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Michigan Technological University

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Full-Text Articles in Biomedical Engineering and Bioengineering

Estimation Of Multi-Directional Ankle Impedance As A Function Of Lower Extremity Muscle Activation, Lauren Knop Jan 2019

Estimation Of Multi-Directional Ankle Impedance As A Function Of Lower Extremity Muscle Activation, Lauren Knop

Dissertations, Master's Theses and Master's Reports

The purpose of this research is to investigate the relationship between the mechanical impedance of the human ankle and the corresponding lower extremity muscle activity. Three experimental studies were performed to measure the ankle impedance about multiple degrees of freedom (DOF), while the ankle was subjected to different loading conditions and different levels of muscle activity. The first study determined the non-loaded ankle impedance in the sagittal, frontal, and transverse anatomical planes while the ankle was suspended above the ground. The subjects actively co-contracted their agonist and antagonistic muscles to various levels, measured using electromyography (EMG). An Artificial Neural Network ...


Estimation And Prediction Of The Human Gait Dynamics For The Control Of An Ankle-Foot Prosthesis, Guilherme Aramizo Ribeiro Jan 2019

Estimation And Prediction Of The Human Gait Dynamics For The Control Of An Ankle-Foot Prosthesis, Guilherme Aramizo Ribeiro

Dissertations, Master's Theses and Master's Reports

With the growing population of amputees, powered prostheses can be a solution to improve the quality of life for many people. Powered ankle-foot prostheses can be made to behave similar to the lost limb via controllers that emulate the mechanical impedance of the human ankle. Therefore, the understanding of human ankle dynamics is of major significance. First, this work reports the modulation of the mechanical impedance via two mechanisms: the co-contraction of the calf muscles and a change of mean ankle torque and angle. Then, the mechanical impedance of the ankle was determined, for the first time, as a multivariable ...


A Smart Implantable Bone Fixation Plate Providing Actuation And Load Monitoring For Orthopedic Fracture Healing, Brad Nelson Jan 2019

A Smart Implantable Bone Fixation Plate Providing Actuation And Load Monitoring For Orthopedic Fracture Healing, Brad Nelson

Dissertations, Master's Theses and Master's Reports

Fracture non-union occurs in roughly 5-10% of all fracture cases, and current interventions are both time-consuming and costly. There is therefore significant incentive to develop new tools to improve fracture healing outcomes. Several studies have shown that low-magnitude, high-frequency (LMHF) mechanical loading can promote faster healing and reduce the risk of refracture in critical-size long bone fractures. This is typically done using whole-body vibration, which may result in undesirable systemic effects on the rest of the body. This work discusses an implantable piezoelectric fixation plate that can both apply LMHF loading directly to the fracture site using flexible scheduling and ...


Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar Jan 2019

Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar

Dissertations, Master's Theses and Master's Reports

Coherent light - such as that from a laser - on interaction with biological tissues, undergoes scattering. This scattered light undergoes interference and the resultant field has randomly added phases and amplitudes. This random interference pattern is known as speckles, and has been the subject of multiple applications, including imaging techniques. These speckle fields inherently contain optical vortices, or phase singularities. These are locations where the intensity (or amplitude) of the interference pattern is zero, and the phase is undefined.

In the research presented in this dissertation, dynamic speckle patterns were obtained through computer simulations as well as laboratory setups involving scattering ...


A Bluetooth Low-Energy Wireless Sensor Platform For Continuous Monitoring Of A Bioreactor Environment During Cell Manufacturing, Brad Nelson Jan 2018

A Bluetooth Low-Energy Wireless Sensor Platform For Continuous Monitoring Of A Bioreactor Environment During Cell Manufacturing, Brad Nelson

Dissertations, Master's Theses and Master's Reports

A wireless sensor platform based on Bluetooth Low-Energy (BLE) technology was designed and prototyped for continuous monitoring of physical conditions and chemical analytes, which could be applied to bioreactors during the cell manufacturing process. Controlling environmental conditions such as pH, oxygen, glucose, temperature, and pressure is vital to ensure the consistency of the manufactured cells and maintain the potency of the product. Current methods to control bioreactor conditions focus only on monitoring the cell culture environment during cell growth, but there is a lack of direct quantification of cell properties to provide an integrated feedback system that can also maintain ...


Studying Mass And Mechanical Property Changes During The Degradation Of A Bioadhesive With Mass Tracking, Rheology And Magnetoelastic (Me) Sensors, Zhongtian Zhang Jan 2018

Studying Mass And Mechanical Property Changes During The Degradation Of A Bioadhesive With Mass Tracking, Rheology And Magnetoelastic (Me) Sensors, Zhongtian Zhang

Dissertations, Master's Theses and Master's Reports

In this research, the degradable polymer 4-arm poly (ethylene glycol)-glutaric acid-dopamine (PEG-GA-DM4) was synthesized. The degradation behavior of crosslinked PEG-GA-DM4 bioadhesive was studied with mass tracking, oscillatory rheology, and magnetoelastic (ME) sensors. Changes in mechanical properties were correlated with both dry mass and wet mass changes during the degradation. The results indicate that the loss of mechanical property in the bioadhesive can take place without losing the dry mass. The mass loss profile cannot describe the degradation behavior completely. In addition to studying the degradation of PEG-GA-DM4, this research also confirms the application of ME sensors ...


An Injectable Thermosensitive Biodegradable Hydrogel Embedded With Snap Containing Plla Microparticles For Sustained Nitric Oxide (No) Delivery For Wound Healing, Nikhil Mittal Jan 2018

An Injectable Thermosensitive Biodegradable Hydrogel Embedded With Snap Containing Plla Microparticles For Sustained Nitric Oxide (No) Delivery For Wound Healing, Nikhil Mittal

Dissertations, Master's Theses and Master's Reports

After injury, wound healing is a complex sequential cascade of events essential for the proper recovery of the wound without the scar formation. Nitric oxide (NO) is a small, endogenous free-radical gas with antimicrobial, vasodilating and growth factor stimulating properties. NO has wide biomedical application especially in wound healing however, its usability is hindered due its administration problem as it is highly unstable.

In this work, poly (l-lactic acid) microparticles encapsulated with NO donor S-nitroso-N-acetyl-D-penicillamine (SNAP) were prepared using water-in-oil-water double emulsion solvent evaporation method for controlled delivery for NO at the specific site. The NO release from SNAP-PLLA microparticles ...


Reversibly Switching Adhesion Of Smart Adhesives Inspired By Mussel Adhesive Chemistry, Ameya R. Narkar Jan 2018

Reversibly Switching Adhesion Of Smart Adhesives Inspired By Mussel Adhesive Chemistry, Ameya R. Narkar

Dissertations, Master's Theses and Master's Reports

Catecholic groups in mussel adhesive proteins transition from being strongly adhesive in a reduced state under acidic conditions to being weakly adhesive in an oxidized state under basic conditions. Here, we exploit this pH responsive behavior of catechol and demonstrate that its oxidation state can be manipulated by incorporation of boronic acid to facilitate reversible transitions between strong and weak adhesion. Our first approach involved the addition of 3- acrylamido phenylboronic acid (APBA) to dopamine methacrylamide (DMA) containing adhesives. The synthesized adhesives showed strong adhesion to quartz surface in an acidic medium (pH 3), while weak adhesion was observed on ...


Structural Characteristics And Corrosion Behavior Of Bio-Degradable Zn-Li Alloys In Stent Application, Shan Zhao Jan 2017

Structural Characteristics And Corrosion Behavior Of Bio-Degradable Zn-Li Alloys In Stent Application, Shan Zhao

Dissertations, Master's Theses and Master's Reports

Zinc has begun to be studied as a bio-degradable material in recent years due to its excellent corrosion rate and optimal biocompatibility. Unfortunately, pure Zn’s intrinsic ultimate tensile strength (UTS; below 120 MPa) is lower than the benchmark (about 300 MPa) for cardiovascular stent materials, raising concerns about sufficient strength to support the blood vessel. Thus, modifying pure Zn to improve its mechanical properties is an important research topic.

In this dissertation project, a new Zn-Li alloy has been developed to retain the outstanding corrosion behavior from Zn while improving the mechanical characteristics and uniform biodegradation once it is ...


A Wireless, Passive Sensor For Measuring Temperature At Orthopedic Implant Sites For Early Diagnosis Of Infections, Salil Sidharthan Karipott Jan 2017

A Wireless, Passive Sensor For Measuring Temperature At Orthopedic Implant Sites For Early Diagnosis Of Infections, Salil Sidharthan Karipott

Dissertations, Master's Theses and Master's Reports

Sensorized implants with embedded wireless, passive temperature sensors were developed for early detection of implant-associated infections. The operation principle of the sensor is based on the hypothesis that infections can lead to an increase in local temperature prior to the rise of body temperature. The sensor was an inductive capacitive (LC) circuit that has been used for monitoring of different parameters wirelessly, often in difficult to access environments. The sensor was fabricated on to an interference screw, which is used for tendon and ligament reconstruction surgeries. In this project, a sensorized interference screw was designed and fabricated by accommodating an ...


Computational Ultrasound Elastography: A Feasibility Study, Yu Wang Jan 2017

Computational Ultrasound Elastography: A Feasibility Study, Yu Wang

Dissertations, Master's Theses and Master's Reports

Ultrasound Elastography (UE) is an emerging set of imaging modalities used to assess the biomechanical properties of soft tissues. UE has been applied to numerous clinical applications. Particularly, results from clinical trials of UE in breast lesion differentiation and staging liver fibrosis indicated that there was a lack of confidence in UE measurements or image interpretation. Confidence on UE measurements interpretation is critically important for improving the clinical utility of UE. The primary objective of my thesis is to develop a computational simulation platform based on open-source software packages including Field II, VTK, FEBio and Tetgen. The proposed virtual simulation ...


Formulation And Testing Of Biodegradable Polymeric Coating On Zinc Wires In Cardiovascular Stent Application, Avishan Arab Shomali Jan 2017

Formulation And Testing Of Biodegradable Polymeric Coating On Zinc Wires In Cardiovascular Stent Application, Avishan Arab Shomali

Dissertations, Master's Theses and Master's Reports

Biodegradable and biocompatible poly (L-lactic-acid) (PLLA) coating was applied on a modified zinc (Zn) substrate by dip coating, with the intent to delay the bio-corrosion and slow the degradation rate of zinc substrate. 3-(Trimethoxysilyl) propyl methacrylate (MPS) was used for modification of the zinc substrate for promoting the adhesion between the metallic substrate and the polymer coating. It is hypothesized that the delay in Zn biodegradation could be useful in the first several weeks to prevent the early loss of mechanical integrity of the endovascular stent and to improve the healing process of the diseased vascular site. The PLLA ...


A 3d Biomimetic Scaffold Using Electrospinning For Tissue Engineering Applications, Samerender Nagam Hanumantharao Jan 2017

A 3d Biomimetic Scaffold Using Electrospinning For Tissue Engineering Applications, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

Electrospinning holds great promise for designing functional 3D biomimetic scaffolds for tissue engineering applications. The technique allows for the reproducible fabrication of 3D scaffolds with control over the porosity and thickness. In this work, a novel method for the synthesis of a 3D electroactive scaffold using electrospinning from polycaprolactone (PCL), Polyvinylidene Fluoride (PVDF) and Polyaniline (PANI) is reported. Additional scaffolds involving different morphologies of PCL, PCL-PVDF and PCL-PANI-PVDF were also fabricated and evaluated. The scaffolds were characterized using electron microscopy to visualize the morphologies. Infrared spectroscopy was used to confirm the presence of polymers and their respective phases in the ...


Computational Studies On Biomechanics Of Concussion And On Efficacy Of Football Helmets, David Labyak Jan 2017

Computational Studies On Biomechanics Of Concussion And On Efficacy Of Football Helmets, David Labyak

Dissertations, Master's Theses and Master's Reports

Football helmets have been used for many years to prevent head injuries to players. Over the years, the helmet design has evolved from a crude leather head covering to the more recent form fitting helmets that are seen today. The one design feature that has been common in the majority of all helmets is a hard polycarbonate shell with a foam cushion padding. The main goal of the padding layer was to reduce the amount of linear acceleration during an impact event. The one feature that has been overlooked is how stiff the padding is in rotation.

The purpose of ...


Design Of Robust Hydrogel Based On Mussel-Inspired Chemistry, Yuan Liu Jan 2017

Design Of Robust Hydrogel Based On Mussel-Inspired Chemistry, Yuan Liu

Dissertations, Master's Theses and Master's Reports

The structure of catechol is found in mussel adhesive proteins and contributed to both wet-resistant adhesion and cohesive curing of these proteins. A synthetic nano-silicate, Laponite was incorporated into catechol-containing hydrogels and the hydrogel network-bound catechol formed strong reversible interfacial interaction with Laponite. The contribution of incorporated catechol-Laponite reversible interfacial interactions to the mechanics of hydrogels constructed by different strategies was studied. In the first strategy, Laponite and catechol were introduced into the double network hydrogel (DN) via the free radical co-polymerization of a catechol-containing monomer, backbone monomer, and crosslinker. The introduction of catechol-Laponite interactions significantly improved the compressive strength ...


Implantable Wireless Sensor Networks: Application To Measuring Temperature For In Vivo Detection Of Infections, Praharsh Madappaly Veetil Jan 2017

Implantable Wireless Sensor Networks: Application To Measuring Temperature For In Vivo Detection Of Infections, Praharsh Madappaly Veetil

Dissertations, Master's Theses and Master's Reports

It is has been proven that infection in the body cause a local temperature increase due to localized inflammation. Therefore, a method to provide early diagnostic or long-term tracking of this infection will provide great benefits to patients with diabetic foot ulcers or sickle cell disease, and those receiving hemodialysis where they suffer from a weakened immune system. The goal of this project is to develop an implantable wireless temperature sensor based on a wireless sensor network system for monitoring infections in situ. The analog signals from the thermistors are digitized and wirelessly transmitted to a computer with an ez430-rf2500 ...


Surface Enabled Lab-On-A-Chip (Loc) Device For Protein Detection And Separation, Zhichao Wang Jan 2017

Surface Enabled Lab-On-A-Chip (Loc) Device For Protein Detection And Separation, Zhichao Wang

Dissertations, Master's Theses and Master's Reports

Sensitive and selective chemical/biological detection/analysis for proteins is essential for applications such as disease diagnosis, species phenotype identification, product quality control, and sample examination. Lab-on-a-chip (LOC) device provides advantages of fast analysis, reduced amount of sample requirements, and low cost, to magnificently facilitate protein detection research. Isoelectric focusing (IEF) is a strong and reliable electrophoretic technique capable of discerning proteins from complex mixtures based on the isoelectric point (pI) differences. It has experienced plenty of fruitful developments during previous decades which has given it the capability of performing with highly robust and reproducible analysis. This progress has made ...


Enhancing Osseointegration Of Orthopaedic Implants With Titania Nanotube Surfaces, Erin A. Baker Jan 2016

Enhancing Osseointegration Of Orthopaedic Implants With Titania Nanotube Surfaces, Erin A. Baker

Dissertations, Master's Theses and Master's Reports

Introduction: As joint arthroplasty surgical procedures increase annually, the development of new strategies, including novel materials and surface modifications, to attain solid bone-implant fixation are needed to increase implant terms of service. In this study, we evaluate two morphologies of titania nanotubes in both in vitro and in vivo experiments to quantify osseointegrative potential and material-level biocompatibility.

Materials and Methods: Samples were prepared via an electrochemical etching process. Two different titania nanotube (TiNT) morphologies were produced, Aligned and Trabecular. For the in vitro experiment, Sprague Dawley (SD) rat marrow-derived bone marrow cells (BMC) were seeded on samples. Alkaline phosphatase (ALP ...


Design And Development Of Optical Elastography Setup, Abhinav Madhavachandran Jan 2016

Design And Development Of Optical Elastography Setup, Abhinav Madhavachandran

Dissertations, Master's Theses and Master's Reports

The mechanical properties of the skin are an indication of its physiological condition. The properties can serve as potential information for dermatologists for diagnosis and qualitative assessment. Elastography is a medical imaging modality developed to extract the elastic properties of a tissue by application of an external force. Optical elastography is a technique of elastography which uses laser speckle tracking to study the elastic properties of several soft tissue including skin.

This work is aimed at developing an optical elastography setup that can study the elastic properties of skin. The setup includes an imaging system and a force-application system controlled ...


Effects Of Scattering And Absorption On Laser Speckle Contrast Imaging, Kosar Khaksari Jan 2016

Effects Of Scattering And Absorption On Laser Speckle Contrast Imaging, Kosar Khaksari

Dissertations, Master's Theses and Master's Reports

Laser Speckle Contrast Imaging (LSCI) is a real-time, non-invasive method in used to investigate blood flow and perfusion in biological tissues with high temporal and spatial resolution. A reduction in speckle contrast due to particle motion is the primary contrast mechanism in LSCI. Motion results in speckle fluctuations in time and reduces the contrast over a given camera integration period. There are a variety of parameters that effect contrast besides motion. The optical properties of the scattering medium are one of the parameters effecting LSCI values. Changes in blood hematocrit levels manifest as changes in optical properties. In this work ...


Use Of Lidar In The Design Of Grassed Waterways: Case Study In Agricultural Management In Oklahoma, Annette Sparks Jan 2016

Use Of Lidar In The Design Of Grassed Waterways: Case Study In Agricultural Management In Oklahoma, Annette Sparks

Dissertations, Master's Theses and Master's Reports

Before the advent of Light Detection and Ranging (LiDAR) technology, farm-level infrastructure for sustainable agriculture was designed using topographic maps. LiDAR is a remote sensing method whereby reflected laser pulses are measured to generate high-resolution 3D images of the terrain. This report compares these two methods in the design of grassed waterways for flood drainage and evaluates how the quantitative difference between the two methods can affect the overall hydrologic design. The benefits of LiDAR are expected to be higher accuracy and precision in design, as well as greater reproducibility or consistency, regardless of the designer. To carry out this ...


Wireless Implantable Magnetoelastic Sensors And Actuators For Biomedical Applications, Andrew Derouin Jan 2016

Wireless Implantable Magnetoelastic Sensors And Actuators For Biomedical Applications, Andrew Derouin

Dissertations, Master's Theses and Master's Reports

Magnetoelastic sensors represent a low-cost wireless and battery-less method for monitoring parameters in embedded or implanted applications; however, some limitations still exist preventing their commercial implementation. Presented in this work are a variety of studies that are aimed at improving the feasibility of magnetoelastic materials for sensing and actuating applications. Magnetoelastic resonant sensors of non-standard geometries were investigated to determine if geometry could play a role on the sensitivity of the sensor response to mass loading. It was shown that a significant increase in sensitivity could be achieved by using triangular sensors rather than standard rectangular strips. A method for ...


Inhibition Of Bacterial Growth And Prevention Of Bacterial Adhesion With Localized Nitric Oxide Delivery, Julia Osborne Jan 2016

Inhibition Of Bacterial Growth And Prevention Of Bacterial Adhesion With Localized Nitric Oxide Delivery, Julia Osborne

Dissertations, Master's Theses and Master's Reports

Bacterial infections continue to be a problem at the site of an indwelling medical device, and over the years, various bacterial strains have become more resistant to current antibiotic treatments. Bacterial infection at an indwelling medical device can be dangerous and affect the performance of the medical device which can ultimately lead to the failure of the device due to bacterial resistance to treatment.

Nitric Oxide (NO) has been shown to possess antibacterial properties to prevent and inhibit bacterial growth. NO releasing coatings on indwelling medical devices could provide a reduction in bacterial infections that occur at the device site ...


Mechanical Impedance Of Ankle As A Function Of Electromyography Signals Of Lower Leg Muscles Using Artificial Neural Network, Chen Jia Jan 2015

Mechanical Impedance Of Ankle As A Function Of Electromyography Signals Of Lower Leg Muscles Using Artificial Neural Network, Chen Jia

Dissertations, Master's Theses and Master's Reports - Open

This paper reports on the feasibility of developing a model to describe the nonlinear relationship between the mechanical impedance of the human ankle within a specified range of frequency and the root mean square (RMS) value of the Electromyography (EMG) signals of the muscles of human ankle using Artificial Neural Network (ANN). A lower extremity rehabilitation robot — Anklebot was used to apply pseudo-random mechanical perturbations to the ankle and measure the angular displacement of the ankle to estimate the data of ankle mechanical impedance. Meanwhile, the surface EMG signals from the selected muscles were monitored and recorded using a Delsys ...


Gelatin Microgel Incorporated Poly (Ethylene Glycol) Bioadhesive With Enhanced Adhesive Property And Bioactivity, Yuting Li Jan 2015

Gelatin Microgel Incorporated Poly (Ethylene Glycol) Bioadhesive With Enhanced Adhesive Property And Bioactivity, Yuting Li

Dissertations, Master's Theses and Master's Reports - Open

In this study, chemically crosslinked gelatin microgels were incorporated into dopamine-modified poly (ethylene glycol) (PEGDM) adhesive to form composite bioadhesive with simultaneously improved adhesive property and bioactivity. Gelatin microgel, with an average diameter of 53.6±14.2μm, was prepared with water in oil emulsification method and chemically crosslinked with
1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Gelatin microgels were incorporated into PEGDM adhesive precursor solution at 1.5wt%, 3.75wt% and 7.5wt%. The cure time of adhesive reduced from 54 seconds to 37 seconds with increasing gelatin microgel content. Additionally, the incorporation of the gelatin microgel also ...


Ph Responsive, Adhesive Hydrogels Based On Reversible Catechol - Boronic Acid Complexation, Ameya Ravindra Narkar Jan 2015

Ph Responsive, Adhesive Hydrogels Based On Reversible Catechol - Boronic Acid Complexation, Ameya Ravindra Narkar

Dissertations, Master's Theses and Master's Reports - Open

Smart hydrogel adhesives with tunable properties consist of adhesive moieties in the polymer network that respond to external stimuli like pH, temperature, etc. Responsiveness of smart adhesives to pH, in particular, is important because of the simple actuation mechanism and the ability to achieve facile bonding and debonding upon command. Covalently crosslinked hydrogel adhesives were prepared by employing an N-HEAA (hydroxyethyl acrylamide) backbone embedded with dopamine methacrylamide (DMA), a marine mussel inspired adhesive protein and 3-acrylamido phenylboronic acid (AAPBA), to determine the effect of pH on the interfacial binding properties of the hydrogel adhesive with a borosilicate glass substrate. Swelling ...


The Influence Of Passive Ankle Joint Power On Balance Recovery, Stephanie E. Hamilton Jan 2015

The Influence Of Passive Ankle Joint Power On Balance Recovery, Stephanie E. Hamilton

Dissertations, Master's Theses and Master's Reports - Open

Over one–third of Americans over the age of 65 fall each year, costing more than $19 billion in health care costs in 2000. Many adults 65+ who have not experienced a fall still fear falling, and fear can decrease quality of life and increase the likelihood of falls. Several factors such as muscle strength, power, stiffness and tendon properties change in the human body with age affecting balance, which has been tagged as a fall risk predictor. Additionally, balance recovery strategies also differ between young and older adults, with young adults primarily utilizing their ankle joint and older adults ...


Development Of A Cell Morphological Analysis Tool To Evaluate The Ultrasound Vibrational Effects On Cell Adhesion, Joseph M. Smith Jan 2015

Development Of A Cell Morphological Analysis Tool To Evaluate The Ultrasound Vibrational Effects On Cell Adhesion, Joseph M. Smith

Dissertations, Master's Theses and Master's Reports - Open

Fibroblast encapsulation is a stage of the wound healing process in which the implanted device is separated from the biological environment due to the formation of fibrotic tissue. Uncontrolled adhesion of fibroblasts, called fibrosis, has the ability to inhibit an implanted device’s functionality over its lifetime. Over time, fibroblasts have been shown to cause loosening and failure of bone-anchor implants which could include the possibility of harming the patient. The encapsulating process could also hinder the sensitivity of implanted biosensors operating in the body for continuous monitoring. Unfortunately, the antifouling surfaces which are commonly used on implanted devices to ...


Engineering Approaches For Suppressing Deleterious Host Responses To Medical Implants, Connor Mccarthy Jan 2015

Engineering Approaches For Suppressing Deleterious Host Responses To Medical Implants, Connor Mccarthy

Dissertations, Master's Theses and Master's Reports

Small diameter (< 6 mm) vascular grafts suffer from serious deleterious effects not encountered with their larger diameter relatives, leading to premature graft failure through restenosis. Platelet activation, inflammation, and smooth muscle cell proliferation are leading contributors to thrombosis and neointimal hyperplasia, both contributors to the progression of restenosis. It may be possible to suppress negative biological responses to vascular implants through the modification of surface properties and incorporation of drug release into blood contacting materials. In this work, bioengineering approaches are presented to improve the biocompatibility of small diameter vascular grafts.

We demonstrate a novel engineering approach for incorporating natural, decollagenized elastin matrices into PEU 1074A reinforced vascular grafts through spray-coating and electrospinning processes in a manner that retains elastin’s excellent blood contacting properties. A vascular construct with excellent mechanical and surgical handling properties demonstrating the suppression of neointimal hyperplasia is presented after 21 days in vivo.

Nitric oxide (NO) has been investigated over the past several decades due to its platelet, inflammation, and smooth muscle cell suppressing effects; and if appropriately delivered, could positively mediate the contributors to restenosis. Here, we characterize a novel macrocyclic NO donor ...


Biocorrosion Rate And Mechanism Of Metallic Magnesium In Model Arterial Environments, Patrick Bowen Jan 2015

Biocorrosion Rate And Mechanism Of Metallic Magnesium In Model Arterial Environments, Patrick Bowen

Dissertations, Master's Theses and Master's Reports

A new paradigm in biomedical engineering calls for biologically active implants that are absorbed by the body over time. One popular application for this concept is in the engineering of endovascular stents that are delivered concurrently with balloon angioplasty. These devices enable the injured vessels to remain patent during healing, but are not needed for more than a few months after the procedure. Early studies of iron- and magnesium-based stents have concluded that magnesium is a potentially suitable base material for such a device; alloys can achieve acceptable mechanical properties and do not seem to harm the artery during degradation ...