Date: Friday, May 26, 2017

Time: 11:00 am

Location: Whitaker Building (BME) room 1103

Committee members:

Dr. Stanislav Emelianov (BME, ECE): Advisor

Dr. Younan Xia (BME)

Dr. Francisco Robles (BME)

Dr. J Brandon Dixon (ME)

Dr. Ravi Kane (CHBE)

Dr. Mostafa El-Sayed (Chemistry)

Title: Gas-generating nanoparticles for the enhanced contrast of ultrasound imaging

Abstract: Despite many advantages of ultrasound imaging, its low contrast often limits the clinical application. Even though microbubbles are commonly used for the enhance contrast, they cannot visualize extravascular diseases, because of their inability to escape from blood vessels as a result of their micron-scale sizes. For the detection of such diseases, ultrasound contrast agents should have nano-scale sizes for extravasation and simultaneously be in micron-scale for echogenicity. Therefore, novel gas-generating nanoparticles as ultrasound contrast agents are proposed. By generating gas bubbles instead of carrying it, their sizes can reduce significantly. The gas-generating nanoparticles consist of azide compounds (for gas generation) and gold nanoparticles (for carrier and photocatalyst). Triggered by laser, the gas-generating contrast agents produce gas bubbles that enhance contrast of ultrasound images. Their properties, such as size distribution, gas-generating rate, contrast enhancement, are characterized. The feasibility in medical imaging is tested through in vivo imaging of mouse models with cancer or metastatic lymph nodes. The novel contrast agents will have a major impact on the application of diagnostic ultrasound imaging.