Investigation Of Gold Nanoshells In The Nanobubbles For Ultrasound Image Of Liver Tumors

Ultrasound contrast agents are used to boost the echo scattering intensity and improve ultrasound diagnostic accuracy. Endothelial cells of tumors form vascular leakage of 380-780 nm due to the rapid growth. It has been proposed that ultrasound contrast agents with size less than 700 nm can penetrate through the tumor blood vessels into the tumor tissue. Nanoscale contrast agents have strong penetrating power and can accumulate in the tumor tissue by EPR effect for selective tumor imaging. O n the other hand, microbubbles, due to the large size, can only be used in blood pool imaging. Nanoscale ultrasound contrast agents have become a hot research topic recently, mainly used in the diagnosis and treatment of tumor, drug delivery, etc. Unfortunately, there are several aspects of nanobubbles needed to be improved.The synthesis of gold nanoparticle has been progressed rapidly. Gold nanoparticles have good biological compatibility, thermal effect, low toxicity and can be modified conveniently and have been used in the diagnosis and treatment of tumor, biochip, etc.To enhance the stability of nanobubbles, we synthesized gold nanoshells in hope to improve the stability of nanobubbles and achieve the purpose of theranostics. The achievements of this thesis mainly included:1) Preliminary studies of synthesis of nanorings: gold nanorings and silver nanorings through different synthetic approaches.2) Synthesis and characterization of gold nanoshells: use 200 nm silver nanoparticles as templates to synthesize 200 nm gold nanoshells; Characterization include: size, zeta potential, TEM, UV-vis absorption, the concentration of gold content, Photothermal effect.3) Ultrasound imaging in vitro and in vivo: analysis of ultrasound images, establishment of subcutaneous tumor model, in vivo ultrasound imaging analysis of the liver and tumor.