archives@tulane.edu / Preeclampsia is a condition that occurs during pregnancy and affects both the mother and fetus. It is the leading cause of fetal and maternal mortality, affecting up to 8% of pregnancies. The disorder is diagnosed after the new onset of maternal high blood pressure and proteinuria. There is currently no cure for preeclampsia, other than delivery of the baby (and placenta), which often has to occur pre-term. Abnormal placental development that results in placental ischemia is a precursor for the development of preeclampsia in the mother. Current clinical imaging systems have been unable to accurately characterize placental function enough to make diagnoses. Therefore, there is a need to further study placental ischemia so that better diagnostic tools and therapies can be developed. Spectral photoacoustic (PA) imaging of placental oxygen saturation is a promising approach to studying placental ischemia.
PA imaging uses nanosecond light pulses to excite endogenous or exogenous chromophores in biological tissue. When a chromophore undergoes a thermo-elastic expansion after absorbing light, a pressure wave is released within the tissue. The pressure wave resulting from the chromophore’s expansion are received by an ultrasound transducer.
Our endogenous chromophore of interest is hemoglobin, an oxygen carrier protein in the blood. Hemoglobin and deoxyhemoglobin have distinctly different absorption
spectra, which allows for the estimation of sO2 in vivo. One aim of this work is to use photoacoustic imaging to study altered levels of induced placental ischemia.
Exogenous contrasts, such as perfluorocarbon microbubbles are commonly used in ultrasound because of their acoustic impedance mismatch with surrounding tissues. Perfluorocarbon nanodroplets are their liquid counterpart and offer longer stability in vivo. Additionally, they can be targeted and phase-changed into gas by a surrounding change in pressure, offering multimodal use. We use a modified perfluorocarbon construct loaded with ICG as an exogenous contrast agent. In this work, we will first investigate the feasibility of nanodroplets as oxygen delivery agents to blood. Then, we explore the utility of oxygen-loaded nanodroplets targeted to the placenta as a potential theranostic for preeclampsia. / 1 / Megan Escott
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_92036 |
| Date | January 2019 |
| Contributors | Escott, Megan (author), (author), Bayer, Carolyn (Thesis advisor), (Thesis advisor), School of Science & Engineering Biomedical Engineering (Degree granting institution), NULL (Degree granting institution) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | electronic, pages: 70 |
| Rights | No embargo, Copyright is in accordance with U.S. Copyright law. |
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