Biomedical Engineering and Bioengineering Commons^™

Design, Development And Biomechanical Analysis Of Scaffolds For Augmentation Of Rotator Cuff Repairs, Amit Aurora

ETD Archive

Rotator cuff tears are a source of debilitating pain that commonly affects more than 40 of our aging population. Despite advances in surgical treatment, the failure rate of rotator cuff repairs is as high as 20-90 . Extracellular matrix (ECM) derived scaffolds have recently been investigated as augmentation devices for rotator cuff repairs, but none has yet demonstrated both the appropriate biological and mechanical properties for mitigating re-tears and enhancing healing. This dissertation proposes to engineer the mechanical properties of allograft fascia lata in a manner that will allow its use as an augmentation device for rotator cuff repairs. This …

Surface Microtopography Modulation Of Biomaterials For Bone Tissue Engineering Applications, Eun Jung Kim

ETD Archive

The ultimate goal of this project is to develop a biodegradable and implantable scaffold with precise surface topographies that can provide osteoconductive stimuli to connective tissue progenitor cells (CTPs), and subsequently, enhance bone regeneration applications without the complications of autogenous cancellous bone grafts. This dissertation presents the modification of surface microtextures to provide osteoconductive stimuli to CTPs for bone regeneration applications. First, the effect of surface topography on cell proliferation and osteogenic differentiation was validated through experiments using surface post microtextures and CTPs. Post microtextures accelerated CTP growth behaviors compared to smooth polydimethylsiloxane (PDMS) and standard cell culture dishes. Second, …

Evaluation Of Upper Motor Neuron Pathology In Amyotrophic Lateral Sclerosis By Mri;Towards Identifying Noninvasive Biomarkers Of The Disease, Venkateswaran Rajagopalan

ETD Archive

Amyotrophic lateral sclerosis (ALS) is the commonest adult motor neuron disease (MND) which causes progressive muscle paralysis and death usually within 5 years of symptom onset. As a result, only ╠â30,000 individuals in the United States are afflicted at any one time even though 5,000 or more individuals are diagnosed yearly. The diagnosis of ALS requires evidence of degeneration in upper motor neurons (UMNs) in the brain and in lower motor neurons (LMNs) that exit the brainstem and spinal cord to innervate skeletal muscles. Diagnosis can be incorrect or delayed when disease is early or atypical because non-invasive objective tests …

Cell-Taught Gene Therapy For The Preservation And Regeneration Of Cardiac Tissue Following Chronic Heart Failure, Srividya Sundararaman

ETD Archive

Heart failure is the primary cause of mortality and morbidity in the Western world. Although cell therapy has demonstrated improvement in cardiac function, these benefits are being attributed to the activation of paracrine factors, rather than the differentiation and integration of the transplanted cells into the host tissue. Based on this knowledge the focus of this thesis work was to deliver paracrine factors, and evaluate its effect on cardiac function. Gene therapy has evolved as a promising option to deliver pro-angiogenic proteins to infarct zones, thus providing cardiac benefit. This study has identified a gene design without the use of …

The Thermodynamics Of Fluid-Phase Benzene Via Molecular Simulation, John L. Tatarko

ETD Archive

Accurate values for thermodynamic properties throughout the fluid phase are a requirement for the design of separation processes. To date, very few pure substances have been completely characterized because of time and monetary constraints. Low cost computing power now permits complete determination of the thermodynamic properties of pure substances via molecular simulation. Molecular simulation is computational statistical mechanics. Benzene is an important industrial chemical and pharmaceutical precursor. It is the prototypical, symmetric, hexagonal molecule and is an ideal candidate for molecular simulation. The molecular models of three researchers in the field are submitted for Monte Carlo simulation in the virtual …

Directional Solidification Of Al - 7 Wt Si Alloy, Ravi Shanker Rajamure

ETD Archive

Al - 7 wt Si alloy has been directionally solidified from an aluminum single crystal seed with its [100] orientation parallel to the growth direction with a positive thermal gradient of 40 K/cm and over the range of growth speeds. Growth speed dependence of primary Dendrite Spacing and Primary Dendrite trunk Diameter has been analyzed during the step increase and step decrease in the growth speeds. Frequency distribution of Nearest Neighbor dendrites obtained from the statistical analysis shows the hexagonal distribution of dendrites. The interdendritic convection was present in the form of transverse macrosegregation and non uniform distribution of dendrites …

A Theoretical Model Of The Effect Of Bone Defects On Anterior Shoulder Instability: A Finite Element Approach, Piyush Walia

ETD Archive

Presence of either a Hill Sachs or a Bony Bankart lesion has been indicated as a possible cause of subluxation and anterior shoulder dislocation. Previous studies have investigated only effects of these isolated lesions on the glenohumeral instability of the shoulder. The purpose of this thesis was to investigate the effect of both Bony Bankart lesion and Hill-Sachs lesion in the glenohumeral joint on the stability of the shoulder. We hypothesize that as the size of the lesion increases, the glenohumeral joint's stability will decrease. We further hypothesize that the presence of both defects together will reduce the glenohumeral joint's …

Application Of Differential Scanning Calorimetry To Characterize Thin Film Deposition Processes, Andrew John Roger Snell

ETD Archive

With the recent increase in awareness on the environmental impact of industrial coating processes, chromate-based coating processes have been elevated to the rank of the technologies targeted by the EPA for rapid replacement by environmentally friendly processes. Therefore, there is a clear need for advances in coating technologies to identify alternative industrial practices. This thesis characterizes a process developed at Cleveland State University as an alternative deposition technique to generate uniform coatings onto solid substrates. A kinetic analysis to extract scale up parameters involved in the reaction kinetics leading to high-performance coatings is demonstrated in this research. The work consists …

Raman Spectroscopic Modeling Of T- Lymphocyte Activation And Detection Of Acute Renal Allograft Rejection, Kristian L. Brown

Wayne State University Dissertations

ABSTRACT

RAMAN SPECTROSCOPIC MODELING OF T-LYMPHOCYTE ACTIVATION AND DETECTION OF ACUTE RENAL ALLOGRAFT REJECTION

By

KRISTIAN L. BROWN

2010

Advisor: Gregory Auner, PhD

Major: Biomedical Engineering

Degree: Doctor of Philosophy

Despite the advances made in the area of kidney transplantation, the disparity between the demand and available donated organs remains a dominant and unresolved issue. Given the paucity of available renal allografts the preservation of existing grafts is vital. One factor that has negatively impacted renal allograft survival is acute rejection (AR). Traditionally, kidney transplant centers have used elevations in serum creatinine as a screening tool for detecting AR. However, …

Identification Of Neuroblastoma And Its Prognostic Markers Using Raman Spectroscopy, Rachel Kast

Wayne State University Dissertations

Introduction: Neuroblastoma is the most common cancer of infancy. It is one of several peripheral nervous system tumors, including ganglioneuroma, peripheral nerve sheath tumor, and pheochromocytoma. It is commonly situated on the adrenal gland. It displays similar histology to other small round blue cell tumors, including non-Hodgkin lymphoma, rhabdomyosarcoma, and Ewing sarcoma. One method of judging neuroblastoma aggressiveness uses tumor histology factors, including mitosis-karyorrhexis index, Schwannian stromal development, degree of differentiation, and patient age. Tumor aggressiveness can also be judged based on the amplification of certain genes, including MYCN. Raman spectroscopy is a physics-based method which identifies the biochemical …

Understanding The Molecular Dynamics Of Ypel3 And Fhit Gene Expression, Kevin Daniel Kelley

Browse all Theses and Dissertations

A comprehensive understanding of the molecular signaling pathways that regulate cell growth and proliferation is essential in the realization of new therapeutic options to facilitate early detection and eradication of malignancy. Understanding the transcriptional regulation of the YPEL3 and FHIT genes forms the basis of this dissertation. YPEL3, or Yippee-like 3, is a newly identified p53 target gene that inhibits tumor cell growth and is thus itself, a novel tumor suppressor gene. FHIT, or Fragile histidine triad, is a well known tumor suppressor gene and is regulated at the transcriptional level by another growth inhibitory protein, FOXO3a, a Forkhead box …

Magnetic Resonance Spectroscopy Study Of Metabolic Profiles In Brain Tumors, Aditya Manoj Patel

Bioengineering Theses - Archive

Metabolic profiles in brain tumors were measured using proton (1H) magnetic resonance spectroscopy (MRS) at 3T. Spectra were obtained from normal tissues and tumor mass regions of 6 low-grade gliomas, 7 anaplastic astrocytomas and 23 glioblastoma (GBM) patients, using PRESS at two echo times (TE = 54 and 112 ms). Glutamate (Glu), glutamine (Gln) and lactate (Lac) were well resolved at TE = 112 ms. The ratio of Gln and Glu concentrations, [Gln]/[Glu], was elevated significantly (p < 0.05) in all the tumor types compared to normal tissue. Elevation of Gln was confirmed through [Gln]/[water]; the ratio was increased in all the three tumor types but the increase was significant only in GBM. Glycine (Gly) was increased significantly in GBM. Alanine was detectable from GBM only, indicating its elevation for most malignant tumor. Other observations included significant increases in choline (Cho) and Lac (p < 0.05) and decrease in NAA (N-acetylaspartate), in consistent with prior studies. The creatine to water ratio was observed to decrease in tumor patients but was not significant. Myo-inositol (mIns) was observed to decrease in low grade patients as compared to normal tissue, but was seen to increase with grade of tumor, but was not significant. [Lac]/[water] was significantly higher and [Cho]/[Lac] significantly lower for GBM patients indicating the increase in Lac as compared to normal tissue.Treatment had a significant impact on tumor cells. After radiation therapy the Lac was observed to be elevated significantly and decrease after bevacizumab treatment. [Cho]/[Cr], [Cho]/[NAA], [Gln]/[Glu] and [Cho]/[Gly] was reduced significantly after the bevacizumab treatment. Gly was not detectable after Bevacizumab treatment. Some of the patients showed no infiltrating tumor cells after successful surgery and therapy with ratios close to that of normal tissue. These observations can help in characterizing the effect of various therapies on brain metabolites and tumor cells.

Targeted Delivery Of Carbon Nanotubes To Cancer Cells, Pavitra Chakravarty

Bioengineering Dissertations - Archive

CD22 is broadly expressed on human B cell lymphomas. Monoclonal anti-CD22 antibodies (MAbs) alone, or coupled to toxins, have been used to selectively target these tumors both in severe combined immunodeficient (SCID) mice with xenografted human lymphomas and in patients. Single-walled carbon nanotubes (CNTs) attached to antibodies or peptides represent another approach to targeting cancer cells. CNTs convert absorbed near-infrared (NIR) light into heat, which can thermally ablate cells in the vicinity of the CNTs. We have made MAb-CNT constructs where the MAb was either noncovalently or covalently coupled to CNTs, and investigated their ability to bind specifically to cells …

Post-Operative Renal Function Analysis Using Visible Dlp® Hyperspectral Imaging System, Abhas Thapa

Bioengineering Theses - Archive

Surgical and clinical settings in medical hospitals strive to keep up with technological innovations in order to improve the current healthcare scenario. Hyperspectral imaging (HSI) is a novel technology that addresses this problem. HSI is a non-invasive imaging technique that can provide information on both structural and functional conditions of tissue. This information is very useful particularly in live surgical procedures wherein the surgeons can get real-time feedback of the anatomical and functional changes of tissue, as they perform the operation. Currently available HSI systems are extremely slow and thus impractical for time restricted surgical or clinical uses. Hence, DLP® …

Enhanced Endothelialization On Surface Modified Poly(L-Lactic Acid), Hao Xu

Bioengineering Dissertations - Archive

Current synthetic vascular grafts and polymer-coated drug-eluting stents (DES) have certain limitations, such as thrombosis and restenosis due to the incomplete recovery of vascular endothelial cells on their luminal sides. Surface modification of these materials is a viable method to enhance the endothelialization on them. In this study, we proposed several way to modify poly(L-lactic acid) (PLLA), a promising material for vascular prostheses to enhance the endothelialization on its surface. In the first method, we modified the material surface with deposition of poly(vinylacetic acid) (PVAA) using plasma polymerization. PVAA having different surface densities of -COOH group or film thickness were …

Wide Field Of View Imaging Of Premotor And Sensorimotor Cortex Activation Patterns By Functional Near Infrared Spectroscopy, Pankaj Chand

Bioengineering Theses - Archive

Functional near infrared spectroscopy (fNIRS) is a non-invasive optical technique which can measure concentration changes of oxygenated (HbO), deoxygenated (HbR), and total hemoglobin (HbT) in brain tissue that are induced by neuronal activation. A major hindrance at present for brain optical imaging research is the limited field of view (FOV) size, which is restricted due to the limited number of source-detector pairs that current fNIRS hardware technology and cost considerations allow. As a result it is challenging to simultaneously capture hemodynamic changes in the premotor, motor and sensory cortex as some of these activations can occur outside the available FOV. …

Novel Animal Model And In Vivo Imaging System To Study Inflammatory Response-Mediated Cancer Metastasis, Cheng-Yu Ko

Bioengineering Dissertations - Archive

Cancer metastasis is the leading cause of death in cancer patients. A vast majority of cancer-related mortality is attributed to this rather than the primary tumor itself, making the understanding of cancer metastasis critically important. Inflammatory responses have been implicated to play an important role in cancer metastasis. However, the investigation of the relationship between inflammation and cancer cell migration is limited by the lack of a reproducible cancer metastasis animal model. To fill the gap, we have recently developed an animal model. This model is composed of a two-step procedure. First, poly-L lactic acid (PLA) microspheres were implanted subcutaneously …

Mechanisms Of Biomaterial Mediated Fibrotic Responses And Strategies To Improve Tissue Reactions To Biomaterial Implants, Paul Todd Thevenot

Bioengineering Dissertations - Archive

Despite considerable advancements in biomaterial synthesis and modification techniques, most tissue engineering scaffolds elicit fibrotic reactions resulting in implant encapsulation, secluding cells and/or therapeutic agents within a thick collagenous matrix. Therefore, strategies to minimize these responses while improving the functionality of recruited/transplanted cells are required. This work set out to improve the host response to biomaterials and identify what cellular responses were attributed to biomaterial-mediated fibrosis. Two strategies were investigated involving two different targets. In the first approach, PLGA scaffolds were RFGD modified to bear -NH2 (amine), -COOH (carboxyl), and -OH (hydroxyl) groups altering surface wettability and charge properties. Surface …

Investigation Of End-Tidal Carbon Dioxide (Etco₂) And Heart Rate Variations During Sleep Apnea, Aditya Bashaboyina

Bioengineering Theses - Archive

Sleep Apnea is a sleep disorder where limitation or cessation of breathing occurs. It is characterized by abnormalities in the respiratory pattern and quantity of ventilation during sleep. According to a study 4% of men and 2% of women have sleep apnea, which is a sizable sector of the adult population. To analyze end-tidal CO₂ and heart hate variations due to apnea, 8 hr polysomnography (Sleep Consultant. Inc, Fort Worth, Texas) was performed on limited sleep apnea subjects and breath hold maneuvers were performed in awake subjects. In the simulated apnea study, 16 volunteer subjects (age: 29 ± 5 yrs, …

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 …