Study On Preparation And Application Of Fe₃O₄@PLGA Polymer Microbubbles Contrast Agent

Ultrasound imaging is one of the most clinical medical diagnostic mode is used, because of its non-invasive, simple operation, low price and real-time imaging has been widely used. But because the ultrasound imaging of low resolution, low penetrability and other shortcomings, development and application have been greatly restricted. Ultrasound contrast agents(UCA) appears to solve this problem, it is through the many particle size composition about 8μm in the microbubble or microbubbles filled with an inert gas, the microbubble structure characteristics, they are able to produce the amplification effect of the acoustic, the microbubble injection into the body, into the various tissues and organs through the blood, improve the effect of ultrasound imaging. Ultrasound contrast agent has important significance in clinical diagnosis of in the target material, loading in contrast, can be identified early tumors and thrombus location, can also display in the site of inflammation. In contrast to load drug, can through the acoustic effect of microbubble destruction, to achieve internal to the effect of the medicine. The traditional methods contrast the preparation complex, cumbersome, low yield.This study was carried out to explore in view of the existing preparation method and modification of contrast-enhanced ultrasound in the aspects of the problem, the development and the preparation methods of microbubble contrast agent imaging quality.At present, albumin and lipid ultrasound contrast agent has poor stability, such as allergic reactions, choice of poly(lactic-co-glycolic acid)(PLGA) as the membrane material. Ultrasound contrast agent preparation process cumbersome, complex faults, this paper prepared by spray drying process of microbubble contrast agent, use B-290 to prepared equipment drying micro bubble, by setting different experimental parameters to get the best sample morphology particle size. The different parameters of the micro bubble both scanning electron microscopy(SEM) and particle size distribution were significantly different, and thus the impact parameter and the sample surface, for the future lay the foundation for further exploration. Through to add oil to precast liquid soluble Fe3O4 nanoparticles, and then use the optimum spray parameters have been explored, the preparation of Fe3O4@PLGA dual modality contrast agent. From the characterization results of the sample, the sample with fine morphology, particle size distribution is reasonable, and the hysteresis loop(VSM), Transmission electron microscope(TEM)and in vivo magnetic resonance also proved that the sample has good magnetic effect, magnetic resonance imaging contrast agents is good. At the same time in vitro and in vivo ultrasound tests on samples, that is a good sample of ultrasound contrast agent.