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- All Subjects: Regenerative Medicine
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Description
The objective of this research is to investigate the relationship among key process design variables associated with the development of nanoscale electrospun polymeric scaffolds capable of tissue regeneration. To date, there has been no systematic approach toward understanding electrospinning process parameters responsible for the production of 3-D nanoscaffold architectures with desired levels quality assurance envisioned to satisfy emerging regenerative medicine market needs. , As such, this study encompassed a more systematic, rational design of experiment (DOE) approach toward the identification of electrospinning process conditions responsible for the production of dextran-polyacrylic acid (DEX-PAA) nanoscaffolds with desired architectures and tissue engineering properties. The latter includes scaffold fiber diameter, pore size, porosity, and degree of crosslinking that together can provide a range of scaffold nanomechanical properties that closely mimics the cell microenvironment. The results obtained from this preliminary DOE study indicate that there exist electrospinning operation conditions capable of producing Dex-PAA nanoarchitecture having potential utility for regenerative medicine applications.
ContributorsEspinoza, Roberta (Author) / Pizziconi, Vincent (Thesis advisor) / Massia, Stephen (Committee member) / Garcia, Antonio (Committee member) / Arizona State University (Publisher)
Created2013
Description
In the search for chemical biosensors designed for patient-based physiological applications, non-invasive diagnostic approaches continue to have value. The work described in this thesis builds upon previous breath analysis studies. In particular, it seeks to assess the adsorptive mechanisms active in both acetone and ethanol biosensors designed for breath analysis. The thermoelectric biosensors under investigation were constructed using a thermopile for transduction and four different materials for biorecognition. The analytes, acetone and ethanol, were evaluated under dry-air and humidified-air conditions. The biosensor response to acetone concentration was found to be both repeatable and linear, while the sensor response to ethanol presence was also found to be repeatable. The different biorecognition materials produced discernible thermoelectric responses that were characteristic for each analyte. The sensor output data is presented in this report. Additionally, the results were evaluated against a mathematical model for further analysis. Ultimately, a thermoelectric biosensor based upon adsorption chemistry was developed and characterized. Additional work is needed to characterize the physicochemical action mechanism.
ContributorsWilson, Kimberly (Author) / Guilbeau, Eric (Thesis advisor) / Pizziconi, Vincent (Thesis advisor) / LaBelle, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2011
Description
The Larynx plays a pivotal role in our ability to breathe and to speak. It is in our best interest to continue improving the status of tissue regeneration concerning the larynx so that patient voice quality of life can be less hindered in the face of laryngeal cancers and diseases. Modern technology can allow us to use CT scans for both diagnosis and treatment. This medical imaging can be converted into three-dimensional patient specific models that are actualized through 3D printing. These implants improve upon the current state of the art because they can be produced in a timely manner, are developed with materials and methods ensuring their biocompatibility, and follow architectures and geometries best suited for the patient to improve their voice quality of life. Additionally they should be able to allow patient speech in the case of partial laryngectomies where the arytenoid has been removed by acting as a permanent vocal fold This treatment process for laryngectomies aligns itself with personalized medicine by targeting its geometry based on that of the patient. Technologies and manufacturing processes utilized to produce them are accessible and could all be used within the clinical space. The life-saving implant required for the laryngectomy healing and recovery process can be ready to implant for the patient within a few days of imaging them.
ContributorsBarry, Colin Patrick (Author) / Pizziconi, Vincent (Thesis director) / Lott, David (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
Description
Volume depletion can lead to migraines, dizziness, and significant decreases in a subject's ability to physically perform. A major cause of volume depletion is dehydration, or loss in fluids due to an imbalance in fluid intake to fluid excretion. Because proper levels of hydration are necessary in order to maintain both short and long term health, the ability to monitor hydration levels is growing in clinical demand. Although devices capable of monitoring hydration level exist, these devices are expensive, invasive, or inaccurate and do not offer a continuous mode of measurement. The ideal hydration monitor for consumer use needs to be characterized by its portability, affordability, and accuracy. Also, this device would need to be noninvasive and offer continuous hydration monitoring in order to accurately assess fluctuations in hydration data throughout a specified time period. One particular method for hydration monitoring that fits the majority of these criteria is known as bioelectric impedance analysis (BIA). Although current devices using BIA do not provide acceptable levels of accuracy, portability, or continuity in data collection, BIA could potentially be modified to fit many, if not all, desired customer specifications. The analysis presented here assesses the viability of using BIA as a new standard in hydration level measurement. The analysis uses data collected from 22 subjects using an existing device that employs BIA. A regression derived for estimating TBW based on the parameters of age, weight, height, sex, and impedance is presented. Using impedance data collected for each subject, a regression was also derived for estimating impedance based on the factors of age, weight, height, and sex. The derived regression was then used to calculate a new impedance value for each subject, and these new impedance values were used to estimate TBW. Through a paired-t test between the TBW values derived by using the direct measurements versus the calculated measurements of impedance, the two samples were found to be comparable. Considerations for BIA as a noninvasive measurement of hydration are discussed.
ContributorsTenorio, Jorge Antonio (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
The American Diabetes Association reports that diabetes costs $322 billion annually and affects 29.1 million Americans. The high out-of-pocket cost of managing diabetes can lead to noncompliance causing serious and expensive complications. There is a large market potential for a more cost-effective alternative to the current market standard of screen-printed self-monitoring blood glucose (SMBG) strips. Additive manufacturing, specifically 3D printing, is a developing field that is growing in popularity and functionality. 3D printers are now being used in a variety of applications from consumer goods to medical devices. Healthcare delivery will change as the availability of 3D printers expands into patient homes, which will create alternative and more cost-effective methods of monitoring and managing diseases, such as diabetes. 3D printing technology could transform this expensive industry. A 3D printed sensor was designed to have similar dimensions and features to the SMBG strips to comply with current manufacturing standards. To make the sensor electrically active, various conductive filaments were tested and the conductive graphene filament was determined to be the best material for the sensor. Experiments were conducted to determine the optimal print settings for printing this filament onto a mylar substrate, the industry standard. The reagents used include a mixture of a ferricyanide redox mediator and flavin adenine dinucleotide dependent glucose dehydrogenase. With these materials, each sensor only costs $0.40 to print and use. Before testing the 3D printed sensor, a suitable design, voltage range, and redox probe concentration were determined. Experiments demonstrated that this novel 3D printed sensor can accurately correlate current output to glucose concentration. It was verified that the sensor can accurately detect glucose levels from 25 mg/dL to 400 mg/dL, with an R2 correlation value as high as 0.97, which was critical as it covered hypoglycemic to hyperglycemic levels. This demonstrated that a 3D-printed sensor was created that had characteristics that are suitable for clinical use. This will allow diabetics to print their own test strips at home at a much lower cost compared to SMBG strips, which will reduce noncompliance due to the high cost of testing. In the future, this technology could be applied to additional biomarkers to measure and monitor other diseases.
ContributorsAdams, Anngela (Author) / LaBelle, Jeffrey (Thesis advisor) / Pizziconi, Vincent (Committee member) / Abbas, James (Committee member) / Arizona State University (Publisher)
Created2017
Description
Tissues within the body enable proper function throughout an individual’s life. After severe injury or disease, many tissues do not fully heal without surgical intervention. The current surgical procedures aimed to repair tissues are not sufficient to fully restore functionality. To address these challenges, current research is seeking new tissue engineering approaches to promote tissue regeneration and functional recovery. Of particular interest, biomaterial scaffolds are designed to induce tissue regeneration by mimicking the biophysical and biochemical aspects of native tissue. While many scaffolds have been designed with homogenous properties, many tissues are heterogenous in nature. Thus, fabricating scaffolds that mimic these complex tissue properties is critical for inducing proper healing after injury. Within this dissertation, scaffolds were designed and fabricated to mimic the heterogenous properties of the following tissues: (1) the vocal fold, which is a complex 3D structure with spatially controlled mechanical properties; and (2) musculoskeletal tissue interfaces, which are fibrous tissues with highly organized gradients in structure and chemistry. A tri-layered hydrogel scaffold was fabricated through layer-by-layer stacking to mimic the mechanical structure of the vocal fold. Furthermore, magnetically-assisted electrospinning and thiol-norbornene photochemistry was used to fabricate fibrous scaffolds that mimic the structural and chemical organization of musculoskeletal interfacial tissues. The work presented in this dissertation further advances the tissue engineering field by using innovative techniques to design scaffolds that recapitulate the natural complexity of native tissues.
ContributorsTindell, Raymond Kevin (Author) / Holloway, Julianne (Thesis advisor) / Green, Matthew (Committee member) / Pizziconi, Vincent (Committee member) / Stephanopoulos, Nicholas (Committee member) / Acharya, Abhinav (Committee member) / Arizona State University (Publisher)
Created2021
Description
Lab-grown food products of animal cell origin, now becoming popularly coined as, ‘Cellular Agriculture’ is a revolutionary breakthrough technology that has the potential to penetrate the lives of every American or citizen of the world. It is important to recognize that the impetus for developing this technology is fueled by environmental concerns with climate change, rising geopolitical instability, and population growth projections, where farm-grown food has now become a growing national security issue. Notwithstanding its potential, in addition to the necessary technological innovation and economic scalability, the market success of cellular agriculture will depend greatly on regulatory oversight by multiple government agencies without which it can cause undue harm to individuals, populations, and the environment. Thus, it is critical for those appropriate United States governing bodies to ensure that the technology being developed is both safe and of an acceptable quality for human consumption and has no adverse environmental impact. As such, animal foods, derived from farms, previously regulated almost exclusively by the United States Department of Agriculture (USDA) are now being regulated under a joint formal agreement between the US Food and Drug Administration (US FDA) and the USDA if derived from the lab, i.e., lab-grown animal foods. The main reason for joint oversight between the FDA and the USDA is that the FDA has developed the in-house expertise to oversee primary cell harvesting and cell storage, as well as, cell growth and differentiation for the development of 3D-engineered tissues intended for tissue and organ replacement for the emerging field of regenerative medicine. As such, the FDA has been given the authority to oversee the ‘front end’ of lab-grown food processes which relies on the very same processes utilized in engineered human tissues to produce food-grade engineered tissues. Oversight then transitions to the USDA-FSIS (Food Safety and Inspection Service) during the harvesting stage of the cell culture process. The USDA-FSIS then oversees the further production and labeling of these products. Included in the agreement is the understanding that both bodies are responsible for communicating necessary information to each other and collaboratively developing new regulatory actions as needed. However, there currently lacks clarity on some topics regarding certain legal, ethical, and scientific issues. Lab-grown meat products require more extensive regulation than farm-grown animal food products to ensure that they are safe and nutritious for consumption. To do this, CFSAN can create new classes of lab-grown foods, such as ‘lab-grown USDA foods,’ ‘lab-grown non-USDA foods,’ ‘lab-grown extinct foods,’ ‘lab-grown human food tissues,’ and ‘medically activated lab-grown foods.’
ContributorsBanen, Samuel (Author) / Pizziconi, Vincent (Thesis director) / Feigal, David (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor) / School of Molecular Sciences (Contributor)
Created2023-05
Description
This thesis aims to incorporate exosomes into an electrospun scaffold for tissue engineering applications. The motivation for this work is to develop an implant to regenerate tissue for patients with laryngeal defects. It was determined that it is feasible to incorporate exosomes into an electrospun scaffold. This addition of exosomes does alter the scaffold properties, by decreasing the average fiber diameter by roughly a factor of three and increasing the average modulus by roughly a factor of two. Cells were cultured on a scaffold with exosomes incorporated and were found to proliferate more than on a scaffold alone. This research lays the groundwork for further developing and optimizing an electrospun scaffold with exosomes incorporated to elicit a tissue regenerative response.
ContributorsKennedy, Maeve (Author) / Pizziconi, Vincent (Thesis director) / McPhail, Michael (Committee member) / School of International Letters and Cultures (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Tissue engineering scaffold fabrication methods often have tradeoffs associated with them that prevent one method from fulfilling all design requirements of a desired scaffold. This undergraduate thesis seeks to combine 3D printing and electrospinning tissue engineering fabrication methods into a hybrid fabrication method that can potentially fulfill more design requirements than each method alone. The hybrid scaffolds were made by inserting electrospun scaffolds between layers of 3D printed scaffolds of increasing print temperature and effects on adhesion and mechanical properties were characterized. The fabrication method proved to be feasible and print temperature affected both adhesion and mechanical properties of the scaffolds. A positive, non-linear relationship was seen between print temperature and adhesion and resulting force. Insertion of electrospun mats led to increased damping of scaffolds. Evidence from characterization indicated factors other than print temperature were likely contributing to adhesion and mechanical properties. If studied further, this fabrication method could potentially be used to improve overall structure and regenerative potential of tissue engineering scaffolds.
ContributorsCornella, Joseph Paul (Author) / Pizziconi, Vincent (Thesis director) / McPhail, Michael J (Committee member) / School of Music (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Protein crystallization is a technique for the formation of three-dimensional protein crystals, which is widely utilized by scientists, engineers, and researchers. Protein crystallography allows for protein structures and functions to be studied. As proteins play a central role in biological systems and life itself, a deeper understanding of their structure-function properties is crucial to elucidating fundamental behaviors, such as protein folding in addition to the role that they play in emerging fields, such as, tissue engineering with application to the emerging field of regenerative medicine. However, a significant limitation toward achieving further advancements in this field is that in order to determine detailed structure of proteins from protein crystals, high-quality and larger size protein crystals are needed. Because it is difficult to produce adequate size, high-quality crystals, it remains difficult to determine the structure of many proteins. However, a new method using a microgravity environment to crystallize proteins has proven effective through various studies conducted on the International Space Station (ISS). In the presence of microgravity, free convection is essentially absent in the bulk solution where crystallization occurs, thus allowing for purely random Brownian motion to exist which favors the nucleation and growth of high-quality protein crystals. Many studies from the ISS to date have demonstrated that growing protein crystals in a microgravity environment produces larger and higher-quality crystals. This method provides new opportunities for better structure identification and analysis of proteins. Although there remains many more limitations and challenges in the field, microgravity protein crystallization holds many opportunities for the future of biotechnology and scientific development. The objective of this thesis was to study the crystallization of hen egg white lysozyme (HEWL) and determine the effects of both unit and microgravity on growth/size and quality of HEWL. Through preliminary trials using a universal ground-based reduced-gravity system, the crystallization of HEWL in a simulated microgravity environment was successfully conducted and the results reported are promising. The utility of continuous, scalable ground-based, microgravity platforms for studies on a wide range of material systems and behavior, such as, protein crystallization, has significant implications regarding its impact on many industries, including drug development as well as regenerative medicine.
ContributorsTran, Amanda Marie (Author) / Pizziconi, Vincent (Thesis director) / Alford, Terry (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12