Biomedical Engineering and Bioengineering Commons^™

Critical Changes In Cortical Neuronal Interactions In Anesthetized And Awake Rats, Anthony G. Hudetz, Jeannette A. Vizuete, Siveshigan Pillay, Kristina M. Ropella

Biomedical Engineering Faculty Research and Publications

Background: Neuronal interactions are fundamental for information processing, cognition, and consciousness. Anesthetics reduce spontaneous cortical activity; however, neuronal reactivity to sensory stimuli is often preserved or augmented. How sensory stimulus–related neuronal interactions change under anesthesia has not been elucidated. In this study, the authors investigated the visual stimulus–related cortical neuronal interactions during stepwise emergence from desflurane anesthesia.

Methods: Parallel spike trains were recorded with 64-contact extracellular microelectrode arrays from the primary visual cortex of chronically instrumented, unrestrained rats (N = 6) at 8, 6, 4, and 2% desflurane anesthesia and wakefulness. Light flashes were delivered to the retina …

Guest Editorial: The 2014 Capstone Design Conference, Steven Beyerlein, Jay R. Goldberg, Susannah Howe, Scott Palo, Renee Rogge, R. Keith Stanfill

Biomedical Engineering Faculty Research and Publications

The goal of the 2014 Capstone Design Conference held in Columbus, OH was to build upon the success of three previous conferences (2007 and 2010 in Boulder, CO, and 2012 in Champaign, IL) and expand the community of educators, students, and industry members engaged in discussing, analyzing, and improving capstone design education. Sessions at the 2014 Capstone Design Conference were designed for vibrant sharing of ideas and experiences across the capstone community via interactive panel sessions, poster session socials, and hands-on workshops. This editorial discusses conference planning, structure, and feedback. Technical papers that follow in this issue document scholarship surrounding …

Automating The Process Of Fabricating Uniform-Sized Cell Spheroids For Three-Dimensional Bioprinting, Ganesh Sosale

Theses and Dissertations

Although researchers have been able to print small, simple, and avascular tissues, they have been unsuccessful in creating large, complex and vascularized organs. Printing large and complex three-dimensional tissues or organs involves utilizing a large quantity of cellular spheroids and layer-by-layer addition of spheroids. In this study, an in-house cell spheroid fabrication system was developed to produce cell spheroids with human liver cells (hepG2), human endothelial cells (hEC), human neural stem cells (hNSC), and induced pluripotent stem cells (iPSC). It offers the ability of fabricating uniform-sized spheroids repeatedly, which is essential when large and complex structures need to be produced. …

Multi-Platform Arabinoxylan Scaffolds As Potential Wound Dressing Materials, Donald C. Aduba Jr

Theses and Dissertations

Biopolymers are becoming more attractive as advanced wound dressings because of their naturally derived origin, abundance, low cost and high compatibility with the wound environment. Arabinoxylan (AX) is a class of polysaccharide polymers derived from cereal grains that are primarily used in food products and cosmetic additives. Its application as a wound dressing material has yet to be realized. In this two-pronged project, arabinoxylan ferulate (AXF) was fabricated into electrospun fibers and gel foams to be evaluated as platforms for wound dressing materials. In the first study, AXF was electrospun with varying amounts of gelatin. In the second study, AXF …

Generation And Delivery Of Charged Aerosols To Infant Airways, Landon T. Holbrook

Theses and Dissertations

The administration of pharmaceutical aerosols to infants on mechanical ventilation needs to be improved by increasing the efficiency of delivery devices and creating better ways of evaluating potential therapies. Aerosolized medicines such as surfactants have been administered to ventilated infants with mixed results, but studies have shown improvement in respiratory function with a much lower dose than with liquid instillation through an endotracheal tube (ETT). An aerosolized medicine must be transported through the ventilation tubing and deposit in the lungs to have the desired therapeutic response.

This work has taken a systematic approach to (i) develop new devices for the …

Computational Modeling To Assess Surgical Procedures For The Treatment Of Adult Acquired Flatfoot Deformity, Brian A. Smith

Theses and Dissertations

Several surgically corrective procedures are considered to treat Adult Acquired Flatfoot Deformity (AAFD) patients, relieve pain, and restore function. Procedure selection is based on best practices and surgeon preference. Recent research created patient specific models of Adult Acquired Flatfoot Deformity (AAFD) to explore their predictive capabilities and examine effectiveness of the surgical procedure used to treat the deformity. The models’ behavior was governed solely by patient bodyweight, soft tissue constraints, and joint contact without the assumption of idealized joints. The current work expanded those models to determine if an alternate procedure would be more effective for the individual. These procedures …

The Effects Of Fatigue On Lower Extremity Kinetics And Kinematics In Subjects With Known Ankle Instability, Lindsay E. Clayton

Theses and Dissertations

The goal of this study was to evaluate biomechanical differences between healthy subjects and those with ankle instability during the gradual onset of lower extremity fatigue from a landing activity. An understanding of these differences is needed in order to prevent future injury to or further debilitation in individuals with ankle instability. A functional fatiguing activity was designed to focus fatigue on the quadriceps muscles, as those are the muscles most frequently fatigued during sport. Measures were taken throughout the progression of fatigue with a force plate and a motion tracking system and included vertical ground reaction force and lower …

Peracetic Acid Sterilization Of Electrospun Polycaprolactone Scaffolds, Suyog Yoganarasimha

Theses and Dissertations

Sterilization of tissue engineered scaffolds is an important regulatory issue and is at the heart of patient safety. With the introduction of new biomaterials and micro/nano structured scaffolds, it is critical that the mode of sterilization preserve these built-in features. Conventional sterilization methods are not optimal for engineered polymeric systems and hence alternate systems need to be identified and validated. PCL is polyester with a low melting point (heat labile), susceptible to hydrolysis and is popular in tissue engineering. Electrospinning generates some nanoscale features within the scaffold, the integrity of which can be affected by sterilization method. Chapter 1 explores …

Peracetic Acid: A Practical Agent For Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds, William R. Trahan

Theses and Dissertations

Advanced biomaterials and sophisticated processing technologies aim to fabricate tissue-engineering scaffolds that can predictably interact within a biological environment at a cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed prior to clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone (PCL), a low melting polymer, and …

Modification And Evaluation Of A Brain Computer Interface System To Detect Motor Intention, Christopher V. Hagerty-Hoff

Theses and Dissertations

It is widely understood that neurons within the brain produce electrical activity, and electroencephalography—a technique used to measure biopotentials with electrodes placed upon the scalp—has been used to observe it. Today, scientists and engineers work to interface these electrical neural signals with computers and machines through the field of Brain-Computer Interfacing (BCI). BCI systems have the potential to greatly improve the quality of life of physically handicapped individuals by replacing or assisting missing or debilitated motor functions. This research thus aims to further improve the efficacy of the BCI based assistive technologies used to aid physically disabled individuals. This study …

Femtosecond Laser Beam Propagation Through Corneal Tissue: Evaluation Of Therapeutic Laser-Stimulated Second And Third-Harmonic Generation, William R. Calhoun Iii

Theses and Dissertations

One of the most recent advancements in laser technology is the development of ultrashort pulsed femtosecond lasers (FSLs). FSLs are improving many fields due to their unique extreme precision, low energy and ablation characteristics. In the area of laser medicine, ophthalmic surgeries have seen very promising developments. Some of the most commonly performed surgical operations in the world, including laser-assisted in-situ keratomileusis (LASIK), lens replacement (cataract surgery), and keratoplasty (cornea transplant), now employ FSLs for their unique abilities that lead to improved clinical outcome and patient satisfaction.

The application of FSLs in medical therapeutics is a recent development, and although …

Engineering Of Polyamidoamine Dendrimers For Cancer Therapy, Leyuan Xu

Theses and Dissertations

Dendrimers are a class of polymers with a highly branched, three-dimensional architecture comprised of an initiator core, several interior layers of repeating units, and multiple active surface terminal groups. Dendrimers have been recognized as the most versatile compositionally and structurally controlled nanoscale building blocks for drug and gene delivery. Polyamidoamine (PAMAM) dendrimers have been most investigated because of their unique structures and properties. Polycationic PAMAM dendrimers form compacted polyplexes with nucleic acids at physiological pH, holding great potential for gene delivery.

Folate receptor (FRα) is expressed at very low levels in normal tissues but expressed at high levels in cancers …

Polysaccharide-Based Shear Thinning Hydrogels For Three-Dimensional Cell Culture, Vasudha Surampudi

Theses and Dissertations

The recreation of the complicated tissue microenvironment is essential to reduce the gap between in vitro and in vivo research. Polysaccharide-based hydrogels form excellent scaffolds to allow for three-dimensional cell culture owing to the favorable properties such as capability to absorb large amount of water when immersed in biological fluids, ability to form “smart hydrogels” by being shear-thinning and thixotropic, and eliciting minimum immunological response from the host. In this study, the biodegradable shear-thinning polysaccharide, gellan-gum based hydrogel was investigated for the conditions and concentrations in which it can be applied for the adhesion, propagation and assembly of different mammalian …

Application And Histology-Driven Refinement Of Active Contour Models To Functional Region And Nerve Delineation: Towards A Digital Brainstem Atlas, Nimal Patel, Sharmin Sultana, Tanweer Rashid, Dean Krusienski, Michel A. Audette

Electrical & Computer Engineering Faculty Publications

This paper presents a methodology for the digital formatting of a printed atlas of the brainstem and the delineation of cranial nerves from this digital atlas. It also describes on-going work on the 3D resampling and refinement of the 2D functional regions and nerve contours. In MRI-based anatomical modeling for neurosurgery planning and simulation, the complexity of the functional anatomy entails a digital atlas approach, rather than less descriptive voxel or surface-based approaches. However, there is an insufficiency of descriptive digital atlases, in particular of the brainstem. Our approach proceeds from a series of numbered, contour-based sketches coinciding with slices …

Large-Scale Spatiotemporal Spike Patterning Consistent With Wave Propagation In Motor Cortex, Kazutaka Takahashi, Sanggyun Kim, Todd P. Coleman, Kevin A. Brown, Aaron J. Suminski, Matthew D. Best, Nicholas G. Hatsopoulos

Biomedical Engineering Faculty Research and Publications

Aggregate signals in cortex are known to be spatiotemporally organized as propagating waves across the cortical surface, but it remains unclear whether the same is true for spiking activity in individual neurons. Furthermore, the functional interactions between cortical neurons are well documented but their spatial arrangement on the cortical surface has been largely ignored. Here we use a functional network analysis to demonstrate that a subset of motor cortical neurons in non-human primates spatially coordinate their spiking activity in a manner that closely matches wave propagation measured in the beta oscillatory band of the local field potential. We also demonstrate …

Virtual Capstone Design Teams: Preparing For Global Innovation (Journal Article), Jay R. Goldberg, Susannah Howe

Biomedical Engineering Faculty Research and Publications

Global innovation requires collaboration between groups of people located in different parts of the world, and is a growing trend in industry. Virtual teams are often used to manage new product development projects. These teams are similar to traditional teams but are geographically separated and rely heavily on virtual methods of communication (email, Skype, teleconferencing, etc.) instead of regular face-to-face meetings. Experience working as a member of a virtual capstone design team can help prepare students for this growing trend. To begin preparing students for work on virtual teams in industry, we co-advised two virtual capstone design projects with students …

In Vivo Detection Of Hyperoxia-Induced Pulmonary Endothelial Cell Death Using 99mTc-Duramycin, Said H. Audi, Elizabeth R. Jacobs, Ming Zhao, David L. Roerig, Steven T. Haworth, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

Introduction

^99mTc-duramycin, DU, is a SPECT biomarker of tissue injury identifying cell death. The objective of this study is to investigate the potential of DU imaging to quantify capillary endothelial cell death in rat lung injury resulting from hyperoxia exposure as a model of acute lung injury.

Methods

Rats were exposed to room air (normoxic) or > 98% O₂ for 48 or 60 hours. DU was injected i.v. in anesthetized rats, scintigraphy images were acquired at steady-state, and lung DU uptake was quantified from the images. Post-mortem, the lungs were removed for histological studies. Sequential lung sections were immunostained …

Fabrication Of Tissue Precursors Induced By Shape-Changing Hydrogels, Olukemi O. Akintewe

USF Tampa Graduate Theses and Dissertations

Scaffold based tissue reconstruction inherently limits regenerative capacity due to inflammatory response and limited cell migration. In contrast, scaffold-free methods promise formation of functional tissues with both reduced adverse host reactions and enhanced integration. Cell-sheet engineering is a well-known bottom-up tissue engineering approach that allows the release of intact cell sheet from a temperature responsive polymer such as poly-N-isopropylacrylamide (pNIPAAm). pNIPAAm is an ideal template for culturing cell sheets because it undergoes a sharp volume-phase transition owing to the hydrophilic and hydrophobic interaction around its lower critical solution temperature (LCST) of 32°C, a temperature close to physiological temperature. Compared to …

Understanding The Role Of Colloidal Particles In Electroporation Mediated Delivery, Alisha Peterson

USF Tampa Graduate Theses and Dissertations

Electroporation (EP) is a physical non-viral technique used to deliver therapeutic molecules across the cell membrane. During electroporation an external electric field is applied across a cell membrane and it causes pores to form. These pores then allow the surrounding media containing the therapeutics to diffuse across the membrane. This technique has been specifically studied as a promising gene and drug delivery system. Colloidal particles have also proven to be promising for a variety of biological applications including molecular delivery, imaging, and tumor ablation, due to their large surface area and tunable properties. In more recent years researchers have explored …

Impedance Measurements As A Means To Improve The Biological Response Of Gene Electrotransfer, Lina Fajardo Gomez

USF Tampa Graduate Theses and Dissertations

When an electric field is locally applied to tissues in vivo the uptake of exogenous DNA can be greatly increased. This approach to gene transfer, called electroporation (EP) or gene electro transfer (GET), has potential applications in the treatment of skin disorders, vaccinations, some types of cancer and metabolic diseases. The eect of electric elds on cells and tissues has been studied and related to the uptake of DNA. Tissue impedance changes have been measured as a result of electroporation. The aim of this study is to explore the predictive accuracy of impedance spectroscopy for the success of GET. Mice …