Biomedical Engineering and Bioengineering Commons^™

Intraocular Pressure Sensing And Control For Glaucoma Research, Simon Antonio Bello

USF Tampa Graduate Theses and Dissertations

Animal models of ocular hypertension are important for glaucoma research but come with experimental costs. Available methods of intraocular pressure (IOP) elevation are not always successful, the amplitude and time course of IOP changes are unpredictable and irreversible, and IOP measurement by tonometry is laborious. This dissertation focuses on the development and implementation of two novel systems for monitoring and controlling IOP without these limitations. The first device consists of a cannula implanted in the anterior chamber of the eye, a pressure sensor that continually measures IOP, and a bidirectional pump driven by control circuitry that can infuse or withdraw …

Corrosion Characteristics Of Magnesium Under Varying Surface Roughness Conditions, Yahya Efe Yayoglu

USF Tampa Graduate Theses and Dissertations

The biggest challenge with magnesium alloy biodegradable implants is the rapid corrosion at the earlier stages of the healing process after implantation. In this research, the impact of surface roughness generated by different means on the corrosion rate of AZ31 magnesium alloy in a simulated biologic environment is investigated. In order to perform accurate experimentation, an in vitro setup is assembled that simulates the human body environment accurately has been prepared using Schinhammer’s in vitro immersion testing setup and Kokubo’s Simulated Body Fluid (SBF). For the immersion test of Mg in SBF, several surface texture groups of Mg have been …

Biomarker Detection At Risk Forecasting Level Using Metal-Enhanced Fluorescence Combined With Surface Acoustic Wave, Jun Liu

USF Tampa Graduate Theses and Dissertations

In this paper, metal-enhanced fluorescence (MEF) technique is used to lower the detection limit of carcinoembryonic antigen (CEA) which is able to be utilized in forecasting the risk of having certain kinds of cancers, especially colon and rectal cancer. By incubating silver nanocubes (Ag NCs) on the surface of the chips, the detection limit goes down to below 1ng/mL of CEA. Also, when combining MEF with surface acoustic wave (SAW) devices, the incubation time between antigen and antibody will decrease significantly with the fluorescence signal keeping similar or higher level.

Mechanotransduction Of Matrix Stiffness Regulates Cell Adhesion Strength: An Analysis Using Biomaterial Surfaces With Tunable Mechanical And Chemical Properties, Asma Sharfeddin Sharfeddin

USF Tampa Graduate Theses and Dissertations

Cells have the ability to sense the rigidity of the extracellular matrix which directly affects the control of cellular functions in development, wound healing and malignant transformation. Polydimethylsiloxane elastomers are useful model biomaterials for mechanotransduction studies because they possess several advantages including ease of fabrication, tunable elasticity and modifiable surface chemistry. In this work, we are investigating the influence of matrix stiffness on adhesion strength and the mechanosensory structures that regulate these processes. In addition, the effect of surface modifications to this elastic substrate system on other physical properties such as local stiffness and topography will be analyzed. Based on …

Differential Association Of Vitronectin And Fibronectin With Glass And Electrospun Fibers Of A Poly (D-Lysine) /Poly (Acrylic Acid), Syed Muhammad Sohaib Zafar Zafar

USF Tampa Graduate Theses and Dissertations

Proteins represent major constituent of the extracellular matrix which plays an important role in the formation, maintenance and remodeling of tissues, this project focuses on adsorption of two specific serum proteins fibronectin (FN) and vitronectin (VTN) responsible for mediating cell matrix interaction through integrin binding, tripeptide Arg-Gly-Asp (RGD) sequence found in these protein features are recognized by αβV₃ integrin which ultimately helps in clot formation.

Tunable Nano-Delivery System For Cancer Treatment: A New Approach For Targeted Localized Drug Delivery, Rana Falahat

USF Tampa Graduate Theses and Dissertations

Localized drug delivery systems have been widely studied as potential replacements for conventional chemotherapy with the capability of providing sustained and controlled drug release in specific targeted sites. They offer numerous benefits over conventional chemotherapy such as enhancing the stability of embedded drugs and preserving their anticancer activity, providing sustained and controlled drug release in the tumor site, reducing toxicity and diminishing subsequent side effects, minimizing the drug loss, averting the need for frequent administrations, and minimizing the cost of therapy.

The aim of this study is to develop a localized drug delivery system with niosomes embedded in a chitosan …

The Development Of A Prosthetic Training Software For Upper Limb Amputees, Tyler Kayne Sullins

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to develop an intuitive software that aids in the field of prosthetic training and rehabilitation by creating an individualized visualization of joint angles. This software is titled “the prosthetic training software (PTS) for individualized joint angle representation”, and it enables the individualized portrayal of predicted or pre-recorded joint angles. The PTS is an intuitive program for clinicians and prosthesis users that produces an animation of a virtual avatar reflecting the user’s segment lengths and amputation for rehabilitation and training purposes.

The PTS consists of a graphical user interface (GUI) and a 3D visualization of …

Biophysical Characterization And Theoretical Analysis Of Molecular Mechanisms Underlying Cell Interactions With Poly(N-Isopropylacrylamide) Hydrogels, Michael C. Cross

USF Tampa Graduate Theses and Dissertations

So-called, “Dynamic biomaterials” comprised of stimuli-responsive hydrogels are useful in a wide variety of biomedical applications including tissue engineering, drug delivery, and biomedical implants. More than 150,000 peer-reviewed articles (as of 2016) have been published on these materials, and more specifically, over 100,000 of these are on the most widely studied, poly(N-isopropylacrylamide). This thermoresponsive polymer in a crosslinked hydrogel network undergoes a large volume phase transition (𝑉/𝑉₀ ~ 10 − 100) within a small temperature range (𝑇 ~ 1 − 3𝐾) making it particularly useful for tissue engineering applications because of the ability to control the topographical configuration of …

Nano-Photonic Waveguides For Chemical And Biomedical Sensing, Surya Venkatasekhar Cheemalapati

USF Tampa Graduate Theses and Dissertations

In this dissertation, advances in the fields of Photonics, and Plasmonics, and specifically, single cell analysis and waveguide sensing will be addressed. The first part of the dissertation is on Finite Difference Time Domain (FDTD) optimization and experimental demonstration of a nano-scale instrument that allows sensing at the cellular and subcellular levels. A new design of plasmonic coupler into a nanoscale waveguide is proposed and optimized using FDTD simulations. Following this, a subcellular nanoendoscope that can locally excite fluorescence in labelled cell organelles and collect the emitted fluorescent light for detailed spectrum analysis is fabricated and tested. The nanoendoscope has …

Graphene Quantum Dots-Based Drug Delivery For Ovarian Cancer Therapy, Yiru Qin

USF Tampa Graduate Theses and Dissertations

Ovarian cancer, one of the most dreadful malignancies of the female reproductive system, poses a lethal threat to women worldwide. In this dissertation, the objective was to introduce a novel type of graphene quantum dots (GQDs) based nano-sized drug delivery systems (DDS) for ovarian cancer treatment. As a starting point, the facile synthesis method of the GQDs was established. Subsequently, the targeting ligand,folic acid (FA), was conjugated to GQDs. Next, a FDA approved chemotherapeutic drug, Doxorubicin (DOX), was loaded to form the GQDs-FA-DOX nano-conjugation as the DDS. Moreover, the uptake profile and anti-cancer effect of the GQDs-FA-DOX were validated in …

Gait And Tremor Monitoring System For Patients With Parkinson’S Disease Using Wearable Sensors, Shyam Vignesh Perumal

USF Tampa Graduate Theses and Dissertations

Typically, a Parkinson’s disease (PD) patient would display instances of tremor and bradykinesia (slowness of movement) at an early stage of the disease and later develop gait disturbances and postural instability. So, it is important to measure the tremor occurrences in subjects to detect the onset of PD. Also, it is equally essential to monitor the gait impairments that the patient displays, as the order at which the PD symptoms appear in subjects vary from one to another.

The primary goal of this thesis is to develop a monitoring system for PD patients using wearable sensors. To achieve that objective, …

Increasing 18f-Fdg Pet/Ct Capabilities In Radiotherapy For Lung And Esophageal Cancer Via Image Feature Analysis, Jasmine Alexandria Oliver

USF Tampa Graduate Theses and Dissertations

Positron Emission Tomography (PET) is an imaging modality that has become increasingly beneficial in Radiotherapy by improving treatment planning (1). PET reveals tumor volumes that are not well visualized on computed tomography CT or MRI, recognizes metastatic disease, and assesses radiotherapy treatment (1). It also reveals areas of the tumor that are more radiosensitive allowing for dose painting - a non-homogenous dose treatment across the tumor (1). However, PET is not without limitations. The quantitative unit of PET images, the Standardized Uptake Value (SUV), is affected by many factors such as reconstruction algorithm, patient weight, and tracer uptake time (2). …

Modulation Of Whole Cell Currents In Human Neuroblastoma Cells Via The Hormone Aldosterone: An In Vitro Study, Harish Kumar Chittam

USF Tampa Graduate Theses and Dissertations

Ion channels play a critical role in maintaining homeostasis by moving various ions in and out of cells. The Na⁺-K⁺-2Cl^- or NKCC1 ion channel is involved in the regulation of Na⁺, K⁺, and Cl^- across cell membranes, and plays a key role in many forms of cellular physiology. In the cochlea, NKCC1 is involved in endolymph production and maintenance of the endocochlear potential. Our hypothesis is that blocking NKCC1 channels should directly impact auditory sensitivity causing hearing loss. Our lab has also shown that the hormone aldosterone (ALD) can upregulate …

Image-Based 3d Morphometric Analysis Of The Clavicle Intramedullary (Im) Canal, Jazmine Aira

USF Tampa Graduate Theses and Dissertations

Midshaft clavicle fractures are very common. Current treatment of choice involves internal fixation with superior or anterior clavicle plating, however their clinical success and patient satisfaction are slowly decreasing. The design of intramedullary (IM) devices is on the rise, but data describing the IM canal parameters is lacking. The aim of this study is to quantify morphometry of the clavicle and its IM canal, and to evaluate the effect of gender and anatomical side. This study used 3-dimensional (3D) image-based models with novel and automated methods of standardization, normalization and bone cross-section evaluation. The data obtained in this thesis presents …

A Trans-Dimensional View Of Drug Resistance Evolution In Multiple Myeloma Patients, Timothy Jacobson

USF Tampa Graduate Theses and Dissertations

Multiple Myeloma (MM) is a treatable, yet incurable, malignancy of bone marrowplasma cells. This cancer affects many patients and many succumb to relapse of tumor burden despite a large number of available chemotherapeutic agents developed for therapy. This is because MM tumors are heterogeneous and receive protection from therapeutic agents by the microenvironment and other mechanisms including homologous MM-MM aggregation. Therefore, therapy failure and frequent patient relapse is due to the evolution of drug resistance, not a lack of available drugs. To analyze and understand this problem, the evolution of drug resistance has been explored and presented herein. We seek …

Regulatory Effect Of Elastin Based Biomaterial On Cellular Behavior And Its Application On Wound Repair And Regeneration, Yuan Yuan

USF Tampa Graduate Theses and Dissertations

Elastin-like peptides (ELPs) are stimulus-responsive protein-based polymers which are attractive material for biomedical research due to their biocompatibility and unique properties. The physical properties of ELPs are dependent on the chain length and the chosen amino acid at the guest residue position. This imparts unlimited flexibility in designing ELP based biomaterials with the desired physical properties.

We have shown that in addition to their physical properties, ELPs have biological activities that are conducive to tissue regeneration. Specifically, we found that ELPs induce fibroblast proliferation via cell surface heparan sulfate proteoglycans (HSPG). Furthermore, our data suggests that ELP based materials with …

Analysis And Processing Of Human Electroretinogram, Abdulrahman Mohammad Alaql

USF Tampa Graduate Theses and Dissertations

Electroretinagram (ERG) is the recording of electrical activity of retinal cells elicited by light stimulation, which has been widely used to help diagnose different types of retinal dysfunctions. The ERG response signal is a short non-stationary signal that contains overlapping components. Different Digital Signal Processing (DSP) techniques are investigated using MATLAB to study the time-frequency responses of the ERG signal such as Short Time Fourier Transform (STFT), Continuous Wavelet Transform (CWT) and Discrete Wavelet Transform (DWT). The Photopic ERG signal was processed and analyzed in this thesis and the results of each technique have been investigated in detail. The Photopic …

Selective Enhancement Of Macropinocytosis For The Treatment Of Non-Small Cell Lung Cancer, Raul Iglesias

USF Tampa Graduate Theses and Dissertations

Over the past few years, researchers have focused their attention on the development of targeted cancer therapies to minimize the side effects associated with non-targeted treatments such as chemotherapy. Specifically, these approaches have focused on blocking growth factor receptors (GFR) that are overexpressed in cancer cells. In this thesis, we also focus on targeting overexpressed GFR; however, instead of blocking the GFR, our novel approach aims at using them to selectively enhance the endocytotic process of macropinocytosis to deliver peptides that either disrupts the mitochondria or inhibits glycolysis.

Herein, we show the selective enhancement of macropinocytosis by the fusion protein …

Elastin Like Polypeptides As Drug Delivery Vehicles In Regenerative Medicine Applications, Alex Leonard

USF Tampa Graduate Theses and Dissertations

Elastin like polypeptides (ELPs) are a class of naturally derived biomaterials that are non-immunogenic, genetically encodable, and biocompatible making them ideal for a variety of biomedical applications, ranging from drug delivery to tissue engineering. Also, ELPs undergo temperature-mediated inverse phase transitioning, which allows them to be purified in a relatively simple manner from bacterial expression hosts. Being able to genetically encode ELPs allows for the incorporation of bioactive peptides and functionalization of ELPs. This work utilizes ELPs for regenerative medicine and drug delivery.

The goal of the first study was to synthesize a biologically active epidermal growth factor-ELP (EGF-ELP) fusion …

Optofluidic Spectroscopy Platform For Detection Of Hemolysis, Edikan Archibong

USF Tampa Graduate Theses and Dissertations

In the United States alone, hundreds of millions of blood tests are performed annually, and a significant number of those tests are compromised due to hemolysis: e.g., 31% compromised in emergency rooms (inpatient) and 10% at blood banks, clinics, and other outpatient venues. Currently there is no way to reliably detect hemolysis without plasma separation. As a result, significant delays ensue, potentially negatively affecting patient diagnosis and treatment. In addition to in vitro hemolysis, which compromises the quality of blood tests, hemolysis can also occur in vivo. The in vivo occurrence of hemolysis is an indication of life-threatening complications. …

Smartphone Based 3d Printed Colorimeter For Biomedical Applications, Karthik Raj Konnaiyan

USF Tampa Graduate Theses and Dissertations

Here we present a novel Smartphone-based colorimeter and demonstrate its application to the measurements of glucose and protein concentrations in biological samples. The key innovation of our approach was to combine powerful image processing encoded into a mobile phone application with a low cost 3D printed sample holder that allowed to control lighting conditions and significantly improved sensitivity. Different solutions with protein and glucose concentrations ranging from 0 to 2000 mg/dL were prepared and analyzed using our system. The Smartphone-based colorimeter always correctly classified the corresponding reagent strip pads, what confirms that it can be used as a low cost …

Development Of Polymer Composite Based Enabling Technologies For Lab-On-A-Chip Devices, Vinicio Carias

USF Tampa Graduate Theses and Dissertations

This dissertation presents enabling technologies to fabricate thermo-responsive polymer composite based Lab-on-a-Chip (LOC) devices. LOC devices, also known as micro-total-analytical systems (microTAS) or microfluidic devices can amalgamate miniaturized laboratory functions on a single chip. This significant size reduction decreases the amount of required fluid volumes down to nano or pico-liters. The main commercial application of LOC devices is the biomedical fields. However, these devices are anticipated to make a technological revolution similar to the way miniaturization changed computers. In fact, medical and chemical analyses are predicted to shift from room-sized laboratories to hand-held portable devices.

This dissertation is divided into …

Assessing Viscoelastic Properties Of Polydimethylsiloxane (Pdms) Using Loading And Unloading Of The Macroscopic Compression Test, Mustafa Fincan

USF Tampa Graduate Theses and Dissertations

Polydimethylsiloxane (PDMS) mechanical properties were measured using custom-built compression test device. PDMS elastic modulus can be varied with the elastomer base to the curing agent ratio, i.e. by changing the cross-linking density. PDMS samples with different crosslink density in terms of their elastic modulus were measured. In this project the PDMS samples with the base/curing agent ratio ranging from 5:1 to 20:1 were tested. The elastic modulus varied with the amount of the crosslinker, and ranged from 0.8 MPa to 4.44 MPa. The compression device was modified by adding digital displacement gauges to measure the lateral strain of the sample, …

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 …

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 …

Silicone Elastomer-Based Combinatorial Biomaterial Gradients For High Throughput Screening Of Cell-Substrate Interactions, Greeshma Mohan

USF Tampa Graduate Theses and Dissertations

Biomaterials have evolved over the years from the passive role of mere biocompatibility to an increasingly active role of presenting instructive cues to elicit precise responses at the molecular and cellular levels. Various characteristics common to synthetic biomaterials in vitro and extracellular matrices in vivo, such as immobilized functional or peptide groups, mechanical stiffness, bulk physical properties and topographical features, are key players that regulate cell response. The dynamics in the cell microenvironment and at the cell adhesive interface trigger a web of cell-material and cell-cell information exchanges that have a profound impact in directing the ultimate cell fate …

Quantification Of Protein Adhesion Strength To Surface Attached Poly (N- Isopropylacrylamide) Networks By Hydrodynamic Detachment Shear Stresses, Gulnur Sanden

USF Tampa Graduate Theses and Dissertations

Stimuli responsive coatings offer a versatile method by which to manipulate interfacial interactions of proteins in a desired way. However, there exists little guidance as to how the structure of a responsive polymer coating influences adsorption of proteins. In this dissertation, the adsorption behavior of immuglobulin G (IgG) on poly (N-isopropylacryamide) (PNIPAAm) hydrogel coatings was investigated as a function of film thickness. PNIPAAm exhibits a hydrophilic to hydrophobic transition above a critical temperature of ~32°C in aqueous solutions. In this research, through the use of quartz crystal microbalance with dissipation (QCM-D) it was observed that the adsorption was thickness dependent …

Development Of An Efficient Human Hepatocyte Culture Platform For Assessing Novel Therapeutic Efficacy Against Plasmodium Liver Parasites, Steven Patrick Maher

USF Tampa Graduate Theses and Dissertations

Malaria is a critical and global public health problem, affecting over 200 million people every year, resulting in over 500,000 deaths. A vaccine is not currently available and only one drug, primaquine, is effective against the dormant stages of Plasmodium vivax. Preclinical assessment of novel therapeutic drugs and vaccines is hampered by the lack of an in vitro liver model for P. falciparum and P. vivax. To provide a stable human hepatocyte-based culture platform for parasite development, we engineered a microfluidic bilayer device capable of both simple and complex culture methods, including perfusion and co-culture, to better understand the requirements …

31p Dynamic Nuclear Polarization Applied To Dimethyl Methyl Phphonate For Functional Imaging And Spectroscopic Studies, Roha Afzal

USF Tampa Graduate Theses and Dissertations

In the recent years, Dynamic Nuclear Polarization (DNP) has emerged as a very promising technique for enhancing the sensitivity of the magnetic resonance spectroscopy and imaging (MRSI). A number of nuclei, namely 13C, 15N, 29Si, 89Y, and 129Xe, have been successfully polarized and a few of them have been employed in the in-vivo studies for functional imaging and metabolism. Hyperpolarized 13C-labeled compounds have wide applications in the metabolic and perfusion studies and can be used for early stage disease diagnosis, response to treatment, prognosis etc. DNP has been demonstrated in the 31P nucleus in nucleotides triphosphates as an application for …