Biomedical Engineering and Bioengineering Commons^™

Interaction Between The Stress Phase Angle (Spa) And The Oscillatory Shear Index (Osi) Affects Endothelial Cell Gene Expression, Ronny Amaya, Limary M. Cancel, John M. Tarbell

Publications and Research

Hemodynamic forces play an important role in the non-uniform distribution of atherosclerotic lesions. Endothelial cells are exposed simultaneously to fluid wall shear stress (WSS) and solid circumferential stress (CS). Due to variations in impedance (global factors) and geometric complexities (local factors) in the arterial circulation a time lag arises between these two forces that can be characterized by the temporal phase angle between CS and WSS (stress phase angle±SPA). Asynchronous flows (SPA close to -180Ê) that are most prominent in coronary arteries have been associated with localization of atherosclerosis. Reversing oscillatory flows characterized by an oscillatory shear index (OSI) that …

The Effects Of Compensatory Auditory Stimulation And High-Definition Transcranial Direct Current Stimulation (Hd-Tdcs) On Tinnitus Perception - A Randomized Pilot Study, Simon Henin, Dovid Fein, Eric Smouha, Lucas C. Parra

Publications and Research

Background Tinnitus correlates with elevated hearing thresholds and reduced cochlear compression. We hypothesized that reduced peripheral input leads to elevated neuronal gain resulting in the perception of a phantom sound. Objective The purpose of this pilot study was to test whether compensating for this peripheral deficit could reduce the tinnitus percept acutely using customized auditory stimulation. To further enhance the effects of auditory stimulation, this intervention was paired with high-definition transcranial direct current stimulation (HD-tDCS).

Methods A randomized sham-controlled, single blind study was conducted in a clinical setting on adult participants with chronic tinnitus (n = 14). Compensatory auditory stimulation …

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.

Mechanotransduction Modulates The Effect Of Mechanical Forces (Fluid Shear Stress And Cyclic Strain) On Embryonic Stem Cell Differentiation Toward Vascular Endothelial Cells, Maria Nikmanesh

Dissertations, Theses, and Capstone Projects

The isolation of human ES cells (hES) in 1998 remarkably elevated the interest in the cell therapy capability of ES cells and moved this concept one step closer to reality. Embryonic stem cells with their potential for both self-renewal and directed differentiation have received increasing attention in applications in tissue engineering and repair, cell therapy, and regenerative medicine.

The differentiation of embryonic stem cells into desired lineages depends on the chemical environment of the “niche”, and for certain lineages such as the vascular lineage that must function in a mechanical environment, the timely imposition of mechanical forces is critical. In …

Engineering And Perception, Maribel Vazquez

Open Educational Resources

An introductory seminar to High School and Freshman-Level Undergraduates that describes how several Biomedical Engineering innovations have been motivated by our senses of sight, sound, smell, taste and touch.

Microfluidic Devices In Biotechnology, Maribel Vazquez

Open Educational Resources

This lecture/laboratory course focuses on the fundamentals of modern microfluidic devices with applications to biomedical measurements. Students will review fundamental properties of microfluidic systems including the effects of viscous flow, heat transfer, and electromagnetic phenomena on biological systems. Multiple laboratory modules will expose students to photolithographic and surface treatment techniques required for device development. An end of term project will require students to analyze designs of upcoming biomedical inventions and present their critiques via written report and oral presentation.

Cuny Summer Stem Institute: Experimental Research In Engineering For High School Students, Maribel Vazquez

Open Educational Resources

Summer HS students were engaged in hands-on experimental research in engineering laboratories in mentorship with CCNY Engineering Undergraduate Researchers. This course was part of the Summer STEM Institute directed by Dr. Joe Barba and Mr. Otto Marte.

Kcnq Channel Openers Reverse Depressive Symptoms Via An Active Resilience Mechanism, Allyson K. Friedman, Barbara Juarez, Stacy M. Ku, Hongxing Zhang, Rhodora C. Calizo, Jessica J. Walsh, Depish Chaudhury, Song Zhang, Angel Hawkins, David M. Dietz, James W. Murrogh, Maria Ribadeneira, Erik H. Wong, Rachael L. Neve, Ming-Hu Han

Publications and Research

Less than half of patients suffering from major depressive disorder, a leading cause of disability worldwide, achieve remission with current antidepressants, making it imperative to develop more effective treatment. A new therapeutic direction is emerging from the increased understanding of natural resilience as an active stress-coping process. It is known that potassium (Kþ) channels in the ventral tegmental area (VTA) are an active mediator of resilience. However, no druggable targets have been identified to potentiate active resilience mechanisms. In the chronic social defeat stress model of depression, we report that KCNQ-type Kþ channel openers, including FDA-approved drug retigabine (ezogabine), show …

Mesenchymal Stem Cell Fate: Applying Biomaterials For Control Of Stem Cell Behavior, Hilary J. Anderson, Jugal Kishore Sahoo, Rein V. Ulijn, Matthew J. Dalby

Publications and Research

The materials pipeline for biomaterials and tissue engineering applications is under continuous development. Specifically, there is great interest in the use of designed materials in the stem cell arena as materials can be used to manipulate the cells providing control of behavior. This is important as the ability to “engineer” complexity and subsequent in vitro growth of tissues and organs is a key objective for tissue engineers. This review will describe the nature of the materials strategies, both static and dynamic, and their influence specifically on mesenchymal stem cell fate.

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 …

Predicted Molecular Signaling Guiding Photoreceptor Cell Migration Following Transplantation Into Damaged Retina, Uchenna John Unachukwu, Alice Warren, Ze Li, Shawn Mishra, Jing Zhou, Moira Sauane, Hyungsik Lim, Maribel Vazquez, Stephen Redenti

Publications and Research

To replace photoreceptors lost to disease or trauma and restore vision, laboratories around the world are investigating photoreceptor replacement strategies using subretinal transplantation of photoreceptor precursor cells (PPCs) and retinal progenitor cells (RPCs). Significant obstacles to advancement of photoreceptor cell-replacement include low migration rates of transplanted cells into host retina and an absence of data describing chemotactic signaling guiding migration of transplanted cells in the damaged retinal microenvironment. To elucidate chemotactic signaling guiding transplanted cell migration, bioinformatics modeling of PPC transplantation into light-damaged retina was performed. The bioinformatics modeling analyzed whole-genome expression data and matched PPC chemotactic cell-surface receptors to …

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 …

Introduction To Biomedical Engineering, Maribel Vazquez

Open Educational Resources

An overview of the field of biomedical engineering designed to acquaint the students with its interdisciplinary nature; research areas presented by the biomedical engineering faculty.

Effect Of Temporal Onset Of Mechanical Loading On Tendon To Bone Healing, Determined With A Novel In-Vivo Device, Mark E. Stasiak

Dissertations, Theses, and Capstone Projects

Background: Exposure to tensile loading has been shown to maintain tendon/ligament homeostasis, with the tensile modulus of the tissue increasing in response to greater loading frequency, and even decreasing in the absence of load. However after injury or surgical repair the effect of tensile load is controversial, with many studies implicating mechanical loading with impaired healing. It is currently unknown when the tensile loading imparted during rehabilitation exercise, can be safely reintroduced after surgical tendon repair or ligament reconstruction, and at what time point it can most benefit the remodeling process. To investigate the effect of tensile loading protocols on …

In Vitro Formation Of Neuroclusters In Microfluidic Devices And Cell Migration As A Function Of Stromal-Derived Growth Factor 1 Gradients, Sean Mccutcheon, Uchenna Unachukwu, Ankush Thakur, Robert Majeska, Stephen Redenti, Maribel Vazquez

Publications and Research

Central nervous system (CNS) cells cultured in vitro as neuroclusters are useful models of tissue regeneration and disease progression. However, the role of cluster formation and collective migration of these neuroclusters to external stimuli has been largely unstudied in vitro. Here, 3 distinct CNS cell types, medulloblastoma (MB), medulloblastoma-derived glial progenitor cells (MGPC), and retinal progenitor cells (RPC), were examined with respect to cluster formation and migration in response to Stromal-Derived Growth Factor (SDF-1). A microfluidic platform was used to distinguish collective migration of neuroclusters from that of individual cells in response to controlled concentration profiles of SDF-1. Cell …

Ultrahigh Field Magnetic Resonance Imaging – Technical Development And Translational Applications, Judy Alper

Dissertations and Theses

Magnetic resonance imaging (MRI) may be used to provide detailed images of the human body with excellent soft tissue contrast. Alongside its current widespread clinical applications for diagnosis and treatment, MRI allows researchers to measure structure and function of different tissue types in order to advance our understanding of human biology and enable new medical applications of MRI. In particular, diseases affecting nerves and vessels, such as trigeminal neuralgia, with uncertain etiology can be studied using multiple MRI modalities so that treatment planning can we more effective and patient outcomes can be improved. Ultrahigh field MRI scanners, such as those …

Direct Current Stimulation Modulates Ltp And Ltd: Activity-Dependence And Dendritic Effects, Gregory Kronberg

Dissertations and Theses

Transcranial direct current stimulation (tDCS) has been reported to improve various forms of learning in humans. Stimulation is often applied during training, producing lasting enhancements that are specific to the learned task. These learning effects are thought be mediated by altered synaptic plasticity. However, the effects of DCS during the induction of endogenous synaptic plasticity remain largely unexplored. To model endogenous plasticity I induced long-term potentiation (LTP) and depression (LTD) at Schaffer collateral synapses in CA1 of rat hippocampal slices. When induction was paired with concurrent DCS, the resulting plasticity was biased towards potentiation, such that LTP was enhanced and …