Biomaterials Commons^™

Nanoindentation Techniques For The Evaluation Of Silicon Nitride Thin Films, Weston T. Mangin

Master's Theses

Silicon nitride thin films are of interest in the biomedical engineering field due to their biocompatibility and favorable tribological properties. Evaluation and understanding of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were subjected to nanoindentation testing to evaluate the mechanical properties of the film. Samples were subjected to nanoimpact testing to compare the damage resistance of the film to separate nanoimpact types. Samples were subjected to …

Use Of A Modified Greenscreen Tool To Conduct A Screening-Level Comparative Hazard Assessment Of Conventional Silver And Two Forms Of Nanosilver., Jennifer Sass, Lauren Heine, Nina Hwang

Environmental and Occupational Health Faculty Publications

BACKGROUND: Increased concern for potential health and environmental impacts of chemicals, including nanomaterials, in consumer products is driving demand for greater transparency regarding potential risks. Chemical hazard assessment is a powerful tool to inform product design, development and procurement and has been integrated into alternative assessment frameworks. The extent to which assessment methods originally designed for conventionally-sized materials can be used for nanomaterials, which have size-dependent physical and chemical properties, have not been well established. We contracted with a certified GreenScreen profiler to conduct three GreenScreen hazard assessments, for conventional silver and two forms of nanosilver. The contractor summarized publicly …

Lipid Coated Microbubbles And Low Intensity Pulsed Ultrasound Enhance Chondrogenesis Of Human Mesenchymal Stem Cells In 3d Printed Scaffolds, Mitra Aliabouzar, Lijie Grace Zhang, Kausik Sarkar

Medicine Faculty Publications

Lipid-coated microbubbles are used to enhance ultrasound imaging and drug delivery. Here we apply these microbubbles along with low intensity pulsed ultrasound (LIPUS) for the first time to enhance proliferation and chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in a 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) hydrogel scaffold. The hMSC proliferation increased up to 40% after 5 days of culture in the presence of 0.5% (v/v) microbubbles and LIPUS in contrast to 18% with LIPUS alone. We systematically varied the acoustic excitation parameters—excitation intensity, frequency and duty cycle—to find 30 mW/cm2, 1.5 MHz and 20% duty cycle to be optimal …

Surface Engineering Of Titanium Alloy To Stimulate The Bone Regeneration, Yubin Meng, Zhenduo Cui, Zhaoyang Li, Xue Li, Jin Zhao, Xubo Yuan, Xianjin Yang

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Fluorescent Materials Design At Nanoscale For Biomedical Photonics In Near Infrared Window, Kohei Soga, Masao Kamimura

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Recent Approaches In Designing Bioadhesive Materials Inspired By Mussel Adhesive Protein, Pegah Kord Forooshani, Bruce P. Lee

Department of Biomedical Engineering Publications

Marine mussels secret protein-based adhesives, which enable them to anchor to various surfaces in a saline, intertidal zone. Mussel foot proteins (Mfps) contain a large abundance of a unique, catecholic amino acid, Dopa, in their protein sequences. Catechol offers robust and durable adhe-sion to various substrate surfaces and contributes to the curing of the adhesive plaques. In this article, we review the unique features and the key functionalities of Mfps, catechol chemistry, and strategies for preparing catechol-functionalized poly- mers. Specifically, we reviewed recent findings on the contributions of various features of Mfps on interfacial binding, which include coacervate formation, surface …

Long-Term Biocompatibility, Imaging Appearance And Tissue Effects Associated With Delivery Of A Novel Radiopaque Embolization Bead For Image-Guided Therapy, Karun Sharma, Zainab Bascal, Hugh Kilpatrick, Koorosh Ashrafi, Sean L. Willis, Matthew R. Dreher, Andrew L. Lewis

Pediatrics Faculty Publications

The objective of this study was to undertake a comprehensive long-term biocompatibility and imaging assessment of a new intrinsically radiopaque bead (LC Bead LUMI™) for use in transarterial embolization. The sterilized device and its extracts were subjected to the raft of ISO10993 biocompatibility tests that demonstrated safety with respect to cytotoxicity, mutagenicity, blood contact, irritation, sensitization, systemic toxicity and tissue reaction. Intra-arterial administration was performed in a swine model of hepatic arterial embolization in which 0.22–1 mL of sedimented bead volume was administered to the targeted lobe(s) of the liver. The beads could be visualized during the embolization procedure with …

Cartilage Engineering: Optimization Of Media For Chondrogenic Differentiation In Vitro, Evan Surma, Sherry L. Harbin, Hongji Zhang, Stacy Halum

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lower back pain from intervertebral disc injury affects around 84% of the population at some point in their life, which at its worst may cause total immobilization. This pain can only be temporarily relieved by spinal fusion or intervertebral disc replacement; however, both of these cause loss of natural motion in patients by removing damaged fibrocartilage discs. While these techniques help mitigate pain briefly, no permanent solution exists currently to both relieve pain and preserve natural motion. My work may be a solution by eventually providing patient-specific implants that resemble native tissue in the regeneration process that could be absorbed …

Alginate Hydrogels As Three-Dimensional Scaffolds For In Vitro Culture Models Of Growth Plate Cartilage Development And Porcine Embryo Elongation, Taylor D. Laughlin

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The establishment of in vitro culture models utilizes tissue engineering principles to design functional mimics of in vivo environments in vitro. Advantages for the use of in vitro culture models include ethical alleviation of animal models for therapeutic testing, cost efficiency, and a greater ability to study specific mechanisms via a systematic, ground-up approach to development. In this thesis, alginate hydrogels are utilized in the development of in vitro culture models of porcine embryo elongation and growth plate cartilage development. First, the effect of scaffold and modifications to the scaffold were explored in both projects. In order to modulate …

Prosthetic Leg Kit For Deployment In Developing Countries, Brian Murphy, Dominique Porcincula, Derek Morgan, Kendall Ruggles, Christian Aguayo

Biomedical Engineering

The World Health Organization estimates that over 30 million people require some sort of prosthetic technology. However, traditional prosthetic fitting practices take a lot of time and cost a lot of money, making them inaccessible to millions of people around the world. StandUP Worldwide is an interdisciplinary project team devoted to creating low-cost prosthetic technologies for use around the world, especially in resource poor areas. They are currently developing a low cost, below-the-knee prosthetic kit that can be easily deployed in a resource-poor area. The following presents their solution for a below-the-knee prosthetic socket, foot, and leg.

Interaction Of Fibrinogen With Fibronectin: Purification And Characterization Of A Room Temperature-Stable Fibrinogen-Fibronectin Complex From Normal Human Plasma, Ayman E. Ismail

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

A fibrinogen-fibronectin complex (γγ’pdFI-pdFN) was purified from normal human plasma using a sequence of cryoprecipitation, ammonium sulfate fractionation, and DEAE Sepharose chromatography. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under reducing condition showed both a 1:1 stoichiometric ratio of fibrinogen (FI) to fibronectin (FN) as well as a stoichiometric ratio of 1:1 of γg to gγ’. The γγ’pdFI-pdFN complex was non-covalent in nature as it was disrupted by affinity adsorption to Gelatin Sepharose where pdFN bound strongly and the disrupted γγ’pdFI fell through the chromatographic column. Surprisingly, the purified γγ’pdFI-pdFN complex was more broadly thermally stable than plasma FI (pdFI) …

Chitosan As An Antiviral, Tayler Pauls

Biomedical Engineering Undergraduate Honors Theses

There is no broad-based antiviral medication available today; there are specific antivirals, for example, the antiretroviral for HIV. However, these specific antivirals are not available in each country and can be problematic for specific patients. Chitosan is proposed as a possible broad-based antiviral, which has already demonstrated antibacterial properties, antiviral properties in plants, is used for wound healing and as a hydrogel among other medical applications. The methods used are transfection of NIH-3T3 cells with GFP-adenovirus with 0.1%, 0.5%, and 1% chitosan added to virus prior to transfection. Fluorescence microscopy and flow cytometry data has validated that the use of …

Isolation Of Metallic Single-Walled Carbon Nanotubes For Electrically Conductive Tissue Engineering Scaffolds, Jakob Hockman

Biomedical Engineering Undergraduate Honors Theses

Metallic single-walled carbon nanotubes (m-SWNTs) were separated from pristine SWNTs using affinity chromatography for use in electrically conductive tissue engineering scaffolds. Approximately one third of SWNTs have metallic properties. Separations were achieved using a protocol modified from Liu & coworkers (2011) in order to improve the method for cell culture environments. Samples enriched in m-SWNTs were isolated and characterized. However, challenges still remain for the complete separation of m-SWNTs from their semiconducting counterpart (s-SWNTs) using this protocol. Approaches to improve separation and reduce the difficulties associated with processing the nanotubes were suggested. One of the ultimate destinations of these nanotubes …

Customization Of Titanate Nanofiber Bioscaffolds, Jared Hopkins

Biomedical Engineering Undergraduate Honors Theses

In the field of orthopedic devices implant loosening is a major issue resulting in the majority of device failures. These failures result in the need for costly secondary procedures. To reduce device loosening an improved method of tissue anchoring is required. A previously studied titanate nanofiber bioscaffold has been shown to be safely implantable and to contribute to the differentiation of mesenchymal stem cells to osteocytes. Through the customization of both physical and chemical characteristics this titanate nanofiber bioscaffold was fabricated as a potential means to enhance tissue anchoring for use with orthopedic devices. This customization was enabled by acoustic …

Investigating The Mechanical Behaviors Of Organic/Inorganic Composite Bone Scaffolds, Parker Davidson

Biomedical Engineering Undergraduate Honors Theses

The regeneration of bone over a large area cannot occur without a structure for the bone cells to bind and divide. The use of an organic/inorganic composite bone scaffold appears to be a promising alternative to the current clinical standard of bone grafting. Bone grafting is very limited, in that the size and shape of the area are hard to replicate and the use of donor tissue can trigger an immunologic response resulting in rejection of the bone tissue. This study experimented with composite bone scaffolds which can be made to fit the shape of the area in which bone …

Bending Stiffness In Cadaveric And Composite Long Bones Following Total Joint Replacement, Danielle Gehron, Anderson Adams Ms, Tatsuya Sueyoshi Md, Scott R. Small Ms

Rose-Hulman Undergraduate Research Publications

Several biomechanics studies have utilized commercially available replicate bone models as an alternative to cadaveric tissue specimens, in part due to their ease of handling and reduced expense. In an effort to validate the use of replicate bone specimens in biomechanics research, a number of studies have compared material properties of whole tibia and femur specimens to those of similar cadaveric specimens. Many of these validation studies have ascertained that the material properties of whole bone composite models fall within the range of those properties of cadaveric specimens, while offering reduced interspecimen variability. Current literature lacks, however, the direct comparison …

Patterned Alginate Hydrogels To Induce Chondrocyte Alignment, Jordan Catherine Verplank, Taylor D. Laughlin, Angela K. Pannier

UCARE: Research Products

The growth plate has an intricate architecture, and this architecture is necessary for directional growth of bones. Specifically, the cells align in longitudinal columns. As the growth plate expands with this pattern, the bone elongates with the same alignment pattern. The purpose of this research is to mimic this single celled, columnar alignment in vitro. In developing this alignment in vitro, this research will contribute to the overall study of growing growth for the development of improved therapeutic treatments and engineered tissues for transplants.

Equilibrium Testing Of Rat Tail Tendon: An Analysis Of The Viscoelastic Properties Of Collagen Under Different Strain Points, Joshua C. Witt

Graduate Theses - Biology & Biomedical Engineering

Instantaneous tensile testing and stress-relaxation testing are forms of mechanical testing used to determine the elastic and viscoelastic properties of biological tissue. Equilibrium testing is a form of testing that combines both of these testing approaches at different strain points to determine the elastic properties of a material and also assess their viscoelastic properties in the same test. This testing method is commonly used on highly viscoelastic materials such as cartilage but has never been fully described in dense collagenous materials such as tendon or ligament. This analysis utilizes different strain points selected to capture the classic non-linear behavior of …

Synthesis And Characterization Of Curcumin Polymer For Application In Radiation Induced Lung Damage, Mark C. Bailey

Theses and Dissertations--Chemical and Materials Engineering

Radiotherapy is used as a primary treatment for many cancers, including lung cancer. Although radiotherapy has proven to be an effective cancer treatment, its use is heavily limited due to the peripheral toxicity to healthy tissue. In this work, the antioxidant, curcumin, was tested as a radioprotectant to reduce radiation damage to healthy cells. Curcumin has been limited in use due to its poor bioavailability. In order to avoid problems associated with free curcumin delivery, curcumin poly(beta-amino ester) (CPBAE) was synthesized.

The first study investigated the in vitro radioprotection effect of curcumin in HUVEC dosed with gamma radiation. Cells treated …

Development And Characterization Of Lung Derived Extracellular Matrix Hydrogels, Robert A. Pouliot

Theses and Dissertations

Chronic obstructive pulmonary disease (COPD) including emphysema is a devastating condition, increasing in prevalence in the US and worldwide. There remains no cure for COPD, rather only symptomatic treatments. Due to unique challenges of the lung, translation of therapies for acute lung injury to target chronic lung diseases like COPD has not been successful. We have been investigating lung derived extracellular matrix (ECM) hydrogels as a novel approach for delivery of cellular therapies to the pulmonary system.

During the course of this work we have developed and characterized a lug derived ECM hydrogel that exhibits “injectability,” allowing cells or dugs …