Biomedical Engineering and Bioengineering Commons^™

Fluid Flow-Induced Mesenchymal Stem Cell Migration: Role Of Fak And Rock Mechanosensors, Brandon D. Riehl

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The study of mesenchymal stem cell (MSC) migration under mechanical stimulation conditions with investigation of the underlying molecular mechanism could lead to a better understanding and outcomes in stem cell-based regenerative medicine. MSCs having multipotent regenerative capability exist in niches in the bone marrow, muscle, vasculature, and in other tissues throughout the body, and their migration through tissues and vasculature for the repair of damaged tissue is a key process of cell and tissue homeostasis, remodeling, and regeneration. While cell migration in response to cytokines and other chemo-attractants is relatively well understood, little is revealed in regard to the effect …

Modeling And Experimental Methods To Predict Oxygen Distribution In Bone Defects Following Cell Transplantation, Christopher M. Heylman, Sharon Santoso, Melissa D. Krebs, Gerald M. Saidel, Eben Alsberg, George F. Muschler

Biomedical Engineering

We have developed a mathematical model that allows simulation of oxygen distribution in a bone defect as a tool to explore the likely effects of local changes in cell concentration, defect size or geometry, local oxygen delivery with oxygen-generating biomaterials (OGBs), and changes in the rate of oxygen consumption by cells within a defect. Experimental data for the oxygen release rate from an OGB and the oxygen consumption rate of a transplanted cell population are incorporated into the model. With these data, model simulations allow prediction of spatiotemporal oxygen concentration within a given defect and the sensitivity of oxygen tension …

Human Hair Keratin Protein, Hair Fibers And Hydroxyapatite (Ha) Composite Scaffold For Bone Tissue Regeneration, Samuel Siyum

ETD Archive

The field of tissue engineering aims at promoting the regeneration of tissues or replacement of failing or malfunctioning tissue by means of combining a scaffold material, adequate cells and bioactive molecules. Different materials have been proposed for use as three-dimensional porous scaffolds for bone tissue engineering procedures. Among them, polymers of natural origin are one of the most attractive options mainly due to their similarities with the extracellular matrix (ECM), chemical versatility as well as typically good biological performance. In this study, two biocompatible composite scaffolds were developed from natural polymer by tissue engineering approach and tested in vitro. The …

Biological Scaffolds For Peripheral Vascular Surgery, George Fercana

All Dissertations

The gold standards for small diameter peripheral vascular graft replacement are autologous arteries or veins; however, one-third of patients lack such vessels due to previous vessel harvesting or advanced vascular disease. A promising approach for patients in this category is tissue engineering with off-the-shelf biological vascular grafts. Three small diameter acellular scaffolds were developed and evaluated as vascular grafts. Porcine renal arteries (2-3 mm diameter, 20 mm length) were decellularized by immersion and stabilized with penta-galloyl glucose (PGG) with and without subsequent heparinization via carbodiimide chemistry. Bovine mammary (4-6 mm ID, 250 mm length) and femoral arteries (6-8 mm ID, …

A Novel Hybrid Hydrogel For Scaffold-Mediated Gene Delivery, Jeremy Zhang

All Dissertations

Scaffold-mediated nonviral gene delivery avoids several drawbacks of systemic injection such as clearance by the reticulo-endothelial system and serum aggregation. Existing synthetic and natural polymers used in gene delivery scaffolds are primarily derived from other tissue engineering applications with design parameters focused on the physicochemical properties of the scaffold and its biocompatibility. Common synthetic materials used in polymeric scaffolds such as PEG are practically bio-inert with minimal cell and protein interaction. Therefore, an opportunity exists for the rational design novel gene delivery scaffolds with components capable of increasing the expression of incorporated transgene by including scaffold components that interact with …

Spatial Control Of Magnetic Nanoparticles Integrated With Cellular Spheroids As Tissue Engineered Building Blocks, Brandon Mattix

All Dissertations

Magnetic nanoparticles (MNPs) have been investigated in tissue engineering applications to provide in situ imaging, drug delivery, and tissue patterning, but direct and prolonged interaction between cells and MNPs can have adverse effects on cell function. Therefore, methods which reduce or limit the interaction of MNPs with cells, or utilize more biocompatible MNP-based strategies will improve upon the commonly used iron oxide MNPs. We investigated a variety of methods to improve upon the use of MNPS in tissue engineering.
Cell aggregates, or spheroids, have been used as tissue engineered building blocks that can closely mimic the native three-dimensional in vivo …

Shelf Life Study Of Electrospun Plga Copolymers, Sean Youra, Nick Hudson

Biomedical Engineering

Poly(lactic-co-glycolic acid) (PLGA) is one of the most commonly used copolymers for electrospinning in tissue engineering applications. However, most research has not focused on the copolymer itself in regards to how long it can be used effectively and if varying the concentrations of polylactic acid (PLA) and polyglycolic acid (PGA) affect the resulting properties. Electrospinning is the method we use to create the three-dimensional constructs, or “scaffolds”, for the blood vessel mimic (BVM) in the tissue engineering lab. The aim of our project was to investigate if the morphology and mechanical properties of the scaffolds changed over time when they …

Multilayer Bioactive Glass/Zirconium Titanate Thin Films In Bone Tissue Engineering And Regenerative Dentistry, Masoud Mozafari, Erfan Salahinejad, Vahid Shabafrooz, Mostafa Yazdimamaghani, Daryoosh Vashaee, Lobat Tayebi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Surface modification, particularly coatings deposition, is beneficial to tissue-engineering applications. In this work, bioactive glass/zirconium titanate composite thin films were prepared by a sol-gel spin-coating method. The surface features of the coatings were studied by scanning electron microscopy, atomic force microscopy, and spectroscopic reflection analyses. The results show that uniform and sound multilayer thin films were successfully prepared through the optimization of the process variables and the application of carboxymethyl cellulose as a dispersing agent. Also, it was found that the thickness and roughness of the multilayer coatings increase nonlinearly with increasing the number of the layers. This new class …

Mesenchymal Stem Cells As Targeted Cell Vehicles To Deliver Drug-Loaded Nanoparticles For Cancer Therapy, Kytai Truong Nguyen

Bioengineering Faculty Publications - Archive

No abstract provided.

Stem Cell Based Tissue Engineering And Regenerative Medicine: A Review Focusing On Adult Stem Cells, Jordan Greenberg, Veronica R. Fortino, Daniel Pelaez, Herman S. Cheung

Biology Faculty Articles

Tissue engineering has emerged as a field that attempts to harness the bodies' own developmental and repair features to treat diseases and illnesses. Many of these illnesses are caused by necrosis or loss of functionality of complete organs or specific cell types. Early discoveries in embryonic stem cells fueled a wave of research that led to claims about possibly regenerating nonfunctioning organs. Although we are still far away from being able to grow functional organs in a Petri dish, the field continues to progress forward, and new clinical trials have been approved for using both embryonic and adult stem cell …

Design Of Experimentation To Systematically Determine The Interaction Between Electrospinning Variables And To Optimize The Fiber Diameter Of Electrospun Poly (D, L-Lactide-Co-Glycolide) Scaffolds For Tissue Engineered Constructs, Yvette S. Castillo

Master's Theses

Cardiac disease causes approximately a third of the deaths in the United States. Furthermore, most of these deaths are due to a condition termed atherosclerosis, which is a buildup of plaque in the coronary arteries, leading to occlusion of normal blood flow to the cardiac muscle. Among the methods to treat the condition, stents are devices that are used to restore normal blood flow in the atherosclerotic arteries. Before advancement can be made to these devices and changes can be tested in live models, a reliable testing method that mimics the environment of the native blood vessel is needed. Dr. …

Quantitative, Spatial Imaging Based Measurements To Assess Cellular Health And Oxygenation In A Tissue Engineered Test System, Erik Bland

All Dissertations

Three-dimensional in vitro tissue test systems are employed to examine cell behavior, test responses to drugs and vaccines, and answer basic biological questions. These systems are more physiologically relevant than two-dimensional cell cultures, and are more relevant, easier and less expensive to maintain than animal models. However, methods used to measure cell behavior and viability have been developed specifically for two-dimensional cell cultures or animal models, and are often not optimally translated to three-dimensional in vitro test systems. The purpose of this work was to aid in the development of three-dimensional, spatially controlled in vitro test systems, and to develop …

Evaluation Of Decellularization Procedures For Porcine Arteries, Charles Clapp

Biomedical Engineering

Coronary artery disease has become the leading cause of death in the United States, with over 425,000 deaths in 2006. Stenting has evolved into the preferred preventative technique for myocardial infarction by opening up an occluded artery, due to its low invasiveness compared to the alternative of coronary artery bypass grafting. Bare metal stents have been improved by coating with anti-proliferative drugs to advance their effects, but even drug eluting stents still have a risk of restenosis, thrombus formation, and necessary revascularization. Continual advancement in stent design necessitates faster, effective pre-clinical evaluation techniques. Kristen Cardinal, Ph.D., developed the blood vessel …

Investigation Of A New Material For Heart Valve Tissue Engineering, Claire Brougham, Nian Shen, Allison Cudsworth, Thomas Flanagan, Stefan Jockenhoevel, Fergal O'Brien

Conference Papers

No abstract provided.

Micropatterned Electrospun Nanofibrous Substrates As Scaffolds For Engineered Salivary Glands, David Alexander Soscia

Legacy Theses & Dissertations (2009 - 2024)

The salivary gland is a complex organ exhibiting a branching, 3-dimensional structure made up of acinar (saliva-producing), and ductal (saliva transporting and modifying) epithelial cells. The high surface area of the gland allows it to efficiently provide the mouth with saliva, maintaining oral cleanliness and comfort. Salivary gland hypofunction, a significant clinical problem often caused by the autoimmune disease Sjögren's syndrome or head and neck radiation for cancer patients, affects millions of Americans and is characterized by a loss of function of salivary gland acinar cells. Chronic xerostomia, or dry mouth, arises as a result of salivary gland hypofunction and …

A Novel In-House Design Of A Bioreactor For The Modeling Of An In Vitro Blood Brain Barrier Model, Ian Mahaffey

Biomedical Engineering

The blood brain barrier is the protector of the central nervous system and a physical barrier that functions to regulate the substances that can pass in and out of the brain; it is the function and integrity of this system that keeps the homeostasis of the central nervous system. Yet this shield against foreign invaders in the blood also prevents drugs designed for treatment of various ailments of the central nervous system from reaching their target in the brain. Developing drugs that can pass through this barrier, and understanding it’s function has become an area of increasing interest. Many researchers …

Magic From Human Regenerative Technologies -- Stem Cells, John M. Ritz

STEMPS Faculty Publications

The article discusses the developments in stem cell research and development. It mentions that through tissue engineering or regenerative medicine, many diseases are finding techniques for improvement and cure. It discusses the role of stem cells in mending the human body and the ethics associated with this technology . It is mentioned that stem cells are divided in 2 types: embryonic stem cells and adult stem cells. It includes the process of cell differentiation which determines the properties and characteristics of cells. It mentions several diseases related to sports injury, spinal cord injuries, blood and heart disorders to be to …

Shape-Shifting Surfaces For Rapid Release And Direct Stamping Of Organized Micro-Tissues, Samuel James Dupont

USF Tampa Graduate Theses and Dissertations

The primary aim of the research in this study is to develop a robust and simple platform for the in vitro organization of cells on surfaces which facilitate rapid cell release and allows for the direct stamping of highly organized micro-tissues. Current approaches towards this goal have been very successful but are lengthy and subject cells to harsh conditions for extended periods of time raising questions regarding cell health and maintenance of physiological state. To address these concerns a platform was developed to allow for rapid cell release by utilizing a release mechanism different from previous work.

Micron-scale structures comprised …

Tissue Engineering An Acellular Bioresorbable Vascular Graft To Promote Regeneration, Patricia Wolfe

Theses and Dissertations

Tissue engineering is an interdisciplinary field that aims to restore, maintain, or improve diseased or damaged tissues. Electrospinning has become one of the most popular means to fabricate a scaffold for various tissue engineering applications as the process is extremely versatile and inexpensive. The ability for electrospinning to consistently create nanofibrous structures capable of mimicking the native extracellular matrix (ECM) is the basis behind why this technique is so successful in tissue engineering. Cardiovascular disease has been the leading cause of death in the United States for over 100 years, and because of this, the need for coronary artery replacements …

Development Of An In-Vitro Hyperglycemic Tissue Engineered Blood Vessel Mimic, Brian C. Wong

Biomedical Engineering

No abstract provided.

A 3-Dimensional Vascularized Cardiac Tri-Culture Model Using Chitosan Nanofiber Scaffolds, Ali Hussain

Dissertations

The development of an in vitro tissue model that can mimic the 3-dimenisonal (3-D) cellular architecture and mosaic of myocardial tissue holds great value for cardiac tissue engineering, modeling, and cardiovascular drug screening applications. The main objective of this project was to develop a 3-D vascularized cardiac tissue model in vitro for improved survival and function.

The cellular mosaic of the myocardial tissue demands the intricate integration of an extracellular matrix-like scaffold, cellular constituents, and biological factors. The first aim of the research was to fabricate and characterize a biodegradable chitosan nanofiber scaffold that would resemble the extracellular matrix (ECM) …

Development Of Physiologic Contact Models For Articular Surfaces, John Owen

Theses and Dissertations

The superficial tangential zone (STZ) plays a significant role in normal articular cartilage’s ability to support loads and retain fluids. To date, tissue engineering efforts have not replicated normal STZ function in cartilage repairs. Finite element models were developed to examine the STZ’s role in normal and repaired articular surfaces under different contact conditions. Models were developed by incrementally adding improvements which culminated in contact loading of curved models by permeable and impermeable rigid surfaces and a normal cartilage layer. In the normal STZ, permeability was strain-dependent on volumetric strain; tension-compression nonlinearity modeled collagen behavior. Nonlinear geometry accounted for finite …

Novel Nanofiber Structures And Advanced Tissue Engineering Applications, Vince Beachley

All Dissertations

Extracellular matrix (ECM) nanofibers such as collagen and elastin make up an important component of natural tissues. These structural components serve to impart mechanical strength and provide locations for cell attachment and biomolecule storage. Cells respond to their structural environment in a wide variety of ways beyond physical support, and it has been demonstrated that this environment directly modulates cell behaviors such as, morphology, differentiation, ECM production, attachment, and migration. ECM nanofibers also play an important role as a template for tissue formation during development, remodeling, and regeneration. Nanofiber based tissue engineering strategies aim to mimic the geometry of the …

A Study On The Applications And Toxicity Assessments Of Carbon Nanotubes In Tissue Engineering, Rena Baktur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carbon nanotubes (CNTs) are one of the most popular nanomaterials. There has been increasing interest in the development and applications of carbon nanotubes due to their huge potential in industrial and medical applications. Recent applications of carbon nanotubes include development of scaffolds and drug delivery systems. Despite rapidly emerging applications of CNTs, little is known about the impact of CNTs on cellular processes, especially mesenchymal stem cell (MSC)'s differentiation. Also, the effects of nanoparticle exposure under different conditions on cellular responses have not been well characterized yet.

To characterize the effects of CNTs on creating nanoscale scaffolds for tissue engineering, …

One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell

ETD Archive

The flow of nutrients through any biological tissue is important to maintain homeostasis. If the transport process is understood, medical research teams can better design medications, prosthetic implants, and tissue scaffolds. Additionally, transport rates help physicians to better understand disease states and wound healing, including minor injuries such as breaks and sprains, which will aid in better diagnoses. We developed a novel method that measures the rate of diffusion in vitro, of fluorescein sodium salt. Samples were incubated at 37°C in a 5 CO2 atmosphere for various periods of time. Samples were sliced and analyzed using Image-Pro Plus and MATLAB …

Characterization And Evaluation Of A Novel Tissue Engineered Aortic Heart Valve Construct, Mary Tedder

All Dissertations

Tissue engineering holds great promise for treatment of valvular diseases. Scaffolds for engineered heart valves must function immediately after implantation, but must also permit repopulation with autologous host cells and facilitate gradual remodeling.
Native aortic heart valves are composed of three layers, i.e. two strong external fibrous layers (ventricularis and fibrosa) separated by a central, highly hydrated spongiosa. The fibrous layers provide strength and resilience while the spongiosa layer facilitates shearing of the external layers. Our working hypothesis is that partially cross-linked collagen scaffolds that closely mimic the layered histo-architecture of the native valve would fulfill these requirements. To test …

Evaluation Of Factors That Modulate Cellular Adipogenesis For Breast Tissue Engineering Strategies, Cheryl Gomillion

All Dissertations

It is estimated that this year more than 200,000 women in the United States will be diagnosed with breast cancer. Treatment for most occurrences of breast cancer will often include surgical removal of the tumorigenic tissue, resulting in a soft tissue defect within the subcutaneous tissue of the skin. Post-surgical reconstruction methods are often sought by patients to restore the aesthetic function of the breast via cellular or non-cellular methods; however, because of complications associated with currently used methods for breast reconstruction, researchers are investigating tissue engineering methods to produce viable autologous adipose tissue for breast reconstruction.
Previous research in …

Effect Of Mechanical Stimulation On Mesenchymal Stem Cell Seeded Cartilage Constructs, Karin Wartella

Theses and Dissertations

Cartilage tissue engineered constructs using mesenchymal stem cells were stimulated with 3 different stimulation algorithms to achieve characteristics mimicking the superficial tangential zone of articular cartilage. The stimulation algorithm of both compression and tension without an offset had the best properties out of all the evaluated groups.

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, …