MSE Master's Thesis Final Presentation: Thy Duong

MSE Master’s Final Thesis Presentation: Thy Duong

TITLE: Characterization of Lipid-shelled Microbubbles Using Mid-infrared Photothermal Microscopy

ADVISOR: Joyce Wong (BME, MSE)

COMMITTEE: Michelle Sander (ECE, BME, MSE)

ABSTRACT: The formation of post-operative adhesions is a common issue often seen after abdominal and pelvic surgery. These adhesions are pathological fibrous scar tissue formations between opposing tissue or organ surfaces as a result of trauma to the abdominal cavity during surgery, and they contribute heavily to complications including chronic abdominal and pelvic pain, infertility, and intestinal obstructions (which can be fatal). One non-invasive method of adhesion detection and treatment we aim to explore is the use of lipid-shelled microbubbles to aid in ultrasound detection of adhesions. These microbubbles act as a strong ultrasound contrast agent that can greatly aid in improving the quality of ultrasound images, which can allow for cheaper and much more effective detection of adhesions compared to MRI. The fibrin-binding peptide CREKA is incorporated onto the surface of lipid-shelled microbubble to diagnose and potentially target newly formed adhesions, where fibrin is highly abundant. Using mid-infrared photothermal microscopy, structural differences between the lipid shells of microbubbles created with different PEG molecules as well as different lipids were characterized in this study. The off-target binding of CREKA to extracellular matrix (ECM) components other than fibrin was also evaluated through brightfield imaging of gels with other ECM proteins such as gelatin or collagen to determine the binding affinity of CREKA-DSPC microbubbles to these proteins.