Nanoscience and Nanotechnology Commons^™

Dual Delivery Systems Based On Polyamine Analog Benspm As Prodrug And Gene Delivery Vectors, Yu Zhu

Wayne State University Dissertations

Combination drug and gene therapy shows promise in cancer treatment. However, the success of such strategy requires careful selection of the therapeutic agents, as well as development of efficient delivery vectors. BENSpm (N1, N11-bisethylnorspermine), a polyamine analogue targeting the intracellular polyamine pathway, draws our special attention because of the following reasons: (1) polyamine pathway is frequently dysregulated in cancer; (2) BENSpm exhibits multiple functions to interfere with the polyamine pathway, such as to up-regulate polyamine metabolism enzymes and down-regulate polyamine biosynthesis enzymes. Therefore BENSpm depletes all natural polyamines and leads to apoptosis and cell growth inhibition in a wide range …

Experimental Development Of Advanced Air Filtration Media Based On Electrospun Polymer Fibers, Negar Ghochaghi

Theses and Dissertations

Electrospinning is a process by which polymer fibers can be produced using an electrostatically driven fluid jet. Electrospun fibers can be produced at the micro- or nano-scale and are, therefore, very promising for air filtration applications. However, because electrospun fibers are electrically charged, it is difficult to control the morphology of filtration media. Fiber size, alignment and uniformity are very important factors that affect filter performance. The focus of this project is to understand the relationship between filter morphology and performance and to develop new methods to create filtration media with optimum morphology.

This study is divided into three focus …

Reference Compensation For Localized Surface-Plasmon Resonance Sensors, Neha Nehru

Theses and Dissertations--Electrical and Computer Engineering

Noble metal nanoparticles supporting localized surface plasmon resonances (LSPR) have been extensively investigated for label free detection of various biological and chemical interactions. When compared to other optical sensing techniques, LSPR sensors offer label-free detection of biomolecular interactions in localized sensing volume solutions. However, these sensors also suffer from a major disadvantage – LSPR sensors remain highly susceptible to interference because they respond to both solution refractive index change and non-specific binding as well as specific binding of the target analyte. These interactions can severely compromise the measurement of the target analyte in a complex unknown media and hence limit …

Polymer Aggregation Correlated Transition From Schottky-Junction To Bulk Heterojunction Organic Solar Cells, Bin Yang, Zhengguo Xiao, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The fullerene-based organic Schottky-junction solar cells have recently attracted intensive research interest because of their unique electrical performance, such as significant photocurrent generation from excitons created in fullerenes and large open-circuit voltage (V_OC) output induced by high Schottky-barrier height between the anode and the fullerene acceptor. This manuscript reports another remarkably appealing advantage that the fullerene-based Schottky-junction solar cells are more stable than the bulk heterojunction counterparts. The better stability is likely due to mitigative polymer photo-oxidation and/or little morphological change of active film in the aged Schottky-junction devices. The transition from Schottky-junction to bulk heterojunction appears at …

Phase Transitions In Mechanically Milled Mn-Al-C Permanent Magnets, Michael J. Lucis, Timothy E. Prost, Xiujuan Jiang, Meiyu Wang, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Mn-Al powders were prepared by rapid solidification followed by high-energy mechanical milling. The rapid solidification resulted in single-phase ε. The milling was performed in both the ε phase and the τ phase, with the τ-phase formation accomplished through a heat treatment at 500 °C for 10 min. For the ε-milled samples, the conversion of the ε to the τ phase was accomplished after milling via the same heat treatment. Mechanical milling induced a significant increase in coercivity in both cases, reaching 4.5 kOe and 4.1 kOe, respectively, followed by a decrease upon further milling. The increase in coercivity was the …

Biomechanical Strain As A Trigger For Pore Formation In Schlemm’S Canal Endothelial Cells, Sietse T. Braakman, Ryan M. Pedrigi, A. Thomas Read, James A. E. Smith, W. Daniel Stamer, C. Ross Ethier, Darryl R. Overby

Department of Mechanical and Materials Engineering: Faculty Publications

The bulk of aqueous humor passing through the conventional outflow pathway must cross the inner wall endothelium of Schlemm’s canal (SC), likely through micron-sized transendothelial pores. SC pore density is reduced in glaucoma, possibly contributing to obstructed aqueous humor outflow and elevated intraocular pressure (IOP). Little is known about the mechanisms of pore formation; however, pores are often observed near dome-like cellular outpouchings known as giant vacuoles (GVs) where significant biomechanical strain acts on SC cells. We hypothesize that biomechanical strain triggers pore formation in SC cells. To test this hypothesis, primary human SC cells were isolated from three non-glaucomatous …

Altered Mechanobiology Of Schlemm’S Canal Endothelial Cells In Glaucoma, Darryl R. Overby, Enhua H. Zhou, Rocio Vargas-Pinto, Ryan M. Pedrigi, Rudolf Fuchshofer, Sietse T. Braakman, Ritika Gupta, Kristin M. Perkumas, Joesph M. Sherwood, Amir Vahabikashi, Quynh Dang, Jae Hun Kim, C. Ross Ethier, W. Daniel Stamer, Jeffrey J. Fredberg, Mark Johnson

Department of Mechanical and Materials Engineering: Faculty Publications

Increased flow resistance is responsible for the elevated intraocular pressure characteristic of glaucoma, but the cause of this resistance increase is not known. We tested the hypothesis that altered biomechanical behavior of Schlemm’s canal (SC) cells contributes to this dysfunction. We used atomic force microscopy, optical magnetic twisting cytometry, and a unique cell perfusion apparatus to examine cultured endothelial cells isolated from the inner wall of SC of healthy and glaucomatous human eyes. Here we establish the existence of a reduced tendency for pore formation in the glaucomatous SC cell—likely accounting for increased outflow resistance—that positively correlates with elevated subcortical …

Arising Applications Of Ferroelectric Materials In Photovoltaic Devices, Yongbo Yuan, Zhengguo Xiao, Bin Yang, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The ferroelectric-photovoltaic (FE-PV) device, in which a homogeneous ferroelectric material is used as a light absorbing layer, has been investigated during the past several decades with numerous ferroelectric oxides. The FE-PV effect is distinctly different from the typical photovoltaic (PV) effect in semiconductor p–n junctions in that the polarization electric field is the driving force for the photocurrent in FE-PV devices. In addition, the anomalous photovoltaic effect, in which the voltage output along the polarization direction can be significantly larger than the bandgap of the ferroelectric materials, has been frequently observed in FE-PV devices. However, a big challenge faced by …

Organic Ferroelectric Evaporator With Substrate Cooling And In Situ Transport Capabilities, Keith Foreman, C. Labedz, M. Shearer, Shireen Adenwalla

Shireen Adenwalla Papers

We report on the design, operation, and performance of a thermal evaporation chamber capable of evaporating organic thin films. Organic thin films are employed in a diverse range of devices and can provide insight into fundamental physical phenomena. However, growing organic thin films is often challenging and requires very specific deposition parameters. The chamber presented here is capable of cooling sample substrates to temperatures below 130 K and allows for the detachment of the sample from the cooling stage and in situ transport. This permits the use of multiple deposition techniques in separate, but connected, deposition chambers without breaking vacuum …

Cnt Membrane Platforms For Transdermal Drug Delivery And Aptamer Modulated Transport, Tao Chen

Theses and Dissertations--Chemical and Materials Engineering

CNT membrane platforms are biomimetic polymeric membranes imbedded with carbon nanotubes which show fast fluid flow, electric conductivity, and the ability to be grafted with chemistry. A novel micro-dialysis probe nicotine concentration sampling technique was proposed and proved in vitro, which could greatly improve the efficiency and accuracy of future animal transdermal studies. To enhance the scope of transdermal drug delivery which was limited to passive diffusion of small, potent lipophilic drugs, a wire mesh lateral electroporation design was also proposed which could periodically disrupt the skin barrier and enhance drug flux.

It was shown that AMP binding aptamer …

Addressing Public Health Risks Of Persistent Pollutants Through Nutritional Modulation And Biomimetic Nanocomposite Remediation Platforms, Bradley J. Newsome

Theses and Dissertations--Chemistry

Due to their relative chemical stability and ubiquity in the environment, chlorinated organic contaminants such as polychlorinated biphenyls (PCBs) pose significant health risks and enduring remediation challenges. Engineered nanoparticles (NPs) provide a novel platform for sensing/remediation of these toxicants, in addition to the growing use of NPs in many industrial and biomedical applications, but there remains concern for their potential long-term health effects. Research highlighted herein also represents a transdisciplinary approach to address human health challenges associated with exposure to PCBs and NPs. The objectives of this dissertation research are two-fold, 1) to develop effective methods for capture/sensing and remediation …

Fluid Dynamic Modeling Of Nano-Thermite Reactions, Karen S. Martirosyan, Maxim Zyskin, Charles M. Jenkins, Yasuyuki Horie

Physics & Astronomy Faculty Publications

This paper presents a direct numerical method based on gas dynamic equations to predict pressure evolution during the discharge of nanoenergetic materials. The direct numerical method provides for modeling reflections of the shock waves from the reactor walls that generates pressure-time fluctuations. The results of gas pressure prediction are consistent with the experimental evidence and estimates based on the self-similar solution. Artificial viscosity provides sufficient smoothing of shock wave discontinuity for the numerical procedure. The direct numerical method is more computationally demanding and flexible than self-similar solution, in particular it allows study of a shock wave in its early stage …

Visible-Light Photocatalyzed Cross-Linking Of Diacetylene Ligands By Quantum Dots To Improve Their Aqueous Colloidal Stability, Marion G. Götz, Hiroko Takeuchi, Matthew J. Goldfogel, Julia M. Warren, Brandon D. Fennel, Colin D. Heyes

Chemistry & Biochemistry Faculty Publications and Presentations

Ligand cross-linking is known to improve the colloidal stability of nanoparticles, particularly in aqueous solutions. However, most cross-linking is performed chemically, in which it is difficult to limit interparticle cross-linking, unless performed at low concentrations. Photochemical cross-linking is a promising approach but usually requires ultraviolet (UV) light to initiate. Using such high-energy photons can be harmful to systems in which the ligand–nanoparticle bond is fairly weak, as is the case for the commonly used semiconductor quantum dots (QDs). Here, we introduce a novel approach to cross-link thiolated ligands on QDs by utilizing the photocatalytic activity of QDs upon absorbing visible …

Role Of Surface Chemistry In Nanoscale Electrokinetic Transport, Secuk Atalay

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation work presents the efforts to study the electrofluidics phenomena, with a focus on surface charge properties in nanoscale systems with the potential applications in imaging, energy conversion, ultrafiltration, DNA analysis/sequencing, DNA and protein transport, drug delivery, biological/chemical agent detection and micro/nano chip sensors.

Since the ion or molecular or particle transport and also liquid confinement in nano-structures are strongly dominated by the surface charge properties, in regards of the fundamental understanding of electrofluidics at nanoscale, we have used surface charge chemistry properties based on 2-pK charging mechanism. Using this mechanism, we theoretically and analytically showed the surface charge …

Development Of A Nitrogen Incorporated Ultrananocrystalline Diamond Film Based Field Emitter Array For A Flat Panel X-Ray Source, Chrystian Mauricio Posada

Doctoral Dissertations

"As an alternative to conventional X-ray sources, a flat panel transmission X-ray source is being developed. A field emitter array (FEA) prototype to be incorporated as cold cathode in this flat panel X-ray source was fabricated for this work. Using the Particle-in-Cell code OOPIC Pro, an initial FEA was designed through simulations. Based on the simulation results, a FEA prototype was fabricated using conventional microfabrication techniques. Planar nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) films were used as field emitters. This N-UNCD based FEA prototype was composed of 9 pixels distributed in a 3x3 array, with a pixel size of 225x225 µm, and …

Spectrally-Selective All-Inorganic Scattering Luminophores For Solar Energy-Harvesting Clear Glass Windows, Ramzy Alghamedi, Mikhail Vasiliev, Mohammad Alam, Kamal Alameh

Research outputs 2014 to 2021

All-inorganic visibly-transparent energy-harvesting clear laminated glass windows are the most practical solution to boosting building-integrated photovoltaics (BIPV) energy outputs significantly while reducing cooling- and heating-related energy consumption in buildings. By incorporating luminophore materials into lamination interlayers and using spectrally-selective thin-film coatings in conjunction with CuInSe₂ solar cells, most of the visible solar radiation can be transmitted through the glass window with minimum attenuation while ultraviolet (UV) radiation is down-converted and routed together with a significant part of infrared radiation to the edges for collection by solar cells. Experimental results demonstrate a 10 cm × 10 cm vertically-placed energy-harvesting clear …

Fabrication Of Yttrium Ferrite Nanoparticles By Solution Combustion Synthesis, A. A. Saukhimov, Mkhitar A. Hobosyan, Gamage C. Dannangoda, N. N. Zhumabekova, S. E. Kumekov

Physics & Astronomy Faculty Publications

The ternary oxide system Y-Fe-O presents fascinating magnetic properties that are sensitive to the crystalline size of particles. There is a major challenge to fabricate these materials in nano-crystalline forms due to particle conglomeration during nucleation and synthesis. In this paper we report the fabrication of nano sized crystalline yttrium ferrite by solution combustion synthesis (SCS) where yttrium and iron nitrates were used as metal precursors with glycine as a fuel. The magnetic properties of the product can be selectively controlled by adjusting the ratio of glycine to metal nitrates. Yttrium ferrite nano-powder was obtained by using three concentration of …