Ultrasound imaging is one of the more cost-effective and wide-spread imaging modalities in the clinic. Soundwaves have deeper penetration capabilities than light, which makes ultrasound one of the premier modalities for deep tissue imaging and allows for the noninvasive diagnosis of diseased states. To improve the image quality and contrast of ultrasound images, gas-filled microbubbles can be administered to serve as ultrasound contrast agents. However, due to their size, current ultrasound contrast agents limit the use of ultrasound imaging to only studying circulation related conditions. My project involves the development of stimuli responsive nanobubbles as ultrasound contrast agents to expand and improve the use of ultrasound to study inflammation, cardiovascular disease, and cancer.