<p> Extracellular matrix (ECM) is a key component and regulator of many biological tissues. Several cardiovascular pathologies are associated with significant changes in the composition of the matrix. Better understanding of these pathologies and the physiological phenomenon behind their development depends on reliable methods that can measure and characterize ECM content and structure. In this dissertation, infrared spectroscopic methodologies are developed to study the changes in extracellular matrix of cardiovascular tissue in two cardiovascular pathologies; myocardial infarction and abdominal aortic aneurysm. </p><p> The specific aims of this dissertation were: 1. To develop a Fourier transform infrared imaging spectroscopy (FT-IRIS) methodology for creating distribution maps of collagen in remodeled cardiac tissue sections after myocardial infarction, and to quantitatively compare maps created by FT-IRIS with conventional staining techniques. 2. To develop an FT-IRIS method to assess elastin and collagen composition in the aortic wall. This will be accomplished using ex vivo animal aorta samples, where the primary ECM components of the wall will be systematically enzymatically degraded. 3. To apply the newly developed FTIR imaging methodology to evaluate changes in the primary ECM components (collagen and elastin) in the wall of human AAA tissues. The infrared absorbance band centered at 1338 ^cm-1, was used to map collagen deposition across heart tissue sections of a rat model of myocardial infarction, and was correlated strongly in the size of the scar (R=0.93) and local intensity of collagen deposition (R=0.86). </p><p> In enzymatically degraded pig aorta samples, as a model of ECM degradation in abdominal aortic aneurysm (AAA), partial least squares (PLS) models were created to predict collagen and elastin content in aorta based on collected FTIR spectra and biochemically measured values. PLS models based on FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (^R2=0.90 and 0.70 respectively). Elastin content prediction from IFOP spectra was successful through a PLS regression model with high correlation (^R2=0.81). </p><p> The PLS regression coefficient from the FT-IRIS models were used to map collagen and elastin human AAA biopsy tissue sections, creating a similar map of each component compared to histologically stained images. The mean value of collagen deposition in each tissue was calculated for 13 pairs of AAA samples where stress had been calculated using finite element modeling. In most pairs with stress values higher than 5 N/m², collagen content was lower in the sample with higher stress value. Collagen maturity had a weak negative correlation (R=-0.35) with collagen content in these samples. </p><p> These results confirm that infrared spectroscopy is a powerful tool that can be applied to replace or complement conventional methods such as histology and biochemical analysis to characterize ECM components in cardiovascular tissues. Furthermore, infrared spectroscopy has the potential for translation to a clinical environment to examine ECM changes in aorta in a minimally invasive fashion using fiber optic technology.</p>

Poor medical adherence attributed to patient compliance has impacted the medical community, at times, in a deleterious fashion. To combat this, the medical community has attempted to provide therapeutics in the form of absorption enhancing techniques. To improve the absorption rate techniques such as drug encapsulation using proteins, liposomes, or nanotransfersomes have been developed using mass spectrometry. These techniques, have aided in the enhanced absorption of analytes with low bioavailability, including curcumin, simvastatin, and lysozyme. Specifically, mass spectrometry allows for the development and monitoring of nanotransfersome encapsulated analytes and the permeation across the dermal membrane. This transdermal delivery would eliminate the problems encountered during first pass metabolism, while allowing for higher concentrations of analyte to be maintained in the blood serum. This can be coupled to a thermosensitive gelatin that provides for a dose control mechanism to be accomplished, allowing multiple doses to be delivered using one transdermal patch system. The novel delivery system developed using mass spectrometry, allows the analyte to be delivered into the circulatory system at a controlled dosage, via transdermal absorption. This system will aid in eliminating problems associated with patient compliance, as the patient is no longer reliant on memory to self-dose. Further, this system mitigates the concerns of patients overdosing with more potent pharmaceuticals.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 68-02, Section: B, page: 0944. Adviser: Kenneth S. Suslick. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph. D.)--Lund University, 1997. / Published dissertation.

Thesis (Ph. D.)--Lund University, 1997. / Published dissertation.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3643. Adviser: Neil L. Kelleher. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6368. Adviser: Kenneth S. Suslick. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

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Master of Science / Department of Chemistry / Daniel A. Higgins / Lithography techniques have been widely used to fabricate optical, electronic and optoelectronic devices with sub-micron scale spatial resolution. In the most common lithographic procedures, a light sensitive polymer, called a photoresist, is exposed and developed to form a binary relief pattern on a substrate. The finest features are produced by X-ray or electron-beam methods, both of which are very expensive to employ. Less expensive methods use ultraviolet (UV) light to expose the photoresist through a photomask. The resolution in these methods is somewhat lower and is governed by diffraction of light by the photomask, the quality of the photomask, and by any chemical/physical development steps subsequently employed. Due to the above limitations, we have been investigating direct-write, ablative multiphoton lithography as an alternative method for preparing high-resolution patterns. With this method, near-IR light from an ultrafast pulsed laser source is focused into a polymer film, leading to depolymerization and vaporization of the polymer. Arbitrary binary patterns can be produced by raster scanning the sample while controlling exposure of the film to the laser. Importantly, high-resolution etching of the polymer film is achieved without the use of a photomask and without chemical development steps. While arbitrary patters are easily prepared, it is also possible to prepare three-dimensional (i.e. grayscale) surface relief structures. In this study, ablative multiphoton photolithography is used to prepare binary and grayscale structures in thin films of PEDOT:PSS, an electrically conductive organic polymer blend. A simple kinetic model is proposed to explain the etching process. Data on the power-dependence of polymer etching can be fit to this model and is used to determine the order of the nonlinear optical process involved. The etch depth as a function of laser focus is also investigated and shown to follow the same kinetic model. The results show that three-dimensional (grayscale) patterns can be prepared by modulating either the laser power or the laser focus. Images of several binary and grayscale structures prepared by this method are presented.

The molecular mechanism of transmembrane signaling is unknown. Investigations have been hampered by the limits of current biophysical methods. Recently developed solid-state nuclear magnetic resonance (NMR) techniques provide a new approach for selective distance measurements probing structure and function of membrane proteins including ligand interactions. The environmental signal transduced by the serine receptor of bacterial chemotaxis is initiated by the attractant molecule serine. We initially demonstrated the feasibility of direct internuclear distance measurements between the 15N-amino labeled serine ligand and phenylalanine 13C-carbonyl labeled receptor. The two 4.0 ± 0.2 Å distances measured from the serine receptor to the ligand match the distances observed in the crystal structure of the ligand-binding domain fragment of the homologous aspartate receptor. Demonstration of the structural similarity between the aspartate receptor and serine receptor instigated further investigations into the mechanism of ligand specificity. To probe transmembrane signaling we developed a new constant time version of the rotational resonance solid-state NMR technique with improved reliability and efficiency. Combined with a site-directed strategy, this is a valuable and general tool for probing structure in large membrane proteins. A CO( i) to Cβ(i + 3) distance measurement along the periplasmic edge of the second membrane-spanning helix, provides a structural constraint for an unmapped region of the serine receptor. The 5.4 Å internuclear distance measured in the presence and in the absence of serine shows that any signaling mechanism must conserve the helical pitch of the second transmembrane domain. To test abundant and conflicting models of transmembrane signaling we measured an inter-helical distance across the dimer interface in the transmembrane region of the receptor. Computer modeling of this distance predicted sensitivity to proposed long-range ligand-induced conformational changes including piston, scissors, and rotational motions. Ile measured 5.0 Å distance provides a valuable structural constraint of tertiary structure. Both ligand-free and -bound signaling states of the receptor show the same inter-helical distance, suggesting that conformational changes are not propagated into the transmembrane domain. This approach provides a means for testing proposed mechanisms and mapping conformational changes involved in transmembrane signaling.