| Microbubbles ultrasound contrast agents (mUCA) have strong echo reflection properties because of its compressible gas core; therefore mUCA is commonly used in medical diagnosis. In recent years, it was found that microbubbles ultrasound contrast agents can be used as a novel gene vector; it can significantly improve gene transfection and expression in local tissues because of its simple, safe and efficient characters in gene transfection. In this paper, gene carried microbubbles preparation and performance testing and other aspects were studied, the main work and conclusions were as following:(1) Explored a coaxial electrospray method that uses glycerol and sucrose mixed with calf thymus DNA, which dissolved in sodium chloride solution, as the coating material of the ultrasound contrast agents to generate mUCA. Firstly, bubble suspensions were produced by magnetic stirring; then use the bubble suspension was subjected to coaxial electrospray with the PLGA solution as outer liquid. The size of the miccrobubble ultrasound contrast agent produced by this method was uniform; most of the micro-bubbles diameter was less than 5 microns.(2) The result showed that the gene loading rate of the micro-bubbles was about 32%; In addition, the changes in concentration of the ultrasound contrast agent as sprayed and after 24 hours were monitored by a cytometer, the life time of the microbubble contrast agents can be estimated. It showed that the ultrasound contrast agent was stable.(3) The acoustic performance of the ultrasound contrast agent prepared in this study was tested by ultrasonic testing equipment. The result showed that the ultrasound contrast agents had obvious echo signals.
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