Abstract:

BACKGROUND: Current ultrasound contrast agents contain micro-bubbles with different gas composition, and the majority of shell materials are surfactant, human blood proteins, lipids and so on. With the development of polymer chemistry, polymer contrast agents are a hotspot in the research field of ultrasound contrast agents.
OBJECTIVE: To investigate the difficulties and solution in the preparation of different ultrasound contrast agents so as to find an ideal polymer contrast agent.
METHODS: A electronic search of Wanfang database (http://www.wanfangdata.com.cn/) to retrieve articles about polymer contrast agents published from January 2005 to December 2010 using keywords of “polymer material, ultrasound, contrast agent”. Repetitive studies, review and Meta-analysis were excluded, and 26 articles were included in the result analysis.
RESULTS AND CONCLUSION: In recent years, more and more attention have been paid on imaging contrast agents with the development of polymer materials and molecule medicine. Polymer contrast agents have become a research hotspot due to their good biocompatibility, particle size uniformity, good compression performance, longer development duration and other characteristics. Targeted micro-bubble contrast agent can reach a specific target via intravenous injection, and improve the resolution of local tissues under the action of low power ultrasound imaging. Targeted micro-bubble contrast carrying drugs or genes in low-frequency (1 MHz) ultrasound can generate transient cavitation to increase cell membrane permeability, and thus, effectively improve the drug or gene transfection efficiency. Today, the targeted micro-bubbles carrying anticancer drugs combined with ultrasound are becoming a new way for cancer treatment. Targeted micro-bubble ultrasound shows a greater advantage in clinical diagnosis and treatment, but the precise biological mechanism is still unclear, and ultrasound treatment parameters need to be further optimized.