Allows them to access the inside of tumor tissues and achieve real target imaging and treatment. Based on the results of this study, the ultrasound-destructible nanobubbles carrying AR siRNA that we prepared could not only enhance the imaging effect of transplanted tumor, but also distribute more widely in the tumor, compared with the control microbubbles. In other normal tissues and organs, such as the liver and the kidney, nanobubbles had longer imaging duration than microbubbles while there was no obvious different distribution between them. Additionally, recent studies have shown that nanobubbles under ultrasonic irradiation can also enhance gene transfection efficiency. Therefore, in theory, nanobubbles show great potential for gene therapy. The difficulty of developing nanobubbles with a high carrying capacity for highly stable drugs and genes prevents the application of ultrasound-destructible nanobubbles as a drug or gene transfection vector. Currently, electrostatic binding and biotin/avidin binding are the two main methods of combining genes with microbubbles. Electrostatic binding is not suitable for wide use due to its instability and low encapsulation rate. Biotin/avidin binding, although stable, cannot be used for nanobubbles because of the large molecular weight of biotin/avidin, which can result in a significant increase in bubble size. Some researchers have utilized the PLL method, which can be regarded as an improved method of electrostatic binding. PLL contains a polycation chain with a positively charged surface, and the prepared nanobubbles have a negatively charged surface. After PLL binding via static electricity, the surface of the nanobubble has a positive charge and can combine with the negatively charged siRNA via electrostatic adsorption. In this study, nanobubbles carrying AR siRNA were prepared based on the above mechanism. Nanobubbles with an average size of 609.5 nm exhibited stable binding to siRNA, as indicated by the finding that the loading capability of the carried nucleic acids remained high after repeated washes with PBS. These results suggest that PLL is an effective method for preparing nanobubbles carrying nucleic acids. Currently, however, the application of nanobubbles carrying genes to inhibit tumor growth remains in the exploratory stage. Many key issues, such as the preparation method, stability, penetration capability, in vivo imaging properties, and transfection efficiency of nanobubbles, still need to be systematically investigated. Therefore, when accompanied by ultrasonic irradiation, these bubbles facilitated a high transfection efficiency in AIPC cells, providing evidence that ultrasound-destructible nanobubbles may represent a viable option for gene therapy delivery to tumors in vivo. Many studies have also shown that the intensity and duration of ultrasonic irradiation and the concentration of microbubbles can inhibit cell growth and even cause cell death.