Engineering Commons^™

Expansion Microscopy: A New Approach To Microscopic Evaluation, Ashley Ferri

Theses and Dissertations

Optical microscopy resolution is limited by the wavelengths of light and the series of microscope lenses and other optical components used to create a magnified image of cell structures in a sample. Often the cell structures are smaller or closer together than the resolution limits of a light microscope. In 2015 the Boyden group at the Massachusetts Institute of Technology (MIT) created a sample preparation technique, expansion microscopy which involves embedding biological samples in a crosslinked, swellable, hydrogel polymer that allows for uniform physical separation of cell components so that they can subsequently be resolved by light microscopy. Using the …

Developing A 3d In Vitro Model By Microfluidics, Hung-Ta Chien

Dissertations and Theses

In vitro tissue models play an important role in providing a platform that mimics the realistic tissue microenvironment for stimulating and characterizing the cellular behavior. In particular, the hydrogel-based 3D in vitro models allow the cells to grow and interact with their surroundings in all directions, thus better mimicking in vivo than their 2D counterparts. The objective of this thesis is to establish a 3D in vitro model that mimics the anatomical and functional complexity of the realistic cancer microenvironment for conveniently studying the transport coupling in porous tissue structures. We pack uniform-sized PEGDA-GelMA microgels in a microfluidic chip to …

Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of regenerative medicine seeks to create replacement tissues and organs, both to repair deficiencies in biological function and to treat structural damage caused by injury. Scaffoldings mimicking extracellular matrix (ECM), the structure to which cells attach to form tissues, have been developed from synthetic polymers and also been prepared by decellularizing adult tissue. However, the structure of ECM undergoes significant remodeling during natural tissue repair, suggesting that ECM-replacement constructs that mirror developing tissues may promote better regeneration than those modeled on adult tissues. This work investigated the effectiveness of a method of viewing the extracellular matrix of developing …

Thickness Measurement Of Dynamic Thin Liquid Films Generated By Plug-Annular Flow In Non-Wetting Microchannels, David C. Deisenroth

Dissertations, Master's Theses and Master's Reports - Open

Surface tension forces are significant at millimeter length-scales, causing profoundly different flow morphologies in microchannels than in macroscale flows. The existence and morphology of thin liquid films is particularly relevant for predicting performance and operational stability of devices containing microscale two phase flows. Analytical, computational, and experimental methods previously employed in the study of thin liquid films are discussed. Thicknesses before and after a novel film morphology, referred to as a `shock,' are measured with a novel film thickness measurement technique that uses confocal microscopy. Film thicknesses predicted by previous work are compared to experimental results. Methods for increasing the …

Fdtd Simulation Of A Confocal Microscope Using A Theta Line Scan, Blair Simon, Charles Dimarzio, Milind Rajadhyaksha, Carey Rappaport

Carey Rappaport

We describe a 2-D computational model of the optical propagation in human skin from a confocal reflectance theta microscope. As an effect of decreasing the size of the microscope so that it is more clinically useful, the usual point source and detector with a raster scan is changed to a line source with a 1-D array detector. Because there is only one dimension of scanning, the microscope is confocal in one direction, but not in the other, however, this results in additional localized decreases in signal. We hypothesize that these result from the interaction of the bi-static imaging configuration with …

Fdtd Simulation Of A Confocal Microscope Using A Theta Line Scan, Blair Simon, Charles Dimarzio, Milind Rajadhyaksha, Carey Rappaport

Charles A. DiMarzio

We describe a 2-D computational model of the optical propagation in human skin from a confocal reflectance theta microscope. As an effect of decreasing the size of the microscope so that it is more clinically useful, the usual point source and detector with a raster scan is changed to a line source with a 1-D array detector. Because there is only one dimension of scanning, the microscope is confocal in one direction, but not in the other, however, this results in additional localized decreases in signal. We hypothesize that these result from the interaction of the bi-static imaging configuration with …

Photo-Thermal Coherent Confocal Microscope, Sean Sullivan, Charles Dimarzio

Charles A. DiMarzio

Confocal microscopy has been shown to be useful in imaging skin slightly below the junction of the dermis and epidermis. However, the depth of imaging is a significant limitation. We present a novel concept designed both to improve the depth of penetration and to increase the information content of images obtained with a reflectance confocal microscope. Using an approach similar to optoacoustics, we plan to explore the use of laser heating to generate tissue expansion, which will be measured by the microscope. The microscope will incorporate a pulsed heating laser along the same optical path as the imaging laser in …

Compact Dual Wedge Point Scanning Confocal Reflectance Microscope, William C. Warger Ii, Stephen A. Guerrera, Charles A. Dimarzio

Charles A. DiMarzio

Confocal reflectance microscopy has been shown to provide optical sectioning and resolution sufficient to provide useful information about skin to a depth below the epidermis. However, existing instruments are large and expensive, because of the need for fast twodimensional scanning in the pupil, and the associated relay optics. A more compact scanning system could lead to an affordable hand-held instrument for in vivo imaging. Several approaches are being considered with different advantages and disadvantages. Here we report one approach that incorporates a dual-wedge scanner within a point-scanning configuration. The dual-wedge scanner is implemented by replacing the two scanning mirrors and …

Smart Packaging: A Novel Technique For Localized Drug Delivery For Ovarian Cancer, Eva Christabel Williams

USF Tampa Graduate Theses and Dissertations

Localized drug delivery is emerging as an effective technique due to its ability to administer therapeutic concentrations and controlled release of drugs to cancer sites in the body. It also prevents the contact of harsh chemotherapy drugs to healthy regions in the body that otherwise would become exposed to current treatments.

This study reports on a model chemotherapy drug delivery system comprising non-ionic surfactant vesicles (niosomes) packaged within a temperature-sensitive chitosan network. This smart packaging, or package-within-a package system, provides two distinct advantages. First, the gel prevents circulation of the niosomes and maintains delivery in the vicinity of a tumor. …

Protective Effects Of Milk Phospholipids Against Uv Photodamage In Human Skin Equivalents, Zyra Achay

Master's Theses

The ultraviolet (UV) spectrum has been known to cause damage to skin in varying degrees. UVB radiation (290-320 nm) in particular, has been proven to be highly mutagenic and carcinogenic in many animal experiments compared to either UVA or UVC. The alarming rate of increase in skin cancer incidence has prompted many investigators to pursue other alternatives to sunscreens including changes in lifestyle habits and dietary consumption in order to boost our efforts in tackling this widespread disease. Previous studies employing confocal reflectance, MTT assay and histology suggest that milk phospholipids may possess protective properties against UVB-mediated damage but the …

Surface Engineering Of Macrophages With Nanoparticles To Generate A Cell-Nanoparticle Hybrid Vehicle For Hypoxia-Targeted Drug Delivery, Christopher A. Holden, Quan Yuan, W. Andrew Yeudall, Deborah A. Lebman, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Tumors frequently contain hypoxic regions that result from a shortage of oxygen due to poorly organized tumor vasculature. Cancer cells in these areas are resistant to radiation- and chemotherapy, limiting the treatment efficacy. Macrophages have inherent hypoxia-targeting ability and hold great advantages for targeted delivery of anticancer therapeutics to cancer cells in hypoxic areas. However, most anticancer drugs cannot be directly loaded into macrophages because of their toxicity. In this work, we designed a novel drug delivery vehicle by hybridizing macrophages with nanoparticles through cell surface modification. Nanoparticles immobilized on the cell surface provide numerous new sites for anticancer drug …

Liquid Crystal Optics For Communications, Signal Processing And 3-D Microscopic Imaging, Sajjad Khan

Electronic Theses and Dissertations

This dissertation proposes, studies and experimentally demonstrates novel liquid crystal (LC) optics to solve challenging problems in RF and photonic signal processing, freespace and fiber optic communications and microscopic imaging. These include free-space optical scanners for military and optical wireless applications, variable fiber-optic attenuators for optical communications, photonic control techniques for phased array antennas and radar, and 3-D microscopic imaging. At the heart of the applications demonstrated in this thesis are LC devices that are non-pixelated and can be controlled either electrically or optically. Instead of the typical pixel-by-pixel control as is custom in LC devices, the phase profile across …

Quantifying The Surface Geometry Of Titanium Implant Material By Different Methods Of Analysis, Clara Pimienta, Rashad Tawashi

Cells and Materials

Biomaterial implant manufacturers have used rough surfaces to ensure better biocompatibility, less rejection and better adaptation of implants in the body. Proper characterization of biological interactions and biocompatibility of biomaterials requires a thorough understanding of surface complexity. Surface roughness has often been shown to be important in influencing biological reactions with the surface. Previous communications from our laboratory have described a dynamic active vision system (MVS camera) capable of measuring three-dimensional coordinates of titanium implant material surfaces. Fractal analysis, due to its straightforward relationship to texture, is used to characterize the degree of irregularity of a surface and is expressed …