Biomaterials Commons^™

Optimized 3d-Printing Of Carbon Fiber-Reinforced Polyether-Ether-Ketone (Cfr-Peek) For Use In Overmolded Lattice Composite, Ryan C. Ogle

Masters Theses

Current orthopedic implants are overwhelmingly composed from metallic materials. These implants show superior mechanical properties, but this can additionally result in stress shielding due to a modulus mismatch between the bone tissue and implanted device. Polymeric implants reduce this stress shielding effect but have much lower mechanical properties, limiting their use. Polylactic acid (PLA) is a widely used biodegradable thermoplastic polymer, however, its use has been limited by the polymer’s mechanical properties and rapid loss of strength during degradation in vivo. Polyether-ether-ketone (PEEK) is another common biocompatible polymer , with chemical and mechanical properties which make it a popular alternative …

Iron Nanoparticles For Magnetic Imaging Applications, Aleia Williams

Masters Theses

Extensive research on iron oxide nanoparticles for various applications including nanomedicine, energy applications, environmental remediation, and magnetic imaging have previously been performed. Many are currently FDA approved as magnetic resonance imaging contrast agents and tracers for magnetic particle imaging applications. Magnetic properties of such materials are crucial to obtain good contrast and resolution. However, studies have shown the magnetic properties of iron oxide nanoparticles are less in comparison to those found in pure iron nanoparticle.

This research involves the synthesis and characterization of iron nanoparticles for applications in magnetic resonance imaging contrast agents, magnetic particle imaging tracers, and therapeutic agents …

Brain Inspired Organic Electronic Devices And Systems For Adaptive Signal Processing, Memory, And Learning., Subhadeep Koner

Doctoral Dissertations

A new class of electronic device has emerged which bear the potential for low powered brain like adaptive signal processing, memory, and learning. It is a non-linear resistor with memory coined as memristor. A memristor is a two-terminal electrical device which simultaneously changes its resistance (processing information) and store the resistance state pertaining to the applied power (memory). Therefore, it can collocate memory and processing much like our brain synapse which can save time and energy for information processing. Leveraging stored memory, it can thereby help future engineered systems to learn autonomously from past experiences. There has been a growing …

Effect Of Ambient Oxidation On Chemical Composition And Structural Properties Of Iron Nanoparticles For Hyperthermia And Medical Imaging, Adam Wesley Evans

Doctoral Dissertations

With magnetization saturation roughly twice that of iron oxide nanoparticles, metallic iron nanoparticles (also termed zero-valent iron nanoparticles) have desirable properties for use as a magnetic resonance imagining (MRI) contrast agent as well as a medium for hyperthermia treatment of cancer. Metallic iron nanoparticles, however, are difficult to synthesize and maintain due to their high degree of reactivity and proclivity for oxidation. The main goal of this study was to investigate how ambient oxidation affects the chemical composition and structural properties of metallic iron nanoparticles initially synthesized through a facile reduction reaction of iron (III) chloride with sodium borohydride. A …

Emergency Eye Simulation Model, Gavin L. Warrington, Christopher Forsyth, Lexus Morris, Natalie Ledezma

Chancellor’s Honors Program Projects

No abstract provided.

Crafting Nanostructured Neural Interfaces With Hydrogel Particles, Emily Ann Morin

Doctoral Dissertations

Central nervous system neural device functionality hinges on effective communication with surrounding neurons. This depends on both the permissiveness of the device material to promote neuron integration and the ability of the device to avoid a chronic inflammatory response. Here, a facile approach has been developed exploring the multiple functionalities of hydrogel particles to provide cues to impart neural integration for such materials. Three distinct, yet interconnected tasks were undertaken: investigating hydrogel particle-modified substrate neuron integration and central nervous system inflammatory response, investigating guided hydrogel particle adsorption, and investigating hydrogel particles as local reservoirs for counteracting adverse effects from oxidative …

Inter-Droplet Membranes For Mechanical Sensing Applications, Nima Tamaddoni Jahromi

Doctoral Dissertations

This dissertation combines self-assembly phenomena of amphiphilic molecules with soft materials to create and characterize mechanoelectrical transducers and sensors whose sensing elements are thin-film bioinspired membranes comprised of phospholipids or amphiphilic polymers. We show that the structures of these amphiphilic molecules tune the mechanical and electrical properties of these membranes. We show that these properties affect the mechanoelectrical sensing characteristic and range of operation of these membrane transducers. In the experiments, we construct and characterize a membrane-based hair cell embodiment that enables the membrane to be responsive to mechanical perturbations of the hair. The resulting oscillations of membranes formed between …

Biodegradable Nano-Hybrid Polymer Composite Networks For Regulating Cellular Behavior, Charles Henley Sprague

Masters Theses

Photo-crosslinkable polymeric biomaterials have emerged in the field of biomedical research to promote tissue regeneration. For example, scaffolds that can be crosslinked and hardened in situ have been known to make suitable implant alternatives. Since injectable and photo-crosslinkable biomaterials offer the advantage of being minimally invasive, they have emerged to compete with autografts, a current highly invasive method to repair diseased tissue. A series of novel photo-crosslinkable, injectable, and biodegradable nano-hybrid polymers consisting of poly(ε-caprolactone fumarate) (PCLF) and polyhedral oligomeric silsesquioxane (POSS) has been synthesized in our laboratory via polycondensation. To engineer the material properties of the nano-hybrid networks, varied …

Engineering The “Pluripotency” Of Zr-Based Bulk Metallic Glasses As Biomedical Materials, Lu Huang

Doctoral Dissertations

Bulk metallic glasses (BMGs) are a family of novel alloys with amorphous microstructures. The combination of their excellent mechanical properties, good chemical stability, high thermal formability, and general biocompatibility has brought up new opportunities for biomaterials. Research in this dissertation was focused on exploring multiple biomedical functionalities of Zr-based BMGs over a wide spectrum, combining materials and biological characterizations, through experimental and computational approaches. Four distinct yet interconnected tasks were endeavored, involving inflammation, hard-tissue implant, soft-tissue prosthesis, and pathogenic infection.

The inflammation that can be potentially triggered by Zr-based BMGs was investigated using macrophages. Lower level or comparable macrophage activations …

Doping Of Fluorchlorozirconate And Borate-Silica Glass Ceramics For Medical Imaging And Fast Neutron Scintillation, Julie Elizabeth Swafford

Masters Theses

Borate silica glass ceramics were produced for neutron scintillation. The Glass ceramics were doped with europium fluoride [EuF₂] and cerium chloride [CeCl₃]. Isotopic lithium fluoride [⁶LiF] and boron oxide [¹⁰B₂O₃] were used in most samples while non-isotopic lithium fluoride [LiF] and boron oxide [ B₂O₃] were used in the rest. When exposed to a neutron beam, samples doped with europium fluoride [EuF₂] scintillated while samples doped with cerium chloride [CeCl₃] did not. This contradicts current literature on fast scintillation. What …

The Advancement Of Bacterial Cellulose As A Bone And Vascular Scaffolds, Ryan Lee Hammonds

Doctoral Dissertations

Bacterial cellulose (BC) is a natural hydrogel made of nanofibers. This material has been used in commercial products, including wound dressings. BC can be modified and optimized for improved performance in multiple applications. This work will focus on producing and characterizing resorbable cellulose, a composite for bone applications, and a composite for a synthetic venous valve leaflet.

BC can be produced and modified to perform as a degradable tissue scaffold. This is achieved by an oxidation procedure after the initial production and purification of native BC. A material characterization of oxidized BC was performed to identify the changes in properties …

Femtosecond Laser Patterned Templates And Imprinted Polymer Structures, Deepak Rajput

Doctoral Dissertations

Femtosecond laser machining is a direct-write lithography technique by which user-defined patterns are efficiently and rapidly generated at the surface or within the bulk of transparent materials. When femtosecond laser machining is performed with tightly focused amplified pulses in single-pulse mode, transparent substrates like fused silica can be surface patterned with high aspect ratio (>10:1) and deep (>10 μm) nanoholes. The main objective behind this dissertation is to develop single-pulse amplified femtosecond laser machining into a novel technique for the production of fused silica templates with user-defined patterns made of high aspect ratio nanoholes. The size of the …

Melt Blown Poly(Lactic Acid) For Application As A Tissue Engineering Scaffold, William Horst Gazzola

Masters Theses

Poly(lactic acid) (PLA) was melt blown (MB) under varying processing conditions to create webs with micro and nano-architecture. Processing parameters varied were primary air flow rate and collector distance. In total, twenty-one webs were produced and the physical properties of the webs were investigated including, mean fiber diameter and fiber diameter distribution, mean pore diameter and pore size distribution, web thickness, degree of crystallinity, tensile modulus and degradation rate. Four webs, two with micro and two with nano-architecture, thought suitable for use as tissue engineering scaffolds were selected for seeding with A375 human malignant melanoma cells. Cell culture was conducted …

Modulation Of Bone And Nerve Cell Behavior Using Biodegradable Polymer Networks, Lei Cai

Doctoral Dissertations

This dissertation presents novel biodegradable and photo-crosslinkable building blocks to achieve polymer networks with controlled surface chemistry, stiffness, and topographical features for investigating cell-material interactions and targeting hard and soft tissue engineering applications. Chapter I reviews the recent progress in polymeric gel systems and how their physical properties can be tailored to regulate cell functions and satisfy the clinical needs. Chapter II presents a facile method to synthesize photo-crosslinkable poly(epsilon-caprolactone) acrylates (PCLAs) and reveal tunable cell responses to photo-crosslinked PCLAs. Chapter III investigates the mechanism of colorization in preparing crosslinkable polymers by reacting hydroxyl-containing polymers with unsaturated anhydrides or acyl …

Synthesis And Characterization Of Diamond-Like Carbon Thin Films For Biomedical Applications, Russell Lee Leonard

Masters Theses

Diamond-like carbon (DLC) thin films were produced by pulsed laser deposition (PLD) on silicon, fused silica, and silicon nitride substrates. The films produced were either undoped, made using a pure graphite target, or doped, using multi-component targets made from a combination of graphite and silicon, silicon nitride, titanium dioxide, or silicon monoxide. These films were evaluated for their potential use in biomedical applications, including coatings for artificial joints, heart stents, and bronchoscopes. The films were characterized by Raman spectroscopy, atomic force microscopy, ball-on-flat tribometry, contact angle measurements, and spectrophotometry. Film thickness was determined by optical profilometry. Film adhesion was checked …

Developing Chitosan-Based Biomaterials For Brain Repair And Neuroprosthetics, Zheng Cao

Masters Theses

Chitosan is widely investigated for biomedical applications due to its excellent properties, such as biocompatibility, biodegradability, bioadhesivity, antibacterial, etc. In the field of neural engineering, it has been extensively studied in forms of film and hydrogel, and has been used as scaffolds for nerve regeneration in the peripheral nervous system and spinal cord. One of the main issues in neural engineering is the incapability of neuron to attach on biomaterials. The present study, from a new aspect, aims to take advantage of the bio-adhesive property of chitosan to develop chitosan-based materials for neural engineering, specifically in the fields of brain …