Engineering Commons^™

Multi-Ligand Nanoparticles For Targeted Drug Delivery To The Injured Vascular Wall, Soujanya Kona

Bioengineering Dissertations - Archive

Pathological conditions like coronary artery disease, acute myocardial infarction, stroke, and peripheral artery diseases as well as cardiovascular interventions used in the treatment of coronary artery diseases such as angioplasty and stenting, damage/injure the blood vessel wall, leading to inflamed or activated endothelial cells that have been implicated in events leading to thrombosis, inflammation, and restenosis. Oral administration of anti-coagulant and anti-inflammatory drugs causes systemic toxicity, bleeding, patient incompliance, and inadequate amounts of drugs at the injured area. Though drug-eluting stents have shown therapeutic benefits, complications such as in-stent restenosis and late thrombosis still remain and are a cause for …

Development Of Orchestrated Stem Cell-Based Regeneration (Oscer) -Strategies To Recruit And Differentiate Autologous Stem Cells For Tissue Regeneration, Ashwin Nair

Bioengineering Dissertations - Archive

Stem cell therapy has shown great promise in curing diseases. However, clinical application of stem cell therapy is often hindered by the lack of reliable sources and convenient methods to recover stem cells. Our laboratory has recently discovered that adult stem cells can be actively recruited via inflammatory chemokines/growth factor. My research was aimed towards the development of a new technology - "Orchestrated Stem Cell-based Regeneration" or OSCeR - to induce stem cell-mediated tissue regeneration by blending stem cell therapy and tissue engineering technology. This work has led to a series of interesting findings as listed below. Shortly after implantation, …

Quantitative Variation Of Blood Pressure Dynamics During Sleep Apnea, Raichel Mary Alex

Bioengineering Theses - Archive

Sleep Apnea is one of the major sleep disorders characterized by complete cessation or decline in breathing for about 10s or more during sleep, thereby adversely affecting the quality of sleep. Studies show that about 6 % of the US adult population suffers from obstructive sleep apnea, which in turn plays a major role in the development of hypertension, heart failure, stroke and is also responsible for reduced performance in everyday activities due to lack of quality sleep. In this study the physiological response to sleep apnea were determined using beat to beat blood pressure in both healthy subjects and …

Innovations In ¹H Mr Tissue Oximetry: New Probes And Pulses, Ujjawal Rastogi

Bioengineering Theses - Archive

Low oxygenation level (hypoxia) of tissue leads to cellular dysfunction, damage and poor response to therapy. Quantitative measurement of tissue oxygenation is critical not only for the study of tissue physiology, but could also help improve efficacy of therapeutic procedures. Our group has previously developed and implemented a novel approach to quantify oxygen tension in tissue using ¹H MRI, known as “PISTOL” (Proton Imaging of Siloxanes to map Tissue Oxygenation Levels). It exploits a linear relationship between the longitudinal relaxation rate (R1) and oxygen tension (pO₂) of a reporter molecule (probe). Due to close proximity of fat (~ 1 ppm) …

A Study Of The Physiological Effects Of Sleep Apnea On Cerebral Blood Flow Velocity, Gauri Bhave

Bioengineering Theses - Archive

It is estimated that sleep apnea is prevalent in the US in about 18 million people. The prevalence rate is approximately 6% in the US. Sleep apnea reduces the quality of life of patients. Sleep apnea is characterized by repetitive pauses in breathing during sleep. Recent studies also show loss of gray matter in people diagnosed with sleep apnea. To study the physiological effects of sleep apnea on cerebral blood flow velocity (CBFV), CBFV was measured in subjects simulating apnea. Sixteen volunteers (29 ± 5 yr and BMI 24.1±4.8, 9M and 7F) were recruited as control subjects. We measured CBFV …

An Investigation Of Peripheral Blood Volume And Oxygen Saturation Change In Obstructive Sleep Apnea, Swathi Iyer

Bioengineering Theses - Archive

Obstructive sleep apnea (OSA) is a type of sleep disordered breathing in which the airway collapse partially or fully and causes arousal to resume breathing. In a 2009 National sleep foundation poll of 1000 people, 63% of men and 50% of the females showed signs of sleep apnea. It also showed that subjects with sleep apnea have high risk of high blood pressure, stroke and mental disorders such as depression especially in female. Also by another group of researcher it has been shown that the prevalence of OSA is 4% in male and 2% in female. It has been also …

In Vivo Tracking Of Mesenchymal Stem Cell Recruitment To Tissue Scaffolds, Manwu Sun

Bioengineering Theses - Archive

The term "Stem cells" has been extensively used to describe precursor undifferentiated cells that have the capacity to self-renew and can also give rise to multiple tissue types. Many studies have been shown improved functional outcome after treated with stem cell therapy. However, almost all of these investigations were analyzed based on histological evaluations which are time-consuming, expensive and fail to provide 3 dimensional and real-time information about stem cell responses. Therefore, there is a need for the development of new method to investigate the migration of stem cells in vivo. Recent evidence supports that fluorescence imaging system offer both …

Attenuation Based Quantification Of Interstitial Lung Disease Using High Resolution Computed Tomography And Correlation With Pulmonary Function Tests, Snehal S. Watharkar

Bioengineering Theses - Archive

Interstitial lung disease (ILD) is a chronic and progressive pulmonary disease of the lung parenchyma resulting in fibrotic scar formation of the pulmonary alveoli. The pathologic changes in the lung result in restrictive impairment of lung function. High resolution computed tomography (HRCT) of the chest has become an essential technique in diagnosing and assessing the extent of ILD. Clinical evaluation by HRCT is usually qualitative, leading to inter-observer variability particularly in detecting early disease. We propose a quantitative attenuation-based analysis to standardize the assessment of regional lung disease. We hypothesize that early ILD is associated with greater regional heterogeneity than …

Quantification Of Vascular Parametric Indices Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging, Areen Khaled Al.Bashir

Wayne State University Dissertations

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a non-invasive method used to evaluate the biological activity in early clinical trials of novel drugs targeting the tumor vasculature using gadolinium-DTPA (Gd) as a contrast agent. However, it has some limitations, such as reproducibility, data acquisition times, the presence of noise, extracting contrast concentration, estimating T1 relaxation and estimating pharmacokinetic parameters.

In this work, a new approach to used fixed T1(0) which provides more reproducible DCE results has been introduced. Using this new algorithm to quantify the vascular changes in DCE-MRI, a pre-clinical renal cell carcinoma (RCC) tumor model was used to …

Computational Structural Modelling Of Coronary Stent Deployment: A Review, David Martin, Fergal Boyle

Articles

The finite element (FE) method is a powerful investigative tool in the field of biomedical engineering, particularly in the analysis of medical devices such as coronary stents whose performance is extremely difficult to evaluate in vivo. In recent years, a number of FE studies have been carried out to simulate the deployment of coronary stents, and the results of these studies have been utilised to assess and optimise the performance of these devices. The aim of this paper is to provide a thorough review of the state-of-the-art research in this area, discussing the aims, methods and conclusions drawn from a …

Theory Of ‘Selectivity’ Of Label-Free Nanobiosensors – A Geometro-Physical Perspective, Pradeep R. Nair, Muhammad A. Alam

Birck and NCN Publications

Modern label-free biosensors are generally far more sensitive and require orders of magnitude less incubation time compared to their classical counterparts. However, a more important characteristic regarding the viability of this technology for applications in Genomics/Proteomics is defined by the ‘Selectivity’, i.e., the ability to concurrently and uniquely detect multiple target biomolecules in the presence of interfering species. Currently, there is no theory of Selectivity that allows optimization of competing factors and there are few experiments to probe this problem systematically. In this article, we use the elementary considerations of surface exclusion, diffusion limited transport, and void distribution function to …

Development Of Magnetic-Based Core-Shell Nanoparticles For Drug Delivery Applications In Melanoma Skin Cancer, Zarna A. Bhavsar

Bioengineering Theses - Archive

Melanoma skin cancer is the most dangerous form of skin cancer and the major cause of deaths related to skin cancer worldwide. Conventional chemotherapeutic treatment is not very effective and faces many problems such as low response rate, development of multidrug resistance, and severe side effects. In order to address these limitations and improve melanoma treatment efficacy, development of a multifunctional nanoparticulate drug delivery system is desired. Thus, we aimed towards the development of magnetic-based core-shell nanoparticles (MBCS NPs) for dual drug release and dual targeting of melanoma tumors. The synthesized nanoparticles were composed of Poly (Lactic-co-glycolic acid) (PLGA) particle …

A Novel Injectable Porous Hydrogel Composite Scaffold For Bone Tissue Engineering, Parvathi Nair

Bioengineering Theses - Archive

Over the past decade there has been an increasing use of bone grafts for orthopedic applications. With the aging US population, the need for suitable bone grafts substitutes has also increased. The aim of this study was to develop a novel in situ crosslinkable hydrogel composite for tissue-engineering critical-sized bone defects. This system consists of a newly developed water-soluble biodegradable hydrogel Poly ((ethylene glycol) maleate citrate) (PEGMC) and hydroxyapatite (HA). The PEGMC/HA system is completely injectable and can be crosslinked in situ into crosslinked PEGMC/HA (CPEGMC/HA) hydrogel composite with or without poly (ethylene glycol) diacrylate (PEGDA) as a crosslinker. The …

Microfluidic Systems For Studying Cell Motility, Srikanth Vasudevan

Bioengineering Theses - Archive

It is very imperative to develop new in vitro platforms that can help in studying the complex interactions that occur between cell-Extracellular Matrix proteins and also during the process of cell migration in vivo. Such tools would facilitate in better understanding of the mechanisms that are employed by the cells during growth and migration. There are two devices that are presented in this study; 1) Multi-biomolecule coated lane device for unbiased cell preferential migration and 2) Novel Microchannel device for real time monitoring of tumor cell migration.The Multi-biomolecule coated lane device is a basic in vitro platform that helps in …

The Influence Of Hydrogen Peroxide On The Static And Fatigue Properties Of Palacos-R Bone Cement, John M. Guerin

Theses

Aseptic loosening is a very costly complication of joint arthroplasty, both in terms of patient quality of life and financially. One potential contributing factor in its development - namely the use of hydrogen peroxide as an effervescent haemostatic agent - was investigated in this study. Clean bone cement samples and samples contaminated with 6% hydrogen peroxide were manufactured and stored either in room air or normal saline prior to testing. Thus four sample types were tested (clean stored wet or dry and contaminated stored wet or dry). Static (tension to failure) and fatigue testing was performed. Analysis was carried out …

Composition-Structure-Property Relationships In Multicomponent Bioactive Glasses, Sharon Murphy

Theses

Silicate glasses function effectively as bone grafts by stimulating bone regeneration through gene activation. However these materials offer little therapeutic potential for the regeneration of healthy bone in those suffering from metabolic bone diseases such as osteoporosis. Examining the composition-structure-property relationships arising from the incorporation of therapeutic ions such as strontium (Sr) and zinc (Zn) into such glasses in order to allow for healthy bone regeneration and antibacterial efficacy, as well as sodium (Na) to allow for controlled ion release was the objective of this work. Eight calcium-strontium-sodium-zinc-silicate glass compositions were produced, based on incremental additions of Sr and Na. …

Evaluation Of Two Novel Aluminum-Free, Zinc-Based Glass Polyalkenoate Cements As Alternatives To Pmma Bone Cement For Use In Vertebroplasty And Balloon Kyphoplasty, Gladius Lewis, Mark R. Towler, Daniel Boyd, Matthew J. German, Anthony W. Wren, Owen M. Clarkin, Andrew Yates

Chemical and Biochemical Engineering Faculty Research & Creative Works

Vertebroplasty (VP) and balloon kyphoplasty (BKP) are now widely used for treating patients in whom the pain due to vertebral compression fractures is severe and has proved to be refractory to conservative treatment. These procedures involve percutaneous delivery of a bolus of an injectable bone cement either directly to the fractured vertebral body, VB (VP) or to a void created in it by an inflatable bone tamp (BKP). Thus, the cement is a vital component of both procedures. In the vast majority of VPs and BKPs, a poly(methyl methacrylate) (PMMA) bone cement is used. This material has many shortcomings, notably …

Frustrated Drift Of An Anchored Scroll-Wave Filament And The Geodesic Principle, Marcel Wellner, Christian W. Zemlin, Arkady M. Pertsov

Bioelectrics Publications

We investigate anchored scroll-wave filaments in an excitable medium whose diffusivity matrix, including its determinant, is spatially nonuniform. The study is motivated by cardiological applications where scroll-wave behavior in the presence of diffusivity gradients is believed to play an important role in the development of severe arrhythmias. A diffusivity gradient is expected to make the filament drift, unless drift is prevented ("frustrated") by anchoring to localized defects in the propagation medium. The resulting stationary filament is a geodesic curve, as demonstrated here in the case of a nonzero but constant gradient. That is, the diffusivity matrix has a determinant that …

Electroporation-Mediated Delivery Of A Naked Dna Plasmid Expressing Vegf To The Porcine Heart Enhances Protein Expression, W. G. Marshall Jr., B. A. Boone, J. D. Burgos, S. I. Gografe, M. K. Baldwin, M. L. Danielson, M. J. Larson, D. R. Caretto, Y. Cruz, B. Ferraro, L. C. Heller, K. E. Ugen, M. J. Jaroszeski, R. Heller

Bioelectrics Publications

Gene therapy is an attractive method for the treatment of cardiovascular disease. However, using current strategies, induction of gene expression at therapeutic levels is often inefficient. In this study, we show a novel electroporation (EP) method to enhance the delivery of a plasmid expressing an angiogenic growth factor (vascular endothelial growth factor, VEGF), which is a molecule previously documented to stimulate revascularization in coronary artery disease. DNA expression plasmids were delivered in vivo to the porcine heart with or without coadministered EP to determine the potential effect of electrically mediated delivery. The results showed that plasmid delivery through EP significantly …

Digital Human Models Of People With Disabilities, Ron Hamameh

Wayne State University Theses

The current state-of-the-art in Digital Human Modeling (DHM) allows for full simulation and analysis of any task a person is required to perform at home, at work, in the military, in space, in sports, etc. The problem is that the software is missing a very important population: people with physical disabilities. What modifications and enhancements must be made to existing, commercially available DHM software to include this population?

Estimation Of 3d Shape In The Patellofemoral Joint Using Statistical Shape Models And 2d Data, Colm O'Kane

Conference Papers

Disorders of the patellofemoral joint (PFJ) including PF osteoarthritis and PF pain disorder have been estimated to represent 25% of all patients presenting for knee joint treatment. The diagnosis and treatment of these disorders is curtailed by lack of understanding of the mechanical operation of the joint. A crucial aspect to be considered in understanding contact patterns and kinematics of the PFJ is the alignment of the patella in the trochlear groove. Investigation of patellar alignment necessitates accurate knowledge of the 3D articular surfaces of both patella and femur, along with underlying bone geometry. These 3D data are generally obtained …

Application Of Magnetic Resonance Imaging To Understanding The Pathogenesis Of The X-Linked Leukodystrophy Pelizaeus-Merzbacher Disease, Jeremy Jerome Laukka

Wayne State University Dissertations

Myelin is a multilamellar membrane structure surrounding axons in both the CNS and PNS that facilitates nerve conduction. In the CNS, myelin is synthesized by oligodendrocytes, while in the PNS, myelin is synthesized by Schwann cells. In the CNS, Proteolipid protein 1 (PLP1), an integral membrane protein, is the major protein component of myelin, constituting ~50% of myelin protein. Mutations of the PLP1 gene in man cause a spectrum of neurological disease, ranging from the severe Pelizaeus-Merzbacher disease (PMD), that typically begins during infancy with nystagmus, seizures and hypotonia and evolves into spastic quadriparesis, cognitive impairment and ataxia, to ¡¥pure¡¦ …

Nanivid : A New Research Tool For Tissue Microenvironment Studies, Waseem Khan Raja

Legacy Theses & Dissertations (2009 - 2024)

Metastatic tumors are heterogeneous in nature and composed of subpopulations of cells having various metastatic potentials. The time progression of a tumor creates a unique microenvironment to improve the invasion capabilities and survivability of cancer cells in different microenvironments. In the early stages of intravasation, cancer cells establish communication with other cell types through a paracrine loop and covers long distances by sensing growth factor gradients through extracellular matrices. Cellular migration both in vitro and in vivo is a complex process and to understand their motility in depth, sophisticated techniques are required to document and record events in real time. …

Characterizing The Controlled Release Of Glial Cell-Line Derived (Gdnf) Neurotrophic Factor From Encapsulated Schwann Cells, Kristy Broadrick

Wayne State University Theses

ABSTRACT

CHARACTERIZING THE CONTROLLED RELEASE OF GDNF IN SCHWANN CELLS

by

KRISTY BROADRICK

May 2010

Advisor: Dr. Pamela VandeVord

Major: Biomedical Engineering

Degree: Masters of Science

Controlled expression of glial cell line derived neurotrophic factor (GDNF) can be integrated in the development of a system for repair of injured peripheral nerves. This delivery strategy was demonstrated via inducible GDNF from microencapsulated cells in barium alginate. The Schwann cell line RT4-D6P2T was initially modified utilizing an ecdysone-based stable transfection system to produce RT4-GDNF cells. During construct preparation, it was found that C6 cells (where GDNF cDNA was isolated) make three GDNF …

The Acute And Sub-Acute Effects Of Electrosurgical And Ultrasonic Surgical Devices On The Neurophysiologic Changes Of Sciatic Nerve Function, Anuja Gopalkrishna Vedpathak

Wayne State University Theses

THE ACUTE AND SUB-ACUTE EFFECTS OF ELECTROSURGICAL AND ULTRASONIC SURGICAL DEVICES ON THE NEUROPHYSIOLOGIC CHANGES OF SCIATIC NERVE FUNCTION

Since the dawn of medicine, blood loss during surgeries has been one of the major concerns for the surgeons. Iatrogenic blood loss can have several harmful effects on the patient condition. With the rapid development in technology, the blood loss can now be significantly minimized by using a variety of vessel sealing devices that use several energy sources to seal the blood vessels or tissue bundles instead of traditional sutures and clips. These devices can be used in several general, colorectal, …

A Biomechanical Comparison Of Locking Compression Plate Constructs With Plugs/Screws In Osteoporotic Bone Model, Krishna P. Desai

Browse all Theses and Dissertations

Locking compression plates are proven to be safe for use in open reduction and internal fixation (ORIF) especially in osteoporotic bones. Because of various combinations of holes, the system provides more options for clinicians to use either locking screws or non-locking screws. This clinical research introduces screw like plugs which can be used along with the screws in case of locking compression plates. Experimental work was performed to determine the effectiveness of the plugs. The results showed that there is not a significant difference between the groups which used plugs and did not use the plugs, both in case of …

An Analytical Model For Rotator Cuff Repairs, A. Aurora, Jorge E. Gatica, Antonie J. Van Den Bogert, J. A. Mccarron, Kathleen A. Derwin

Mechanical Engineering Faculty Publications

Background

Currently, natural and synthetic scaffolds are being explored as augmentation devices for rotator cuff repair. When used in this manner, these devices are believed to offer some degree of load sharing; however, no studies have quantified this effect. Furthermore, the manner in which loads on an augmented rotator cuff repair are distributed among the various components of the repair is not known, nor is the relative biomechanical importance of each component. The objectives of this study are to (1) develop quasi-static analytical models of simplified rotator cuff repairs, (2) validate the models, and (3) predict the degree of load …

Correlating The Magnitude And Spatial Gradient Of Alternans, Stuart Traxel

University of Kentucky Master's Theses

Electrical restitution has been shown to inaccurately predict the occurrence of alternans of action potential duration. A new method using the spatial gradient of alternans (SGA) is proposed to predict alternans and cardiac electrical stability. A simulated 1-D strand of tissue was used to compare indexes computed from restitution methods and the SGA method to changes in the amplitude of alternans using different electro-physiological alterations. The SGA method correlated better with changes in the amplitude of alternans than restitution methods for a decrease in the transient outward current (I_to) and conduction velocity. Restitution methods correlated better with changes …

Implementation Of Risk Management In The Medical Device Industry, Rachelo Dumbrique

Master's Theses

This study looks at the implementation and effectiveness of risk management (RM) activities in the medical device industry. An online survey was distributed to medical device professionals who were asked to identify RM-related activities performed during the device life cycle. RM activities and techniques included Establishing Risk Acceptance Criteria, Hazard Identification, Human Factors/Usability, Fault Tree Analysis (FTA), Design Failure Mode and Effects Analysis (DFMEA), Process Failure Mode and Effects Analysis (PFMEA), Hazard and Operability Study (HAZOP), Hazard Analysis and Critical Control Point (HACCP), Risk Benefit Analysis, and Risk Assessment of Customer Complaint. Devices were identified by type (therapeutic, surgical/clinical tools, …

Incorporation Of Vascular Endothelial Growth Factor And Pleiotrophin Into A Multiluminal Biosynthetic Nerve Implant For The Repair Of Peripheral Nerve Long Gap Defects, An Hai Nguyen

Bioengineering Theses - Archive

To repair a fully transected nerve without putting undue tension on the nerve stumps, and too circumvent many of the obvious problems of using harvested nerve grafts synthetic nerve guides have been used in the clinical setting. Thus far this strategy has met with minimal success for the repair of short defects (i.e. 1 - 2.5 cm) while any defect larger than 3 cm have failed. We hypothesize that neurotorphic support, early vascularization, and contact guidance are needed to successfully regenerate a nerve across a long-gap defect. To this end we proposed a biosynthetic nerve implant (BNI) with a multiluminal …