Biomaterials Commons^™

Butyl Rubber-Aliphatic Polyester Graft Copolymers For Biomedical Applications: Synthesis And Analysis Of Chemical, Physical And Biological Properties, Bethany A. Turowec

Electronic Thesis and Dissertation Repository

Biomaterials can be used in a wide variety of medical applications owing to their breadth of characteristics that can be imparted by varying their chemical structures. Butyl rubber (IIR), which is a copolymer of isobutylene (IB) and small percentages of isoprene (IP), is particularly attractive as a biomaterial because of its elastomeric mechanical properties, biocompatibility, impermeability and high damping characteristics. IIR is typically vulcanized through chemical-based crosslinking mechanisms. However, these methods are not acceptable for biological applications. This thesis focuses on the synthesis of IIR-polyester graft copolymers by grafting biodegradable and biocompatible polyesters including poly(caprolactone) (PCL) and poly(d,l-lactide) (PDLLA) to …

An Assessment Of Novel Biodegradable Magnesium Alloys For Endovascular Biomaterial Applications, Dharam Persaud-Sharma

FIU Electronic Theses and Dissertations

Magnesium alloys have been widely explored as potential biomaterials, but several limitations to using these materials have prevented their widespread use, such as uncontrollable degradation kinetics which alter their mechanical properties. In an attempt to further the applicability of magnesium and its alloys for biomedical purposes, two novel magnesium alloys Mg-Zn-Cu and Mg-Zn-Se were developed with the expectation of improving upon the unfavorable qualities shown by similar magnesium based materials that have previously been explored. The overall performance of these novel magnesium alloys has been assessesed in three distinct phases of research: 1) analysing the mechanical properties of the as-cast …

Materials Education And Research In Art And Design: A New Role For Libraries (Website), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Sheet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Booklet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Survey Stats), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Collection Creation And Administration: A New Role For Libraries (White Paper), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

The Problem/Opportunity: To define, identify, and guide design-based materials collections in academic settings and foster community among those with existing collections and/or those considering creating and supporting one.

Contents and topics:

1. What is a materials collection?
2. Why have a materials collection?
3. Acquisition strategies
4. Organizational approaches
5. Programming possibilities
6. Symposium summary
7. Resources

Evaluation Of Thermophile Algae In Horizontal Photo-Bioreactor, Olivier Schmied

BioResource and Agricultural Engineering

No abstract provided.

Electrospun Plant Protein Scaffolds With Fibers Oriented Randomly And Evenly In Three-Dimensions For Soft Tissue Engineering Applications, Shaobo Cai

Department of Textiles, Merchandising, and Fashion Design: Dissertations, Theses, and Student Research

In this work, electrospinnable and water stable soyprotein was extracted by using a reducing agent in mild alkaline condition, and novel 3D zein and 3D pure soyprotein electrospun scaffolds with three-dimensionally and randomly oriented fibers and large interconnected pores were successfully fabricated by reducing surface resistivity of materials. This unique structure is different from most electrospun scaffolds with fibers oriented mainly in one direction. The structure of novel 3D scaffolds could more closely mimic the 3D randomly oriented fibrous architectures in many native extracellular matrixes (ECM). Confocal laser scanning microscope shows that instead of becoming flattened cells when cultured in …

Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes

Materials Engineering

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength, …

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 …

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 …

Design Of An Experimental Approach To Study The Growth Of Biofilm On Polymethylmethacrylate, Eireen S. Escalona

Biomedical Engineering

Biofilms are present in virtually every solid-liquid contact surface and are partially responsible for some diseases and water cleaning. They are a community of a variety of organisms that live symbiotically and are bound together by extracellular polymeric substances, or EPS. Biofilms go through five stages of development. These include initial and irreversible attachments, maturations I and II, and dispersion. In the dental world, biofilms are often associated with mouth infections including dental caries, gingivitis and periodontitis. Elderly denture wearers are susceptible to the pathogen-causing bacteria associated with these diseases, particularly those who have Alzheimer's disease or other forms of …

Modeling The Zimmer Fitmore And Ml Taper Implantation, Tyler Kazuo Franklin

Master's Theses

With more young adults requiring total hip

arthroplasties the need for bone saving implants becomes

more important. The Zimmer Fitmore is a new bone saving

implant that utilizes an implantation technique that

reduces the damage to the muscle tissue allowing for

patients to have a short recovery time as well as a new

design that allows it to rest on the medial cortex. There

has been anecdotal evidence that this device leads to early

revision within six months of implantation due to failures

occurring in the medial cortex. The main goal of this

study was to computationally model the Zimmer …

Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type …

Sol-Gel Derived Biodegradable And Bioactive Organic-Inorganic Hybrid Biomaterials For Bone Tissue Engineering, Bedilu A. Allo

Electronic Thesis and Dissertation Repository

Treatments of bone injuries and defects have been largely centered on replacing the lost bone with tissues of allogeneic or xenogeneic sources as well as synthetic bone substitutes, which in all lead to limited degree of structural and functional recovery. As a result, tissue engineering has emerged as a viable technology to regenerate the structures and therefore recover the functions of bone tissue rather than replacement alone. Hence, the current strategies of bone tissue engineering and regeneration rely on bioactive scaffolds to mimic the natural extracellular matrix (ECM) as templates onto which cells attach, multiply, migrate and function.

In this …

Multifunctional Nanoparticles In Cancer: In Vitro Characterization, In Vivo Distribution, Tingjun Lei

FIU Electronic Theses and Dissertations

A novel biocompatible and biodegradable polymer, termed poly(Glycerol malate co-dodecanedioate) (PGMD), was prepared by thermal condensation method and used for fabrication of nanoparticles (NPs). PGMD NPs were prepared using the single oil emulsion technique and loaded with an imaging/hyperthermia agent (IR820) and a chemotherapeutic agent (doxorubicin, DOX). The size of the void PGMD NPs, IR820-PGMD NPs and DOX-IR820-PGMD NPs were approximately 90 nm, 110 nm, and 125 nm respectively. An acidic environment (pH=5.0) induced higher DOX and IR820 release compared to pH=7.4. DOX release was also enhanced by exposure to laser, which increased the temperature to 42°C. Cytotoxicity of DOX-IR820-PGMD …

Bacterial Growth On Metal And Non-Metal Surfaces In A Static Bioreactor, Rolan Yuk Loong Liong

Master's Theses

Research was conducted to observe bacterial growth on the surface of metals in a static bioreactor. Metal and non-metal samples were subjected to bacterial exposure (1 day and 9 days). The metal samples were surface treated prior to bacterial exposure. The microstructures of the surface treated samples were analyzed by optical microscopy. After exposure, the microstructures of the samples were analyzed by scanning electron microscopy (SEM). The analysis suggested that microbial attachment on the surface was related to the underlying microstructure of steel. The preferential attachment of microbes could potentially be influenced by cathodic and anodic regions created by the …

Engineering Nanocomposites For Antimicrobial Application, Binyu Yu

Electronic Thesis and Dissertation Repository

In this thesis, active and passive antimicrobial methods have been applied to fabricate antifouling surfaces. In the first study, we reported the synthesis and characterization of neat TiO₂ and Ag-TiO₂ composite nanofilms prepared on silicon wafer by sol-gel method. The synthesized Ag-TiO₂ thin films showed enhanced bactericidal activities compared to the neat TiO₂ nanofilm both in the dark and under UV illumination. The advantage of Ag-TiO₂ nano-composites is to expand the nanomaterial’s antibacterial function to a broader range of working conditions. In the second study, we reported the synthesis, characterization and environmental application of nitrogen …

Microfabricated Nanotopological Surfaces For Study Of Adhesion-Dependent Cell Mechanosensitivity, Weiqiang Chen, Yubing Sun, Jianping Fu

Weiqiang Chen

Cells exhibit high sensitivity and diverse responses to the intrinsic nanotopography of the extracellular matrix through their nanoscale cellular sensing machinery. A simple microfabrication method for precise control and spatial patterning of the local nanoroughness on glass surfaces by using photolithography and reactive ion etching is reported. It is demonstrated that local nanoroughness as a biophysical cue could regulate a diverse array of NIH/3T3 fi broblast behaviors, including cell morphology, adhesion, proliferation, migration, and cytoskeleton contractility. The capability to control and further predict cellular responses to nanoroughness might suggest novel methods for developing biomaterials mimicking nanotopographic structures in vivo for …

Surface-Micromachined Microfiltration Membranes For Efficient Isolation And Functional Immunophenotyping Of Subpopulations Of Immune Cells, Weiqiang Chen, Nien-Tsu Huang, Boram Oh, Raymond H. W. Lam, Rong Fan, Timothy T. Cornell, Thomas P. Shanley, Katsuo Kurabayashi, Jianping Fu

Weiqiang Chen

An accurate measurement of the immune status in patients with immune system disorders is critical in evaluating the stage of diseases and tailoring drug treatments. The functional cellular immunity test is a promising method to establish the diagnosis of immune dysfunctions. The conventional functional cellular immunity test involves measurements of the capacity of peripheral blood mononuclear cells to produce pro-inflammatory cytokines when stimulated ex vivo. However, this “bulk” assay measures the overall reactivity of a population of lymphocytes and monocytes, making it difficult to pinpoint the phenotype or real identity of the reactive immune cells involved. In this research, we …

Development Of A Multilayered Association Polymer System For Sequential Drug Delivery, Sharath Kumar Chinnakavanam Sundararaj

Theses and Dissertations--Biomedical Engineering

As all the physiological processes in our body are controlled by multiple biomolecules, comprehensive treatment of certain disease conditions may be more effectively achieved by administration of more than one type of drug. Thus, the primary objective of this research was to develop a multilayered, polymer-based system for sequential delivery of multiple drugs. This particular device was designed aimed at the treatment of periodontitis, a highly prevalent oral inflammatory disease that affects 90% of the world population. This condition is caused by bacterial biofilm on the teeth, resulting in a chronic inflammatory response that leads to loss of alveolar bone …

Growth Plate Regeneration Using Polymer-Based Scaffolds Releasing Growth Factor, Amanda Clark

Theses and Dissertations--Biomedical Engineering

Currently growth plate fractures account for nearly 18.5% of fractures in children and can lead to stunted bone growth or angular deformation. If the body is unable to heal itself a bony bar forms, preventing normal bone growth. Clinical treatment involves removing the bony bar and replacing it with a filler substance, which causes poor results 60% of the time.

Using primarily poly(lactic-co-glycolic acid) (PLGA) as the scaffold material, the goal was to develop an implant that would support to the implant site, allow for cell ingrowth, and degrade away over time. Porous scaffolds were fabricated from PLGA microspheres using …

Techno-Economic And Fluid Dynamics Analysis For Growing Microalgae With The Intent Of Producing Biofuel Using A System Model, Leah R. Raffaeli

Electronic Theses and Dissertations

Techno-economic and systems studies on microalgal growth scenarios to date are abbreviated and missing a number of important variables. By including these variables in a detailed model integrating biology, chemistry, engineering, and financial aspects, a more defined systems analysis is possible. Through optimizing the model productivity based on the resulting net profit, the system analysis results in a more accurate assessment of environmental and economic sustainability of specific algal growth scenarios. Photobioreactor algal growth scenario optimization in the system model has resulted in realistic engineering design requirements based on algal growth requirements and fluid dynamics analysis. Results show feasibility for …

Surface- And Hydrogel-Mediated Delivery Of Nucleic Acid Nanoparticles, Angela K. Pannier, Tatiana Segura

Department of Biological Systems Engineering: Papers and Publications

Gene expression within a cell population can be directly altered through gene delivery approaches. Traditionally for nonviral delivery, plasmids or siRNA molecules, encoding or targeting the gene of interest, are packaged within nanoparticles. These nanoparticles are then delivered to the media surrounding cells seeded onto tissue culture plastic; this technique is termed bolus delivery. Although bolus delivery is widely utilized to screen for efficient delivery vehicles and to study gene function in vitro, this delivery strategy may not result in efficient gene transfer for all cell types or may not identify those delivery vehicles that will be efficient in vivo. …

An Investigation Of The Biochemical Properties Of Tetrazines As Potential Coating Additives, Swarna Jaiswal, Brendan Duffy, Luke O'Neill, Patrick Mchale

Articles

1,2,4,5-Tetrazine and its 3,6-disubstituted derivatives are currently used for a range of industrial and medical applications as they exhibit particular coordination chemistries, characterized by electron and charge transfer phenomena. The aim of the present work is to describe the synthesis of two tetrazine derivatives, namely 3,6-dihydrazino-1,2,4,5-tetrazine (DHDTZ) and 1,2,4,5-tetrazine dicarboxylic acid (DCTZ), and determine their antibacterial, antioxidant and anticorrosion characteristics as additives in a sol-gel coating on SS316L steel. The structure of the tetrazines was confirmed by NMR and FTIR while the surface morphology of bacterial cells in their presence was observed by AFM. Their ability to inhibit corrosion on …

Preparation Of New Versatile And Implantable Titanate Nanofiber-Bioscaffolds Via Efficient Cation Exchanges, Keaton Piper

Inquiry: The University of Arkansas Undergraduate Research Journal

For the first time in the implantable biomaterials field, efficient hydrothermal cation exchange methods were developed suitable for mass-production of implantable material. The cation exchange conditions were performed by various methods of temperature, pressure, and time exposure. To confirm both chemical and physical alteration of the scaffold, XRD shift analysis, EDX atomic composition, and SEM imaging were conducted. The optimal results are to use aqueous solutions of 0.5 M chloride salts in sealed heated containers at 180 ̊C for eight hours. Cation exchange capacities are determined for K+, Na+, Li+, Ca2+, and Sr2+; future studies demanding durable, highly specific composition …

Nanomechanics Of Electrospun Nanofibres For Tissue Engineering Of The Tympanic Membrane, Sara Makaremi

Electronic Thesis and Dissertation Repository

The Tympanic Membrane (TM), also known as the eardrum, includes layers of organized collagen nanofibres which play an essential role in sound transmission. Perforations that are caused by infection or accident must be repaired in order to restore hearing. Tympanoplasty is performed using grafts that are prepared from bladder, cartilage, temporal fascia and cadaveric skin. However, since mechanical properties of these grafts do not match those of the original TM, normal hearing is not fully restored. The goal of this study is to develop nanofibrous scaffolds for tissue engineering of the TM in order to circumvent the complications addressed with …

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 …

Nanoroughened Surfaces For Efficient Capture Of Circulating Tumor Cells Without Using Capture Antibodies, Weiqiang Chen, Shinuo Weng, Feng Zhang, Steven Allen, Xiang Li, Liwei Bao, Raymond H. W. Lam, Jill A. Macoska, Sofia D. Merajver, Jianping Fu

Weiqiang Chen

Circulating tumor cells (CTCs) detached from both primary and metastatic lesions represent a potential alternative to invasive biopsies as a source of tumor tissue for the detection, characterization and monitoring of cancers. Here we report a simple yet effective strategy for capturing CTCs without using capture antibodies. Our method uniquely utilized the differential adhesion preference of cancer cells to nanorough surfaces when compared to normal blood cells and thus did not depend on their physical size or surface protein expression, a significant advantage as compared to other existing CTC capture techniques.