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Full-Text Articles in Engineering
Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter, Nicholas Ciaffone
Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter, Nicholas Ciaffone
Electronic Theses and Dissertations
The complexity of biological soft matter at the sub-micrometer level is fundamentally correlated to the functionalities at the larger scale. Reflecting the level of heterogeneities in the properties of systems remains challenging when probing small scales, due to the mismatch between the area surveyed with the tools offering nanoscale resolution, such as atomic force microscopy (AFM), and the scale of natural variations inherent to biology. Hence, to understand the physiological and mechanical alterations that occur within a single cell relative to a cell population, a multiscale approach is necessary. In this work we show that it is possible to observe …
Tunable Effect Of Metal Ions On Polyelectrolyte Mechanics, Angie Diaz
Tunable Effect Of Metal Ions On Polyelectrolyte Mechanics, Angie Diaz
Electronic Theses and Dissertations
Polyelectrolyte based hydrogel fibers can mimic extracellular matrix and have applications such as drug delivery and tissue scaffolding. Metal ions play a critical role in hydrogel fiber stability via electrostatic interactions, but knowledge of how they modulate mechanical properties of individual polyelectrolyte polymers is lacking. In this study, electrospun polyacrylic acid with chitosan is used as a model system to evaluate ferric ion effect on nanofiber mechanics. Using dark field microscopy imaging and persistence length analysis, we demonstrate that ferric ions modulate the bending stiffness of nanofibers. Young's modulus of individual nanofibers is estimated at values of a few kilopascals, …
A Multisystem Approach For The Characterization Of Bacteria For Sustainable Agriculture, Briana Lee
A Multisystem Approach For The Characterization Of Bacteria For Sustainable Agriculture, Briana Lee
Electronic Theses and Dissertations
The chemical, physical, and biological properties of bacteria developing resistance have been explored in animal based bacteria while plant bacteria have been largely neglected. Thus, the ability to probe changes in stiffness, adhesion, binding interactions and molecular traits of bacteria causing plant diseases is of great interest to develop a new generation of more potent, yet sustainable, pesticides. Our study aims to investigate the physical and chemical properties of bacterial systems, in particular their cell walls. Building upon this fundamental understanding of the cells, we also investigate the physicochemical responses associated to multivalent nanoparticle-based bactericide treatments on bacterial systems identified …
Size, Charge And Dose Dependent In-Vitro Kinetics Of Polystyrene Nanoparticles, Yasmine Abdellatif
Size, Charge And Dose Dependent In-Vitro Kinetics Of Polystyrene Nanoparticles, Yasmine Abdellatif
Electronic Theses and Dissertations
The aim of the study described herein is to quantify the in-vitro kinetics of internalization of polystyrene nanoparticles (PS NPs) by cells. We used different charges, sizes and doses of fluorescently labelled PS NPs. Nanoparticles were characterized with UV-Vis, Fluorescence emission Dynamic Light Scattering (DLS) and Zeta potential for knowing their absorption, fluorescence spectra, size, charge, respectively. Additionally, cell viability was tested to know the toxicity of PS NPs. The quantitative uptake, the kinetics profile and rate of uptake were studied by using a new in-vitro fluorescence assay. This was achieved quantitatively and qualitatively by fluorescent plate reader and confocal …