高分子材料超声对比剂的制备及显影特征

背景:目前所用的超声对比剂均为内含不同气体成分的微气泡,其外壳材料多数为表面活性剂类、人血蛋白质类、脂类等。随着高分子化学的发展,高分子材料对比剂成为超声对比剂研究领域的热点。目的:探讨各种超声对比剂制备中遇到的困难以及解决方法,从而最终寻找合理的高分子材料超声对比剂。方法:采用电子检索的方式,在万方数据库(http://www.wanfangdata.com.cn/)中检索2005-01/2010-12有关高分子材料应用于超声造影方面的研究文章,关键词为"高分子材料,超声,对比剂"。排除重复研究、普通综述或Meta分析类文章,筛选纳入26篇文献进行评价。结果与结论:近年来随着高分子科学与多学科融合的分子医学的兴起和快速发展,显像对比剂受到了越来越广泛的关注。高分子材料超声对比剂由于具有好的生物相容性,粒径大小均匀,良好的抗压性能,较长的显影持续时间等特点,已成为目前研究的热点。其中靶向微泡对比剂经静脉注射可到达特定靶区,低功率超声作用下可提高局部组织显影的分辨率。携带治疗药物或基因的靶向微泡对比剂在低频(1MHz)超声作用下可以产生瞬态空化效应,迫使细胞膜的通透性增加,从而有效提高了药物或基因的转染率。如今,靶向微泡携抗肿瘤药物联合超声作用正逐渐成为治疗肿瘤的一种新模式,是近期医学研究的一个热点。超声联合靶向微泡技术在临床诊断和治疗中显示出了较大的优势,但其准确的生物学机制目前医学界还未清楚,超声治疗参数需进一步优化。

Preparation and imaging characteristics of polymer ultrasound contrast agents

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.