Biomedical Engineering and Bioengineering Commons^™

An Injectable, Calcium Responsive Composite Hydrogel For The Treatment Of Acute Spinal Cord Injury, Christopher A. Mckay, Rebecca D. Pomrenke, Joshua S. Mclane, Nicholas J. Schaub, Elise K. Desimone, Lee A. Ligon, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Immediately following spinal cord injury, further injury can occur through several secondary injury cascades. As a consequence of cell lysis, an increase in extracellular Ca²⁺ results in additional neuronal loss by inducing apoptosis. Thus, hydrogels that reduce extracellular Ca²⁺ concentration may reduce secondary injury severity. The goal of this study was to develop composite hydrogels consisting of alginate, chitosan, and genipin that interact with extracellular Ca²⁺ to enable in situ gelation while maintaining an elastic modulus similar to native spinal cord (∼1000 Pa). It was hypothesized that incorporation of genipin and chitosan would regulate hydrogel electrostatic characteristics …

Enhanced Glt-1 Mediated Glutamate Uptake And Migration Of Primary Astrocytes Directed By Fibronectin-Coated Electrospun Poly-L-Lactic Acid Fibers, Jonathan M. Zuidema, María C. Hyzinski-García, Kristien Van Vlasselaer, Nicholas W. Zaccor, George E. Plopper, Alexander A. Mongin, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioengineered fiber substrates are increasingly studied as a means to promote regeneration and remodeling in the injured central nervous system (CNS). Previous reports largely focused on the ability of oriented scaffolds to bridge injured regions and direct outgrowth of axonal projections. In the present work, we explored the effects of electro spun microfibers on the migration and physiological properties of brain astroglial cells. Primary rat astrocytes were cultured on either fibronectin-coated poly-l-lactic acid (PLLA) films, fibronectin-coated randomly oriented PLLA electro spun fibers, or fibronectin-coated aligned PLLA electro spun fibers. Aligned PLLA fibers strongly altered astrocytic morphology, orienting cell processes, actin …

A Lensing Effect Of Inner Retinal Cysts On Images Of The Photoreceptor Mosaic, Christopher S. Langlo, John A. Flatter, Alfredo Dubra, William J. Wirostko, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Modulation Of Leukocyte Infiltration And Phenotype In Microporous Tissue Engineering Scaffolds Via Vector Induced Il-10 Expression, R. Michael Gower, Ryan M. Boehler, Samira M. Azarin, Christine F. Ricci, Joshua N. Leonard, Lonnie D. Shea

Faculty Publications

Biomaterial scaffolds are central to many tissue engineering strategies as they create a space for tissue growth and provide a support for cell adhesion and migration. However, biomaterial implantation results in unavoidable injury resulting in an inflammatory response, which can impair integration with the host and tissue regeneration. Toward the goal of reducing inflammation, we investigated the hypothesis that a lentiviral gene therapy-based approach to localized and sustained IL-10 expression at a scaffold could modulate the number, relative proportions, and cytokine production of infiltrating leukocyte populations. Flow cytometry was used to quantify infiltration of six leukocyte populations for 21 days …

Utilizing Fast Spin Echo Mri To Reduce Image Artifacts And Improve Implant/Tissue Interface Detection In Refractory Parkinson’S Patients With Deep Brain Stimulators, Subhendra N. Sarkar, Pooja R. Sarkar, Efstathios Papavassiliou, Rafael Rojas

Publications and Research

Introduction. In medically refractory Parkinson’s disease (PD) deep-brain stimulation (DBS) is an effective therapeutic tool. Postimplantation MRI is important in assessing tissue damage and DBS lead placement accuracy. We wanted to identify which MRI sequence can detectDBS leads with smallest artifactual signal void, allowing better tissue/electrode edge conspicuity.

Methods. Using an IRB approved protocol 8 advanced PDpatientswere imagedwithinMRconditional safety guidelines at lowRF power (SAR ≤ 0.1 W/kg) in coronal plane at 1.5T by various sequences.The image slices were subjectively evaluated for diagnostic quality and the lead contact diameters were compared to identify a sequence least affected by metallic leads.

Results …

Design Of Controlled Environment For Tissue Engineering, Malcolm Gerald Lapera

Master's Theses

Design of Controlled Environment for Tissue Engineering

Malcolm Lapera

Tissue engineering aims at relieving the need for donor tissue and organs by developing a process of creating viable tissues in the laboratory setting. With over 120,000 people awaiting a transplant, the need for generating tissue engineered organs is very large [3]. In order for organs to be engineered, a few issues need to be overcome. A work space that both creates an environment which maintains cell viability over an extended period of time as well as accommodates the necessary fabrication equipment will be needed to further tissue engineering research. Therefore, …

Rate Alterable Traumatic Brain Injury Device For Rodent Models, Radia Abdul Wahab

Dissertations

Traumatic Brain Injury (TBI) is a physical impact to the head resulting in functional deficits in memory and motor systems. TBI is a prevalent problem occurring in 1.7 million people annually in the United States (Faul et al. 2010). TBIs can differ greatly in terms of the biomechanics of the impact such as magnitude, direction and rate. Indeed, it is likely that the wide range of TBI outcomes may be due to the physical characteristics of the trauma. Studies to date on impact have used injury devices with limited alterable parameters. Therefore, the existing impact studies have considered the effect …

The Effect Of Mechanical Vestibular Stimulation On Muscle Tone And Spasticity In Individuals With Neurological Impairment, Ghaith J. Androwis

Dissertations

In the desire to better understand spasticity mainly in Cerebral Palsy (CP) and to examine vestibular stimulation as a future intervention for .muscle tone reduction, and to be able to describe the change in level of spasticity in subjects with disability and describe interventions effects, a series of experiments are done on children with spasticity. In addition to understanding the otoliths in the vestibular system and their projections, properties and pathways a more important major objective of this work is to validate the changes in otoliths signal caused by vestibular stimulation based on the Equilibrium Point Hypothesis and the inclusion …

Construction And Assessment Of A Computer Graphics-Based Model For Wheelchair Propulsion, Brooke Marie Odle

Dissertations

Upper limb overuse injuries are common in manual wheelchair using persons with spinal cord injury (SCI), especially those with tetraplegia. Biomechanical analyses involving kinetics, kinematics, and muscle mechanics provide an opportunity to identify modifiable risk factors associated with wheelchair propulsion and upper limb overuse injuries that may be used toward developing prevention and treatment interventions. However, these analyses are limited because they cannot estimate muscle forces in vivo. Patient-specific computer graphics-based models have enhanced biomechanical analyses by determining in vivo estimates of shoulder muscle and joint contact forces. Current models do not include deep shoulder muscles. Also, patient-specific models …

In Vitro Modeling And Analysis Of Axon Stretch Growth For The Sustained Growth Of Long Nerve Fibers, Joseph Rocco Loverde

Dissertations

The integration of long nerve fibers throughout the body is distinctive among somatic tissues. Single, individual motor neurons grow to a meter in length or more as they maintain connectivity with sacral areas of the spinal cord from the brain. Similarly, homologous growth also occurs via spinal ganglion neurons within the peripheral nervous system. The most widely studied aspect of nerve development has been the migration and extension of growth cones towards synaptic targets during early development. However, following growth cone extension, axonal fibers continue to grow in synchrony with the expansion of limbs and mit otic tissues throughout childhood …

Mathematically Modeling The Mechanical Constants Of Thoracolumbar Fascia Under Compression, In Vivo, Vrajeshri Patel

Theses

The thoracolumbar fascia (TLF) is a complex structure made of many interconnecting aponeurosis and muscle fascia. It plays a role in posture, stabilizing the lumbosacral spine, load transfer, and respiration. Its complex structure and connections have mostly been observed through cadaveric studies while its mechanical properties have been addressed in only a few studies. Recently, new advances in ultrasound imaging have made it possible to move towards measuring tissue strain. Since this is an in vivo method, mechanical data of tissues in their natural environment allows a more accurate representation of tissue strain. However, many different methods of analyzing ultrasound …

Differentiating Schizophrenic Patients From Healthy Control; Application Of Machine Learning To Resting State Fmri, Hossein Ebrahimi Nezhad

Theses

In recent years, one analysis approach that has grown in popularity is the use of machine learning algorithms to train classifiers to decode stimuli, mental states, behaviors and other variables of interest from fMRI data. Most of these studies focus on fMRI low frequency oscillations. This study focuses on the amplitude of low-frequency fluctuations (ALFF) and fractional amplitude of low-frequency fluctuations (fALFF). A Voxel-wise analysis is performed on the whole brain for two groups of subjects. A machine learning algorithm is applied to two independent groups of subjects (a total of 160 healthy control and schizophrenic subjects) to classify Schizophrenia …

Developing A Labview Based Thermally Stimulated Current (Tsc) Controller To Measure Residual Charge In Electrospinning, Jai Abhishekh Veezhinathan

Theses

Electrospinning is an electrohydrodynamic process for the fabrication of nanofibers which are widely used in therapeutical tissue engineering approaches. It utilizes the potential difference of an electrostatic field to overcome the surface tension of the polymer solution to extrude a fine jet of fluid which deposits on the grounded collector as a nanofiber mat. Using this process, nanofibers with diameters less than a micron can be produced.

Previous studies have shown the presence of residual charge in electrospun nanofibers. The presence and decay of residual charge during cell culture media is still unknown. In an attempt to clarify the presence …

Using The Piezoelectric Backscatter Signal For Remote Sensing Of Neural Signals, Eren Alay

Theses

In recent studies, various methods to sense neural signals are used and new methods for remote sensing of neural signals are being developed. However, there are still major difficulties in building long-term implantable neural interface systems that can reliably record neural activity and serve as the basis of brain-machine interfaces (BMI). Therefore, this research is conducted to design a remote neural sensing system that is based on modulation of the backscatter signal from a piezoelectric element by the neural signals. The hypothesis is that if the neural signal is detected with a simple amplifier and the output of this amplifier …

Advances In Optics For Biotechnology, Medicine And Surgery, Maryann Fitzmaurice, Brian W. Pogue, Guillermo J. Tearney, James W. Tunnell

Dartmouth Scholarship

The guest editors introduce a Biomedical Optics Express feature issue that includes contributions from participants at the 2013 conference on Advances in Optics for Biotechnology, Medicine and Surgery XIII.

A Glycosaminoglycan Based, Modular Tissue Scaffold System For Rapid Assembly Of Perfusable, High Cell Density, Engineered Tissues, Ramkumar Tiruvannamalai-Annamalai, David Randall Armant, Howard W. T Matthew

Biomedical Engineering Faculty Research Publications

The limited ability to vascularize and perfuse thick, cell-laden tissue constructs has hindered efforts to engineer complex tissues and organs, including liver, heart and kidney. The emerging field of modular tissue engineering aims to address this limitation by fabricating constructs from the bottom up, with the objective of recreating native tissue architecture and promoting extensive vascularization. In this paper, we report the elements of a simple yet efficient method for fabricating vascularized tissue constructs by fusing biodegradable microcapsules with tunable interior environments. Parenchymal cells of various types, (i.e. trophoblasts, vascular smooth muscle cells, hepatocytes) were suspended in glycosaminoglycan (GAG) solutions …

An Imaging-Based Platform For High-Content, Quantitative Evaluation Of Therapeutic Response In 3d Tumour Models, Jonathan P. Celli, Imran Rizvi, Adam R. Blanden, Iqbal Massodi, Iqbal Massodi, Michael D. Glidden, Brian Pogue, Tayyaba Hasan

Dartmouth Scholarship

While it is increasingly recognized that three-dimensional (3D) cell culture models recapitulate drug responses of human cancers with more fidelity than monolayer cultures, a lack of quantitative analysis methods limit their implementation for reliable and routine assessment of emerging therapies. Here, we introduce an approach based on computational analysis of fluorescence image data to provide high-content readouts of dose-dependent cytotoxicity, growth inhibition, treatment-induced architectural changes and size-dependent response in 3D tumour models. We demonstrate this approach in adherent 3D ovarian and pancreatic multiwell extracellular matrix tumour overlays subjected to a panel of clinically relevant cytotoxic modalities and appropriately designed controls …

High Resolution Cine Displacement Encoding With Stimulated Echoes (Dense) At 3t With Navigator Feedback For Quantification Of Cardiac Mechanics, Gregory J. Wehner, Jonathan D. Suever, Christopher M. Haggerty, Linyuan Jing, David Powell, Xiaodong Zhong, Frederick H. Epstein, Brandon K. Fornwalt

Biomedical Engineering Presentations

Background: Measures of cardiac mechanics such as myocardial wall strain are better predictors of outcomes in patients with heart disease compared to traditional clinical measures and ejection fraction. Cine displacement encoding with stimulated echoes (DENSE) is an ideal method for quantifying cardiac motion which encodes tissue displacement in the phase of the MR signal and provides pixel-level resolution for quantifying cardiac mechanics. To date, DENSE has been implemented with resolution limited to 2-3 pixels across the myocardium. While this resolution is higher than most other techniques for quantifying cardiac mechanics, it may limit the ability of DENSE to quantify finer …

Ranbp9 Overexpression Accelerates Loss Of Pre And Postsynaptic Proteins In The Apδe9 Transgenic Mouse Brain, Hongjie Wang, Ruizhi Wang, Shaohua Xu, Madepalli Krishnappa Lakshmana

Biomedical Engineering and Sciences Faculty Publications

There is now compelling evidence that the neurodegenerative process in Alzheimer's disease (AD) begins in synapses. Loss of synaptic proteins and functional synapses in the amyloid precursor protein (APP) transgenic mouse models of AD is well established. However, what is the earliest age at which such loss of synapses occurs, and whether known markers of AD progression accelerate functional deficits is completely unknown. We previously showed that RanBP9 overexpression leads to robustly increased amyloid β peptide (Aβ) generation leading to enhanced amyloid plaque burden in a mouse model of AD. In this study we compared synaptic protein levels among four …

Quantification Of Transhumeral Prosthetic Socket Residual Limb Interface Movement Using Motion Capture And A Slip Detection Sensor, Matthew Wernke

USF Tampa Graduate Theses and Dissertations

Current literature focusing on the prosthetic socket is limited by measurement techniques and modeling assumptions, leading to a limited understanding of the forces and motions occurring between the residual limb and prosthesis and how they can be used to influence socket design and fitting. Prosthetic socket fitting and prescription would benefit from an elegant method for comparing socket designs. This dissertation focuses on the development and implementation of a 3D motion capture model and a Slip Detection Sensor to quantify rotations and translations at the prosthetic socket-residual limb interface. The 3D motion capture model defines the residual limb bone position …