Biomaterials Commons^™

In Vitro And In Vivo Diabetic Models For Assessment Of Tissue Engineered Vascular Grafts, Juan Carlos Carrillo Garcia

All Dissertations

Diabetes has become one of the leading causes of lower-limb loss worldwide. Every 30 seconds, a person loses a limb due to diabetic-related vascular complications. About one-third of patients needing lower-limb bypass surgery have debilitated autologous vessels unsuitable for use, and no other good long-term options are available. These detrimental effects on the vasculature are caused mainly by the hyperglycemic and hyperlipidemic conditions derived from diabetes. Under these conditions, an increase in advanced glycation end products (AGEs) and reactive oxygen species leads to irreversible crosslinks of extracellular matrix proteins, accelerating vascular pathology through vascular stiffening, endothelial dysfunction, inflammation, atherosclerosis, fibrosis, …

Highly Adherent Antimicrobial Coatings For Orthopedic Implants, Mikhail Bredikhin

All Dissertations

Fracture-related infections (FRIs) are the most devasting sort of complications associated with fracture fixation devices, as they lead to patients’ morbidity, prolonged hospitalization, amputations, and even death.External fixators additionally suffer from pin site infections (PSIs), which initiate at the skin entry points of the skin-metallic pin interface present in the external fixation of the damaged bones, often causing deep tissue infection and osteomyelitis. Small percutaneous pins, commonly known as Kirschner wires (K-wires), are used to treat complex fractures and deformities.They are drilled inside the diseased bone for the healing period and are left protruding outside the skin for fixation adjustments …

Alternative Fixation Of Venous Valves For Bioprosthetic Applications, Makenzie Kapales

Biomedical Engineering Undergraduate Honors Theses

Venous valve failure allows for the retrograde, or backward, flow of blood into the lower extremities, which leads to Chronic Venous Insufficiency (CVI). CVI infringes upon quality of life through ulceration and can result in death due to Deep Vein Thrombosis (DVT), or blood clots, causing pulmonary embolism. A successful treatment of CVI restores valve function and prevents retrograde blood flow; however, current bioprosthetic venous valves exhibit low patency and high calcification. To improve upon bioprosthetic venous valves and CVI treatment, the University of Arkansas’s Cardiovascular Biomechanics Lab conducts studies with the purpose of comparing the properties and performance of …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Incorporation Of Lignin In Natural And Synthetic Biomaterials To Alter Mechanical And Biochemical Properties For Enhanced Wound Healing, Jorge Alfonso Belgodere

LSU Doctoral Dissertations

It is estimated that chronic, non-healing wounds affect more than 6.5 million Americans annually, with an estimated healthcare cost beyond $14 billion. Here, we attempted to create composites of natural (collagen type I or gelatin-methacrylate) or synthetic (poly(ethylene glycol) polymers incorporating a natural plant component, lignin, to combat the costs and limitations current wound healing methods face. Three-dimensional matrices of collagen type I (Col I) are widely used in tissue engineering applications for its abundance in many tissues, bioactivity with many cell types, and excellent biocompatibility. Inspired by the structural role of lignin in plant tissue, we found that sodium …

Pilot Study Exploring The Effect Of Targeted Cox-2 Inhibition In Macrophages Responding To Neuronal Injury; Promoting Enhanced Axonal Regeneration, Alyssa Brauckmann

Electronic Theses and Dissertations

Celecoxib nanoemulsion (CXB-NE) has been developed as a macrophage targeted analgesics by Dr. Janjic and her team at Duquesne University, (Janjic et al, 2018; Liu et al, 2020; Saleem et al, 2019b; Vasudeva et al, 2014). The CXB-NE nanoemulsion carrying a Nonsteroidal Anti-inflammatory (NSAID) inhibitor of COX-2 activity result in a reduction in PGE2 expression in macrophages. Using CXB-NE in rats that have peripheral nerve injury constricting the sciatic nerve relieves hypersensitivity, a pain-like behavior. The treatment also decreases inflammation associated with this chronic constriction injury (Janjic et al, 2018; Saleem et al, 2019b; Stevens et al, 2019). In this …

Modified Stent Design For A Coronary Bifurcation Lesion, Abigail Nowell

Biological Sciences Undergraduate Honors Theses

Currently, 18.2 million adults aged 20 and older are diagnosed with Coronary Artery Disease (CAD) (Benjamin et al., 2019). Stenosis is the most common intervention. However, when a patient has a bifurcated artery, treatment becomes more difficult and is often unsuccessful. This project created a new stent and balloon complex that was tested in vitro using a gel phantom artery model. Two separate prototypes have been created and tested so far, with improvements made upon each. Testing is still underway with Prototype 2.

Investigating Virus Clearance Via Ph Inactivation During Biomanufacturing, Wenbo Xu

Biomedical Engineering Undergraduate Honors Theses

In the processing of biopharmaceuticals, viral clearance and viral safety are important for the development of monoclonal antibodies. Murine xenotropic leukemia virus (XMuLV) is one of the retroviruses, recommended by Food and Drug Administration (FDA) as a model virus for viral clearance via inactivation from therapeutics derived from Chinese hamster ovary cells (CHO). A robust and effective method was investigated to clear or inactivate endogenous viruses by low pH inactivation. The effects of different conductivity and inactivated time on XMuLV clearance was determined. Acetate buffer was prepared with different conductivity, and 2% XMuLV was spiked into acetate buffer. XMuLV virus …

Development Of In Situ Forming Hydrogels For Intra-Articular Drug Delivery, Andy Prince

Electronic Thesis and Dissertation Repository

Hydrogels are 3-dimensional crosslinked polymer networks that can absorb significant amounts of water. The physical properties associated with hydrogels affords them resemblance to biological tissues making them good candidates for biomedical applications. Many pharmaceuticals, specifically non-steroidal anti-inflammatory drugs (NSAIDs), have poor aqueous solubility, which limits their bioavailability and efficacy. People suffering from chronic osteoarthritis (OA) are required to frequently take large doses to mitigate pain, which can lead to serious side effects. Hydrogels are good strategies to deliver NSAIDs via articular injection because they can form solid gels in situ. This thesis describes the synthesis, formulation, mechanical testing, in …

Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline A. De Lora

Biomedical Sciences ETDs

Adaptation of cancer cells to changes in the biochemical microenvironment in an expanding tumor mass is a crucial aspect of malignant progression, tumor metabolism, and drug efficacy. In vitro, it is challenging to mimic the evolution of biochemical gradients and the cellular heterogeneity that characterizes cancer tissues found in vivo. It is well accepted that more realistic and controllable in vitro 3D model systems are required to improve the overall cancer research paradigm and thus improve on the translation of results, but multidisciplinary approaches are needed for these advances. This work develops such approaches and demonstrates that new droplet-based cell-encapsulation …

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 …

Mimicking The Arterial Microenvironment With Peg-Pc To Investigate The Roles Of Physicochemical Stimuli In Smc Phenotype And Behavior, William G. Herrick

Doctoral Dissertations

The goal of this dissertation was to parse the roles of physical, mechanical and chemical cues in the phenotype plasticity of smooth muscle cells (SMCs) in atherosclerosis. We first developed and characterized a novel synthetic hydrogel with desirable traits for studying mechanotransduction in vitro. This hydrogel, PEG-PC, is a co-polymer of poly(ethylene glycol) and phosphorylcholine with an incredible range of Young’s moduli (~1 kPa - 9 MPa) that enables reproduction of nearly any tissue stiffness, exceptional optical and anti-fouling properties, and support for covalent attachment of extracellular matrix (ECM) proteins. To our knowledge, this combination of mechanical range, low …

Evaluation Of Tissue-Engineered Tendon Enthesis Polymer Constructs, Joshua A. Bundy Bs, Mary Beth Wade Phd, Hitomi Nakao Md, Phillip Mcclellan Phd, Qing Yu Phd, Robin Jacquet-Childs Ms, William J. Landis Phd

Williams Honors College, Honors Research Projects

Both scientists and clinicians have proposed tissue engineering as the future of medicine. The possibilities for tissue engineering, that is, fabrication of tissues and organs in the laboratory and their translation to patients, appear to be endless, and many believe that this new approach in medicine will result in abolishing many common ailments, injuries, and congenital defects. Injuries to a tendon enthesis, the normal tissue connection between tendon and bone, are of particular concern to clinicians because of their frequency and failure to repair as a result of surgery. While these injuries may not be life threatening, they can certainly …