Nanotechnology Commons^™

Unveiling Pain: Wearables For Objective Pain Measurement, Hanqing Tang

Masters Theses

">">Pain perception is a subjective experience that differs significantly among individuals, often leading to inconsistencies in assessment and management. A critical issue within this context is the gender bias in pain evaluation, which contributes to unequal treatment and perpetuates gender inequality within the healthcare system. This thesis presents an in-depth investigation of the problem and proposes the development of a wearable device for objective pain assessment. Physiological parameters — Electrocardiography (ECG) can be collected from cardiac sound signals auscultated by fabrics via nanometre-scale vibrations. Machine learning methods can accurately classify heart rate and acute pain intensity of participants. …

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …

Molecular Dynamics Simulations Of Self-Assemblies In Nature And Nanotechnology, Phu Khanh Tang

Dissertations, Theses, and Capstone Projects

Nature usually divides complex systems into smaller building blocks specializing in a few tasks since one entity cannot achieve everything. Therefore, self-assembly is a robust tool exploited by Nature to build hierarchical systems that accomplish unique functions. The cell membrane distinguishes itself as an example of Nature’s self-assembly, defining and protecting the cell. By mimicking Nature’s designs using synthetically designed self-assemblies, researchers with advanced nanotechnological comprehension can manipulate these synthetic self-assemblies to improve many aspects of modern medicine and materials science. Understanding the competing underlying molecular interactions in self-assembly is always of interest to the academic scientific community and industry. …

Development Of Biomaterials For Drug Delivery, Raquel De Castro

Graduate Theses and Dissertations

Drug delivery systems (DDS) have highly evolved in the last decades with the development of hydrogels and nanoparticles. However, high systemic uptake, side effects, low bioavailability, and encapsulation efficiency continue to be a major hurdle faced by such DDSs.

Nanoparticles and hydrogels can be specifically designed for targeted DDSs to mitigate some of the problems. This dissertation aimed to design two DDSs for ocular drug delivery and one for cancer treatment. The first project sought to develop chitosan nanoparticles (Cs-NP) using PEGDA as a copolymer to encapsulate gentamicin (GtS) for ocular drug delivery. Cs-NPs contain positive charges that can interact …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Nature-Inspired Electrode Materials For Next Generation Sustainable Energy Storage, Mikhail Miroshnikov

Dissertations, Theses, and Capstone Projects

Despite revolutionizing the world of portable electronics, the contemporary lithium-ion battery (LIB) suffers from challenges associated with the cost, safety, and environmental impact of transition metal oxide-based intercalation cathodes. To alleviate these issues, naturally occurring organic molecules may serve as sustainable alternatives to traditional inorganic cathode materials. The electrochemical properties of organic compounds are derived from redox-active functional groups containing oxygen, nitrogen and sulfur. Additionally, these functional groups are capable of coordinating metal ions beyond lithium, allowing for compatibility with sodium-ion batteries (SIBs) and other earth abundant metal-based energy storage systems. However, despite competitive performance against commercialized cathode materials, much …

Engineered Nanoparticles For Site-Specific Bioorthogonal Catalysis: Imaging And Therapy, Riddha Das

Doctoral Dissertations

Bioorthogonal catalysis offers a strategy for chemical transformations complementary to bioprocesses and has proven to be a powerful tool in biochemistry and medical sciences. Transition metal catalysts (TMCs) have emerged as a powerful tool to execute selective chemical transformations, however, lack of biocompatibility and stability limits their use in biological applications. Incorporation of TMCs into nanoparticle monolayers provides a versatile strategy for the generation of bioorthogonal nanocatalysts known as “nanozymes”. We have fabricated a family of nanozymes using gold nanoparticles (AuNPs) as scaffolds featuring diverse chemical functional groups for controlled localization of nanozymes in biological environments, providing unique strategies for …

Shape Tuning Of Silicon Nano-Tip Arrays Through Reactive Ion Etching For Cold Field Emission, Giridhar Tulasi Ram Sankabathula

Graduate Research Theses & Dissertations

Large area silicon nano-tip arrays have been predominantly used as cold cathode electron sources in the wide range of field emission applications. Various fabrication methodologies have been developed over the decades to obtain sharp-pointed field emitters. In this thesis, we mainly emphasized on reproducing high aspect ratio field emitters and to study their surface topographical changes encountered through reactive ion etching. A discrete set of high-density field emitters have been fabricated over the large area surfaces through a three-step nanofabrication process. The surface curvatures of the obtained emitter tips are finely tuned with multiple oxidation cycles to achieve a tip’s …

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, …

Role Of Rigidity And Flexibility Of Functional Groups Within The Interior Of Supramolecular Assemblies And Their Implications, Oyuntuya Munkhbat

Doctoral Dissertations

Engineering of supramolecular assemblies at molecular level renders functional nanomaterials that present explicit response to certain environmental changes. Systematic structure-property correlation studies will unravel the fundamental design constraints of these functional nanomaterials that fulfill the emergent need. This dissertation will primarily focus on understanding the role of rigidity and flexibility of functional groups within amphiphilic assemblies and employing this basic concept in drug delivery and diagnostics applications. Supramolecular assemblies formed by amphiphilic dendrimers and polymers are preferred for this study as they exhibit high thermodynamic stability and structural flexibility. The role of aromatic interaction on the unimer-aggregate dynamic equilibrium was …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Ginseng Polysaccharides Nanoparticles - Synthesis, Characterization, And Biological Activity, Kazi Farida Akhter

Electronic Thesis and Dissertation Repository

North American (NA) ginseng is a widely used medicinal plant. Polysaccharides (PS), the major medicinal fractions derived from NA ginseng root, have been shown several biological activities including anti-carcinogenic, anti-aging, immunostimulatory and antioxidant activity. This work focused on nanoprocessing of ginseng PS for enhancing their immunostimulation. Herein, we have developed a novel microfluidic approach to synthesize ginseng PS nanoparticles (NPs) from NA ginseng root. The microfluidics was found to provide unimodal PS spheres down to 20 nm with very narrow particle size distributions. In addition, the immunostimulating effect was investigated on Murine macrophage cell lines, with the results revealing an …

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 …

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual examination of suspicious regions …

Synthesis Of Zinc Oxide Nanorods And Use In Biosensor Applications, Anishkumar Manoharan

Graduate Theses and Dissertations

The main aim of this research was to develop a nanorod based biosensor for biomedical applications. In this project I use zinc oxide nanorods as the bio-material for biosensor. I fabricated these nanorods using a solution-based technique. Initially I coated a zinc oxide seed layer as the base. This seed layer was then annealed at 350 degrees for almost 1 hour. As a next step, interdigitated electrodes were fabricated on the top of the seed layer using a lift off process. The zinc oxide nanorods were then grown at 90 degrees for almost 4 hours along the electrodes. In this …