Events Calendar

MSE Masters Thesis Final Presentation: Yeling Luo

TITLE: Towards Noninvasive Detection of Peritoneal Adhesions: A Stepwise Study of Lipid-Based Microbubble Contrast Agents in Simulated Abdominal Environments

ADVISOR: Joyce Wong MSE,BME

COMMITTEE: Joel Henderson Department of Pathology & Laboratory Medicine

ABSTRACT: Peritoneal adhesions are a common and often serious complication following abdominal surgery, leading to chronic pain, infertility, and bowel obstruction. Despite their clinical impact, current diagnostic methods are limited, often relying on invasive procedures or imaging techniques with insufficient sensitivity. Lipid-based microbubbles, as ultrasound contrast agents, have emerged as a promising tool for noninvasive imaging due to their strong acoustic response and potential for molecular targeting. However, their application in adhesion imaging remains underexplored, particularly under conditions simulating the peritoneal environment. This study presents a systematic investigation of lipid-based microbubble contrast agents for ultrasound detection of peritoneal adhesions, with a focus on their physicochemical characteristics, stability, and targeting performance. In the first part, we examined the morphology and composition of custom-made microbubbles through optical and FTIR analysis, while also referencing freezing protocols from commercial microbubble preparation to improve reproducibility and structural integrity. In the second part, we evaluated microbubble stability in progressively more physiologically relevant environments: saline solution (0.9% NaCl), ex vivo rat peritoneal cavities, and patient-derived ascitic fluid. To assess acoustic stability over time, microbubbles were imaged using a closed agar-based phantom under the Terason ultrasound system and Verasonics system at various time points, mimicking clinical imaging conditions. The third part of the study focused on targeted microbubbles designed to bind to fibrin, a key component of post-surgical adhesions. We tested their binding behavior under both in vitro and ex vivo conditions, followed by ultrasound imaging within a phantom setup embedded with fibrin to simulate adhesion tissue. The binding efficiency and acoustic signal enhancement were used to evaluate targeting performance. Together, these investigations provide critical insights into the behavior of lipid-based microbubbles in complex biological environments and demonstrate their potential for future application in noninvasive diagnosis of peritoneal adhesions. This work also offers a foundation for further development of targeted contrast agents in abdominal imaging.