Biomedical Engineering and Bioengineering Commons^™

Optimized Production And Evaluation Of Cellulose Nanocrystals Derived From Pre-Extracted Kraft Pulp Of Different Wood Species, Gurshagan Kandhola

Graduate Theses and Dissertations

Production of nanocellulose from a variety of naturally abundant, locally available and industrially significant wood species provides an opportunity for diversifying the portfolio of traditional pulp and paper industries. The U.S. has a prolific forest products industry with a well-established infrastructure that could be utilized for optimized and customized production of cellulose nanomaterials. However, to achieve that, it is important to a) understand how biorefining strategies for complete fractionation of biomass affect the downstream processing of pulp into nanocellulose, b) maximize the yields of cellulose nanocrystals and nanofibers (CNCs and CNFs) from pretreated raw materials, and c) evaluate if the …

Label-Free Microrna Optical Biosensors, Meimei Lai, Gymama Slaughter

Bioelectrics Publications

MicroRNAs (miRNAs) play crucial roles in regulating gene expression. Many studies show that miRNAs have been linked to almost all kinds of disease. In addition, miRNAs are well preserved in a variety of specimens, thereby making them ideal biomarkers for biosensing applications when compared to traditional protein biomarkers. Conventional biosensors for miRNA require fluorescent labeling, which is complicated, time-consuming, laborious, costly, and exhibits low sensitivity. The detection of miRNA remains a big challenge due to their intrinsic properties such as small sizes, low abundance, and high sequence similarity. A label-free biosensor can simplify the assay and enable the direct detection …

Bioinspired Complex Nanoarchitectures By Dna Supramolecular Polymerization, Laura A. Lanier

Doctoral Dissertations

Bioinspired nanoarchitectures are of great interest for applications in fields such as nanomedicine, tissue engineering, and biosensing. With this interest, understanding how the physical properties of these complex nanostructures relate to their function is increasingly important. This dissertation describes the creation of complex nanoarchitectures with controlled structure and the investigation of the effect of nanocarrier physical properties on cell uptake for applications in nanomedicine. DNA self-assembly by supramolecular polymerization was chosen to create complex nanostructures of controlled architectures. We demonstrated that the supramolecular polymerization of DNA known as hybridization chain reaction (HCR) is in fact a living polymerization. The living …

Engineering Nanomaterials For Imaging And Therapy Of Bacteria And Biofilm-Associated Infections, Akash Gupta

Doctoral Dissertations

Infections caused by multidrug-resistant (MDR) bacteria pose a serious global burden of mortality, causing thousands of deaths each year. The “superbug” risk is further exacerbated by chronic infections generated from antibiotic-resistant biofilms that are highly resistant to available treatments. Synthetic macromolecules such as polymers and nanoparticles have emerged as promising antimicrobials. Moreover, ability to modulate nanomaterial interaction with bacterial cellular systems plays a pivotal role in improving the efficacy of the strategy. In the initial studies on engineering nanoparticle surface chemistry, I investigated the role played by surface ligands in determining the antimicrobial activity of the nanoparticles. In further study, …

Diagnostic Sequence Detection Against A Complex Background Using A Dna Molecular Computation Framework, Adan Leon Myers Y Gutierrez

Nanoscience and Microsystems ETDs

Diagnostic assays are designed to detect a unique analyte profile in a disease of interest. Nucleic acids contain an information-dense sequence, and thus are ideal candidates for unique analytes. The gold-standard of nucleic-acid-based detection is PCR which has high sensitivity, but involves time, expertise, and cost. DNA molecular logic technology holds much promise as an alternative molecular detection method due to the potential to save cost and expertise, while also achieving a high sensitivity. However, nucleic acid detection in biomedical applications carries with it the difficulty of choice of appropriate sequence and potential biological sample background.

This work describes the …

Application Of Halloysite Nanotubes In Bone Disease Remediation And Bone Regeneration, Yangyang Luo

Doctoral Dissertations

Customized patient therapy has been a major research focus in recent years. There are two research fields that have made a significant contribution to realizing individualized-based treatment: targeted drug delivery and three-dimensional (3D) printing technology. With benefit from the advances in nanotechnology and biomaterial science, various drug delivery systems have been established to provide precise control of therapeutic agents release in time and space. The emergence of three-dimensional (3D) printing technology enables the fabrication of complicated structures that effectively mimic native tissues and makes it possible to print patient-specific implants. My dissertation research used a clay nanoparticle, halloysite, to develop …

Effects Of Three Dry Powder Inhalers On Deposition Of Aerosolized Medicine In The Human Oral-Pharyngeal-Laryngeal Regions, Mohammed Ali

Mohammed Ali

The dry powder inhaler (DPI) is a popular, effective and convenient drug delivery device for inhalation therapy to treat asthma. However, a large quantity (approximately 54%) of inhaled aerosols deposit in the oropharyngeal region. Deposition in this region is undesirable because it provides minimum therapeutic benefits and has adverse localized or systemic side effects. This study reports a method of examining electrostatic charge effects on deposition of three DPI aerosols (Spiriva^™ Handihaler, Advair Diskus^™, and Pulmicort^™ Turbohaler) in a cadaver-based cast of the human oral-pharyngeal-laryngeal (OPL) regions. Experimental aerosols were generated from the three commercially available …

A Study Of Protein And Peptide-Directed Nanoparticle Synthesis For Catalytic Materials, Abdollah Mosleh

Graduate Theses and Dissertations

Nanoparticles have received much attentions due to their unique properties that makes them suitable candidates for a broad range of applications. As the size of particles decreases, their surface area-to-volume ratio would increase which is the main cause of much attention. In addition to the size, their morphologies and compositions may also play important roles for defining unique properties. Nanoparticle synthesis include both bottom-up and top-down strategies. To control the process of inorganic nanoparticles synthesis one could follow the bottom-up approach to have atom-level control over their compositions, morphologies, phases, and sizes which is the subject of this work. Due …

A Ph-Sensitive Delivery System For The Prevention Of Dental Caries Using Salivary Protein, Yi Zhu, Yizhi Xiao, Elizabeth Gillies, Walter L. Siqueira

Western Research Forum

Dental caries remains one of the most common chronic diseases worldwide. In previous studies, salivary proteins (e.g. histatin 3, statherin) have demonstrated biological functions including the inhibition of crystal growth, antibacterial activities, which are directly related to tooth homeostasis and prevention of dental caries. However, proteins are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparticles (CNs) have been proposed as potential carriers to protect proteins against enzymatic degradation at physiological salivary pH, in addition to swell selectively at lower pH conditions to facilitate the release of the encapsulated proteins, as major oral complications occur …

A Ph-Sensitive Delivery System For The Prevention Of Dental Caries Using Salivary Proteins, Yi Zhu

Electronic Thesis and Dissertation Repository

Dental caries remains one of the most common chronic diseases worldwide. Salivary proteins such as histatins have demonstrated biological functions directly related to tooth homeostasis and prevention of dental caries. However, histatins are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparticles (CNs) have been proposed as potential carriers to target major oral diseases that occur under acidic conditions (e.g. dental caries and dental erosion). Four different types of chitosan polymers were investigated and the optimized CNs successfully loaded histatin 3 and released it selectively under acidic conditions. Through loading the survival time of histatin …

Assessing Commonly Used Methods In Measuring Yield Of Cellulose Nanocrystals, Marilyn Pharr

Biological and Agricultural Engineering Undergraduate Honors Theses

Cellulose is a ubiquitous, renewable biopolymer found in plants that can be broken down to isolate cellulose nanocrystals (CNCs). CNCs have been utilized in various applications that include biomedical technology, structural composites, and barrier films because of their unique mechanical, optical, and physicochemical properties. CNCs can be produced by a variety of approaches from cellulosic materials; however, strong acid hydrolysis is the most common and effective technique as it results in stable colloidal suspensions. Existing literature reveals a wide range of CNC yields, depending on the production process, raw material used, and the method of yield estimation. The yields of …

The Modeling, Design, Fabrication, And Application Of Biosensor Based On Electric Cell-Substrate Impedance Sensing (Ecis) Technique In Environmental Monitoring, Xudong Zhang, William Wang, Sunghoon Jang

Publications and Research

In this research, the modeling, design, fabrication, and application of ECIS sensors in environmental monitoringare studied. The ECIS sensors are able to qualify the water toxicity through measuring the cell impedance. A novel mathematical model is proposed to analyze the distribution of electric potential and current of ECIS. This mathematical model is validated by experimental data and can be used to optimize the dimension of ECIS electrodes in order to satisfy environmental monitors. The detection sensitivity of ECIS sensors is analyzed by the mathematical model and experimental data. The simulated and experimental results show that ECIS sensors with smaller radius …

Incorporation Of Egfr And Ron Receptors Into Nanodiscs, Cristina Flores-Cadengo

Biomedical Engineering ETDs

Understanding the structure-function relationship of membrane receptors is essential to comprehend the crosstalk between key signaling pathways. Aberrant trans-activation between receptors can lead to tumorigenesis. Two of these receptors known to be involved in cancer development are receptor tyrosine kinases (RTKs), RON (Recepteur d'Origine Nantais) and EGFR (Epidermal Growth Factor Receptor). There has been evidence of heterodimerization and crosstalk between these two receptors based on co-immunoprecipitation, however the structural requirements behind these interactions remain unknown. Structural studies could provide insights into these RTKs’ modes of dimerization and structure-function relationship. However, structural studies of full-length membrane proteins are often difficult due …

The Effect Of Defects And Surface Modification On Biomolecular Assembly And Transport, Haneen Martinez

Nanoscience and Microsystems ETDs

Nanoscale transport using the kinesin-microtubule (MT) biomolecular system has been successfully used in a wide range of nanotechnological applications including self-assembly, nanofluidic transport, and biosensing. Most of these applications use the ‘gliding motility geometry’, in which surface-adhered kinesin motors attach and propel MT filaments across the surface, a process driven by ATP hydrolysis. It has been demonstrated that active assembly facilitated by these biomolecular motors results in complex, non-equilibrium nanostructures currently unattainable through conventional self-assembly methods. In particular, MTs functionalized with biotin assemble into rings and spools upon introduction of streptavidin and/or streptavidin-coated nanoparticles. Upon closer examination of these structures …

Development Of A Counter-Flow Thermal Gradient Microfluidic Device, Shayan Davani

Doctoral Dissertations

This work presents a novel counter-flow design for thermal stabilization of microfluidic thermal reactors. In these reactors, precise control of temperature of the liquid sample is achieved by moving the liquid sample through the thermal zones established ideally through the conduction in the solid material of the device. The goal here is to establish a linear thermal distribution when there is no flow and to minimize the temperature change at flow condition. External convection as well as internal flowinduced effects influence the prescribed thermal distribution. The counter-flow thermal gradient device developed in this study is capable of both stabilizing the …

Titanium Nitride Nanotube Electrode, Gui Chen, Marcella Gatti

Research Opportunities for Engineering Undergraduates (ROEU) Program 2018-19

This project presents a corrosion-resistant and high capacity implantable TiN nanotube electrode to work as a neural probe. Smaller electrode size allows for reduced tissue damage while the nanopore morphology of the TiN gives a larger surface area and stability to the electrode. The electrode offers improved biocompatibility, reduced tissue damage, reduced cost, and increased usability over time.

Towards The Rational Design And Application Of Polymers For Gene Therapy: Internalization And Intracellular Fate, Landon Alexander Mott

Theses and Dissertations--Chemical and Materials Engineering

Gene therapy is an approach for the treatment of acquired cancers, infectious disease, degenerative disease, and inherited genetic indications. Developments in the fields of immunotherapies and CRISPR/Cas9 genome editing are revitalizing the efforts to move gene therapy to the forefront of modern medicine. However, slow progress and poor clinical outcomes have plagued the field due to regulatory and safety concerns associated with the flagship delivery vector, the recombinant virus. Immunogenicity and poor transduction in certain cell types severely limits the utility of viruses as a delivery agent of nucleic acids. As a result, significant efforts are being made to develop …

Fabrication And Characterization Of Nanofiber Nylon-6-Mwcnt As An Electrochemical Sensor For Sodium Ions Concentration Detection In Sweat, Kelsey Mills

Williams Honors College, Honors Research Projects

Fabrication and characterization nylon-6-MWCNT nanofiber as an electrochemical sensor to detect sodium ion concentrations specifically in sweat. Using contact angle to determine surface morphology and chronoamperometry testing to identify ideal sensor conditions, tests optimized parameters like weight percent of nylon or other polymers, carbon nanotube (CNT) isomer, and solution concentration to determine reproducibility of functional sensors. Utilizing the electric qualities of carbon nanotubes partnered with the sodium ion selectivity of calixarene treatment and polymers unique properties like flexibility and scalability create open an arena for optimizing sodium ion sensors for further development for functional prototypes. Morphology tests showed that the …