Biomedical Engineering and Bioengineering Commons^™

Collective Behaviour In Video Viewing: A Thermodynamic Analysis Of Gaze Position, Kate Burleson-Lesser, Flaviano Morone, Paul Deguzman, Lucas C. Parra, Hernan Makse

Publications and Research

Videos and commercials produced for large audiences can elicit mixed opinions. We wondered whether this diversity is also reflected in the way individuals watch the videos. To answer this question, we presented 65 commercials with high production value to 25 individuals while recording their eye movements, and asked them to provide preference ratings for each video. We find that gaze positions for the most popular videos are highly correlated. To explain the correlations of eye movements, we model them as ªinteractionsº between individuals. A thermodynamic analysis of these interactions shows that they approach a ªcritical º point such that any …

Electro-Chemotactic Fields Induce Cooperative Movement Of Cns Cells, Shawn Mishra, Stephen Redenti, Maribel Vazquez

Publications and Research

Vision loss in adults with Age Related Macular Degeneration (AMD) is attributed to damage of retinal photoreceptor cells that initiate vision by absorbing light. Mouse models have suggested that transplantation of precursor cells may be a novel approach to restore vision. This project uses a combination of electrotactic and chemotactic stimuli to promote and guide CNS cell migration within a microdevice model.

P2x7r-Panx1 Complex Impairs Bone Mechanosignaling Under High Glucose Levels Associated With Type-1 Diabetes, Zeynep Seref-Ferlengez, Stephanie Maung, Mitchell B. Schaffler, David C. Spray, Sylvia O. Suadicani, Mia M. Thi

Publications and Research

Type 1 diabetes (T1D) causes a range of skeletal problems, including reduced bone density and increased risk for bone fractures. However, mechanisms underlying skeletal complications in diabetes are still not well understood.We hypothesize that high glucose levels in T1D alters expression and function of purinergic receptors (P2Rs) and pannexin 1 (Panx1) channels, and thereby impairs ATP signaling that is essential for proper bone response to mechanical loading and maintenance of skeletal integrity. We first established a key role for P2X7 receptor-Panx1 in osteocyte mechanosignaling by showing that these proteins are co-expressed to provide a major pathway for flow-induced ATP release. …

Controlled Microfluidics To Examine Growth-Factor Induced Migration Of Neural Progenitors In The Drosophila Visual System, Cade Beck, Tanya Singh, Angela Farooqi, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

BACKGROUND:

The developing visual system in Drosophila melanogaster provides an excellent model with which to examine the effects of changing microenvironments on neural cell migration via microfluidics, because the combined experimental system enables direct genetic manipulation, in vivo observation, and in vitro imaging of cells, post-embryo. Exogenous signaling from ligands such as fibroblast growth factor (FGF) is well-known to control glia differentiation, cell migration, and axonal wrapping central to vision.

NEW METHOD:

The current study employs a microfluidic device to examine how controlled concentration gradient fields of FGF are able to regulate the migration of vision-critical glia cells with and …

Genesis And Growth Of Extracellular Vesicle-Derived Microcalcification In Atherosclerotic Plaques, Joshua D. Hutcheson, Claudia Goettsch, Sergio Bertazzo, Natalia Maldonado, Jessica L. Ruiz, Wilson Goh, Katsumi Yabusaki, Tyler Faits, Carlijn Bouten, Gregory Franck, Thibaut Quillard, Peter Libby, Masanori Aikawa, Sheldon Weinbaum, Elena Aikawa

Publications and Research

Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the …

Monitoring The Progression Of Spontaneous Articular Cartilage Healing With Infrared Spectroscopy, Megan P. O'Brien, Madhuri Penmatsa, Uday Palukuru, Paul West, Xu Yang, Mathias P. G. Bostrom, Theresa Freeman, Nancy Pleshko

Publications and Research

Objective. Evaluation of early compositional changes in healing articular cartilage is critical for understanding tissue repair and for therapeutic decision-making. Fourier transform infrared imaging spectroscopy (FT-IRIS) can be used to assess the molecular composition of harvested repair tissue. Furthermore, use of an infrared fiber-optic probe (IFOP) has the potential for translation to a clinical setting to provide molecular information in situ. In the current study, we determined the feasibility of IFOP assessment of cartilage repair tissue in a rabbit model, and assessed correlations with gold-standard histology.

Design. Bilateral osteochondral defects were generated in mature white New Zealand rabbits, and …

Role Of Epidermal Growth Factor-Triggered Pi3k/Akt Signaling In The Migration Of Medulloblastoma-Derived Cells, Veronica Dudu, Richard A. Able, Jr., Veronica Rotari, Qingjun Kong, Maribel Vazquez

Publications and Research

Medulloblastoma (MB) is the most common brain cancer diagnosed among children. The cellular pathways that regulate MB invasion in response to environmental cues remain incompletely understood. Herein, we examine the migratory response of human MB-derived Daoy cells to different concentration profiles of Epidermal Growth Factor (EGF) using a microfluidic system. Our findings provide the first quantitative evidence that EGF concentration gradients modulate the chemotaxis of MB-derived cells in a dose-dependent manner via the EGF receptor (EGF-R). Data illustrates that higher concentration gradients caused increased number of cells to migrate. In addition, our results show that EGF-induced receptor phosphorylation triggered the …

Computational Model Of Neuron-Astrocyte Interputational Model Of Neuron-Astrocyte Interactions During Focal Seizure Generationactions During Focal Seizure Generation, Davide Reato, Mario Cammarota, Lucas C. Parra, Giorgio Carmignoto

Publications and Research

Empirical research in the last decade revealed that astrocytes can respond to neurotransmitters with Ca2+ elevations and generate feedback signals to neurons which modulate synaptic transmission and neuronal excitability. This discovery changed our basic understanding of brain function and provided new perspectives for how astrocytes can participate not only to information processing, but also to the genesis of brain disorders, such as epilepsy. Epilepsy is a neurological disorder characterized by recurrent seizures that can arise focally at restricted areas and propagate throughout the brain. Studies in brain slice models suggest that astrocytes contribute to epileptiform activity by increasing neuronal excitability …

Sendai Virus-Based Liposomes Enable Targeted Cytosolic Delivery Of Nanoparticles In Brain Tumor-Derived Cells, Veronica Dudu, Veronica Rotari, Maribel Vazquez

Publications and Research

BACKGROUND: Nanotechnology-based bioassays that detect the presence and/or absence of a combination of cell markers are increasingly used to identify stem or progenitor cells, assess cell heterogeneity, and evaluate tumor malignancy and/or chemoresistance. Delivery methods that enable nanoparticles to rapidly detect emerging, intracellular markers within cell clusters of biopsies will greatly aid in tumor characterization, analysis of functional state and development of treatment regimens.

RESULTS: Experiments utilized the Sendai virus to achieve in vitro, cytosolic delivery of Quantum dots in cells cultured from Human brain tumors. Using fluorescence microscopy and Transmission Electron Microscopy, in vitro experiments illustrated that these virus-based …

Migration And Invasion Of Brain Tumors, Richard A. Able, Jr., Veronica Dudu, Maribel Vazquez

Publications and Research

Recent advances in molecular biology have led to new insights in the development, growth and infiltrative behaviors of primary brain tumors (Demuth and Berens, 2004; Huse and Holland, 2010; Johnson et al., 2009; Kanu et al., 2009). These tumors are derived from various brain cell lineages and have been historically classified on the basis of morphological and, more recently, immunohistochemical features with less emphasis on their underlying molecular pathogenesis (Huse and Holland, 2010). The detailed molecular characterization of brain tumors has laid the groundwork for augmentation of standard treatment with patient-specific designed targeted therapies (Johnson et al., 2009; Kanu et …

Low Concentration Microenvironments Enhance The Migration Of Neonatal Cells Of Glial Lineage, Richard A. Able, Jr., Celestin Ngnabeuye, Cade Beck, Eric C. Holland, Maribel Vazquez

Publications and Research

Glial tumors have demonstrated abilities to sustain growth via recruitment of glial progenitor cells (GPCs), which is believed to be driven by chemotactic cues. Previous studies have illustrated that mouse GPCs of different genetic backgrounds are able to replicate the dispersion pattern seen in the human disease. How GPCs with genetic backgrounds transformed by tumor paracrine signaling respond to extracellular cues via migration is largely unexplored, and remains a limiting factor in utilizing GPCs as therapeutic targets. In this study, we utilized a microfluidic device to examine the chemotaxis of three genetically-altered mouse GPC populations towards tumor conditioned media, as …