived Smcs Maintains Their Pro-Elastogenic Trophic Effects On Aneurysmal Smcs, G. Swaminathan, B. Sivaraman, I. Stoilov, Mickey Shah, Ge Zhang, R.P. Mecham, A. Ramamurthi Sep 2015

Magnetic Labeling Of Bm-Msc-Derived Smcs Maintains Their Pro-Elastogenic Trophic Effects On Aneurysmal Smcs, G. Swaminathan, B. Sivaraman, I. Stoilov, Mickey Shah, Ge Zhang, R.P. Mecham, A. Ramamurthi

Ge Zhang

No abstract provided.


Polyethlyene Glycol Microgels To Deliver Bioactive Nerve Growth Factor, Jessica Stukel, Susan Thompson, Laurent Simon, Rebecca Willits Aug 2015

Polyethlyene Glycol Microgels To Deliver Bioactive Nerve Growth Factor, Jessica Stukel, Susan Thompson, Laurent Simon, Rebecca Willits

Rebecca K. Willits

Delivery of bioactive molecules is a critical step in fabricating materials for regenerative medicine, yet, this step is particularly challenging in hydrated scaffolds such as hydrogels. Although bulk photocrosslinked poly(ethylene glycol) (PEG) hydrogels have been used for a variety of tissue engineering applications, their capability as drug delivery scaffolds has been limited due to undesirable release profiles and reduction in bioactivity of molecules. To solve these problems, this article presents the fabrication of degradable PEG microgels, which are micron-sized spherical hydrogels, to deliver bioactive nerve growth factor (NGF). NGF release and activity was measured after encapsulation in microgels formed from …


High Throughput, Polymeric Aqueous Two-Phase Printing Of Tumor Spheroids, Ehsan Atefi, Stephanie Lemmo, Darcy Fyffe, Gary Luker, Hossein Tavana Aug 2015

High Throughput, Polymeric Aqueous Two-Phase Printing Of Tumor Spheroids, Ehsan Atefi, Stephanie Lemmo, Darcy Fyffe, Gary Luker, Hossein Tavana

Hossein Tavana

This paper presents a new 3D culture microtechnology for high throughput production of tumor spheroids and validates its utility for screening anti-cancer drugs. Two immiscible polymeric aqueous solutions are used and a submicroliter drop of the “patterning” phase containing cells is microprinted into a bath of the “immersion” phase. Selecting proper formulations of biphasic systems using a panel of biocompatible polymers results in the formation of a round drop that confines cells to facilitate spontaneous formation of a spheroid without any external stimuli. Adapting this approach to robotic tools enables straightforward generation and maintenance of spheroids of well-defined size in …


3d Scaffolds In Tissue Engineering And Regenerative Medicine: Beyond Structural Templates?, Tierney Deluzio, Dawit Seifu, Kibret Mequanint Aug 2015

3d Scaffolds In Tissue Engineering And Regenerative Medicine: Beyond Structural Templates?, Tierney Deluzio, Dawit Seifu, Kibret Mequanint

Tierney GB Deluzio

The objective of this article is to systematically present the emerging understanding that 3D porous scaffolds serve not only as structural templates for tissue fabrication but also provide complex signaling cues to cells and facilitate oxygen and therapeutic agent delivery. Strategies in the field of tissue engineering and regenerative medicine often rely on 3D scaffolds to mimic the natural extracellular matrix as structural templates that support cell adhesion, migration, differentiation and proliferation, and provide guidance for neo-tissue formation. In addition to providing a temporary support for tissue fabrication, 3D scaffolds have also been used to study cell signaling that best …


3d Scaffolds In Tissue Engineering And Regenerative Medicine: Beyond Structural Templates?, Tierney Deluzio, Dawit Seifu, Kibret Mequanint Aug 2015

3d Scaffolds In Tissue Engineering And Regenerative Medicine: Beyond Structural Templates?, Tierney Deluzio, Dawit Seifu, Kibret Mequanint

Tierney GB Deluzio

The objective of this article is to systematically present the emerging understanding that 3D porous scaffolds serve not only as structural templates for tissue fabrication but also provide complex signaling cues to cells and facilitate oxygen and therapeutic agent delivery. Strategies in the field of tissue engineering and regenerative medicine often rely on 3D scaffolds to mimic the natural extracellular matrix as structural templates that support cell adhesion, migration, differentiation and proliferation, and provide guidance for neo-tissue formation. In addition to providing a temporary support for tissue fabrication, 3D scaffolds have also been used to study cell signaling that best …


The Impact Of Boundary Conditions On Surface Curvature Of Polypropylene Mesh In Response To Uniaxial Loading, William Barone, Rouzbeh Amini, Spandan Maiti, Pamela Moalli, Steven Abramowitch Aug 2015

The Impact Of Boundary Conditions On Surface Curvature Of Polypropylene Mesh In Response To Uniaxial Loading, William Barone, Rouzbeh Amini, Spandan Maiti, Pamela Moalli, Steven Abramowitch

Rouzbeh Amini

Exposure following pelvic organ prolapse repair has been observationally associated with wrinkling of the implanted mesh. The purpose of this study was to quantify the impact of variable boundary conditions on the out-of-plane deformations of mesh subjected to tensile loading. Using photogrammetry and surface curvature analyses, deformed geometries were accessed for two commercially available products. Relative to standard clamping methods, the amount of out-of-plane deformation significantly increased when point loads were introduced to simulate suture fixation in-vivo. These data support the hypothesis that regional increases in the concentration of mesh potentially enhance the host׳s foreign body response, leading to exposure.


Three-Dimensional Confocal Microscopy Indentation Method For Hydrogel Elasticity Measurement, Donghee Lee, Md Mahmudur Rahman, You Zhou, Sangjin Ryu Aug 2015

Three-Dimensional Confocal Microscopy Indentation Method For Hydrogel Elasticity Measurement, Donghee Lee, Md Mahmudur Rahman, You Zhou, Sangjin Ryu

Md Mahmudur Rahman

No abstract provided.


3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner Jul 2015

3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner

Richard A. Malthaner

The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the …


3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner Jul 2015

3d Thoracoscopic Ultrasound Volume Measurement Validation In An Ex Vivo And In Vivo Porcine Model Of Lung Tumours, V. Hornblower, E. Yu, A. Fenster, J. Battista, R. Malthaner

Richard A. Malthaner

The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the …


Netloc: Network Based Protein Localization Prediction Using Protein-Protein Interaction And Co-Expression Networks, A. Mondal, Jianjun Hu Jun 2015

Netloc: Network Based Protein Localization Prediction Using Protein-Protein Interaction And Co-Expression Networks, A. Mondal, Jianjun Hu

Jianjun Hu

No abstract provided.


Efficient Protein-Ligand Docking Using Sustainable Evolutionary Algorithms, E. Atilgan, Jianjun Hu Jun 2015

Efficient Protein-Ligand Docking Using Sustainable Evolutionary Algorithms, E. Atilgan, Jianjun Hu

Jianjun Hu

No abstract provided.


Dose-Responsive Gene Expression Changes In Juvenile And Adult Mummichogs (Fundulus Heteroclitus) After Arsenic Exposure, H. Gonzalez, Jianjun Hu, K. Gaworecki, J. Roling, W. Baldwin, J. Gardea-Torresdey, L. Bain Jun 2015

Dose-Responsive Gene Expression Changes In Juvenile And Adult Mummichogs (Fundulus Heteroclitus) After Arsenic Exposure, H. Gonzalez, Jianjun Hu, K. Gaworecki, J. Roling, W. Baldwin, J. Gardea-Torresdey, L. Bain

Jianjun Hu

No abstract provided.


Bayesian Classifier For Anchored Protein Sorting Discovery, F. Zhang, Jianjun Hu Jun 2015

Bayesian Classifier For Anchored Protein Sorting Discovery, F. Zhang, Jianjun Hu

Jianjun Hu

No abstract provided.


Wireless Access Point Configuration By Genetic Programming, Jianjun Hu, E. Goodman Jun 2015

Wireless Access Point Configuration By Genetic Programming, Jianjun Hu, E. Goodman

Jianjun Hu

No abstract provided.


Mutation Analysis Of Disease Causing Proteins, A. Mondai, Jianjun Hu Jun 2015

Mutation Analysis Of Disease Causing Proteins, A. Mondai, Jianjun Hu

Jianjun Hu

No abstract provided.


Review Of Emg-Based Speech Recognition, Amean Al_Safi, Liqaa Alhafadhi May 2015

Review Of Emg-Based Speech Recognition, Amean Al_Safi, Liqaa Alhafadhi

Amean S Al_Safi

This study represents a review of the main studies in EMG-based speech recognition. Its main goal is to support the researchers in the biomedical field with a survey of the solved and unsolved problem in the direction since it has received a great attention during last decade due to its promise applications such as underwater communication and silent speech recognition. Hence this study is a very good starting point for the researchers interested in this area of research